Research ArticleCorrosion Inhibition Mechanism of Mild Steel byAmylose-AcetateCarboxymethyl Chitosan Composites inAcidic Media
Maria Erna Herdini Herdini and Dedi Futra
Department of Chemistry Education Universitas Riau Kampus Binawidya KM 12 5 Pekanbaru 28293 Riau Indonesia
Correspondence should be addressed to Maria Erna mariaernalecturerunriacid and Dedi Futra futradediyahoocom
Received 27 August 2018 Revised 3 November 2018 Accepted 7 November 2018 Published 14 February 2019
Academic Editor Michael Harris
Copyright copy 2019 Maria Erna et al is is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
is article details an investigation on the mechanism of corrosion inhibition of mild steel using amylose-acetate-blendedcarboxymethyl chitosan (AA-CMCh) in acidic media in the context of kinetic and thermodynamic parameters e surface ofmild steel was exposed to test solutions and evaluated using scanning electron microscopy (SEM) and energy dispersive X-rayspectroscopy (EDX) e activation energy (Ea) free energy of adsorption (ΔG) enthalpy of activation (ΔHads) and entropy ofactivation (ΔSads) were determined in order to elucidate the mechanism of corrosion inhibition e results confirmed that AAcould be improved using CMCh as a corrosion inhibitor e corrosion rate decreased from 110900 to 22970mdd (7929)while corrosion inhibition increased from 3513 to 8972 Sulfate acid (H2SO4) of 025M also helped in decreasing the corrosionrate from 26644 to 104167mdd (609) while also in increasing corrosion inhibition from 5694 to 6831e calculated valuesfor ΔG ΔHads and ΔSads were minus3322 kJmiddotmolminus1 minus4856 kJmiddotmolminus1 and 00495 kJmiddotmolminus1middotKminus1 respectively e mechanism ofcorrosion inhibition of mild steel in the acidic condition is dominated and precipitated by the formation of the Fe-chelatecompound which was confirmed by the SEMEDS spectrum e reactions were spontaneous exothermic and irregular andtakes place on the surface of mild steel
1 Introduction
Mild steel is widely used for the fabrication of reactionvessels storage tanks and petroleum refineries e usage ofcorrosive agents in industries which are detrimental tometals is unavoidable To protect metallic surfaces fromthese agents various strategies have been proposed andstudied such as cathodic protection anodic protectioncorrosion protection coating and corrosion inhibitors euse of inhibitors appears to be the more common due to itslow cost ease-of-procedure and high efficiency [1 2] Manysynthetic organics extracted plants and inorganic chemicalscan be used as inhibitors to prevent mild steel from cor-roding Inorganic compounds (eg sodium chromatephosphate and molybdate) have been proposed as corrosioninhibitors for mild steel in many forms of aqueous mediaKarekar et al [3] reported the use of zinc molybdate
nanoparticles as a center nanocontainer for inhibiting thecorrosion of mild steel e zinc molybdate nanoparticleswere embedded in a three-layer material consisting ofpolyaniline benzotriazole and polyacrylic acidse highestcorrosion inhibition was reported to be at 5 NaOH and 5NaCl However inorganic compound harms the environ-ment due to its release of toxins and carcinogens to theenvironment [2]
Extracted plants are widely used as green corrosioninhibitors for mild steel in many acidic media Abrishamiet al [4] proposed the usage of zinc acetylacetonate-modifiedUrtica dioica leaf extract as an active corrosion inhibitor toprotect mild steel in chloride solutions e proposedcorrosion inhibitor reported excellent inhibition efficiencyKrishnan et al [5] reported the usage of biogenic corrosioninhibition for the protection of mild steel e biogeniccorrosion inhibition based on Turbinaria ornata could be
HindawiInternational Journal of Chemical EngineeringVolume 2019 Article ID 8514132 12 pageshttpsdoiorg10115520198514132
properly utilized as an anti-corrosion agent to reach aninhibition efficiency of 100 at 25 gL for 5mins of expo-sure Other plants extracted from Aegle marmelos fruit [6]Pongamia pinnata leaf [7] Chlorococcum sp [8] Cuscutareflexa fruit [9] and Eriobotrya japonica Lindl [10] havebeen utilized as active corrosion inhibitors for mild steel inmany acidic mediums Corrosion inhibitors based onextracted plants reported inhibition efficiency of gt80 [6]gt90 for 5 hrs [7] gt95 at 117 ppm [8] above 95 at500 ppm [9] and above 95 for 4 hrs [10] Generallycorrosion inhibition based on green materials performs wellin protecting mild steel from corrosion Green materialscontain polar functional groups ie N S and O hetero-cyclic compound where its p-electrons are responsible forinhibiting corrosion
Organic chemicals are popularly used as corrosion in-hibitors due to the organic compound being easily adsorbedonto metal surfaces Bouidina et al [11] analyzed two organiccompounds namely 12-dibenzylidenehydrazine and 12-bis(1-phenylethylidene)hydrazine as corrosion inhibitors formild steel in 10M HCl e former reported inhibition ef-ficiency that was twice that of the latter in the range of26ndash83 Chaouiki et al [12] studied the synthetic organiccompounds ie 4-(isopentylamino)-3-nitrobenzonitrile and3-amino-4-(isopentylamino)benzonitrile for corrosion in-hibition of mild steel in a 10M HCl solution and reportedthat 4-(isopentylamino)-3-nitrobenzonitrile resulted in im-provements to inhibition efficiency Other synthetic organicssuch as 1-hydroxyethyl-3-methylimidazolium hexa-fluorophosphate and 1-hydroxyethyl-3-methylimidazoliumbis-(trifluoromethylsulfonyl)imide [13] clopidogrel [14]p-vinyl benzene sulfonate and vinyl sulfonate-functionalizedpolyvinyl alcohol [15] 4-mercaptopyridine-modified sodiumdodecyl sulfate [16] 1H-perimidine and 1H-perimidin-2-amine [17] tetrazole derivatives [18] 4-((23-dichlorobenzylidene)amino)-3-methyl-1H-124-triazole-5(4H)-thione [19] 5-aminopyrazole carbonitriles [20]2-(1-piperidyl)ethyl 3-methyl-4-oxo-2-phenylchromene-8-carboxylate [21] and 1-(2-ami-noethyl)-1-dodecyl-2-(trifluoromethyl)-45-dihydro-1H-imidazol-1-ium chloride[22] have been investigated as corrosion inhibitors for theprotection of mild steel in HCl H2SO4 and phosphoric acidsolution at room temperature e results confirmed that thecompounds reported an inhibition efficiency in the range of571ndash814 [15] 970ndash986 [16] 346ndash923 [17] 711ndash942 [19] 568ndash955 [20] 912ndash979 [21] and 806ndash992[22] e high efficiency of these compounds as corrosioninhibitors is due to the polar functions from the presence of SO or N atoms which are used as centers to establish theadsorption process [23 24]
Chitosan derivatives are currently being touted as apotential material for the protection of metal surfaces fromcorrosive agents due to their unique structural features suchas rich surface chemistry biodegradability bioactivitybiocompatibility polycationic and high molecular weightand the fact that it is renewable [25 26] ese organiccompounds are incubated in acidic mediums at a pH of lt65producing a linear poly-base electrolyte with a highly pos-itive charge density is phenomenon contributed to
chitosan and its derivatives becoming highly biocompatibleand biodegradable [27] Many chitosan derivatives havebeen used to inhibit corrosion in the acidic medium Chenget al [28] reported an anodic corrosion inhibitor based oncarboxymethyl chitosan (CMCh) to prevent corrosion onmild steel in an HCl solution e results confirmed that theCMCh could potentially inhibit corrosion and be used as acontrol agent to address mild steel corrosion problems Wanet al [29] proposed carboxymethyl hydroxypropyl chitosanto inhibit corrosion on the surface of mild steel in a 10MHCl solution It could also be used as an anticorrosionmaterial at a low concentration to obtain an inhibition ef-ficiency of 953 in 1000 ppm (by weight) Salomon et al[30] utilized chitosan particle-modified silver nanoparticlesto enhance the inhibition of corrosion is was tested on aSt37 steel and 15 H2SO4 solution e corrosion inhibitorbased on chitosan-modified silver nanoparticles reported aninhibition efficiency gt94 Alsabagh et al [31] developedcorrosion inhibition based on natural polymer chitosan andused it on carbon steel in a 10M HCl solution e agentwas found to increase the hydrophobic character of chitosanand further enhance its surface-active properties e resultsdemonstrated that corrosion inhibition was attained at anefficiency of 250 ppm Umeron et al [32] proposed anothercorrosion inhibitor based on natural polymer chitosan toprotect the surface of mild steel and reported excellent ef-ficiency (96) at room temperature e obtained efficiencyin corrosion inhibition was generally due to the specificinteraction between functional groups of -COOH and -NH2and the metal surface
is study investigates corrosion inhibition based onamylose acetate-modified carboxymethyl chitosan ecorrosion inhibition efficiency of AA-modified CMCh wasused on the surface of mild steel in HCl and H2SO4 mediae corrosion inhibitions of AA-modified CMCh on themild steel surface using kinetic and thermodynamic datawere also investigated e morphological form of thecorroding mild steel surface in the presence of AA-modifiedCMCh was analyzed using scanning electron microscopy(SEM) and energy dispersive X-ray spectroscopy (EDX)enovelty of this work lies in the use of amylose acetate-blended carboxymethyl chitosan as a green corrosion in-hibitor for the protection of mild steel in both the HCl andH2SO4 solutions e benefit of this AA-modified CMCh isits high inhibition efficiency (gt95) low inhibitor con-centration (in the ppm level) long working period (3 days)and strong bond(s) between the steel and inhibitor solution
2 Experimental
21 Chemicals All of the chemical used in this work were ofanalytical grade and the solutions were prepared usingdeionized water Chitosan carboxymethyl chitosan di-oxane acetate acid and silicon carbide sand paper (100 200and 400 grades) were purchased from Sigma-Aldrich (StLouis USA) while monochloroacetate acid isopropanolmethanol ethanol acetone chloroform chloride acid(HCl) and sulfuric acid (H2SO4) were purchased fromMerck (Darmstadt Germany) Tapioca tuber and detergent
2 International Journal of Chemical Engineering
were procured from the supermarket e mild steel plateBJTP-24 with an area measuring 20times10 cm2 used in thiswork reported a chemical composition of C 016Si 019 Mn 48 P 016 S 022 and balancedFe
22 Instruments e FT-IR spectra of amylase acetate wereobtained using Spectrum FTIR GX infrared spectropho-tometer (PerkinElmer) e surface morphologies of mildsteel were imaged using the scanning electron microscope-dispersive X-ray spectrum (SEM-EDS) e pH values of thesolutions were measured using a pH meter (ermo Sci-entific) e glassware used in this work was cleaned usingdistilled and deionized waters
23 Amylose Isolation and Surface Modification eamylose powders were obtained from its cassava base via asimple extraction techniquee preparation of amylose wasslightly modified from the one reported in Erna et al [33] Inbrief the cassava sample was first cleaned using fresh waterto remove any soil or contaminant e cleaned cassava wascontinuously shredded and directly mixed into fresh waterto create a rough pulp is rough pulp was then shaken andsqueezed to obtain a suspension of amylose e extractedamylose was carefully filtered using gauze to obtain a slurryamylose and carefully rinsed with fresh water several timesto get a clean starchis isolated starch was then air-dried atambient temperature e dried starch was thoroughlycrushed using a mortar and pestle and immediately purifiedusing a dioxane solution for 4 h to remove any remainingacid(s) en the purified starch was again dried at 80degCand carefully dispersed in a solution of n-butanol eobtained amylose was then sterilized using an autoclavefor 2 h at a pressure of 15 psi and left to cool at 25degC for24 hrs e sterilized amylose was collected via centrifuga-tion (6500 rpm and 10min) and washed thoroughly usingdeionized water and absolute methanol thrice
To modify the surface of amylose sim5 g of amylose wasimmediately acetylated with 25mL of acetate acid glacial andmanually stirred until the solution becomes homogeneousen a mixture consisting of 02mL sulfate acid and 50mLacetate glacial was immediately added into the acetylatedamylose and stirred for 1 h at 37degC A solution of 165mLacetate acid anhydride was carefully added and stirred foranother 44 hrs at 37degC en the final acetate-modifiedamylose was slowly deposited into 200mL of isopropanolsolution and stirred at room temperature e formedprecipitation was then filtered and thoroughly washed withhot distilled water and then air-dried overnight at roomtemperature e modified amylose was directly charac-terized using a spectrum FTIR GX infrared spectropho-tometer (PerkinElmer)
24 Fabrication of Corrosion Inhibition Based on AA-BlendedCMCh Carboxymethyl chitosan was prepared as per Panget al [34] In brief sim10 g of chitosan powder was mixed with135 g of NaOH and immediately dissolved in 80mL
isopropanol containing 20mL of distilled water e mix-ture was then kept in a water bath at 60degC A mixture of 15 gof monochloroacetate in 20mL isopropanol was drippedinto the chitosan suspension and left for 4 h at ambienttemperature e reaction was stopped via the addition of asolution of 20mL ethanol (70) e obtained CMCh wasthen filtered and washed with ethanol several times followedby air drying at room temperature
To make the AA-modified CMCh a mixture consistingof 200mgL CMCh in chloric acid (10M) and 500mgLCMCh in sulfate acid (025M) was immediately added into asample bottle containing 10ndash50mg AA and then carefullystirred until its homogeneouse CMChmodified with AAwas applied on mild steel to analyze the mechanism ofcorrosion inhibition based on the kinetics and thermody-namics study
25 Preparation of Mild Steel Plates A mild steel plate wasprepared measuring 10times 20 cm2 and directly cleanedusing SiC sand paper (grades 100 200 and 400)e cleanedmild steel plate was then rinsed with distilled water acetoneand ethanol several times It was then immediately dried inan oven for 15min at 40degC e dried mild steel was thenweighed and its weight was recorded
26 Determination of Corrosion Rate of Mild Steel in AcidicMedia sim200mgL and 500mgL of AA-functionalizedCMCh were separately added into a solution of 10MHCl and 025M H2SO4 respectively en mild steelspecimens were directly immersed into HCl and H2SO4media for 3 days and a day respectively e steel couponswere carefully rinsed with chloroform and acetone severaltimes e washed steel coupons were thoroughly brushedand washed with distilled water and ethanol thrice followedby drying in an oven at 60degC en mild steel specimenswere weighed again to compare its respective rates of cor-rosion e determination of the corrosion rate of mild steelin acidic media without inhibitors was also conducted for thecomparison purposes e corrosion rate (gmiddotcmminus2middothminus1) wascalculated using equation (1) where W1 and W2 are theweights of mild steel coupons before and after incubationrespectively in a test medium S represents the surface areaof corroded steel (dm2) while t represents the immersiontime (h)
corrosion rate(CR) W1 minusW2
S middot t (1)
27 Determination of Inhibition Efficiency Surface Coverageand Adsorption-Free Energy Values e determination ofinhibition efficiency was conducted using HCl and H2SO4solutions A series of AA-functionalized CMCh concen-trations from 200 to 600mgL and 500 to 900mgL werethoroughly poured into sample bottles containing HCl andH2SO4 solutions respectively e prepared steel couponswere then incubated in the HCl and H2SO4 solution andcarefully rinsed with distilled water acetone and ethanol
International Journal of Chemical Engineering 3
and then dried in an oven for 15min at 40degC e inhibitionefficiency (IE) was calculated using equation (2) while thesurface coverage (θ) value was determined using equation(3) where CRblank and CRinh are the values of the corrosionrates of mild steel in the absence and presence of inhibitorsrespectively Meanwhile the Langmuir isotherm adsorptioncurve was determined using equation (4) and the free en-ergy of adsorption (ΔGo
ads) was investigated using equation(5) where Kads represents the equilibrium constant of theadsorption process and C represents the inhibitorrsquos con-centration(s) R represents the gas constant while T rep-resents the absolute temperature
IE CRblank minusCRinh
CRblanktimes 100 (2)
θ CRblank minusCRinh
CRblank (3)
Kads C θ
1minus θ (4)
ΔGoads minusRT ln 555Kads( 1113857 (5)
28 Determination of Activation of Energy Enthalpy andEntropy eprepared steel coupons have been immersed inHCl and H2SO4 solutions containing and not containinginhibitors en the mild steel plates were placed in athermostat at various temperatures from 284 to 600degC esteel plate was rinsed with distilled water acetone andethanol Afterwards it was oven-dried for 15min at 40degCe activation energy (Ea) was determined using equation(6) where R represents the gas constant CR represents thecorrosion inhibition K represents the preexponential factorand T represents the absolute temperature e values of Eawere calculated from the linear regression between lnCRand 1T e activation enthalpy (ΔHo
ads) and entropy(ΔSoads) can be calculated using equation (7)
CR k exp minusEa
RT1113874 1113875 (6)
ΔGoads ΔHo
ads minusTΔSoads (7)
29 Surface Analysis of Mild Steel e prepared mild steelplates measuring 20times10 cm2 were incubated in HCl andH2SO4 in the absencepresence of inhibitor under optimumconditions for 3 days ereafter the mild steel specimenswere removed washed with distilled water degreased withacetone and then dried at room temperature e steelspecimens were mechanically cut into 10 cm2 chips andthen immediately analyzed with SEM and EDX SEM wasperformed at a voltage of 5 kV and 5kx magnification on aLEO 1450 VP instrument e chemical compositions wereanalyzed using an EDX detector e attached functionalgroups on the mild steel surface were investigated using FT-IR spectroscopy equipment (PerkinElmer instrument)
3 Results and Discussion
31 Characterization of Amylose-Acetate e acetate-modified amylose powder for corrosion inhibition isshown in Figure 1 e acetate-functionalized amylosepowders are traditionally prepared using the acetylatingmethod e synthesis of AA involved mixing sulfuric andacetate acids and directly acetylate them via stirring epowders of acetate functionalized amylose were clearlywhite FTIR spectrum of the amylose-acetate is detailed inFigure 2 e O-H stretch peak at 349324 cmminus1 is from theamylose molecules e peaks at 174565 cmminus1 to123642 cmminus1 represent a carbonyl (COOH) group of theacetate ese peaks confirmed the occurrence of esterifi-cation between amylose and acetate molecules
32 Effect of Inhibitor Concentrations In order to determinethe best condition for the corrosion inhibition response theinhibitor loading was optimized to include both AA and AA-CMCh e inhibition efficiency response of corrosionstudies based on AA towards mild steel in an acidic mediumis shown in Figure 3 In the HCl solution the inhibitionefficiency response gradually increased alongside AArsquosconcentration from 100 to 400mgL (Figure 3(a)) while inthe H2SO4 solution the inhibition efficiency response alsoincreased alongside AA loading from 100 to 400mgL(Figure 3(b)) e increasing inhibition efficiency along-side inhibitor concentration is assumed to be due to theadsorption of inhibitor molecules on the surface of mild steel[35] With further increase in AA concentration from 400 to600 ppm in HCl solution and 400 to 500 ppm in H2SO4solution the responses of inhibition efficiency decreasedbecause the inhibitor has been fully adsorbed onto the mildsteelrsquos surface is confirms that the carboxylic group(COOH) of AA and iron (Fe) of mild steel has bonded einhibitor molecules could form a film layer and act as abarrier between mild steel and corrosive media e optimalAA concentration in HCl and H2SO4 solutions at 400 ppmwas used for further experiments
e effect of the CMCh AA ratio towards the inhibitionefficiency of mild steel in HCl and H2SO4 solution is il-lustrated in Figure 4 It can be seen that the inhibition ef-ficiency signal increases alongside the CMCh AA volumeloading changed from 1 18 to 8 4 ww in the HCl solution(Figure 4(a)) When CMCh AA changed from 8 4 to 9 2ww the signal of inhibition efficiency significantly declinede optimum ratio of CMCh AA was found at 8 4 wwwith its value of inhibition efficiency at 8886 is ratio(8 4 ww) contributed to the interaction energy between themild steelrsquos surface and thin layer of inhibitor being higherthan the interaction energy between the surface of mild steeland water and consequently the inhibition efficiency wasfound to be quite significant
As can be seen in Figure 4(b) the inhibition efficiencyresponse stabilized when CMCh AA volume loadingchanged from 5 36 to 30 16 ww in an H2SO4 solutionWhen the ratio of CMCh AA volume changed from 30 16to 35 12 ww the inhibition efficiency response increased
4 International Journal of Chemical Engineering
e CMCh AA volume loading changed again from 35 12to 45 4 ww (Figure 4(b)) and the response of inhibitioneciency gradually reduced in response to this change ismeans that the interaction energy between the mild steelrsquossurface and thin layer of the inhibitor took place slowly withthe thin layer of the inhibitor being unable to prevent attacksof the sulfuric ion on the mild steelrsquos surface is resulted inincreased corrosion on the surface [36] erefore theoptimum ratio of CMCh AA in H2SO4 solution at 35 12ww was utilized for the subsequent evaluation of corrosioninhibition
33 Determination of Activation Energy e activationenergy (Ea) of the system in the presence of AA-CMCh wasdetermined using the Arrhenius equation e Arrheniusplots for mild steel in 1M HCl with 400 ppm inhibitor isshown in Figure 5 e Ea value determined from theArrhenius plots in the presence of AA-CMCh was98089 kJmiddotmolminus1 is high value of Ea in the presence of aninhibitor was due to the high-energy barrier of the corrosion
rate [37] conrming the formation of a complex compoundbetween the inhibitor and Fe ion of mild steel
34 Adsorption Isotherm e performance of the AA-CMCh as a successful corrosion inhibitor is mainly dueto their adsorption ability on the surface of mild steel isability has been utilized to determine its mechanism ofcorrosion inhibition e Langmuir adsorption isothermfrom a plot of Cθ against C at 28degC is shown in Figure 5evalue of the correlation coecient for AA-CMCh is close toone which implies that the adsorption of AA-CMCh on themild steelrsquos surface is well tted to the Langmuir adsorptionisotherm e calculated Kads and ΔG values are10496 kJmiddotmolminus1 and minus3322 kJmiddotmolminus1 respectively esevalues demonstrated that the adsorption types of inhibitorson mild steel surfaces are chemical adsorption e Lang-muir adsorption isotherms from a plot of Cθ against C in1M HCl solution at 40degC and 60degC were also plotted (gurenot shown) e Kads and ΔG values at 40degC were7650 kJmiddotmolminus1and minus33722 kJmiddotmolminus1 respectively while the
3517
3534
9324 29
5700
2732
29
2120
82 1935
65
1745
6516
4246
1542
1514
3607
1373
38
1236
4211
5252
1037
7594
516
9008
0
7648
169
923
6442
560
182 5680
652
080
4629
4
50010001500200025003000350040004500(1cm)
0
15
30
45
60
75
90
105
120
T
Amylose-acetate
Figure 2 FT-IR spectrum of amylose modied with acetate
Figure 1 Powder of the amylose functionalized with acetate
International Journal of Chemical Engineering 5
Kads and ΔG values at 60degC were found to be1773 kJmiddotmolminus1and minus31831 kJmiddotmolminus1 respectively Generallythe obtained values of the ∆Gads were within minus3322 kJmiddotmolminus1
to minus3383 kJmiddotmolminus1 e ∆Gads values are simminus33 kJmiddotmolminus1 ormore negative suggesting chemisorption where chargesharing or charge transfer from an organic compound to themild steel surface takes place to form a coordinate-typemetallic bond [24 38]
e thermodynamic performance for the corrosion ofthe mild steel surface in 1M HCl at multiple concentrationsof AA-CMCh composites was obtained from a plot oflog(CRT) versus 1T and calculated using equation (7) evalues of activation enthalpy (∆H) and activation entropy(∆S) were minus4856 kJmiddotmolminus1 and 00495 kJmiddotmolminus1middotKminus1 re-spectively e negative value of ΔH indicates the exo-thermic nature of the activated-complex formation fromthe reactants for the rate-determining step of the steelassociation process e positive values of ΔS demonstrateirregularity of the adsorbed inhibitors on the mild steelsurface [39] is implies that the activated complex in the
rate-determining step represents a dissociation instead of anassociation process [32]
35 Potentiodynamic Polarization Studies e performanceof potentiodynamic polarization for mild steel in an HClsolution (10M) at multiple concentrations of inhibitors at301K after 60min of immersion time is shown in Figure 6e current anodic and cathodic response decreased as theAA-CMCh loading increased from 100 to 400 ppm due tothe large amounts of inhibitor on the electrodersquos surface andalso the moving corrosion potential towards increasednegativity is resulted in the classication of the inhibitoras the mixed type
e electrochemical parameters ie corrosion potential(Ecorr) anodic and cathodic Tafel slope (szligc szliga) corrosioncurrent density (icorr) and inhibition eciency (IE) obtainedfrom the corresponding polarization curves are shown inTable 1 In the proposed corrosion inhibitor the IE () wascalculated using the following equation
where i0corr and icorrprime represent the corrosion current densitieswithout and with the addition of inhibitors respectivelyeresults conrmed that the inhibition eciency responseincreased while the corrosion current density decreasedwhen the addition of inhibitors concentration increasedis implies that the inhibitor adsorption on the mild steelrsquossurface and the adsorption process is enhanced and in-creased inhibition eciency
36 Surface Characterization SEM and EDX In order todetermine the eiexclectiveness of the formatted thin layer of theinhibitor on the mild steelrsquos surface the treated mild steelwas imaged using an SEM SEM images of the mild steelsurface in the presenceabsence of CMCh in HCl and H2SO4solutions are shown in Figures 7 and 8 In the presence of AAat their respective optimum concentrations (400 ppm) inHCl (Figure 7(a)) and H2SO4 solutions (Figure 8(a)) asmooth surface of mild steel can be seen (Figures 7(a) and
8(a)) In the presence of AA-CMCh in HCl (Figure 7(b)) andH2SO4 solution (Figure 8(b)) a smoother surface of the mildspecimen can be seen (Figures 7(b) and 8(b)) is impliesthat the AA-CMCh is more eiexclective in inhibiting corrosionon mild steelrsquos surface compared to the AA inhibitor isfeature probably contributed to the homogeneity and bio-compatibility of the AA-CMCh composites on the mildsteelrsquos surface Generally a smoother surface of themild steelspecimen denote that the AA-CMCh has adsorbed onto themild steelrsquos surface and protected specimens from direct acidattacks
e EDX spectra of the mild steel and control specimenin HCl solution is shown in Figure 9 e surface of mildsteels as a control specimen before treatment (Figure 9(c))and the presence of AA-CMCh (Figure 9(b)) exhibit asmooth and uniform surface e morphology in thepresence AA was slightly damaged and rough (Figure 9(a))is conrmed that the mild steel surface is well protectedfrom acidic attacks and prevented from corroding Table 2shows the percentage of atomic contents in the inhibitor andcontrol specimens e EDX spectrum in the presence ofAA-CMCh conrmed that the concentration of the Cl ion is
Figure 6 Potentiodynamic polarization curves of mild steel in 10MHCl solutionmeasured in the absence (a) and presence of (b) 100 ppm(c) 200 ppm (d) 300 ppm and (e) 400 ppm of amylose-acetatecarboxymethyl chitosan (AA-CMCh)
Table 1 Electrochemical parameters obtained from polarization measurement in 10M HCl in the presence and absence of a diiexclerentconcentration of AA-CMCh
Figure 8 SEM micrographs of the mild steel surface in 025M H2SO4 with AA (a) and AA-CMCh (b)
(a) (b)
Figure 7 SEM images of mild steel surfaces in 1M HCl with AA (a) and AA-CMCh (b)
(a) (b)
Figure 9 Continued
International Journal of Chemical Engineering 9
higher than that of the presence of AA whilst the con-centration of C in the control specimen prior to treatmentwas lower than that of the treated specimen due to theinhibitor absorbed onto the mild steelrsquos surface e con-centration of Fe and O from the inhibitor of AA is notsignificantly different than the inhibitor of AA-CMCh(Table 2) Generally both AA and AA-CMCh inhibitorsare able to inhibit the mild steel specimen from a directattack by the Cl ion which protects the mild steel surfacefrom an aggressive environment
37Mechanismof Inhibition e adsorption of AA-blendedCMCh on mild steel can be clearly defined by consideringthe chemisorption processes e specific mechanism ofcorrosion inhibition of AA-CMCh to the surface of mildsteel coupons is detailed in the following equations
Fe + AA-CMCh⟷ Fe(AA-CMCh)ads (9)
Fe(AA-CMCh)ads⟷ Fe2++ AA-CMCh + neminus (10)
AA-CMChaq + H2Oads⟷AA-CMChads + H2Oaq
(11)
e chemisorption of AA-CMCh on mild steel isdenoted by the donor-acceptor interactions between thelone pair of the electron from the carbonyl and amine groupsof AA-CMCh with the d-orbitals of Fe e value of freeenergy from the AA-CMCh adsorption was minus33 kJmiddotmolminus1 ormore negative is confirms that the adsorption mecha-nism of the AA-CMCh on the surface of the mild steelcoupon was chemically adsorbed e inhibition of
corrosion begins by the displacement of water molecules bythe inhibitorrsquos capacity toward specific adsorption of theinhibitor on the metalrsquos surface [40]
4 Conclusions
e corrosion inhibition mechanism based on carbox-ymethyl chitosanamylose-acetate composites used to pro-tect mild steel in an acidic medium was successfullyinvestigatede AA-CMCh base inhibitor showed excellentinhibition performance in the case of mild steel in a 1MHClsolution e inhibiting efficiencies decreased in the order ofAA-CMChgtAA e inhibitor adsorptions on the mildsteelrsquos surface are chemically adsorbed while the corrosioninhibition mechanism on the mild steelrsquos surface wasspontaneous exothermal and irregular and took place dueto the formation of the Fe-chelate compound on the surfaceof the mild steel specimen e adsorption of the inhibitorson the mild steel specimen in acidic media solution com-ports with that of the Langmuir adsorption isotherm enegative values of the ∆Gads and ∆H indicated that theadsorption reaction took place spontaneously andexothermally
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this work
Acknowledgments
e authors gratefully acknowledge financial support fromthe Directorate General of Higher Education of Ministry(DIKTI) the Ministry of Research Technology and HigherEducation through a fundamental grant of the UniversitasRiau Indonesia
(c)
Figure 9 SEMEDX spectra of the mild steel surface in 1M HCl (a) AA (b) AA-CMCh blended (c) control
Table 2 Percentage atomic contents of elements measured usingthe EDX technique
Inhibitors Fe O S Cl CControl 9664 197 mdash 012 027AA 7769 2226 mdash 006 1346AA-CMCh 7761 2223 mdash 015 1649
10 International Journal of Chemical Engineering
References
[1] B Xu W Yang Y Liu X Yin W Gong and Y ChenldquoExperimental and theoretical evaluation of two pyr-idinecarboxaldehyde thiosemicarbazone compounds as cor-rosion inhibitors for mild steel in hydrochloric acid solutionrdquoCorrosion Science vol 78 pp 260ndash268 2014
[2] S A Umoren and U M Eduok ldquoApplication of carbohydratepolymers as corrosion inhibitors for metal substrates indifferent media a reviewrdquo Carbohydrate Polymers vol 140pp 314ndash341 2016
[3] S E Karekar U D Bagale S H Sonawane B A Bhanvaseand D V Pinjari ldquoA smart coating established with encap-sulation of Zinc Molybdate centred nanocontainer for activecorrosion protection of mild steel release kinetics of corro-sion inhibitorrdquo Composite Interfaces vol 25 no 9 pp 785ndash808 2018
[4] S Abrishami R Naderi and B Ramezanzadeh ldquoFabricationand characterization of zinc acetylacetonateUrtica dioicaleaves extract complex as an effective organicinorganic hy-brid corrosion inhibitive pigment for mild steel protection inchloride solutionrdquo Applied Surface Science vol 457pp 487ndash496 2018
[5] M Krishnan H Subramanian H-U Dahms et al ldquoBiogeniccorrosion inhibitor on mild steel protection in concentratedHCl mediumrdquo Scientific Report vol 8 p 2609 2018
[6] N Bhardwaj D Prasad and R Haldhar ldquoStudy of the Aeglemarmelos as a green corrosion inhibitor for mild steel in acidicmedium experimental and theoretical approachrdquo Journal ofBio- and Tribo-Corrosion vol 4 no 4 p 61 2018
[7] T K Bhuvaneswari V S Vasantha and C JeyaprabhaldquoPongamia pinnata as a green corrosion inhibitor for mildsteel in 1N sulfuric acid mediumrdquo Silicon vol 10 no 5pp 1793ndash1807 2018
[8] M P Rai A Khanra S Rai M Srivastava and R PrakashldquoPivotal role of levoglucosenone and hexadecanoic acid frommicroalgae Chlorococcum sp for corrosion resistance on mildsteel electrochemical microstructural and theoretical anal-ysisrdquo Journal of Molecular Liquids vol 266 pp 279ndash2902018
[9] A Saxena D Prasad and R Haldhar ldquoInvestigation ofcorrosion inhibition effect and adsorption activities of Cus-cuta reflexa extract for mild steel in 05 M H2SO4rdquo Bio-electrochemistry vol 124 pp 156ndash164 2018
[10] X Zheng M Gong Q Li and L Guo ldquoCorrosion inhibitionof mild steel in sulfuric acid solution by loquat (Eriobotryajaponica Lindl) leaves extractrdquo Scientific Report vol 8p 9140 2018
[11] A Bouoidina F El-Hajjaji M Drissi et al ldquoTowards a deeperunderstanding of the anticorrosive properties of hydrazinederivatives in acid medium experimental DFT and MDsimulation assessmentrdquo Metallurgical and Materials Trans-actions A vol 49 no 10 pp 5180ndash5191 2018
[12] A Chaouiki H Lgaz I-M Chung et al ldquoUnderstandingcorrosion inhibition of mild steel in acid medium by newbenzonitriles insights from experimental and computationalstudiesrdquo Journal of Molecular Liquids vol 266 pp 603ndash6162018
[13] Y Guo Z Chen Y Zuo Y Chen W Yang and B Xu ldquoIonicliquids with two typical hydrophobic anions as acidic cor-rosion inhibitorsrdquo Journal of Molecular Liquids vol 269pp 886ndash895 2018
[14] E Naseri M Hajisafari A Kosari M Talari S Hosseinpourand A Davoodi ldquoInhibitive effect of Clopidogrel as a green
corrosion inhibitor for mild steel statistical modeling andquantum Monte Carlo simulation studiesrdquo Journal of Mo-lecular Liquids vol 269 pp 193ndash202 2018
[15] R Geethanjali and S Subhashini ldquoSynthesis and kinetics ofcorrosion inhibition of water-soluble terpolymer of polyvinylalcohol functionalized with vinyl sulfonate and p-vinyl ben-zene sulfonate in molar HClrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4 p 60 2018
[16] P Han W Li H Tian et al ldquoDesigning and fabricating oftime-depend self-strengthening inhibitor film synergisticinhibition of sodium dodecyl sulfate and 4-mercaptopyridinefor mild steelrdquo Journal of Molecular Liquids vol 268pp 425ndash437 2018
[17] X He J Mao Q Ma and Y Tang ldquoCorrosion inhibition ofperimidine derivatives for mild steel in acidic media elec-trochemical and computational studiesrdquo Journal of MolecularLiquids vol 269 pp 260ndash268 2018
[18] A A Mahmmod I A Kazarinov A A Khadom andH B Mahood ldquoExperimental and theoretical studies of mildsteel corrosion inhibition in phosphoric acid using tetrazolesderivativesrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4p 58 2018
[19] M Messali M Larouj H Lgaz et al ldquoA new schiff basederivative as an effective corrosion inhibitor for mild steel inacidic media experimental and computer simulations stud-iesrdquo Journal of Molecular Structure vol 1168 pp 39ndash48 2018
[20] A Mishra C Verma S Chauhan et al ldquoCharacterizationand corrosion inhibition performance of 5-aminopyrazolecarbonitriles towards mild steel acidic corrosionrdquo Journal ofBio- and Tribo-Corrosion vol 4 p 53 2018
[21] N Saini R Kumar H Lgaz et al ldquoMinified dose of urispasdrug as better corrosion constraint for soft steel in sulphuricacid solutionrdquo Journal of Molecular Liquids vol 269pp 371ndash380 2018
[22] K Zhang W Yang Y Chen et al ldquoEnhanced inhibitiveperformance of fluoro-substituted imidazolium-based ionicliquid for mild steel corrosion in hydrochloric acid at elevatedtemperaturerdquo Journal of Materials Science vol 53 no 20pp 14666ndash14680 2018
[23] K R Ansari M A Quraishi and A Singh ldquoCorrosion in-hibition of mild steel in hydrochloric acid by some pyridinederivatives an experimental and quantum chemical studyrdquoJournal of Industrial and Engineering Chemistry vol 25pp 89ndash98 2015
[24] L O Olasunkanmi I B Obot M M Kabanda andE E Ebenso ldquoSome quinoxalin-6-yl derivatives as corrosioninhibitors for mild steel in hydrochloric acid experimentaland theoretical studiesrdquo Journal of Physical Chemistry Cvol 119 no 28 pp 16004ndash16019 2015
[25] M Ewis S S Elkholy and M Z Esabee ldquoAntifungal efficacyof chitosan and its thiourea derivatives upon the growth ofsome sugar-beet pathogensrdquo International Journal of Bi-ological Macromolecules vol 38 no 1 pp 1ndash8 2006
[26] Z-X Tang J-Q Qian and L-E Shi ldquoCharacterizations ofimmobilized neutral lipase on chitosan nano-particlesrdquoMaterials Letters vol 61 no 1 pp 37ndash40 2007
[27] M N El-Haddad ldquoChitosan as a green inhibitor for coppercorrosion in acidic mediumrdquo International Journal of Bi-ological Macromolecules vol 55 pp 142ndash149 2013
[28] S Cheng S Chen T Liu X Chang and Y Yin ldquoCarbox-ymenthylchitosan as an ecofriendly inhibitor for mild steel in1 MHClrdquoMaterials Letters vol 61 no 14-15 pp 3276ndash32802007
International Journal of Chemical Engineering 11
[29] K Wan P Feng B Hou and Y Li ldquoEnhanced corrosioninhibition properties of carboxymethyl hydroxypropyl chi-tosan for mild steel in 10 M HCl solutionrdquo RSC Advancesvol 6 no 81 pp 77515ndash77524 2016
[30] M M Solomon H Gerengi T Kaya and S A UmorenldquoEnhanced corrosion inhibition effect of chitosan for St37 in15 H2SO4 environment by silver nanoparticlesrdquo In-ternational Journal of Biological Macromolecules vol 104pp 638ndash649 2017
[31] A M Alsabagh M Z Elsabee Y M Moustafa A Elfky andR E Morsi ldquoCorrosion inhibition efficiency of somehydrophobically modified chitosan surfactants in relation totheir surface active propertiesrdquo Egyptian Journal of Petroleumvol 23 no 4 pp 349ndash359 2014
[32] S A Umoren M J Banera T Alonso-Garcia C A Gervasiand M V Mirıfico ldquoInhibition of mild steel corrosion in HClsolution using chitosanrdquo Cellulose vol 20 no 5 pp 2529ndash2545 2013
[33] M Erna Y Eryanti and A Dahliaty ldquoModifikasi amilosa daripati tapioka dan garut menjadi amilosa asetatrdquo Jurnal PilarSains vol 7 pp 28ndash30 2008
[34] H T Pang X G Chen H J Park D S Cha andJ F Kennedy ldquoPreparation and rheological properties ofdeoxycholate-chitosan and carboxymethyl-chitosan inaqueous systemsrdquo Carbohydrate Polymers vol 69 no 3pp 419ndash425 2007
[35] K K Anupama and J Abraham ldquoElectroanalytical studies onthe corrosion inhibition behavior of guava (Psidium guajava)leaves extract on mild steel in hydrochloric acidrdquo Research onChemical Intermediates vol 39 no 9 pp 4067ndash4080 2012
[36] M E Al-Dokheily H M Kredy and R N Al-Jabery ldquoIn-hibition of copper corrosion in H2SO4 NaCl and NaOHsolutions by Citrullus colocynthis fruits extractrdquo Journal ofNatural Sciences Research vol 4 pp 60ndash73 2014
[37] M H Hussin andM J Kassim ldquoe corrosion inhibition andadsorption behavior ofUncaria gambir extract onmild steel in1M HClrdquo Materials Chemistry and Physics vol 125 no 3pp 461ndash468 2011
[38] K R Ansari M A Quraishi and A Singh ldquoIsatin derivativesas a non-toxic corrosion inhibitor for mild steel in 20H2SO4rdquo Corrosion Science vol 95 pp 62ndash70 2015
[39] B Zerga A Attayibat M Sfaira et al ldquoEffect of some tripodalbipyrazolic compounds on C38 steel corrosion in hydro-chloric acid solutionrdquo Journal of Applied Electrochemistryvol 40 no 9 pp 1575ndash1582 2010
[40] H Ashassi-Sorkhabi and S A Nabavi-Amri ldquoCorrosioninhibition of carbon steel in petroleumwater mixtures byn-containing compoundsrdquo Acta Chimica Slovenica vol 47pp 507ndash517 2000
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
properly utilized as an anti-corrosion agent to reach aninhibition efficiency of 100 at 25 gL for 5mins of expo-sure Other plants extracted from Aegle marmelos fruit [6]Pongamia pinnata leaf [7] Chlorococcum sp [8] Cuscutareflexa fruit [9] and Eriobotrya japonica Lindl [10] havebeen utilized as active corrosion inhibitors for mild steel inmany acidic mediums Corrosion inhibitors based onextracted plants reported inhibition efficiency of gt80 [6]gt90 for 5 hrs [7] gt95 at 117 ppm [8] above 95 at500 ppm [9] and above 95 for 4 hrs [10] Generallycorrosion inhibition based on green materials performs wellin protecting mild steel from corrosion Green materialscontain polar functional groups ie N S and O hetero-cyclic compound where its p-electrons are responsible forinhibiting corrosion
Organic chemicals are popularly used as corrosion in-hibitors due to the organic compound being easily adsorbedonto metal surfaces Bouidina et al [11] analyzed two organiccompounds namely 12-dibenzylidenehydrazine and 12-bis(1-phenylethylidene)hydrazine as corrosion inhibitors formild steel in 10M HCl e former reported inhibition ef-ficiency that was twice that of the latter in the range of26ndash83 Chaouiki et al [12] studied the synthetic organiccompounds ie 4-(isopentylamino)-3-nitrobenzonitrile and3-amino-4-(isopentylamino)benzonitrile for corrosion in-hibition of mild steel in a 10M HCl solution and reportedthat 4-(isopentylamino)-3-nitrobenzonitrile resulted in im-provements to inhibition efficiency Other synthetic organicssuch as 1-hydroxyethyl-3-methylimidazolium hexa-fluorophosphate and 1-hydroxyethyl-3-methylimidazoliumbis-(trifluoromethylsulfonyl)imide [13] clopidogrel [14]p-vinyl benzene sulfonate and vinyl sulfonate-functionalizedpolyvinyl alcohol [15] 4-mercaptopyridine-modified sodiumdodecyl sulfate [16] 1H-perimidine and 1H-perimidin-2-amine [17] tetrazole derivatives [18] 4-((23-dichlorobenzylidene)amino)-3-methyl-1H-124-triazole-5(4H)-thione [19] 5-aminopyrazole carbonitriles [20]2-(1-piperidyl)ethyl 3-methyl-4-oxo-2-phenylchromene-8-carboxylate [21] and 1-(2-ami-noethyl)-1-dodecyl-2-(trifluoromethyl)-45-dihydro-1H-imidazol-1-ium chloride[22] have been investigated as corrosion inhibitors for theprotection of mild steel in HCl H2SO4 and phosphoric acidsolution at room temperature e results confirmed that thecompounds reported an inhibition efficiency in the range of571ndash814 [15] 970ndash986 [16] 346ndash923 [17] 711ndash942 [19] 568ndash955 [20] 912ndash979 [21] and 806ndash992[22] e high efficiency of these compounds as corrosioninhibitors is due to the polar functions from the presence of SO or N atoms which are used as centers to establish theadsorption process [23 24]
Chitosan derivatives are currently being touted as apotential material for the protection of metal surfaces fromcorrosive agents due to their unique structural features suchas rich surface chemistry biodegradability bioactivitybiocompatibility polycationic and high molecular weightand the fact that it is renewable [25 26] ese organiccompounds are incubated in acidic mediums at a pH of lt65producing a linear poly-base electrolyte with a highly pos-itive charge density is phenomenon contributed to
chitosan and its derivatives becoming highly biocompatibleand biodegradable [27] Many chitosan derivatives havebeen used to inhibit corrosion in the acidic medium Chenget al [28] reported an anodic corrosion inhibitor based oncarboxymethyl chitosan (CMCh) to prevent corrosion onmild steel in an HCl solution e results confirmed that theCMCh could potentially inhibit corrosion and be used as acontrol agent to address mild steel corrosion problems Wanet al [29] proposed carboxymethyl hydroxypropyl chitosanto inhibit corrosion on the surface of mild steel in a 10MHCl solution It could also be used as an anticorrosionmaterial at a low concentration to obtain an inhibition ef-ficiency of 953 in 1000 ppm (by weight) Salomon et al[30] utilized chitosan particle-modified silver nanoparticlesto enhance the inhibition of corrosion is was tested on aSt37 steel and 15 H2SO4 solution e corrosion inhibitorbased on chitosan-modified silver nanoparticles reported aninhibition efficiency gt94 Alsabagh et al [31] developedcorrosion inhibition based on natural polymer chitosan andused it on carbon steel in a 10M HCl solution e agentwas found to increase the hydrophobic character of chitosanand further enhance its surface-active properties e resultsdemonstrated that corrosion inhibition was attained at anefficiency of 250 ppm Umeron et al [32] proposed anothercorrosion inhibitor based on natural polymer chitosan toprotect the surface of mild steel and reported excellent ef-ficiency (96) at room temperature e obtained efficiencyin corrosion inhibition was generally due to the specificinteraction between functional groups of -COOH and -NH2and the metal surface
is study investigates corrosion inhibition based onamylose acetate-modified carboxymethyl chitosan ecorrosion inhibition efficiency of AA-modified CMCh wasused on the surface of mild steel in HCl and H2SO4 mediae corrosion inhibitions of AA-modified CMCh on themild steel surface using kinetic and thermodynamic datawere also investigated e morphological form of thecorroding mild steel surface in the presence of AA-modifiedCMCh was analyzed using scanning electron microscopy(SEM) and energy dispersive X-ray spectroscopy (EDX)enovelty of this work lies in the use of amylose acetate-blended carboxymethyl chitosan as a green corrosion in-hibitor for the protection of mild steel in both the HCl andH2SO4 solutions e benefit of this AA-modified CMCh isits high inhibition efficiency (gt95) low inhibitor con-centration (in the ppm level) long working period (3 days)and strong bond(s) between the steel and inhibitor solution
2 Experimental
21 Chemicals All of the chemical used in this work were ofanalytical grade and the solutions were prepared usingdeionized water Chitosan carboxymethyl chitosan di-oxane acetate acid and silicon carbide sand paper (100 200and 400 grades) were purchased from Sigma-Aldrich (StLouis USA) while monochloroacetate acid isopropanolmethanol ethanol acetone chloroform chloride acid(HCl) and sulfuric acid (H2SO4) were purchased fromMerck (Darmstadt Germany) Tapioca tuber and detergent
2 International Journal of Chemical Engineering
were procured from the supermarket e mild steel plateBJTP-24 with an area measuring 20times10 cm2 used in thiswork reported a chemical composition of C 016Si 019 Mn 48 P 016 S 022 and balancedFe
22 Instruments e FT-IR spectra of amylase acetate wereobtained using Spectrum FTIR GX infrared spectropho-tometer (PerkinElmer) e surface morphologies of mildsteel were imaged using the scanning electron microscope-dispersive X-ray spectrum (SEM-EDS) e pH values of thesolutions were measured using a pH meter (ermo Sci-entific) e glassware used in this work was cleaned usingdistilled and deionized waters
23 Amylose Isolation and Surface Modification eamylose powders were obtained from its cassava base via asimple extraction techniquee preparation of amylose wasslightly modified from the one reported in Erna et al [33] Inbrief the cassava sample was first cleaned using fresh waterto remove any soil or contaminant e cleaned cassava wascontinuously shredded and directly mixed into fresh waterto create a rough pulp is rough pulp was then shaken andsqueezed to obtain a suspension of amylose e extractedamylose was carefully filtered using gauze to obtain a slurryamylose and carefully rinsed with fresh water several timesto get a clean starchis isolated starch was then air-dried atambient temperature e dried starch was thoroughlycrushed using a mortar and pestle and immediately purifiedusing a dioxane solution for 4 h to remove any remainingacid(s) en the purified starch was again dried at 80degCand carefully dispersed in a solution of n-butanol eobtained amylose was then sterilized using an autoclavefor 2 h at a pressure of 15 psi and left to cool at 25degC for24 hrs e sterilized amylose was collected via centrifuga-tion (6500 rpm and 10min) and washed thoroughly usingdeionized water and absolute methanol thrice
To modify the surface of amylose sim5 g of amylose wasimmediately acetylated with 25mL of acetate acid glacial andmanually stirred until the solution becomes homogeneousen a mixture consisting of 02mL sulfate acid and 50mLacetate glacial was immediately added into the acetylatedamylose and stirred for 1 h at 37degC A solution of 165mLacetate acid anhydride was carefully added and stirred foranother 44 hrs at 37degC en the final acetate-modifiedamylose was slowly deposited into 200mL of isopropanolsolution and stirred at room temperature e formedprecipitation was then filtered and thoroughly washed withhot distilled water and then air-dried overnight at roomtemperature e modified amylose was directly charac-terized using a spectrum FTIR GX infrared spectropho-tometer (PerkinElmer)
24 Fabrication of Corrosion Inhibition Based on AA-BlendedCMCh Carboxymethyl chitosan was prepared as per Panget al [34] In brief sim10 g of chitosan powder was mixed with135 g of NaOH and immediately dissolved in 80mL
isopropanol containing 20mL of distilled water e mix-ture was then kept in a water bath at 60degC A mixture of 15 gof monochloroacetate in 20mL isopropanol was drippedinto the chitosan suspension and left for 4 h at ambienttemperature e reaction was stopped via the addition of asolution of 20mL ethanol (70) e obtained CMCh wasthen filtered and washed with ethanol several times followedby air drying at room temperature
To make the AA-modified CMCh a mixture consistingof 200mgL CMCh in chloric acid (10M) and 500mgLCMCh in sulfate acid (025M) was immediately added into asample bottle containing 10ndash50mg AA and then carefullystirred until its homogeneouse CMChmodified with AAwas applied on mild steel to analyze the mechanism ofcorrosion inhibition based on the kinetics and thermody-namics study
25 Preparation of Mild Steel Plates A mild steel plate wasprepared measuring 10times 20 cm2 and directly cleanedusing SiC sand paper (grades 100 200 and 400)e cleanedmild steel plate was then rinsed with distilled water acetoneand ethanol several times It was then immediately dried inan oven for 15min at 40degC e dried mild steel was thenweighed and its weight was recorded
26 Determination of Corrosion Rate of Mild Steel in AcidicMedia sim200mgL and 500mgL of AA-functionalizedCMCh were separately added into a solution of 10MHCl and 025M H2SO4 respectively en mild steelspecimens were directly immersed into HCl and H2SO4media for 3 days and a day respectively e steel couponswere carefully rinsed with chloroform and acetone severaltimes e washed steel coupons were thoroughly brushedand washed with distilled water and ethanol thrice followedby drying in an oven at 60degC en mild steel specimenswere weighed again to compare its respective rates of cor-rosion e determination of the corrosion rate of mild steelin acidic media without inhibitors was also conducted for thecomparison purposes e corrosion rate (gmiddotcmminus2middothminus1) wascalculated using equation (1) where W1 and W2 are theweights of mild steel coupons before and after incubationrespectively in a test medium S represents the surface areaof corroded steel (dm2) while t represents the immersiontime (h)
corrosion rate(CR) W1 minusW2
S middot t (1)
27 Determination of Inhibition Efficiency Surface Coverageand Adsorption-Free Energy Values e determination ofinhibition efficiency was conducted using HCl and H2SO4solutions A series of AA-functionalized CMCh concen-trations from 200 to 600mgL and 500 to 900mgL werethoroughly poured into sample bottles containing HCl andH2SO4 solutions respectively e prepared steel couponswere then incubated in the HCl and H2SO4 solution andcarefully rinsed with distilled water acetone and ethanol
International Journal of Chemical Engineering 3
and then dried in an oven for 15min at 40degC e inhibitionefficiency (IE) was calculated using equation (2) while thesurface coverage (θ) value was determined using equation(3) where CRblank and CRinh are the values of the corrosionrates of mild steel in the absence and presence of inhibitorsrespectively Meanwhile the Langmuir isotherm adsorptioncurve was determined using equation (4) and the free en-ergy of adsorption (ΔGo
ads) was investigated using equation(5) where Kads represents the equilibrium constant of theadsorption process and C represents the inhibitorrsquos con-centration(s) R represents the gas constant while T rep-resents the absolute temperature
IE CRblank minusCRinh
CRblanktimes 100 (2)
θ CRblank minusCRinh
CRblank (3)
Kads C θ
1minus θ (4)
ΔGoads minusRT ln 555Kads( 1113857 (5)
28 Determination of Activation of Energy Enthalpy andEntropy eprepared steel coupons have been immersed inHCl and H2SO4 solutions containing and not containinginhibitors en the mild steel plates were placed in athermostat at various temperatures from 284 to 600degC esteel plate was rinsed with distilled water acetone andethanol Afterwards it was oven-dried for 15min at 40degCe activation energy (Ea) was determined using equation(6) where R represents the gas constant CR represents thecorrosion inhibition K represents the preexponential factorand T represents the absolute temperature e values of Eawere calculated from the linear regression between lnCRand 1T e activation enthalpy (ΔHo
ads) and entropy(ΔSoads) can be calculated using equation (7)
CR k exp minusEa
RT1113874 1113875 (6)
ΔGoads ΔHo
ads minusTΔSoads (7)
29 Surface Analysis of Mild Steel e prepared mild steelplates measuring 20times10 cm2 were incubated in HCl andH2SO4 in the absencepresence of inhibitor under optimumconditions for 3 days ereafter the mild steel specimenswere removed washed with distilled water degreased withacetone and then dried at room temperature e steelspecimens were mechanically cut into 10 cm2 chips andthen immediately analyzed with SEM and EDX SEM wasperformed at a voltage of 5 kV and 5kx magnification on aLEO 1450 VP instrument e chemical compositions wereanalyzed using an EDX detector e attached functionalgroups on the mild steel surface were investigated using FT-IR spectroscopy equipment (PerkinElmer instrument)
3 Results and Discussion
31 Characterization of Amylose-Acetate e acetate-modified amylose powder for corrosion inhibition isshown in Figure 1 e acetate-functionalized amylosepowders are traditionally prepared using the acetylatingmethod e synthesis of AA involved mixing sulfuric andacetate acids and directly acetylate them via stirring epowders of acetate functionalized amylose were clearlywhite FTIR spectrum of the amylose-acetate is detailed inFigure 2 e O-H stretch peak at 349324 cmminus1 is from theamylose molecules e peaks at 174565 cmminus1 to123642 cmminus1 represent a carbonyl (COOH) group of theacetate ese peaks confirmed the occurrence of esterifi-cation between amylose and acetate molecules
32 Effect of Inhibitor Concentrations In order to determinethe best condition for the corrosion inhibition response theinhibitor loading was optimized to include both AA and AA-CMCh e inhibition efficiency response of corrosionstudies based on AA towards mild steel in an acidic mediumis shown in Figure 3 In the HCl solution the inhibitionefficiency response gradually increased alongside AArsquosconcentration from 100 to 400mgL (Figure 3(a)) while inthe H2SO4 solution the inhibition efficiency response alsoincreased alongside AA loading from 100 to 400mgL(Figure 3(b)) e increasing inhibition efficiency along-side inhibitor concentration is assumed to be due to theadsorption of inhibitor molecules on the surface of mild steel[35] With further increase in AA concentration from 400 to600 ppm in HCl solution and 400 to 500 ppm in H2SO4solution the responses of inhibition efficiency decreasedbecause the inhibitor has been fully adsorbed onto the mildsteelrsquos surface is confirms that the carboxylic group(COOH) of AA and iron (Fe) of mild steel has bonded einhibitor molecules could form a film layer and act as abarrier between mild steel and corrosive media e optimalAA concentration in HCl and H2SO4 solutions at 400 ppmwas used for further experiments
e effect of the CMCh AA ratio towards the inhibitionefficiency of mild steel in HCl and H2SO4 solution is il-lustrated in Figure 4 It can be seen that the inhibition ef-ficiency signal increases alongside the CMCh AA volumeloading changed from 1 18 to 8 4 ww in the HCl solution(Figure 4(a)) When CMCh AA changed from 8 4 to 9 2ww the signal of inhibition efficiency significantly declinede optimum ratio of CMCh AA was found at 8 4 wwwith its value of inhibition efficiency at 8886 is ratio(8 4 ww) contributed to the interaction energy between themild steelrsquos surface and thin layer of inhibitor being higherthan the interaction energy between the surface of mild steeland water and consequently the inhibition efficiency wasfound to be quite significant
As can be seen in Figure 4(b) the inhibition efficiencyresponse stabilized when CMCh AA volume loadingchanged from 5 36 to 30 16 ww in an H2SO4 solutionWhen the ratio of CMCh AA volume changed from 30 16to 35 12 ww the inhibition efficiency response increased
4 International Journal of Chemical Engineering
e CMCh AA volume loading changed again from 35 12to 45 4 ww (Figure 4(b)) and the response of inhibitioneciency gradually reduced in response to this change ismeans that the interaction energy between the mild steelrsquossurface and thin layer of the inhibitor took place slowly withthe thin layer of the inhibitor being unable to prevent attacksof the sulfuric ion on the mild steelrsquos surface is resulted inincreased corrosion on the surface [36] erefore theoptimum ratio of CMCh AA in H2SO4 solution at 35 12ww was utilized for the subsequent evaluation of corrosioninhibition
33 Determination of Activation Energy e activationenergy (Ea) of the system in the presence of AA-CMCh wasdetermined using the Arrhenius equation e Arrheniusplots for mild steel in 1M HCl with 400 ppm inhibitor isshown in Figure 5 e Ea value determined from theArrhenius plots in the presence of AA-CMCh was98089 kJmiddotmolminus1 is high value of Ea in the presence of aninhibitor was due to the high-energy barrier of the corrosion
rate [37] conrming the formation of a complex compoundbetween the inhibitor and Fe ion of mild steel
34 Adsorption Isotherm e performance of the AA-CMCh as a successful corrosion inhibitor is mainly dueto their adsorption ability on the surface of mild steel isability has been utilized to determine its mechanism ofcorrosion inhibition e Langmuir adsorption isothermfrom a plot of Cθ against C at 28degC is shown in Figure 5evalue of the correlation coecient for AA-CMCh is close toone which implies that the adsorption of AA-CMCh on themild steelrsquos surface is well tted to the Langmuir adsorptionisotherm e calculated Kads and ΔG values are10496 kJmiddotmolminus1 and minus3322 kJmiddotmolminus1 respectively esevalues demonstrated that the adsorption types of inhibitorson mild steel surfaces are chemical adsorption e Lang-muir adsorption isotherms from a plot of Cθ against C in1M HCl solution at 40degC and 60degC were also plotted (gurenot shown) e Kads and ΔG values at 40degC were7650 kJmiddotmolminus1and minus33722 kJmiddotmolminus1 respectively while the
3517
3534
9324 29
5700
2732
29
2120
82 1935
65
1745
6516
4246
1542
1514
3607
1373
38
1236
4211
5252
1037
7594
516
9008
0
7648
169
923
6442
560
182 5680
652
080
4629
4
50010001500200025003000350040004500(1cm)
0
15
30
45
60
75
90
105
120
T
Amylose-acetate
Figure 2 FT-IR spectrum of amylose modied with acetate
Figure 1 Powder of the amylose functionalized with acetate
International Journal of Chemical Engineering 5
Kads and ΔG values at 60degC were found to be1773 kJmiddotmolminus1and minus31831 kJmiddotmolminus1 respectively Generallythe obtained values of the ∆Gads were within minus3322 kJmiddotmolminus1
to minus3383 kJmiddotmolminus1 e ∆Gads values are simminus33 kJmiddotmolminus1 ormore negative suggesting chemisorption where chargesharing or charge transfer from an organic compound to themild steel surface takes place to form a coordinate-typemetallic bond [24 38]
e thermodynamic performance for the corrosion ofthe mild steel surface in 1M HCl at multiple concentrationsof AA-CMCh composites was obtained from a plot oflog(CRT) versus 1T and calculated using equation (7) evalues of activation enthalpy (∆H) and activation entropy(∆S) were minus4856 kJmiddotmolminus1 and 00495 kJmiddotmolminus1middotKminus1 re-spectively e negative value of ΔH indicates the exo-thermic nature of the activated-complex formation fromthe reactants for the rate-determining step of the steelassociation process e positive values of ΔS demonstrateirregularity of the adsorbed inhibitors on the mild steelsurface [39] is implies that the activated complex in the
rate-determining step represents a dissociation instead of anassociation process [32]
35 Potentiodynamic Polarization Studies e performanceof potentiodynamic polarization for mild steel in an HClsolution (10M) at multiple concentrations of inhibitors at301K after 60min of immersion time is shown in Figure 6e current anodic and cathodic response decreased as theAA-CMCh loading increased from 100 to 400 ppm due tothe large amounts of inhibitor on the electrodersquos surface andalso the moving corrosion potential towards increasednegativity is resulted in the classication of the inhibitoras the mixed type
e electrochemical parameters ie corrosion potential(Ecorr) anodic and cathodic Tafel slope (szligc szliga) corrosioncurrent density (icorr) and inhibition eciency (IE) obtainedfrom the corresponding polarization curves are shown inTable 1 In the proposed corrosion inhibitor the IE () wascalculated using the following equation
where i0corr and icorrprime represent the corrosion current densitieswithout and with the addition of inhibitors respectivelyeresults conrmed that the inhibition eciency responseincreased while the corrosion current density decreasedwhen the addition of inhibitors concentration increasedis implies that the inhibitor adsorption on the mild steelrsquossurface and the adsorption process is enhanced and in-creased inhibition eciency
36 Surface Characterization SEM and EDX In order todetermine the eiexclectiveness of the formatted thin layer of theinhibitor on the mild steelrsquos surface the treated mild steelwas imaged using an SEM SEM images of the mild steelsurface in the presenceabsence of CMCh in HCl and H2SO4solutions are shown in Figures 7 and 8 In the presence of AAat their respective optimum concentrations (400 ppm) inHCl (Figure 7(a)) and H2SO4 solutions (Figure 8(a)) asmooth surface of mild steel can be seen (Figures 7(a) and
8(a)) In the presence of AA-CMCh in HCl (Figure 7(b)) andH2SO4 solution (Figure 8(b)) a smoother surface of the mildspecimen can be seen (Figures 7(b) and 8(b)) is impliesthat the AA-CMCh is more eiexclective in inhibiting corrosionon mild steelrsquos surface compared to the AA inhibitor isfeature probably contributed to the homogeneity and bio-compatibility of the AA-CMCh composites on the mildsteelrsquos surface Generally a smoother surface of themild steelspecimen denote that the AA-CMCh has adsorbed onto themild steelrsquos surface and protected specimens from direct acidattacks
e EDX spectra of the mild steel and control specimenin HCl solution is shown in Figure 9 e surface of mildsteels as a control specimen before treatment (Figure 9(c))and the presence of AA-CMCh (Figure 9(b)) exhibit asmooth and uniform surface e morphology in thepresence AA was slightly damaged and rough (Figure 9(a))is conrmed that the mild steel surface is well protectedfrom acidic attacks and prevented from corroding Table 2shows the percentage of atomic contents in the inhibitor andcontrol specimens e EDX spectrum in the presence ofAA-CMCh conrmed that the concentration of the Cl ion is
Figure 6 Potentiodynamic polarization curves of mild steel in 10MHCl solutionmeasured in the absence (a) and presence of (b) 100 ppm(c) 200 ppm (d) 300 ppm and (e) 400 ppm of amylose-acetatecarboxymethyl chitosan (AA-CMCh)
Table 1 Electrochemical parameters obtained from polarization measurement in 10M HCl in the presence and absence of a diiexclerentconcentration of AA-CMCh
Figure 8 SEM micrographs of the mild steel surface in 025M H2SO4 with AA (a) and AA-CMCh (b)
(a) (b)
Figure 7 SEM images of mild steel surfaces in 1M HCl with AA (a) and AA-CMCh (b)
(a) (b)
Figure 9 Continued
International Journal of Chemical Engineering 9
higher than that of the presence of AA whilst the con-centration of C in the control specimen prior to treatmentwas lower than that of the treated specimen due to theinhibitor absorbed onto the mild steelrsquos surface e con-centration of Fe and O from the inhibitor of AA is notsignificantly different than the inhibitor of AA-CMCh(Table 2) Generally both AA and AA-CMCh inhibitorsare able to inhibit the mild steel specimen from a directattack by the Cl ion which protects the mild steel surfacefrom an aggressive environment
37Mechanismof Inhibition e adsorption of AA-blendedCMCh on mild steel can be clearly defined by consideringthe chemisorption processes e specific mechanism ofcorrosion inhibition of AA-CMCh to the surface of mildsteel coupons is detailed in the following equations
Fe + AA-CMCh⟷ Fe(AA-CMCh)ads (9)
Fe(AA-CMCh)ads⟷ Fe2++ AA-CMCh + neminus (10)
AA-CMChaq + H2Oads⟷AA-CMChads + H2Oaq
(11)
e chemisorption of AA-CMCh on mild steel isdenoted by the donor-acceptor interactions between thelone pair of the electron from the carbonyl and amine groupsof AA-CMCh with the d-orbitals of Fe e value of freeenergy from the AA-CMCh adsorption was minus33 kJmiddotmolminus1 ormore negative is confirms that the adsorption mecha-nism of the AA-CMCh on the surface of the mild steelcoupon was chemically adsorbed e inhibition of
corrosion begins by the displacement of water molecules bythe inhibitorrsquos capacity toward specific adsorption of theinhibitor on the metalrsquos surface [40]
4 Conclusions
e corrosion inhibition mechanism based on carbox-ymethyl chitosanamylose-acetate composites used to pro-tect mild steel in an acidic medium was successfullyinvestigatede AA-CMCh base inhibitor showed excellentinhibition performance in the case of mild steel in a 1MHClsolution e inhibiting efficiencies decreased in the order ofAA-CMChgtAA e inhibitor adsorptions on the mildsteelrsquos surface are chemically adsorbed while the corrosioninhibition mechanism on the mild steelrsquos surface wasspontaneous exothermal and irregular and took place dueto the formation of the Fe-chelate compound on the surfaceof the mild steel specimen e adsorption of the inhibitorson the mild steel specimen in acidic media solution com-ports with that of the Langmuir adsorption isotherm enegative values of the ∆Gads and ∆H indicated that theadsorption reaction took place spontaneously andexothermally
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this work
Acknowledgments
e authors gratefully acknowledge financial support fromthe Directorate General of Higher Education of Ministry(DIKTI) the Ministry of Research Technology and HigherEducation through a fundamental grant of the UniversitasRiau Indonesia
(c)
Figure 9 SEMEDX spectra of the mild steel surface in 1M HCl (a) AA (b) AA-CMCh blended (c) control
Table 2 Percentage atomic contents of elements measured usingthe EDX technique
Inhibitors Fe O S Cl CControl 9664 197 mdash 012 027AA 7769 2226 mdash 006 1346AA-CMCh 7761 2223 mdash 015 1649
10 International Journal of Chemical Engineering
References
[1] B Xu W Yang Y Liu X Yin W Gong and Y ChenldquoExperimental and theoretical evaluation of two pyr-idinecarboxaldehyde thiosemicarbazone compounds as cor-rosion inhibitors for mild steel in hydrochloric acid solutionrdquoCorrosion Science vol 78 pp 260ndash268 2014
[2] S A Umoren and U M Eduok ldquoApplication of carbohydratepolymers as corrosion inhibitors for metal substrates indifferent media a reviewrdquo Carbohydrate Polymers vol 140pp 314ndash341 2016
[3] S E Karekar U D Bagale S H Sonawane B A Bhanvaseand D V Pinjari ldquoA smart coating established with encap-sulation of Zinc Molybdate centred nanocontainer for activecorrosion protection of mild steel release kinetics of corro-sion inhibitorrdquo Composite Interfaces vol 25 no 9 pp 785ndash808 2018
[4] S Abrishami R Naderi and B Ramezanzadeh ldquoFabricationand characterization of zinc acetylacetonateUrtica dioicaleaves extract complex as an effective organicinorganic hy-brid corrosion inhibitive pigment for mild steel protection inchloride solutionrdquo Applied Surface Science vol 457pp 487ndash496 2018
[5] M Krishnan H Subramanian H-U Dahms et al ldquoBiogeniccorrosion inhibitor on mild steel protection in concentratedHCl mediumrdquo Scientific Report vol 8 p 2609 2018
[6] N Bhardwaj D Prasad and R Haldhar ldquoStudy of the Aeglemarmelos as a green corrosion inhibitor for mild steel in acidicmedium experimental and theoretical approachrdquo Journal ofBio- and Tribo-Corrosion vol 4 no 4 p 61 2018
[7] T K Bhuvaneswari V S Vasantha and C JeyaprabhaldquoPongamia pinnata as a green corrosion inhibitor for mildsteel in 1N sulfuric acid mediumrdquo Silicon vol 10 no 5pp 1793ndash1807 2018
[8] M P Rai A Khanra S Rai M Srivastava and R PrakashldquoPivotal role of levoglucosenone and hexadecanoic acid frommicroalgae Chlorococcum sp for corrosion resistance on mildsteel electrochemical microstructural and theoretical anal-ysisrdquo Journal of Molecular Liquids vol 266 pp 279ndash2902018
[9] A Saxena D Prasad and R Haldhar ldquoInvestigation ofcorrosion inhibition effect and adsorption activities of Cus-cuta reflexa extract for mild steel in 05 M H2SO4rdquo Bio-electrochemistry vol 124 pp 156ndash164 2018
[10] X Zheng M Gong Q Li and L Guo ldquoCorrosion inhibitionof mild steel in sulfuric acid solution by loquat (Eriobotryajaponica Lindl) leaves extractrdquo Scientific Report vol 8p 9140 2018
[11] A Bouoidina F El-Hajjaji M Drissi et al ldquoTowards a deeperunderstanding of the anticorrosive properties of hydrazinederivatives in acid medium experimental DFT and MDsimulation assessmentrdquo Metallurgical and Materials Trans-actions A vol 49 no 10 pp 5180ndash5191 2018
[12] A Chaouiki H Lgaz I-M Chung et al ldquoUnderstandingcorrosion inhibition of mild steel in acid medium by newbenzonitriles insights from experimental and computationalstudiesrdquo Journal of Molecular Liquids vol 266 pp 603ndash6162018
[13] Y Guo Z Chen Y Zuo Y Chen W Yang and B Xu ldquoIonicliquids with two typical hydrophobic anions as acidic cor-rosion inhibitorsrdquo Journal of Molecular Liquids vol 269pp 886ndash895 2018
[14] E Naseri M Hajisafari A Kosari M Talari S Hosseinpourand A Davoodi ldquoInhibitive effect of Clopidogrel as a green
corrosion inhibitor for mild steel statistical modeling andquantum Monte Carlo simulation studiesrdquo Journal of Mo-lecular Liquids vol 269 pp 193ndash202 2018
[15] R Geethanjali and S Subhashini ldquoSynthesis and kinetics ofcorrosion inhibition of water-soluble terpolymer of polyvinylalcohol functionalized with vinyl sulfonate and p-vinyl ben-zene sulfonate in molar HClrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4 p 60 2018
[16] P Han W Li H Tian et al ldquoDesigning and fabricating oftime-depend self-strengthening inhibitor film synergisticinhibition of sodium dodecyl sulfate and 4-mercaptopyridinefor mild steelrdquo Journal of Molecular Liquids vol 268pp 425ndash437 2018
[17] X He J Mao Q Ma and Y Tang ldquoCorrosion inhibition ofperimidine derivatives for mild steel in acidic media elec-trochemical and computational studiesrdquo Journal of MolecularLiquids vol 269 pp 260ndash268 2018
[18] A A Mahmmod I A Kazarinov A A Khadom andH B Mahood ldquoExperimental and theoretical studies of mildsteel corrosion inhibition in phosphoric acid using tetrazolesderivativesrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4p 58 2018
[19] M Messali M Larouj H Lgaz et al ldquoA new schiff basederivative as an effective corrosion inhibitor for mild steel inacidic media experimental and computer simulations stud-iesrdquo Journal of Molecular Structure vol 1168 pp 39ndash48 2018
[20] A Mishra C Verma S Chauhan et al ldquoCharacterizationand corrosion inhibition performance of 5-aminopyrazolecarbonitriles towards mild steel acidic corrosionrdquo Journal ofBio- and Tribo-Corrosion vol 4 p 53 2018
[21] N Saini R Kumar H Lgaz et al ldquoMinified dose of urispasdrug as better corrosion constraint for soft steel in sulphuricacid solutionrdquo Journal of Molecular Liquids vol 269pp 371ndash380 2018
[22] K Zhang W Yang Y Chen et al ldquoEnhanced inhibitiveperformance of fluoro-substituted imidazolium-based ionicliquid for mild steel corrosion in hydrochloric acid at elevatedtemperaturerdquo Journal of Materials Science vol 53 no 20pp 14666ndash14680 2018
[23] K R Ansari M A Quraishi and A Singh ldquoCorrosion in-hibition of mild steel in hydrochloric acid by some pyridinederivatives an experimental and quantum chemical studyrdquoJournal of Industrial and Engineering Chemistry vol 25pp 89ndash98 2015
[24] L O Olasunkanmi I B Obot M M Kabanda andE E Ebenso ldquoSome quinoxalin-6-yl derivatives as corrosioninhibitors for mild steel in hydrochloric acid experimentaland theoretical studiesrdquo Journal of Physical Chemistry Cvol 119 no 28 pp 16004ndash16019 2015
[25] M Ewis S S Elkholy and M Z Esabee ldquoAntifungal efficacyof chitosan and its thiourea derivatives upon the growth ofsome sugar-beet pathogensrdquo International Journal of Bi-ological Macromolecules vol 38 no 1 pp 1ndash8 2006
[26] Z-X Tang J-Q Qian and L-E Shi ldquoCharacterizations ofimmobilized neutral lipase on chitosan nano-particlesrdquoMaterials Letters vol 61 no 1 pp 37ndash40 2007
[27] M N El-Haddad ldquoChitosan as a green inhibitor for coppercorrosion in acidic mediumrdquo International Journal of Bi-ological Macromolecules vol 55 pp 142ndash149 2013
[28] S Cheng S Chen T Liu X Chang and Y Yin ldquoCarbox-ymenthylchitosan as an ecofriendly inhibitor for mild steel in1 MHClrdquoMaterials Letters vol 61 no 14-15 pp 3276ndash32802007
International Journal of Chemical Engineering 11
[29] K Wan P Feng B Hou and Y Li ldquoEnhanced corrosioninhibition properties of carboxymethyl hydroxypropyl chi-tosan for mild steel in 10 M HCl solutionrdquo RSC Advancesvol 6 no 81 pp 77515ndash77524 2016
[30] M M Solomon H Gerengi T Kaya and S A UmorenldquoEnhanced corrosion inhibition effect of chitosan for St37 in15 H2SO4 environment by silver nanoparticlesrdquo In-ternational Journal of Biological Macromolecules vol 104pp 638ndash649 2017
[31] A M Alsabagh M Z Elsabee Y M Moustafa A Elfky andR E Morsi ldquoCorrosion inhibition efficiency of somehydrophobically modified chitosan surfactants in relation totheir surface active propertiesrdquo Egyptian Journal of Petroleumvol 23 no 4 pp 349ndash359 2014
[32] S A Umoren M J Banera T Alonso-Garcia C A Gervasiand M V Mirıfico ldquoInhibition of mild steel corrosion in HClsolution using chitosanrdquo Cellulose vol 20 no 5 pp 2529ndash2545 2013
[33] M Erna Y Eryanti and A Dahliaty ldquoModifikasi amilosa daripati tapioka dan garut menjadi amilosa asetatrdquo Jurnal PilarSains vol 7 pp 28ndash30 2008
[34] H T Pang X G Chen H J Park D S Cha andJ F Kennedy ldquoPreparation and rheological properties ofdeoxycholate-chitosan and carboxymethyl-chitosan inaqueous systemsrdquo Carbohydrate Polymers vol 69 no 3pp 419ndash425 2007
[35] K K Anupama and J Abraham ldquoElectroanalytical studies onthe corrosion inhibition behavior of guava (Psidium guajava)leaves extract on mild steel in hydrochloric acidrdquo Research onChemical Intermediates vol 39 no 9 pp 4067ndash4080 2012
[36] M E Al-Dokheily H M Kredy and R N Al-Jabery ldquoIn-hibition of copper corrosion in H2SO4 NaCl and NaOHsolutions by Citrullus colocynthis fruits extractrdquo Journal ofNatural Sciences Research vol 4 pp 60ndash73 2014
[37] M H Hussin andM J Kassim ldquoe corrosion inhibition andadsorption behavior ofUncaria gambir extract onmild steel in1M HClrdquo Materials Chemistry and Physics vol 125 no 3pp 461ndash468 2011
[38] K R Ansari M A Quraishi and A Singh ldquoIsatin derivativesas a non-toxic corrosion inhibitor for mild steel in 20H2SO4rdquo Corrosion Science vol 95 pp 62ndash70 2015
[39] B Zerga A Attayibat M Sfaira et al ldquoEffect of some tripodalbipyrazolic compounds on C38 steel corrosion in hydro-chloric acid solutionrdquo Journal of Applied Electrochemistryvol 40 no 9 pp 1575ndash1582 2010
[40] H Ashassi-Sorkhabi and S A Nabavi-Amri ldquoCorrosioninhibition of carbon steel in petroleumwater mixtures byn-containing compoundsrdquo Acta Chimica Slovenica vol 47pp 507ndash517 2000
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
were procured from the supermarket e mild steel plateBJTP-24 with an area measuring 20times10 cm2 used in thiswork reported a chemical composition of C 016Si 019 Mn 48 P 016 S 022 and balancedFe
22 Instruments e FT-IR spectra of amylase acetate wereobtained using Spectrum FTIR GX infrared spectropho-tometer (PerkinElmer) e surface morphologies of mildsteel were imaged using the scanning electron microscope-dispersive X-ray spectrum (SEM-EDS) e pH values of thesolutions were measured using a pH meter (ermo Sci-entific) e glassware used in this work was cleaned usingdistilled and deionized waters
23 Amylose Isolation and Surface Modification eamylose powders were obtained from its cassava base via asimple extraction techniquee preparation of amylose wasslightly modified from the one reported in Erna et al [33] Inbrief the cassava sample was first cleaned using fresh waterto remove any soil or contaminant e cleaned cassava wascontinuously shredded and directly mixed into fresh waterto create a rough pulp is rough pulp was then shaken andsqueezed to obtain a suspension of amylose e extractedamylose was carefully filtered using gauze to obtain a slurryamylose and carefully rinsed with fresh water several timesto get a clean starchis isolated starch was then air-dried atambient temperature e dried starch was thoroughlycrushed using a mortar and pestle and immediately purifiedusing a dioxane solution for 4 h to remove any remainingacid(s) en the purified starch was again dried at 80degCand carefully dispersed in a solution of n-butanol eobtained amylose was then sterilized using an autoclavefor 2 h at a pressure of 15 psi and left to cool at 25degC for24 hrs e sterilized amylose was collected via centrifuga-tion (6500 rpm and 10min) and washed thoroughly usingdeionized water and absolute methanol thrice
To modify the surface of amylose sim5 g of amylose wasimmediately acetylated with 25mL of acetate acid glacial andmanually stirred until the solution becomes homogeneousen a mixture consisting of 02mL sulfate acid and 50mLacetate glacial was immediately added into the acetylatedamylose and stirred for 1 h at 37degC A solution of 165mLacetate acid anhydride was carefully added and stirred foranother 44 hrs at 37degC en the final acetate-modifiedamylose was slowly deposited into 200mL of isopropanolsolution and stirred at room temperature e formedprecipitation was then filtered and thoroughly washed withhot distilled water and then air-dried overnight at roomtemperature e modified amylose was directly charac-terized using a spectrum FTIR GX infrared spectropho-tometer (PerkinElmer)
24 Fabrication of Corrosion Inhibition Based on AA-BlendedCMCh Carboxymethyl chitosan was prepared as per Panget al [34] In brief sim10 g of chitosan powder was mixed with135 g of NaOH and immediately dissolved in 80mL
isopropanol containing 20mL of distilled water e mix-ture was then kept in a water bath at 60degC A mixture of 15 gof monochloroacetate in 20mL isopropanol was drippedinto the chitosan suspension and left for 4 h at ambienttemperature e reaction was stopped via the addition of asolution of 20mL ethanol (70) e obtained CMCh wasthen filtered and washed with ethanol several times followedby air drying at room temperature
To make the AA-modified CMCh a mixture consistingof 200mgL CMCh in chloric acid (10M) and 500mgLCMCh in sulfate acid (025M) was immediately added into asample bottle containing 10ndash50mg AA and then carefullystirred until its homogeneouse CMChmodified with AAwas applied on mild steel to analyze the mechanism ofcorrosion inhibition based on the kinetics and thermody-namics study
25 Preparation of Mild Steel Plates A mild steel plate wasprepared measuring 10times 20 cm2 and directly cleanedusing SiC sand paper (grades 100 200 and 400)e cleanedmild steel plate was then rinsed with distilled water acetoneand ethanol several times It was then immediately dried inan oven for 15min at 40degC e dried mild steel was thenweighed and its weight was recorded
26 Determination of Corrosion Rate of Mild Steel in AcidicMedia sim200mgL and 500mgL of AA-functionalizedCMCh were separately added into a solution of 10MHCl and 025M H2SO4 respectively en mild steelspecimens were directly immersed into HCl and H2SO4media for 3 days and a day respectively e steel couponswere carefully rinsed with chloroform and acetone severaltimes e washed steel coupons were thoroughly brushedand washed with distilled water and ethanol thrice followedby drying in an oven at 60degC en mild steel specimenswere weighed again to compare its respective rates of cor-rosion e determination of the corrosion rate of mild steelin acidic media without inhibitors was also conducted for thecomparison purposes e corrosion rate (gmiddotcmminus2middothminus1) wascalculated using equation (1) where W1 and W2 are theweights of mild steel coupons before and after incubationrespectively in a test medium S represents the surface areaof corroded steel (dm2) while t represents the immersiontime (h)
corrosion rate(CR) W1 minusW2
S middot t (1)
27 Determination of Inhibition Efficiency Surface Coverageand Adsorption-Free Energy Values e determination ofinhibition efficiency was conducted using HCl and H2SO4solutions A series of AA-functionalized CMCh concen-trations from 200 to 600mgL and 500 to 900mgL werethoroughly poured into sample bottles containing HCl andH2SO4 solutions respectively e prepared steel couponswere then incubated in the HCl and H2SO4 solution andcarefully rinsed with distilled water acetone and ethanol
International Journal of Chemical Engineering 3
and then dried in an oven for 15min at 40degC e inhibitionefficiency (IE) was calculated using equation (2) while thesurface coverage (θ) value was determined using equation(3) where CRblank and CRinh are the values of the corrosionrates of mild steel in the absence and presence of inhibitorsrespectively Meanwhile the Langmuir isotherm adsorptioncurve was determined using equation (4) and the free en-ergy of adsorption (ΔGo
ads) was investigated using equation(5) where Kads represents the equilibrium constant of theadsorption process and C represents the inhibitorrsquos con-centration(s) R represents the gas constant while T rep-resents the absolute temperature
IE CRblank minusCRinh
CRblanktimes 100 (2)
θ CRblank minusCRinh
CRblank (3)
Kads C θ
1minus θ (4)
ΔGoads minusRT ln 555Kads( 1113857 (5)
28 Determination of Activation of Energy Enthalpy andEntropy eprepared steel coupons have been immersed inHCl and H2SO4 solutions containing and not containinginhibitors en the mild steel plates were placed in athermostat at various temperatures from 284 to 600degC esteel plate was rinsed with distilled water acetone andethanol Afterwards it was oven-dried for 15min at 40degCe activation energy (Ea) was determined using equation(6) where R represents the gas constant CR represents thecorrosion inhibition K represents the preexponential factorand T represents the absolute temperature e values of Eawere calculated from the linear regression between lnCRand 1T e activation enthalpy (ΔHo
ads) and entropy(ΔSoads) can be calculated using equation (7)
CR k exp minusEa
RT1113874 1113875 (6)
ΔGoads ΔHo
ads minusTΔSoads (7)
29 Surface Analysis of Mild Steel e prepared mild steelplates measuring 20times10 cm2 were incubated in HCl andH2SO4 in the absencepresence of inhibitor under optimumconditions for 3 days ereafter the mild steel specimenswere removed washed with distilled water degreased withacetone and then dried at room temperature e steelspecimens were mechanically cut into 10 cm2 chips andthen immediately analyzed with SEM and EDX SEM wasperformed at a voltage of 5 kV and 5kx magnification on aLEO 1450 VP instrument e chemical compositions wereanalyzed using an EDX detector e attached functionalgroups on the mild steel surface were investigated using FT-IR spectroscopy equipment (PerkinElmer instrument)
3 Results and Discussion
31 Characterization of Amylose-Acetate e acetate-modified amylose powder for corrosion inhibition isshown in Figure 1 e acetate-functionalized amylosepowders are traditionally prepared using the acetylatingmethod e synthesis of AA involved mixing sulfuric andacetate acids and directly acetylate them via stirring epowders of acetate functionalized amylose were clearlywhite FTIR spectrum of the amylose-acetate is detailed inFigure 2 e O-H stretch peak at 349324 cmminus1 is from theamylose molecules e peaks at 174565 cmminus1 to123642 cmminus1 represent a carbonyl (COOH) group of theacetate ese peaks confirmed the occurrence of esterifi-cation between amylose and acetate molecules
32 Effect of Inhibitor Concentrations In order to determinethe best condition for the corrosion inhibition response theinhibitor loading was optimized to include both AA and AA-CMCh e inhibition efficiency response of corrosionstudies based on AA towards mild steel in an acidic mediumis shown in Figure 3 In the HCl solution the inhibitionefficiency response gradually increased alongside AArsquosconcentration from 100 to 400mgL (Figure 3(a)) while inthe H2SO4 solution the inhibition efficiency response alsoincreased alongside AA loading from 100 to 400mgL(Figure 3(b)) e increasing inhibition efficiency along-side inhibitor concentration is assumed to be due to theadsorption of inhibitor molecules on the surface of mild steel[35] With further increase in AA concentration from 400 to600 ppm in HCl solution and 400 to 500 ppm in H2SO4solution the responses of inhibition efficiency decreasedbecause the inhibitor has been fully adsorbed onto the mildsteelrsquos surface is confirms that the carboxylic group(COOH) of AA and iron (Fe) of mild steel has bonded einhibitor molecules could form a film layer and act as abarrier between mild steel and corrosive media e optimalAA concentration in HCl and H2SO4 solutions at 400 ppmwas used for further experiments
e effect of the CMCh AA ratio towards the inhibitionefficiency of mild steel in HCl and H2SO4 solution is il-lustrated in Figure 4 It can be seen that the inhibition ef-ficiency signal increases alongside the CMCh AA volumeloading changed from 1 18 to 8 4 ww in the HCl solution(Figure 4(a)) When CMCh AA changed from 8 4 to 9 2ww the signal of inhibition efficiency significantly declinede optimum ratio of CMCh AA was found at 8 4 wwwith its value of inhibition efficiency at 8886 is ratio(8 4 ww) contributed to the interaction energy between themild steelrsquos surface and thin layer of inhibitor being higherthan the interaction energy between the surface of mild steeland water and consequently the inhibition efficiency wasfound to be quite significant
As can be seen in Figure 4(b) the inhibition efficiencyresponse stabilized when CMCh AA volume loadingchanged from 5 36 to 30 16 ww in an H2SO4 solutionWhen the ratio of CMCh AA volume changed from 30 16to 35 12 ww the inhibition efficiency response increased
4 International Journal of Chemical Engineering
e CMCh AA volume loading changed again from 35 12to 45 4 ww (Figure 4(b)) and the response of inhibitioneciency gradually reduced in response to this change ismeans that the interaction energy between the mild steelrsquossurface and thin layer of the inhibitor took place slowly withthe thin layer of the inhibitor being unable to prevent attacksof the sulfuric ion on the mild steelrsquos surface is resulted inincreased corrosion on the surface [36] erefore theoptimum ratio of CMCh AA in H2SO4 solution at 35 12ww was utilized for the subsequent evaluation of corrosioninhibition
33 Determination of Activation Energy e activationenergy (Ea) of the system in the presence of AA-CMCh wasdetermined using the Arrhenius equation e Arrheniusplots for mild steel in 1M HCl with 400 ppm inhibitor isshown in Figure 5 e Ea value determined from theArrhenius plots in the presence of AA-CMCh was98089 kJmiddotmolminus1 is high value of Ea in the presence of aninhibitor was due to the high-energy barrier of the corrosion
rate [37] conrming the formation of a complex compoundbetween the inhibitor and Fe ion of mild steel
34 Adsorption Isotherm e performance of the AA-CMCh as a successful corrosion inhibitor is mainly dueto their adsorption ability on the surface of mild steel isability has been utilized to determine its mechanism ofcorrosion inhibition e Langmuir adsorption isothermfrom a plot of Cθ against C at 28degC is shown in Figure 5evalue of the correlation coecient for AA-CMCh is close toone which implies that the adsorption of AA-CMCh on themild steelrsquos surface is well tted to the Langmuir adsorptionisotherm e calculated Kads and ΔG values are10496 kJmiddotmolminus1 and minus3322 kJmiddotmolminus1 respectively esevalues demonstrated that the adsorption types of inhibitorson mild steel surfaces are chemical adsorption e Lang-muir adsorption isotherms from a plot of Cθ against C in1M HCl solution at 40degC and 60degC were also plotted (gurenot shown) e Kads and ΔG values at 40degC were7650 kJmiddotmolminus1and minus33722 kJmiddotmolminus1 respectively while the
3517
3534
9324 29
5700
2732
29
2120
82 1935
65
1745
6516
4246
1542
1514
3607
1373
38
1236
4211
5252
1037
7594
516
9008
0
7648
169
923
6442
560
182 5680
652
080
4629
4
50010001500200025003000350040004500(1cm)
0
15
30
45
60
75
90
105
120
T
Amylose-acetate
Figure 2 FT-IR spectrum of amylose modied with acetate
Figure 1 Powder of the amylose functionalized with acetate
International Journal of Chemical Engineering 5
Kads and ΔG values at 60degC were found to be1773 kJmiddotmolminus1and minus31831 kJmiddotmolminus1 respectively Generallythe obtained values of the ∆Gads were within minus3322 kJmiddotmolminus1
to minus3383 kJmiddotmolminus1 e ∆Gads values are simminus33 kJmiddotmolminus1 ormore negative suggesting chemisorption where chargesharing or charge transfer from an organic compound to themild steel surface takes place to form a coordinate-typemetallic bond [24 38]
e thermodynamic performance for the corrosion ofthe mild steel surface in 1M HCl at multiple concentrationsof AA-CMCh composites was obtained from a plot oflog(CRT) versus 1T and calculated using equation (7) evalues of activation enthalpy (∆H) and activation entropy(∆S) were minus4856 kJmiddotmolminus1 and 00495 kJmiddotmolminus1middotKminus1 re-spectively e negative value of ΔH indicates the exo-thermic nature of the activated-complex formation fromthe reactants for the rate-determining step of the steelassociation process e positive values of ΔS demonstrateirregularity of the adsorbed inhibitors on the mild steelsurface [39] is implies that the activated complex in the
rate-determining step represents a dissociation instead of anassociation process [32]
35 Potentiodynamic Polarization Studies e performanceof potentiodynamic polarization for mild steel in an HClsolution (10M) at multiple concentrations of inhibitors at301K after 60min of immersion time is shown in Figure 6e current anodic and cathodic response decreased as theAA-CMCh loading increased from 100 to 400 ppm due tothe large amounts of inhibitor on the electrodersquos surface andalso the moving corrosion potential towards increasednegativity is resulted in the classication of the inhibitoras the mixed type
e electrochemical parameters ie corrosion potential(Ecorr) anodic and cathodic Tafel slope (szligc szliga) corrosioncurrent density (icorr) and inhibition eciency (IE) obtainedfrom the corresponding polarization curves are shown inTable 1 In the proposed corrosion inhibitor the IE () wascalculated using the following equation
where i0corr and icorrprime represent the corrosion current densitieswithout and with the addition of inhibitors respectivelyeresults conrmed that the inhibition eciency responseincreased while the corrosion current density decreasedwhen the addition of inhibitors concentration increasedis implies that the inhibitor adsorption on the mild steelrsquossurface and the adsorption process is enhanced and in-creased inhibition eciency
36 Surface Characterization SEM and EDX In order todetermine the eiexclectiveness of the formatted thin layer of theinhibitor on the mild steelrsquos surface the treated mild steelwas imaged using an SEM SEM images of the mild steelsurface in the presenceabsence of CMCh in HCl and H2SO4solutions are shown in Figures 7 and 8 In the presence of AAat their respective optimum concentrations (400 ppm) inHCl (Figure 7(a)) and H2SO4 solutions (Figure 8(a)) asmooth surface of mild steel can be seen (Figures 7(a) and
8(a)) In the presence of AA-CMCh in HCl (Figure 7(b)) andH2SO4 solution (Figure 8(b)) a smoother surface of the mildspecimen can be seen (Figures 7(b) and 8(b)) is impliesthat the AA-CMCh is more eiexclective in inhibiting corrosionon mild steelrsquos surface compared to the AA inhibitor isfeature probably contributed to the homogeneity and bio-compatibility of the AA-CMCh composites on the mildsteelrsquos surface Generally a smoother surface of themild steelspecimen denote that the AA-CMCh has adsorbed onto themild steelrsquos surface and protected specimens from direct acidattacks
e EDX spectra of the mild steel and control specimenin HCl solution is shown in Figure 9 e surface of mildsteels as a control specimen before treatment (Figure 9(c))and the presence of AA-CMCh (Figure 9(b)) exhibit asmooth and uniform surface e morphology in thepresence AA was slightly damaged and rough (Figure 9(a))is conrmed that the mild steel surface is well protectedfrom acidic attacks and prevented from corroding Table 2shows the percentage of atomic contents in the inhibitor andcontrol specimens e EDX spectrum in the presence ofAA-CMCh conrmed that the concentration of the Cl ion is
Figure 6 Potentiodynamic polarization curves of mild steel in 10MHCl solutionmeasured in the absence (a) and presence of (b) 100 ppm(c) 200 ppm (d) 300 ppm and (e) 400 ppm of amylose-acetatecarboxymethyl chitosan (AA-CMCh)
Table 1 Electrochemical parameters obtained from polarization measurement in 10M HCl in the presence and absence of a diiexclerentconcentration of AA-CMCh
Figure 8 SEM micrographs of the mild steel surface in 025M H2SO4 with AA (a) and AA-CMCh (b)
(a) (b)
Figure 7 SEM images of mild steel surfaces in 1M HCl with AA (a) and AA-CMCh (b)
(a) (b)
Figure 9 Continued
International Journal of Chemical Engineering 9
higher than that of the presence of AA whilst the con-centration of C in the control specimen prior to treatmentwas lower than that of the treated specimen due to theinhibitor absorbed onto the mild steelrsquos surface e con-centration of Fe and O from the inhibitor of AA is notsignificantly different than the inhibitor of AA-CMCh(Table 2) Generally both AA and AA-CMCh inhibitorsare able to inhibit the mild steel specimen from a directattack by the Cl ion which protects the mild steel surfacefrom an aggressive environment
37Mechanismof Inhibition e adsorption of AA-blendedCMCh on mild steel can be clearly defined by consideringthe chemisorption processes e specific mechanism ofcorrosion inhibition of AA-CMCh to the surface of mildsteel coupons is detailed in the following equations
Fe + AA-CMCh⟷ Fe(AA-CMCh)ads (9)
Fe(AA-CMCh)ads⟷ Fe2++ AA-CMCh + neminus (10)
AA-CMChaq + H2Oads⟷AA-CMChads + H2Oaq
(11)
e chemisorption of AA-CMCh on mild steel isdenoted by the donor-acceptor interactions between thelone pair of the electron from the carbonyl and amine groupsof AA-CMCh with the d-orbitals of Fe e value of freeenergy from the AA-CMCh adsorption was minus33 kJmiddotmolminus1 ormore negative is confirms that the adsorption mecha-nism of the AA-CMCh on the surface of the mild steelcoupon was chemically adsorbed e inhibition of
corrosion begins by the displacement of water molecules bythe inhibitorrsquos capacity toward specific adsorption of theinhibitor on the metalrsquos surface [40]
4 Conclusions
e corrosion inhibition mechanism based on carbox-ymethyl chitosanamylose-acetate composites used to pro-tect mild steel in an acidic medium was successfullyinvestigatede AA-CMCh base inhibitor showed excellentinhibition performance in the case of mild steel in a 1MHClsolution e inhibiting efficiencies decreased in the order ofAA-CMChgtAA e inhibitor adsorptions on the mildsteelrsquos surface are chemically adsorbed while the corrosioninhibition mechanism on the mild steelrsquos surface wasspontaneous exothermal and irregular and took place dueto the formation of the Fe-chelate compound on the surfaceof the mild steel specimen e adsorption of the inhibitorson the mild steel specimen in acidic media solution com-ports with that of the Langmuir adsorption isotherm enegative values of the ∆Gads and ∆H indicated that theadsorption reaction took place spontaneously andexothermally
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this work
Acknowledgments
e authors gratefully acknowledge financial support fromthe Directorate General of Higher Education of Ministry(DIKTI) the Ministry of Research Technology and HigherEducation through a fundamental grant of the UniversitasRiau Indonesia
(c)
Figure 9 SEMEDX spectra of the mild steel surface in 1M HCl (a) AA (b) AA-CMCh blended (c) control
Table 2 Percentage atomic contents of elements measured usingthe EDX technique
Inhibitors Fe O S Cl CControl 9664 197 mdash 012 027AA 7769 2226 mdash 006 1346AA-CMCh 7761 2223 mdash 015 1649
10 International Journal of Chemical Engineering
References
[1] B Xu W Yang Y Liu X Yin W Gong and Y ChenldquoExperimental and theoretical evaluation of two pyr-idinecarboxaldehyde thiosemicarbazone compounds as cor-rosion inhibitors for mild steel in hydrochloric acid solutionrdquoCorrosion Science vol 78 pp 260ndash268 2014
[2] S A Umoren and U M Eduok ldquoApplication of carbohydratepolymers as corrosion inhibitors for metal substrates indifferent media a reviewrdquo Carbohydrate Polymers vol 140pp 314ndash341 2016
[3] S E Karekar U D Bagale S H Sonawane B A Bhanvaseand D V Pinjari ldquoA smart coating established with encap-sulation of Zinc Molybdate centred nanocontainer for activecorrosion protection of mild steel release kinetics of corro-sion inhibitorrdquo Composite Interfaces vol 25 no 9 pp 785ndash808 2018
[4] S Abrishami R Naderi and B Ramezanzadeh ldquoFabricationand characterization of zinc acetylacetonateUrtica dioicaleaves extract complex as an effective organicinorganic hy-brid corrosion inhibitive pigment for mild steel protection inchloride solutionrdquo Applied Surface Science vol 457pp 487ndash496 2018
[5] M Krishnan H Subramanian H-U Dahms et al ldquoBiogeniccorrosion inhibitor on mild steel protection in concentratedHCl mediumrdquo Scientific Report vol 8 p 2609 2018
[6] N Bhardwaj D Prasad and R Haldhar ldquoStudy of the Aeglemarmelos as a green corrosion inhibitor for mild steel in acidicmedium experimental and theoretical approachrdquo Journal ofBio- and Tribo-Corrosion vol 4 no 4 p 61 2018
[7] T K Bhuvaneswari V S Vasantha and C JeyaprabhaldquoPongamia pinnata as a green corrosion inhibitor for mildsteel in 1N sulfuric acid mediumrdquo Silicon vol 10 no 5pp 1793ndash1807 2018
[8] M P Rai A Khanra S Rai M Srivastava and R PrakashldquoPivotal role of levoglucosenone and hexadecanoic acid frommicroalgae Chlorococcum sp for corrosion resistance on mildsteel electrochemical microstructural and theoretical anal-ysisrdquo Journal of Molecular Liquids vol 266 pp 279ndash2902018
[9] A Saxena D Prasad and R Haldhar ldquoInvestigation ofcorrosion inhibition effect and adsorption activities of Cus-cuta reflexa extract for mild steel in 05 M H2SO4rdquo Bio-electrochemistry vol 124 pp 156ndash164 2018
[10] X Zheng M Gong Q Li and L Guo ldquoCorrosion inhibitionof mild steel in sulfuric acid solution by loquat (Eriobotryajaponica Lindl) leaves extractrdquo Scientific Report vol 8p 9140 2018
[11] A Bouoidina F El-Hajjaji M Drissi et al ldquoTowards a deeperunderstanding of the anticorrosive properties of hydrazinederivatives in acid medium experimental DFT and MDsimulation assessmentrdquo Metallurgical and Materials Trans-actions A vol 49 no 10 pp 5180ndash5191 2018
[12] A Chaouiki H Lgaz I-M Chung et al ldquoUnderstandingcorrosion inhibition of mild steel in acid medium by newbenzonitriles insights from experimental and computationalstudiesrdquo Journal of Molecular Liquids vol 266 pp 603ndash6162018
[13] Y Guo Z Chen Y Zuo Y Chen W Yang and B Xu ldquoIonicliquids with two typical hydrophobic anions as acidic cor-rosion inhibitorsrdquo Journal of Molecular Liquids vol 269pp 886ndash895 2018
[14] E Naseri M Hajisafari A Kosari M Talari S Hosseinpourand A Davoodi ldquoInhibitive effect of Clopidogrel as a green
corrosion inhibitor for mild steel statistical modeling andquantum Monte Carlo simulation studiesrdquo Journal of Mo-lecular Liquids vol 269 pp 193ndash202 2018
[15] R Geethanjali and S Subhashini ldquoSynthesis and kinetics ofcorrosion inhibition of water-soluble terpolymer of polyvinylalcohol functionalized with vinyl sulfonate and p-vinyl ben-zene sulfonate in molar HClrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4 p 60 2018
[16] P Han W Li H Tian et al ldquoDesigning and fabricating oftime-depend self-strengthening inhibitor film synergisticinhibition of sodium dodecyl sulfate and 4-mercaptopyridinefor mild steelrdquo Journal of Molecular Liquids vol 268pp 425ndash437 2018
[17] X He J Mao Q Ma and Y Tang ldquoCorrosion inhibition ofperimidine derivatives for mild steel in acidic media elec-trochemical and computational studiesrdquo Journal of MolecularLiquids vol 269 pp 260ndash268 2018
[18] A A Mahmmod I A Kazarinov A A Khadom andH B Mahood ldquoExperimental and theoretical studies of mildsteel corrosion inhibition in phosphoric acid using tetrazolesderivativesrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4p 58 2018
[19] M Messali M Larouj H Lgaz et al ldquoA new schiff basederivative as an effective corrosion inhibitor for mild steel inacidic media experimental and computer simulations stud-iesrdquo Journal of Molecular Structure vol 1168 pp 39ndash48 2018
[20] A Mishra C Verma S Chauhan et al ldquoCharacterizationand corrosion inhibition performance of 5-aminopyrazolecarbonitriles towards mild steel acidic corrosionrdquo Journal ofBio- and Tribo-Corrosion vol 4 p 53 2018
[21] N Saini R Kumar H Lgaz et al ldquoMinified dose of urispasdrug as better corrosion constraint for soft steel in sulphuricacid solutionrdquo Journal of Molecular Liquids vol 269pp 371ndash380 2018
[22] K Zhang W Yang Y Chen et al ldquoEnhanced inhibitiveperformance of fluoro-substituted imidazolium-based ionicliquid for mild steel corrosion in hydrochloric acid at elevatedtemperaturerdquo Journal of Materials Science vol 53 no 20pp 14666ndash14680 2018
[23] K R Ansari M A Quraishi and A Singh ldquoCorrosion in-hibition of mild steel in hydrochloric acid by some pyridinederivatives an experimental and quantum chemical studyrdquoJournal of Industrial and Engineering Chemistry vol 25pp 89ndash98 2015
[24] L O Olasunkanmi I B Obot M M Kabanda andE E Ebenso ldquoSome quinoxalin-6-yl derivatives as corrosioninhibitors for mild steel in hydrochloric acid experimentaland theoretical studiesrdquo Journal of Physical Chemistry Cvol 119 no 28 pp 16004ndash16019 2015
[25] M Ewis S S Elkholy and M Z Esabee ldquoAntifungal efficacyof chitosan and its thiourea derivatives upon the growth ofsome sugar-beet pathogensrdquo International Journal of Bi-ological Macromolecules vol 38 no 1 pp 1ndash8 2006
[26] Z-X Tang J-Q Qian and L-E Shi ldquoCharacterizations ofimmobilized neutral lipase on chitosan nano-particlesrdquoMaterials Letters vol 61 no 1 pp 37ndash40 2007
[27] M N El-Haddad ldquoChitosan as a green inhibitor for coppercorrosion in acidic mediumrdquo International Journal of Bi-ological Macromolecules vol 55 pp 142ndash149 2013
[28] S Cheng S Chen T Liu X Chang and Y Yin ldquoCarbox-ymenthylchitosan as an ecofriendly inhibitor for mild steel in1 MHClrdquoMaterials Letters vol 61 no 14-15 pp 3276ndash32802007
International Journal of Chemical Engineering 11
[29] K Wan P Feng B Hou and Y Li ldquoEnhanced corrosioninhibition properties of carboxymethyl hydroxypropyl chi-tosan for mild steel in 10 M HCl solutionrdquo RSC Advancesvol 6 no 81 pp 77515ndash77524 2016
[30] M M Solomon H Gerengi T Kaya and S A UmorenldquoEnhanced corrosion inhibition effect of chitosan for St37 in15 H2SO4 environment by silver nanoparticlesrdquo In-ternational Journal of Biological Macromolecules vol 104pp 638ndash649 2017
[31] A M Alsabagh M Z Elsabee Y M Moustafa A Elfky andR E Morsi ldquoCorrosion inhibition efficiency of somehydrophobically modified chitosan surfactants in relation totheir surface active propertiesrdquo Egyptian Journal of Petroleumvol 23 no 4 pp 349ndash359 2014
[32] S A Umoren M J Banera T Alonso-Garcia C A Gervasiand M V Mirıfico ldquoInhibition of mild steel corrosion in HClsolution using chitosanrdquo Cellulose vol 20 no 5 pp 2529ndash2545 2013
[33] M Erna Y Eryanti and A Dahliaty ldquoModifikasi amilosa daripati tapioka dan garut menjadi amilosa asetatrdquo Jurnal PilarSains vol 7 pp 28ndash30 2008
[34] H T Pang X G Chen H J Park D S Cha andJ F Kennedy ldquoPreparation and rheological properties ofdeoxycholate-chitosan and carboxymethyl-chitosan inaqueous systemsrdquo Carbohydrate Polymers vol 69 no 3pp 419ndash425 2007
[35] K K Anupama and J Abraham ldquoElectroanalytical studies onthe corrosion inhibition behavior of guava (Psidium guajava)leaves extract on mild steel in hydrochloric acidrdquo Research onChemical Intermediates vol 39 no 9 pp 4067ndash4080 2012
[36] M E Al-Dokheily H M Kredy and R N Al-Jabery ldquoIn-hibition of copper corrosion in H2SO4 NaCl and NaOHsolutions by Citrullus colocynthis fruits extractrdquo Journal ofNatural Sciences Research vol 4 pp 60ndash73 2014
[37] M H Hussin andM J Kassim ldquoe corrosion inhibition andadsorption behavior ofUncaria gambir extract onmild steel in1M HClrdquo Materials Chemistry and Physics vol 125 no 3pp 461ndash468 2011
[38] K R Ansari M A Quraishi and A Singh ldquoIsatin derivativesas a non-toxic corrosion inhibitor for mild steel in 20H2SO4rdquo Corrosion Science vol 95 pp 62ndash70 2015
[39] B Zerga A Attayibat M Sfaira et al ldquoEffect of some tripodalbipyrazolic compounds on C38 steel corrosion in hydro-chloric acid solutionrdquo Journal of Applied Electrochemistryvol 40 no 9 pp 1575ndash1582 2010
[40] H Ashassi-Sorkhabi and S A Nabavi-Amri ldquoCorrosioninhibition of carbon steel in petroleumwater mixtures byn-containing compoundsrdquo Acta Chimica Slovenica vol 47pp 507ndash517 2000
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
and then dried in an oven for 15min at 40degC e inhibitionefficiency (IE) was calculated using equation (2) while thesurface coverage (θ) value was determined using equation(3) where CRblank and CRinh are the values of the corrosionrates of mild steel in the absence and presence of inhibitorsrespectively Meanwhile the Langmuir isotherm adsorptioncurve was determined using equation (4) and the free en-ergy of adsorption (ΔGo
ads) was investigated using equation(5) where Kads represents the equilibrium constant of theadsorption process and C represents the inhibitorrsquos con-centration(s) R represents the gas constant while T rep-resents the absolute temperature
IE CRblank minusCRinh
CRblanktimes 100 (2)
θ CRblank minusCRinh
CRblank (3)
Kads C θ
1minus θ (4)
ΔGoads minusRT ln 555Kads( 1113857 (5)
28 Determination of Activation of Energy Enthalpy andEntropy eprepared steel coupons have been immersed inHCl and H2SO4 solutions containing and not containinginhibitors en the mild steel plates were placed in athermostat at various temperatures from 284 to 600degC esteel plate was rinsed with distilled water acetone andethanol Afterwards it was oven-dried for 15min at 40degCe activation energy (Ea) was determined using equation(6) where R represents the gas constant CR represents thecorrosion inhibition K represents the preexponential factorand T represents the absolute temperature e values of Eawere calculated from the linear regression between lnCRand 1T e activation enthalpy (ΔHo
ads) and entropy(ΔSoads) can be calculated using equation (7)
CR k exp minusEa
RT1113874 1113875 (6)
ΔGoads ΔHo
ads minusTΔSoads (7)
29 Surface Analysis of Mild Steel e prepared mild steelplates measuring 20times10 cm2 were incubated in HCl andH2SO4 in the absencepresence of inhibitor under optimumconditions for 3 days ereafter the mild steel specimenswere removed washed with distilled water degreased withacetone and then dried at room temperature e steelspecimens were mechanically cut into 10 cm2 chips andthen immediately analyzed with SEM and EDX SEM wasperformed at a voltage of 5 kV and 5kx magnification on aLEO 1450 VP instrument e chemical compositions wereanalyzed using an EDX detector e attached functionalgroups on the mild steel surface were investigated using FT-IR spectroscopy equipment (PerkinElmer instrument)
3 Results and Discussion
31 Characterization of Amylose-Acetate e acetate-modified amylose powder for corrosion inhibition isshown in Figure 1 e acetate-functionalized amylosepowders are traditionally prepared using the acetylatingmethod e synthesis of AA involved mixing sulfuric andacetate acids and directly acetylate them via stirring epowders of acetate functionalized amylose were clearlywhite FTIR spectrum of the amylose-acetate is detailed inFigure 2 e O-H stretch peak at 349324 cmminus1 is from theamylose molecules e peaks at 174565 cmminus1 to123642 cmminus1 represent a carbonyl (COOH) group of theacetate ese peaks confirmed the occurrence of esterifi-cation between amylose and acetate molecules
32 Effect of Inhibitor Concentrations In order to determinethe best condition for the corrosion inhibition response theinhibitor loading was optimized to include both AA and AA-CMCh e inhibition efficiency response of corrosionstudies based on AA towards mild steel in an acidic mediumis shown in Figure 3 In the HCl solution the inhibitionefficiency response gradually increased alongside AArsquosconcentration from 100 to 400mgL (Figure 3(a)) while inthe H2SO4 solution the inhibition efficiency response alsoincreased alongside AA loading from 100 to 400mgL(Figure 3(b)) e increasing inhibition efficiency along-side inhibitor concentration is assumed to be due to theadsorption of inhibitor molecules on the surface of mild steel[35] With further increase in AA concentration from 400 to600 ppm in HCl solution and 400 to 500 ppm in H2SO4solution the responses of inhibition efficiency decreasedbecause the inhibitor has been fully adsorbed onto the mildsteelrsquos surface is confirms that the carboxylic group(COOH) of AA and iron (Fe) of mild steel has bonded einhibitor molecules could form a film layer and act as abarrier between mild steel and corrosive media e optimalAA concentration in HCl and H2SO4 solutions at 400 ppmwas used for further experiments
e effect of the CMCh AA ratio towards the inhibitionefficiency of mild steel in HCl and H2SO4 solution is il-lustrated in Figure 4 It can be seen that the inhibition ef-ficiency signal increases alongside the CMCh AA volumeloading changed from 1 18 to 8 4 ww in the HCl solution(Figure 4(a)) When CMCh AA changed from 8 4 to 9 2ww the signal of inhibition efficiency significantly declinede optimum ratio of CMCh AA was found at 8 4 wwwith its value of inhibition efficiency at 8886 is ratio(8 4 ww) contributed to the interaction energy between themild steelrsquos surface and thin layer of inhibitor being higherthan the interaction energy between the surface of mild steeland water and consequently the inhibition efficiency wasfound to be quite significant
As can be seen in Figure 4(b) the inhibition efficiencyresponse stabilized when CMCh AA volume loadingchanged from 5 36 to 30 16 ww in an H2SO4 solutionWhen the ratio of CMCh AA volume changed from 30 16to 35 12 ww the inhibition efficiency response increased
4 International Journal of Chemical Engineering
e CMCh AA volume loading changed again from 35 12to 45 4 ww (Figure 4(b)) and the response of inhibitioneciency gradually reduced in response to this change ismeans that the interaction energy between the mild steelrsquossurface and thin layer of the inhibitor took place slowly withthe thin layer of the inhibitor being unable to prevent attacksof the sulfuric ion on the mild steelrsquos surface is resulted inincreased corrosion on the surface [36] erefore theoptimum ratio of CMCh AA in H2SO4 solution at 35 12ww was utilized for the subsequent evaluation of corrosioninhibition
33 Determination of Activation Energy e activationenergy (Ea) of the system in the presence of AA-CMCh wasdetermined using the Arrhenius equation e Arrheniusplots for mild steel in 1M HCl with 400 ppm inhibitor isshown in Figure 5 e Ea value determined from theArrhenius plots in the presence of AA-CMCh was98089 kJmiddotmolminus1 is high value of Ea in the presence of aninhibitor was due to the high-energy barrier of the corrosion
rate [37] conrming the formation of a complex compoundbetween the inhibitor and Fe ion of mild steel
34 Adsorption Isotherm e performance of the AA-CMCh as a successful corrosion inhibitor is mainly dueto their adsorption ability on the surface of mild steel isability has been utilized to determine its mechanism ofcorrosion inhibition e Langmuir adsorption isothermfrom a plot of Cθ against C at 28degC is shown in Figure 5evalue of the correlation coecient for AA-CMCh is close toone which implies that the adsorption of AA-CMCh on themild steelrsquos surface is well tted to the Langmuir adsorptionisotherm e calculated Kads and ΔG values are10496 kJmiddotmolminus1 and minus3322 kJmiddotmolminus1 respectively esevalues demonstrated that the adsorption types of inhibitorson mild steel surfaces are chemical adsorption e Lang-muir adsorption isotherms from a plot of Cθ against C in1M HCl solution at 40degC and 60degC were also plotted (gurenot shown) e Kads and ΔG values at 40degC were7650 kJmiddotmolminus1and minus33722 kJmiddotmolminus1 respectively while the
3517
3534
9324 29
5700
2732
29
2120
82 1935
65
1745
6516
4246
1542
1514
3607
1373
38
1236
4211
5252
1037
7594
516
9008
0
7648
169
923
6442
560
182 5680
652
080
4629
4
50010001500200025003000350040004500(1cm)
0
15
30
45
60
75
90
105
120
T
Amylose-acetate
Figure 2 FT-IR spectrum of amylose modied with acetate
Figure 1 Powder of the amylose functionalized with acetate
International Journal of Chemical Engineering 5
Kads and ΔG values at 60degC were found to be1773 kJmiddotmolminus1and minus31831 kJmiddotmolminus1 respectively Generallythe obtained values of the ∆Gads were within minus3322 kJmiddotmolminus1
to minus3383 kJmiddotmolminus1 e ∆Gads values are simminus33 kJmiddotmolminus1 ormore negative suggesting chemisorption where chargesharing or charge transfer from an organic compound to themild steel surface takes place to form a coordinate-typemetallic bond [24 38]
e thermodynamic performance for the corrosion ofthe mild steel surface in 1M HCl at multiple concentrationsof AA-CMCh composites was obtained from a plot oflog(CRT) versus 1T and calculated using equation (7) evalues of activation enthalpy (∆H) and activation entropy(∆S) were minus4856 kJmiddotmolminus1 and 00495 kJmiddotmolminus1middotKminus1 re-spectively e negative value of ΔH indicates the exo-thermic nature of the activated-complex formation fromthe reactants for the rate-determining step of the steelassociation process e positive values of ΔS demonstrateirregularity of the adsorbed inhibitors on the mild steelsurface [39] is implies that the activated complex in the
rate-determining step represents a dissociation instead of anassociation process [32]
35 Potentiodynamic Polarization Studies e performanceof potentiodynamic polarization for mild steel in an HClsolution (10M) at multiple concentrations of inhibitors at301K after 60min of immersion time is shown in Figure 6e current anodic and cathodic response decreased as theAA-CMCh loading increased from 100 to 400 ppm due tothe large amounts of inhibitor on the electrodersquos surface andalso the moving corrosion potential towards increasednegativity is resulted in the classication of the inhibitoras the mixed type
e electrochemical parameters ie corrosion potential(Ecorr) anodic and cathodic Tafel slope (szligc szliga) corrosioncurrent density (icorr) and inhibition eciency (IE) obtainedfrom the corresponding polarization curves are shown inTable 1 In the proposed corrosion inhibitor the IE () wascalculated using the following equation
where i0corr and icorrprime represent the corrosion current densitieswithout and with the addition of inhibitors respectivelyeresults conrmed that the inhibition eciency responseincreased while the corrosion current density decreasedwhen the addition of inhibitors concentration increasedis implies that the inhibitor adsorption on the mild steelrsquossurface and the adsorption process is enhanced and in-creased inhibition eciency
36 Surface Characterization SEM and EDX In order todetermine the eiexclectiveness of the formatted thin layer of theinhibitor on the mild steelrsquos surface the treated mild steelwas imaged using an SEM SEM images of the mild steelsurface in the presenceabsence of CMCh in HCl and H2SO4solutions are shown in Figures 7 and 8 In the presence of AAat their respective optimum concentrations (400 ppm) inHCl (Figure 7(a)) and H2SO4 solutions (Figure 8(a)) asmooth surface of mild steel can be seen (Figures 7(a) and
8(a)) In the presence of AA-CMCh in HCl (Figure 7(b)) andH2SO4 solution (Figure 8(b)) a smoother surface of the mildspecimen can be seen (Figures 7(b) and 8(b)) is impliesthat the AA-CMCh is more eiexclective in inhibiting corrosionon mild steelrsquos surface compared to the AA inhibitor isfeature probably contributed to the homogeneity and bio-compatibility of the AA-CMCh composites on the mildsteelrsquos surface Generally a smoother surface of themild steelspecimen denote that the AA-CMCh has adsorbed onto themild steelrsquos surface and protected specimens from direct acidattacks
e EDX spectra of the mild steel and control specimenin HCl solution is shown in Figure 9 e surface of mildsteels as a control specimen before treatment (Figure 9(c))and the presence of AA-CMCh (Figure 9(b)) exhibit asmooth and uniform surface e morphology in thepresence AA was slightly damaged and rough (Figure 9(a))is conrmed that the mild steel surface is well protectedfrom acidic attacks and prevented from corroding Table 2shows the percentage of atomic contents in the inhibitor andcontrol specimens e EDX spectrum in the presence ofAA-CMCh conrmed that the concentration of the Cl ion is
Figure 6 Potentiodynamic polarization curves of mild steel in 10MHCl solutionmeasured in the absence (a) and presence of (b) 100 ppm(c) 200 ppm (d) 300 ppm and (e) 400 ppm of amylose-acetatecarboxymethyl chitosan (AA-CMCh)
Table 1 Electrochemical parameters obtained from polarization measurement in 10M HCl in the presence and absence of a diiexclerentconcentration of AA-CMCh
Figure 8 SEM micrographs of the mild steel surface in 025M H2SO4 with AA (a) and AA-CMCh (b)
(a) (b)
Figure 7 SEM images of mild steel surfaces in 1M HCl with AA (a) and AA-CMCh (b)
(a) (b)
Figure 9 Continued
International Journal of Chemical Engineering 9
higher than that of the presence of AA whilst the con-centration of C in the control specimen prior to treatmentwas lower than that of the treated specimen due to theinhibitor absorbed onto the mild steelrsquos surface e con-centration of Fe and O from the inhibitor of AA is notsignificantly different than the inhibitor of AA-CMCh(Table 2) Generally both AA and AA-CMCh inhibitorsare able to inhibit the mild steel specimen from a directattack by the Cl ion which protects the mild steel surfacefrom an aggressive environment
37Mechanismof Inhibition e adsorption of AA-blendedCMCh on mild steel can be clearly defined by consideringthe chemisorption processes e specific mechanism ofcorrosion inhibition of AA-CMCh to the surface of mildsteel coupons is detailed in the following equations
Fe + AA-CMCh⟷ Fe(AA-CMCh)ads (9)
Fe(AA-CMCh)ads⟷ Fe2++ AA-CMCh + neminus (10)
AA-CMChaq + H2Oads⟷AA-CMChads + H2Oaq
(11)
e chemisorption of AA-CMCh on mild steel isdenoted by the donor-acceptor interactions between thelone pair of the electron from the carbonyl and amine groupsof AA-CMCh with the d-orbitals of Fe e value of freeenergy from the AA-CMCh adsorption was minus33 kJmiddotmolminus1 ormore negative is confirms that the adsorption mecha-nism of the AA-CMCh on the surface of the mild steelcoupon was chemically adsorbed e inhibition of
corrosion begins by the displacement of water molecules bythe inhibitorrsquos capacity toward specific adsorption of theinhibitor on the metalrsquos surface [40]
4 Conclusions
e corrosion inhibition mechanism based on carbox-ymethyl chitosanamylose-acetate composites used to pro-tect mild steel in an acidic medium was successfullyinvestigatede AA-CMCh base inhibitor showed excellentinhibition performance in the case of mild steel in a 1MHClsolution e inhibiting efficiencies decreased in the order ofAA-CMChgtAA e inhibitor adsorptions on the mildsteelrsquos surface are chemically adsorbed while the corrosioninhibition mechanism on the mild steelrsquos surface wasspontaneous exothermal and irregular and took place dueto the formation of the Fe-chelate compound on the surfaceof the mild steel specimen e adsorption of the inhibitorson the mild steel specimen in acidic media solution com-ports with that of the Langmuir adsorption isotherm enegative values of the ∆Gads and ∆H indicated that theadsorption reaction took place spontaneously andexothermally
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this work
Acknowledgments
e authors gratefully acknowledge financial support fromthe Directorate General of Higher Education of Ministry(DIKTI) the Ministry of Research Technology and HigherEducation through a fundamental grant of the UniversitasRiau Indonesia
(c)
Figure 9 SEMEDX spectra of the mild steel surface in 1M HCl (a) AA (b) AA-CMCh blended (c) control
Table 2 Percentage atomic contents of elements measured usingthe EDX technique
Inhibitors Fe O S Cl CControl 9664 197 mdash 012 027AA 7769 2226 mdash 006 1346AA-CMCh 7761 2223 mdash 015 1649
10 International Journal of Chemical Engineering
References
[1] B Xu W Yang Y Liu X Yin W Gong and Y ChenldquoExperimental and theoretical evaluation of two pyr-idinecarboxaldehyde thiosemicarbazone compounds as cor-rosion inhibitors for mild steel in hydrochloric acid solutionrdquoCorrosion Science vol 78 pp 260ndash268 2014
[2] S A Umoren and U M Eduok ldquoApplication of carbohydratepolymers as corrosion inhibitors for metal substrates indifferent media a reviewrdquo Carbohydrate Polymers vol 140pp 314ndash341 2016
[3] S E Karekar U D Bagale S H Sonawane B A Bhanvaseand D V Pinjari ldquoA smart coating established with encap-sulation of Zinc Molybdate centred nanocontainer for activecorrosion protection of mild steel release kinetics of corro-sion inhibitorrdquo Composite Interfaces vol 25 no 9 pp 785ndash808 2018
[4] S Abrishami R Naderi and B Ramezanzadeh ldquoFabricationand characterization of zinc acetylacetonateUrtica dioicaleaves extract complex as an effective organicinorganic hy-brid corrosion inhibitive pigment for mild steel protection inchloride solutionrdquo Applied Surface Science vol 457pp 487ndash496 2018
[5] M Krishnan H Subramanian H-U Dahms et al ldquoBiogeniccorrosion inhibitor on mild steel protection in concentratedHCl mediumrdquo Scientific Report vol 8 p 2609 2018
[6] N Bhardwaj D Prasad and R Haldhar ldquoStudy of the Aeglemarmelos as a green corrosion inhibitor for mild steel in acidicmedium experimental and theoretical approachrdquo Journal ofBio- and Tribo-Corrosion vol 4 no 4 p 61 2018
[7] T K Bhuvaneswari V S Vasantha and C JeyaprabhaldquoPongamia pinnata as a green corrosion inhibitor for mildsteel in 1N sulfuric acid mediumrdquo Silicon vol 10 no 5pp 1793ndash1807 2018
[8] M P Rai A Khanra S Rai M Srivastava and R PrakashldquoPivotal role of levoglucosenone and hexadecanoic acid frommicroalgae Chlorococcum sp for corrosion resistance on mildsteel electrochemical microstructural and theoretical anal-ysisrdquo Journal of Molecular Liquids vol 266 pp 279ndash2902018
[9] A Saxena D Prasad and R Haldhar ldquoInvestigation ofcorrosion inhibition effect and adsorption activities of Cus-cuta reflexa extract for mild steel in 05 M H2SO4rdquo Bio-electrochemistry vol 124 pp 156ndash164 2018
[10] X Zheng M Gong Q Li and L Guo ldquoCorrosion inhibitionof mild steel in sulfuric acid solution by loquat (Eriobotryajaponica Lindl) leaves extractrdquo Scientific Report vol 8p 9140 2018
[11] A Bouoidina F El-Hajjaji M Drissi et al ldquoTowards a deeperunderstanding of the anticorrosive properties of hydrazinederivatives in acid medium experimental DFT and MDsimulation assessmentrdquo Metallurgical and Materials Trans-actions A vol 49 no 10 pp 5180ndash5191 2018
[12] A Chaouiki H Lgaz I-M Chung et al ldquoUnderstandingcorrosion inhibition of mild steel in acid medium by newbenzonitriles insights from experimental and computationalstudiesrdquo Journal of Molecular Liquids vol 266 pp 603ndash6162018
[13] Y Guo Z Chen Y Zuo Y Chen W Yang and B Xu ldquoIonicliquids with two typical hydrophobic anions as acidic cor-rosion inhibitorsrdquo Journal of Molecular Liquids vol 269pp 886ndash895 2018
[14] E Naseri M Hajisafari A Kosari M Talari S Hosseinpourand A Davoodi ldquoInhibitive effect of Clopidogrel as a green
corrosion inhibitor for mild steel statistical modeling andquantum Monte Carlo simulation studiesrdquo Journal of Mo-lecular Liquids vol 269 pp 193ndash202 2018
[15] R Geethanjali and S Subhashini ldquoSynthesis and kinetics ofcorrosion inhibition of water-soluble terpolymer of polyvinylalcohol functionalized with vinyl sulfonate and p-vinyl ben-zene sulfonate in molar HClrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4 p 60 2018
[16] P Han W Li H Tian et al ldquoDesigning and fabricating oftime-depend self-strengthening inhibitor film synergisticinhibition of sodium dodecyl sulfate and 4-mercaptopyridinefor mild steelrdquo Journal of Molecular Liquids vol 268pp 425ndash437 2018
[17] X He J Mao Q Ma and Y Tang ldquoCorrosion inhibition ofperimidine derivatives for mild steel in acidic media elec-trochemical and computational studiesrdquo Journal of MolecularLiquids vol 269 pp 260ndash268 2018
[18] A A Mahmmod I A Kazarinov A A Khadom andH B Mahood ldquoExperimental and theoretical studies of mildsteel corrosion inhibition in phosphoric acid using tetrazolesderivativesrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4p 58 2018
[19] M Messali M Larouj H Lgaz et al ldquoA new schiff basederivative as an effective corrosion inhibitor for mild steel inacidic media experimental and computer simulations stud-iesrdquo Journal of Molecular Structure vol 1168 pp 39ndash48 2018
[20] A Mishra C Verma S Chauhan et al ldquoCharacterizationand corrosion inhibition performance of 5-aminopyrazolecarbonitriles towards mild steel acidic corrosionrdquo Journal ofBio- and Tribo-Corrosion vol 4 p 53 2018
[21] N Saini R Kumar H Lgaz et al ldquoMinified dose of urispasdrug as better corrosion constraint for soft steel in sulphuricacid solutionrdquo Journal of Molecular Liquids vol 269pp 371ndash380 2018
[22] K Zhang W Yang Y Chen et al ldquoEnhanced inhibitiveperformance of fluoro-substituted imidazolium-based ionicliquid for mild steel corrosion in hydrochloric acid at elevatedtemperaturerdquo Journal of Materials Science vol 53 no 20pp 14666ndash14680 2018
[23] K R Ansari M A Quraishi and A Singh ldquoCorrosion in-hibition of mild steel in hydrochloric acid by some pyridinederivatives an experimental and quantum chemical studyrdquoJournal of Industrial and Engineering Chemistry vol 25pp 89ndash98 2015
[24] L O Olasunkanmi I B Obot M M Kabanda andE E Ebenso ldquoSome quinoxalin-6-yl derivatives as corrosioninhibitors for mild steel in hydrochloric acid experimentaland theoretical studiesrdquo Journal of Physical Chemistry Cvol 119 no 28 pp 16004ndash16019 2015
[25] M Ewis S S Elkholy and M Z Esabee ldquoAntifungal efficacyof chitosan and its thiourea derivatives upon the growth ofsome sugar-beet pathogensrdquo International Journal of Bi-ological Macromolecules vol 38 no 1 pp 1ndash8 2006
[26] Z-X Tang J-Q Qian and L-E Shi ldquoCharacterizations ofimmobilized neutral lipase on chitosan nano-particlesrdquoMaterials Letters vol 61 no 1 pp 37ndash40 2007
[27] M N El-Haddad ldquoChitosan as a green inhibitor for coppercorrosion in acidic mediumrdquo International Journal of Bi-ological Macromolecules vol 55 pp 142ndash149 2013
[28] S Cheng S Chen T Liu X Chang and Y Yin ldquoCarbox-ymenthylchitosan as an ecofriendly inhibitor for mild steel in1 MHClrdquoMaterials Letters vol 61 no 14-15 pp 3276ndash32802007
International Journal of Chemical Engineering 11
[29] K Wan P Feng B Hou and Y Li ldquoEnhanced corrosioninhibition properties of carboxymethyl hydroxypropyl chi-tosan for mild steel in 10 M HCl solutionrdquo RSC Advancesvol 6 no 81 pp 77515ndash77524 2016
[30] M M Solomon H Gerengi T Kaya and S A UmorenldquoEnhanced corrosion inhibition effect of chitosan for St37 in15 H2SO4 environment by silver nanoparticlesrdquo In-ternational Journal of Biological Macromolecules vol 104pp 638ndash649 2017
[31] A M Alsabagh M Z Elsabee Y M Moustafa A Elfky andR E Morsi ldquoCorrosion inhibition efficiency of somehydrophobically modified chitosan surfactants in relation totheir surface active propertiesrdquo Egyptian Journal of Petroleumvol 23 no 4 pp 349ndash359 2014
[32] S A Umoren M J Banera T Alonso-Garcia C A Gervasiand M V Mirıfico ldquoInhibition of mild steel corrosion in HClsolution using chitosanrdquo Cellulose vol 20 no 5 pp 2529ndash2545 2013
[33] M Erna Y Eryanti and A Dahliaty ldquoModifikasi amilosa daripati tapioka dan garut menjadi amilosa asetatrdquo Jurnal PilarSains vol 7 pp 28ndash30 2008
[34] H T Pang X G Chen H J Park D S Cha andJ F Kennedy ldquoPreparation and rheological properties ofdeoxycholate-chitosan and carboxymethyl-chitosan inaqueous systemsrdquo Carbohydrate Polymers vol 69 no 3pp 419ndash425 2007
[35] K K Anupama and J Abraham ldquoElectroanalytical studies onthe corrosion inhibition behavior of guava (Psidium guajava)leaves extract on mild steel in hydrochloric acidrdquo Research onChemical Intermediates vol 39 no 9 pp 4067ndash4080 2012
[36] M E Al-Dokheily H M Kredy and R N Al-Jabery ldquoIn-hibition of copper corrosion in H2SO4 NaCl and NaOHsolutions by Citrullus colocynthis fruits extractrdquo Journal ofNatural Sciences Research vol 4 pp 60ndash73 2014
[37] M H Hussin andM J Kassim ldquoe corrosion inhibition andadsorption behavior ofUncaria gambir extract onmild steel in1M HClrdquo Materials Chemistry and Physics vol 125 no 3pp 461ndash468 2011
[38] K R Ansari M A Quraishi and A Singh ldquoIsatin derivativesas a non-toxic corrosion inhibitor for mild steel in 20H2SO4rdquo Corrosion Science vol 95 pp 62ndash70 2015
[39] B Zerga A Attayibat M Sfaira et al ldquoEffect of some tripodalbipyrazolic compounds on C38 steel corrosion in hydro-chloric acid solutionrdquo Journal of Applied Electrochemistryvol 40 no 9 pp 1575ndash1582 2010
[40] H Ashassi-Sorkhabi and S A Nabavi-Amri ldquoCorrosioninhibition of carbon steel in petroleumwater mixtures byn-containing compoundsrdquo Acta Chimica Slovenica vol 47pp 507ndash517 2000
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
e CMCh AA volume loading changed again from 35 12to 45 4 ww (Figure 4(b)) and the response of inhibitioneciency gradually reduced in response to this change ismeans that the interaction energy between the mild steelrsquossurface and thin layer of the inhibitor took place slowly withthe thin layer of the inhibitor being unable to prevent attacksof the sulfuric ion on the mild steelrsquos surface is resulted inincreased corrosion on the surface [36] erefore theoptimum ratio of CMCh AA in H2SO4 solution at 35 12ww was utilized for the subsequent evaluation of corrosioninhibition
33 Determination of Activation Energy e activationenergy (Ea) of the system in the presence of AA-CMCh wasdetermined using the Arrhenius equation e Arrheniusplots for mild steel in 1M HCl with 400 ppm inhibitor isshown in Figure 5 e Ea value determined from theArrhenius plots in the presence of AA-CMCh was98089 kJmiddotmolminus1 is high value of Ea in the presence of aninhibitor was due to the high-energy barrier of the corrosion
rate [37] conrming the formation of a complex compoundbetween the inhibitor and Fe ion of mild steel
34 Adsorption Isotherm e performance of the AA-CMCh as a successful corrosion inhibitor is mainly dueto their adsorption ability on the surface of mild steel isability has been utilized to determine its mechanism ofcorrosion inhibition e Langmuir adsorption isothermfrom a plot of Cθ against C at 28degC is shown in Figure 5evalue of the correlation coecient for AA-CMCh is close toone which implies that the adsorption of AA-CMCh on themild steelrsquos surface is well tted to the Langmuir adsorptionisotherm e calculated Kads and ΔG values are10496 kJmiddotmolminus1 and minus3322 kJmiddotmolminus1 respectively esevalues demonstrated that the adsorption types of inhibitorson mild steel surfaces are chemical adsorption e Lang-muir adsorption isotherms from a plot of Cθ against C in1M HCl solution at 40degC and 60degC were also plotted (gurenot shown) e Kads and ΔG values at 40degC were7650 kJmiddotmolminus1and minus33722 kJmiddotmolminus1 respectively while the
3517
3534
9324 29
5700
2732
29
2120
82 1935
65
1745
6516
4246
1542
1514
3607
1373
38
1236
4211
5252
1037
7594
516
9008
0
7648
169
923
6442
560
182 5680
652
080
4629
4
50010001500200025003000350040004500(1cm)
0
15
30
45
60
75
90
105
120
T
Amylose-acetate
Figure 2 FT-IR spectrum of amylose modied with acetate
Figure 1 Powder of the amylose functionalized with acetate
International Journal of Chemical Engineering 5
Kads and ΔG values at 60degC were found to be1773 kJmiddotmolminus1and minus31831 kJmiddotmolminus1 respectively Generallythe obtained values of the ∆Gads were within minus3322 kJmiddotmolminus1
to minus3383 kJmiddotmolminus1 e ∆Gads values are simminus33 kJmiddotmolminus1 ormore negative suggesting chemisorption where chargesharing or charge transfer from an organic compound to themild steel surface takes place to form a coordinate-typemetallic bond [24 38]
e thermodynamic performance for the corrosion ofthe mild steel surface in 1M HCl at multiple concentrationsof AA-CMCh composites was obtained from a plot oflog(CRT) versus 1T and calculated using equation (7) evalues of activation enthalpy (∆H) and activation entropy(∆S) were minus4856 kJmiddotmolminus1 and 00495 kJmiddotmolminus1middotKminus1 re-spectively e negative value of ΔH indicates the exo-thermic nature of the activated-complex formation fromthe reactants for the rate-determining step of the steelassociation process e positive values of ΔS demonstrateirregularity of the adsorbed inhibitors on the mild steelsurface [39] is implies that the activated complex in the
rate-determining step represents a dissociation instead of anassociation process [32]
35 Potentiodynamic Polarization Studies e performanceof potentiodynamic polarization for mild steel in an HClsolution (10M) at multiple concentrations of inhibitors at301K after 60min of immersion time is shown in Figure 6e current anodic and cathodic response decreased as theAA-CMCh loading increased from 100 to 400 ppm due tothe large amounts of inhibitor on the electrodersquos surface andalso the moving corrosion potential towards increasednegativity is resulted in the classication of the inhibitoras the mixed type
e electrochemical parameters ie corrosion potential(Ecorr) anodic and cathodic Tafel slope (szligc szliga) corrosioncurrent density (icorr) and inhibition eciency (IE) obtainedfrom the corresponding polarization curves are shown inTable 1 In the proposed corrosion inhibitor the IE () wascalculated using the following equation
where i0corr and icorrprime represent the corrosion current densitieswithout and with the addition of inhibitors respectivelyeresults conrmed that the inhibition eciency responseincreased while the corrosion current density decreasedwhen the addition of inhibitors concentration increasedis implies that the inhibitor adsorption on the mild steelrsquossurface and the adsorption process is enhanced and in-creased inhibition eciency
36 Surface Characterization SEM and EDX In order todetermine the eiexclectiveness of the formatted thin layer of theinhibitor on the mild steelrsquos surface the treated mild steelwas imaged using an SEM SEM images of the mild steelsurface in the presenceabsence of CMCh in HCl and H2SO4solutions are shown in Figures 7 and 8 In the presence of AAat their respective optimum concentrations (400 ppm) inHCl (Figure 7(a)) and H2SO4 solutions (Figure 8(a)) asmooth surface of mild steel can be seen (Figures 7(a) and
8(a)) In the presence of AA-CMCh in HCl (Figure 7(b)) andH2SO4 solution (Figure 8(b)) a smoother surface of the mildspecimen can be seen (Figures 7(b) and 8(b)) is impliesthat the AA-CMCh is more eiexclective in inhibiting corrosionon mild steelrsquos surface compared to the AA inhibitor isfeature probably contributed to the homogeneity and bio-compatibility of the AA-CMCh composites on the mildsteelrsquos surface Generally a smoother surface of themild steelspecimen denote that the AA-CMCh has adsorbed onto themild steelrsquos surface and protected specimens from direct acidattacks
e EDX spectra of the mild steel and control specimenin HCl solution is shown in Figure 9 e surface of mildsteels as a control specimen before treatment (Figure 9(c))and the presence of AA-CMCh (Figure 9(b)) exhibit asmooth and uniform surface e morphology in thepresence AA was slightly damaged and rough (Figure 9(a))is conrmed that the mild steel surface is well protectedfrom acidic attacks and prevented from corroding Table 2shows the percentage of atomic contents in the inhibitor andcontrol specimens e EDX spectrum in the presence ofAA-CMCh conrmed that the concentration of the Cl ion is
Figure 6 Potentiodynamic polarization curves of mild steel in 10MHCl solutionmeasured in the absence (a) and presence of (b) 100 ppm(c) 200 ppm (d) 300 ppm and (e) 400 ppm of amylose-acetatecarboxymethyl chitosan (AA-CMCh)
Table 1 Electrochemical parameters obtained from polarization measurement in 10M HCl in the presence and absence of a diiexclerentconcentration of AA-CMCh
Figure 8 SEM micrographs of the mild steel surface in 025M H2SO4 with AA (a) and AA-CMCh (b)
(a) (b)
Figure 7 SEM images of mild steel surfaces in 1M HCl with AA (a) and AA-CMCh (b)
(a) (b)
Figure 9 Continued
International Journal of Chemical Engineering 9
higher than that of the presence of AA whilst the con-centration of C in the control specimen prior to treatmentwas lower than that of the treated specimen due to theinhibitor absorbed onto the mild steelrsquos surface e con-centration of Fe and O from the inhibitor of AA is notsignificantly different than the inhibitor of AA-CMCh(Table 2) Generally both AA and AA-CMCh inhibitorsare able to inhibit the mild steel specimen from a directattack by the Cl ion which protects the mild steel surfacefrom an aggressive environment
37Mechanismof Inhibition e adsorption of AA-blendedCMCh on mild steel can be clearly defined by consideringthe chemisorption processes e specific mechanism ofcorrosion inhibition of AA-CMCh to the surface of mildsteel coupons is detailed in the following equations
Fe + AA-CMCh⟷ Fe(AA-CMCh)ads (9)
Fe(AA-CMCh)ads⟷ Fe2++ AA-CMCh + neminus (10)
AA-CMChaq + H2Oads⟷AA-CMChads + H2Oaq
(11)
e chemisorption of AA-CMCh on mild steel isdenoted by the donor-acceptor interactions between thelone pair of the electron from the carbonyl and amine groupsof AA-CMCh with the d-orbitals of Fe e value of freeenergy from the AA-CMCh adsorption was minus33 kJmiddotmolminus1 ormore negative is confirms that the adsorption mecha-nism of the AA-CMCh on the surface of the mild steelcoupon was chemically adsorbed e inhibition of
corrosion begins by the displacement of water molecules bythe inhibitorrsquos capacity toward specific adsorption of theinhibitor on the metalrsquos surface [40]
4 Conclusions
e corrosion inhibition mechanism based on carbox-ymethyl chitosanamylose-acetate composites used to pro-tect mild steel in an acidic medium was successfullyinvestigatede AA-CMCh base inhibitor showed excellentinhibition performance in the case of mild steel in a 1MHClsolution e inhibiting efficiencies decreased in the order ofAA-CMChgtAA e inhibitor adsorptions on the mildsteelrsquos surface are chemically adsorbed while the corrosioninhibition mechanism on the mild steelrsquos surface wasspontaneous exothermal and irregular and took place dueto the formation of the Fe-chelate compound on the surfaceof the mild steel specimen e adsorption of the inhibitorson the mild steel specimen in acidic media solution com-ports with that of the Langmuir adsorption isotherm enegative values of the ∆Gads and ∆H indicated that theadsorption reaction took place spontaneously andexothermally
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this work
Acknowledgments
e authors gratefully acknowledge financial support fromthe Directorate General of Higher Education of Ministry(DIKTI) the Ministry of Research Technology and HigherEducation through a fundamental grant of the UniversitasRiau Indonesia
(c)
Figure 9 SEMEDX spectra of the mild steel surface in 1M HCl (a) AA (b) AA-CMCh blended (c) control
Table 2 Percentage atomic contents of elements measured usingthe EDX technique
Inhibitors Fe O S Cl CControl 9664 197 mdash 012 027AA 7769 2226 mdash 006 1346AA-CMCh 7761 2223 mdash 015 1649
10 International Journal of Chemical Engineering
References
[1] B Xu W Yang Y Liu X Yin W Gong and Y ChenldquoExperimental and theoretical evaluation of two pyr-idinecarboxaldehyde thiosemicarbazone compounds as cor-rosion inhibitors for mild steel in hydrochloric acid solutionrdquoCorrosion Science vol 78 pp 260ndash268 2014
[2] S A Umoren and U M Eduok ldquoApplication of carbohydratepolymers as corrosion inhibitors for metal substrates indifferent media a reviewrdquo Carbohydrate Polymers vol 140pp 314ndash341 2016
[3] S E Karekar U D Bagale S H Sonawane B A Bhanvaseand D V Pinjari ldquoA smart coating established with encap-sulation of Zinc Molybdate centred nanocontainer for activecorrosion protection of mild steel release kinetics of corro-sion inhibitorrdquo Composite Interfaces vol 25 no 9 pp 785ndash808 2018
[4] S Abrishami R Naderi and B Ramezanzadeh ldquoFabricationand characterization of zinc acetylacetonateUrtica dioicaleaves extract complex as an effective organicinorganic hy-brid corrosion inhibitive pigment for mild steel protection inchloride solutionrdquo Applied Surface Science vol 457pp 487ndash496 2018
[5] M Krishnan H Subramanian H-U Dahms et al ldquoBiogeniccorrosion inhibitor on mild steel protection in concentratedHCl mediumrdquo Scientific Report vol 8 p 2609 2018
[6] N Bhardwaj D Prasad and R Haldhar ldquoStudy of the Aeglemarmelos as a green corrosion inhibitor for mild steel in acidicmedium experimental and theoretical approachrdquo Journal ofBio- and Tribo-Corrosion vol 4 no 4 p 61 2018
[7] T K Bhuvaneswari V S Vasantha and C JeyaprabhaldquoPongamia pinnata as a green corrosion inhibitor for mildsteel in 1N sulfuric acid mediumrdquo Silicon vol 10 no 5pp 1793ndash1807 2018
[8] M P Rai A Khanra S Rai M Srivastava and R PrakashldquoPivotal role of levoglucosenone and hexadecanoic acid frommicroalgae Chlorococcum sp for corrosion resistance on mildsteel electrochemical microstructural and theoretical anal-ysisrdquo Journal of Molecular Liquids vol 266 pp 279ndash2902018
[9] A Saxena D Prasad and R Haldhar ldquoInvestigation ofcorrosion inhibition effect and adsorption activities of Cus-cuta reflexa extract for mild steel in 05 M H2SO4rdquo Bio-electrochemistry vol 124 pp 156ndash164 2018
[10] X Zheng M Gong Q Li and L Guo ldquoCorrosion inhibitionof mild steel in sulfuric acid solution by loquat (Eriobotryajaponica Lindl) leaves extractrdquo Scientific Report vol 8p 9140 2018
[11] A Bouoidina F El-Hajjaji M Drissi et al ldquoTowards a deeperunderstanding of the anticorrosive properties of hydrazinederivatives in acid medium experimental DFT and MDsimulation assessmentrdquo Metallurgical and Materials Trans-actions A vol 49 no 10 pp 5180ndash5191 2018
[12] A Chaouiki H Lgaz I-M Chung et al ldquoUnderstandingcorrosion inhibition of mild steel in acid medium by newbenzonitriles insights from experimental and computationalstudiesrdquo Journal of Molecular Liquids vol 266 pp 603ndash6162018
[13] Y Guo Z Chen Y Zuo Y Chen W Yang and B Xu ldquoIonicliquids with two typical hydrophobic anions as acidic cor-rosion inhibitorsrdquo Journal of Molecular Liquids vol 269pp 886ndash895 2018
[14] E Naseri M Hajisafari A Kosari M Talari S Hosseinpourand A Davoodi ldquoInhibitive effect of Clopidogrel as a green
corrosion inhibitor for mild steel statistical modeling andquantum Monte Carlo simulation studiesrdquo Journal of Mo-lecular Liquids vol 269 pp 193ndash202 2018
[15] R Geethanjali and S Subhashini ldquoSynthesis and kinetics ofcorrosion inhibition of water-soluble terpolymer of polyvinylalcohol functionalized with vinyl sulfonate and p-vinyl ben-zene sulfonate in molar HClrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4 p 60 2018
[16] P Han W Li H Tian et al ldquoDesigning and fabricating oftime-depend self-strengthening inhibitor film synergisticinhibition of sodium dodecyl sulfate and 4-mercaptopyridinefor mild steelrdquo Journal of Molecular Liquids vol 268pp 425ndash437 2018
[17] X He J Mao Q Ma and Y Tang ldquoCorrosion inhibition ofperimidine derivatives for mild steel in acidic media elec-trochemical and computational studiesrdquo Journal of MolecularLiquids vol 269 pp 260ndash268 2018
[18] A A Mahmmod I A Kazarinov A A Khadom andH B Mahood ldquoExperimental and theoretical studies of mildsteel corrosion inhibition in phosphoric acid using tetrazolesderivativesrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4p 58 2018
[19] M Messali M Larouj H Lgaz et al ldquoA new schiff basederivative as an effective corrosion inhibitor for mild steel inacidic media experimental and computer simulations stud-iesrdquo Journal of Molecular Structure vol 1168 pp 39ndash48 2018
[20] A Mishra C Verma S Chauhan et al ldquoCharacterizationand corrosion inhibition performance of 5-aminopyrazolecarbonitriles towards mild steel acidic corrosionrdquo Journal ofBio- and Tribo-Corrosion vol 4 p 53 2018
[21] N Saini R Kumar H Lgaz et al ldquoMinified dose of urispasdrug as better corrosion constraint for soft steel in sulphuricacid solutionrdquo Journal of Molecular Liquids vol 269pp 371ndash380 2018
[22] K Zhang W Yang Y Chen et al ldquoEnhanced inhibitiveperformance of fluoro-substituted imidazolium-based ionicliquid for mild steel corrosion in hydrochloric acid at elevatedtemperaturerdquo Journal of Materials Science vol 53 no 20pp 14666ndash14680 2018
[23] K R Ansari M A Quraishi and A Singh ldquoCorrosion in-hibition of mild steel in hydrochloric acid by some pyridinederivatives an experimental and quantum chemical studyrdquoJournal of Industrial and Engineering Chemistry vol 25pp 89ndash98 2015
[24] L O Olasunkanmi I B Obot M M Kabanda andE E Ebenso ldquoSome quinoxalin-6-yl derivatives as corrosioninhibitors for mild steel in hydrochloric acid experimentaland theoretical studiesrdquo Journal of Physical Chemistry Cvol 119 no 28 pp 16004ndash16019 2015
[25] M Ewis S S Elkholy and M Z Esabee ldquoAntifungal efficacyof chitosan and its thiourea derivatives upon the growth ofsome sugar-beet pathogensrdquo International Journal of Bi-ological Macromolecules vol 38 no 1 pp 1ndash8 2006
[26] Z-X Tang J-Q Qian and L-E Shi ldquoCharacterizations ofimmobilized neutral lipase on chitosan nano-particlesrdquoMaterials Letters vol 61 no 1 pp 37ndash40 2007
[27] M N El-Haddad ldquoChitosan as a green inhibitor for coppercorrosion in acidic mediumrdquo International Journal of Bi-ological Macromolecules vol 55 pp 142ndash149 2013
[28] S Cheng S Chen T Liu X Chang and Y Yin ldquoCarbox-ymenthylchitosan as an ecofriendly inhibitor for mild steel in1 MHClrdquoMaterials Letters vol 61 no 14-15 pp 3276ndash32802007
International Journal of Chemical Engineering 11
[29] K Wan P Feng B Hou and Y Li ldquoEnhanced corrosioninhibition properties of carboxymethyl hydroxypropyl chi-tosan for mild steel in 10 M HCl solutionrdquo RSC Advancesvol 6 no 81 pp 77515ndash77524 2016
[30] M M Solomon H Gerengi T Kaya and S A UmorenldquoEnhanced corrosion inhibition effect of chitosan for St37 in15 H2SO4 environment by silver nanoparticlesrdquo In-ternational Journal of Biological Macromolecules vol 104pp 638ndash649 2017
[31] A M Alsabagh M Z Elsabee Y M Moustafa A Elfky andR E Morsi ldquoCorrosion inhibition efficiency of somehydrophobically modified chitosan surfactants in relation totheir surface active propertiesrdquo Egyptian Journal of Petroleumvol 23 no 4 pp 349ndash359 2014
[32] S A Umoren M J Banera T Alonso-Garcia C A Gervasiand M V Mirıfico ldquoInhibition of mild steel corrosion in HClsolution using chitosanrdquo Cellulose vol 20 no 5 pp 2529ndash2545 2013
[33] M Erna Y Eryanti and A Dahliaty ldquoModifikasi amilosa daripati tapioka dan garut menjadi amilosa asetatrdquo Jurnal PilarSains vol 7 pp 28ndash30 2008
[34] H T Pang X G Chen H J Park D S Cha andJ F Kennedy ldquoPreparation and rheological properties ofdeoxycholate-chitosan and carboxymethyl-chitosan inaqueous systemsrdquo Carbohydrate Polymers vol 69 no 3pp 419ndash425 2007
[35] K K Anupama and J Abraham ldquoElectroanalytical studies onthe corrosion inhibition behavior of guava (Psidium guajava)leaves extract on mild steel in hydrochloric acidrdquo Research onChemical Intermediates vol 39 no 9 pp 4067ndash4080 2012
[36] M E Al-Dokheily H M Kredy and R N Al-Jabery ldquoIn-hibition of copper corrosion in H2SO4 NaCl and NaOHsolutions by Citrullus colocynthis fruits extractrdquo Journal ofNatural Sciences Research vol 4 pp 60ndash73 2014
[37] M H Hussin andM J Kassim ldquoe corrosion inhibition andadsorption behavior ofUncaria gambir extract onmild steel in1M HClrdquo Materials Chemistry and Physics vol 125 no 3pp 461ndash468 2011
[38] K R Ansari M A Quraishi and A Singh ldquoIsatin derivativesas a non-toxic corrosion inhibitor for mild steel in 20H2SO4rdquo Corrosion Science vol 95 pp 62ndash70 2015
[39] B Zerga A Attayibat M Sfaira et al ldquoEffect of some tripodalbipyrazolic compounds on C38 steel corrosion in hydro-chloric acid solutionrdquo Journal of Applied Electrochemistryvol 40 no 9 pp 1575ndash1582 2010
[40] H Ashassi-Sorkhabi and S A Nabavi-Amri ldquoCorrosioninhibition of carbon steel in petroleumwater mixtures byn-containing compoundsrdquo Acta Chimica Slovenica vol 47pp 507ndash517 2000
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
Kads and ΔG values at 60degC were found to be1773 kJmiddotmolminus1and minus31831 kJmiddotmolminus1 respectively Generallythe obtained values of the ∆Gads were within minus3322 kJmiddotmolminus1
to minus3383 kJmiddotmolminus1 e ∆Gads values are simminus33 kJmiddotmolminus1 ormore negative suggesting chemisorption where chargesharing or charge transfer from an organic compound to themild steel surface takes place to form a coordinate-typemetallic bond [24 38]
e thermodynamic performance for the corrosion ofthe mild steel surface in 1M HCl at multiple concentrationsof AA-CMCh composites was obtained from a plot oflog(CRT) versus 1T and calculated using equation (7) evalues of activation enthalpy (∆H) and activation entropy(∆S) were minus4856 kJmiddotmolminus1 and 00495 kJmiddotmolminus1middotKminus1 re-spectively e negative value of ΔH indicates the exo-thermic nature of the activated-complex formation fromthe reactants for the rate-determining step of the steelassociation process e positive values of ΔS demonstrateirregularity of the adsorbed inhibitors on the mild steelsurface [39] is implies that the activated complex in the
rate-determining step represents a dissociation instead of anassociation process [32]
35 Potentiodynamic Polarization Studies e performanceof potentiodynamic polarization for mild steel in an HClsolution (10M) at multiple concentrations of inhibitors at301K after 60min of immersion time is shown in Figure 6e current anodic and cathodic response decreased as theAA-CMCh loading increased from 100 to 400 ppm due tothe large amounts of inhibitor on the electrodersquos surface andalso the moving corrosion potential towards increasednegativity is resulted in the classication of the inhibitoras the mixed type
e electrochemical parameters ie corrosion potential(Ecorr) anodic and cathodic Tafel slope (szligc szliga) corrosioncurrent density (icorr) and inhibition eciency (IE) obtainedfrom the corresponding polarization curves are shown inTable 1 In the proposed corrosion inhibitor the IE () wascalculated using the following equation
where i0corr and icorrprime represent the corrosion current densitieswithout and with the addition of inhibitors respectivelyeresults conrmed that the inhibition eciency responseincreased while the corrosion current density decreasedwhen the addition of inhibitors concentration increasedis implies that the inhibitor adsorption on the mild steelrsquossurface and the adsorption process is enhanced and in-creased inhibition eciency
36 Surface Characterization SEM and EDX In order todetermine the eiexclectiveness of the formatted thin layer of theinhibitor on the mild steelrsquos surface the treated mild steelwas imaged using an SEM SEM images of the mild steelsurface in the presenceabsence of CMCh in HCl and H2SO4solutions are shown in Figures 7 and 8 In the presence of AAat their respective optimum concentrations (400 ppm) inHCl (Figure 7(a)) and H2SO4 solutions (Figure 8(a)) asmooth surface of mild steel can be seen (Figures 7(a) and
8(a)) In the presence of AA-CMCh in HCl (Figure 7(b)) andH2SO4 solution (Figure 8(b)) a smoother surface of the mildspecimen can be seen (Figures 7(b) and 8(b)) is impliesthat the AA-CMCh is more eiexclective in inhibiting corrosionon mild steelrsquos surface compared to the AA inhibitor isfeature probably contributed to the homogeneity and bio-compatibility of the AA-CMCh composites on the mildsteelrsquos surface Generally a smoother surface of themild steelspecimen denote that the AA-CMCh has adsorbed onto themild steelrsquos surface and protected specimens from direct acidattacks
e EDX spectra of the mild steel and control specimenin HCl solution is shown in Figure 9 e surface of mildsteels as a control specimen before treatment (Figure 9(c))and the presence of AA-CMCh (Figure 9(b)) exhibit asmooth and uniform surface e morphology in thepresence AA was slightly damaged and rough (Figure 9(a))is conrmed that the mild steel surface is well protectedfrom acidic attacks and prevented from corroding Table 2shows the percentage of atomic contents in the inhibitor andcontrol specimens e EDX spectrum in the presence ofAA-CMCh conrmed that the concentration of the Cl ion is
Figure 6 Potentiodynamic polarization curves of mild steel in 10MHCl solutionmeasured in the absence (a) and presence of (b) 100 ppm(c) 200 ppm (d) 300 ppm and (e) 400 ppm of amylose-acetatecarboxymethyl chitosan (AA-CMCh)
Table 1 Electrochemical parameters obtained from polarization measurement in 10M HCl in the presence and absence of a diiexclerentconcentration of AA-CMCh
Figure 8 SEM micrographs of the mild steel surface in 025M H2SO4 with AA (a) and AA-CMCh (b)
(a) (b)
Figure 7 SEM images of mild steel surfaces in 1M HCl with AA (a) and AA-CMCh (b)
(a) (b)
Figure 9 Continued
International Journal of Chemical Engineering 9
higher than that of the presence of AA whilst the con-centration of C in the control specimen prior to treatmentwas lower than that of the treated specimen due to theinhibitor absorbed onto the mild steelrsquos surface e con-centration of Fe and O from the inhibitor of AA is notsignificantly different than the inhibitor of AA-CMCh(Table 2) Generally both AA and AA-CMCh inhibitorsare able to inhibit the mild steel specimen from a directattack by the Cl ion which protects the mild steel surfacefrom an aggressive environment
37Mechanismof Inhibition e adsorption of AA-blendedCMCh on mild steel can be clearly defined by consideringthe chemisorption processes e specific mechanism ofcorrosion inhibition of AA-CMCh to the surface of mildsteel coupons is detailed in the following equations
Fe + AA-CMCh⟷ Fe(AA-CMCh)ads (9)
Fe(AA-CMCh)ads⟷ Fe2++ AA-CMCh + neminus (10)
AA-CMChaq + H2Oads⟷AA-CMChads + H2Oaq
(11)
e chemisorption of AA-CMCh on mild steel isdenoted by the donor-acceptor interactions between thelone pair of the electron from the carbonyl and amine groupsof AA-CMCh with the d-orbitals of Fe e value of freeenergy from the AA-CMCh adsorption was minus33 kJmiddotmolminus1 ormore negative is confirms that the adsorption mecha-nism of the AA-CMCh on the surface of the mild steelcoupon was chemically adsorbed e inhibition of
corrosion begins by the displacement of water molecules bythe inhibitorrsquos capacity toward specific adsorption of theinhibitor on the metalrsquos surface [40]
4 Conclusions
e corrosion inhibition mechanism based on carbox-ymethyl chitosanamylose-acetate composites used to pro-tect mild steel in an acidic medium was successfullyinvestigatede AA-CMCh base inhibitor showed excellentinhibition performance in the case of mild steel in a 1MHClsolution e inhibiting efficiencies decreased in the order ofAA-CMChgtAA e inhibitor adsorptions on the mildsteelrsquos surface are chemically adsorbed while the corrosioninhibition mechanism on the mild steelrsquos surface wasspontaneous exothermal and irregular and took place dueto the formation of the Fe-chelate compound on the surfaceof the mild steel specimen e adsorption of the inhibitorson the mild steel specimen in acidic media solution com-ports with that of the Langmuir adsorption isotherm enegative values of the ∆Gads and ∆H indicated that theadsorption reaction took place spontaneously andexothermally
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this work
Acknowledgments
e authors gratefully acknowledge financial support fromthe Directorate General of Higher Education of Ministry(DIKTI) the Ministry of Research Technology and HigherEducation through a fundamental grant of the UniversitasRiau Indonesia
(c)
Figure 9 SEMEDX spectra of the mild steel surface in 1M HCl (a) AA (b) AA-CMCh blended (c) control
Table 2 Percentage atomic contents of elements measured usingthe EDX technique
Inhibitors Fe O S Cl CControl 9664 197 mdash 012 027AA 7769 2226 mdash 006 1346AA-CMCh 7761 2223 mdash 015 1649
10 International Journal of Chemical Engineering
References
[1] B Xu W Yang Y Liu X Yin W Gong and Y ChenldquoExperimental and theoretical evaluation of two pyr-idinecarboxaldehyde thiosemicarbazone compounds as cor-rosion inhibitors for mild steel in hydrochloric acid solutionrdquoCorrosion Science vol 78 pp 260ndash268 2014
[2] S A Umoren and U M Eduok ldquoApplication of carbohydratepolymers as corrosion inhibitors for metal substrates indifferent media a reviewrdquo Carbohydrate Polymers vol 140pp 314ndash341 2016
[3] S E Karekar U D Bagale S H Sonawane B A Bhanvaseand D V Pinjari ldquoA smart coating established with encap-sulation of Zinc Molybdate centred nanocontainer for activecorrosion protection of mild steel release kinetics of corro-sion inhibitorrdquo Composite Interfaces vol 25 no 9 pp 785ndash808 2018
[4] S Abrishami R Naderi and B Ramezanzadeh ldquoFabricationand characterization of zinc acetylacetonateUrtica dioicaleaves extract complex as an effective organicinorganic hy-brid corrosion inhibitive pigment for mild steel protection inchloride solutionrdquo Applied Surface Science vol 457pp 487ndash496 2018
[5] M Krishnan H Subramanian H-U Dahms et al ldquoBiogeniccorrosion inhibitor on mild steel protection in concentratedHCl mediumrdquo Scientific Report vol 8 p 2609 2018
[6] N Bhardwaj D Prasad and R Haldhar ldquoStudy of the Aeglemarmelos as a green corrosion inhibitor for mild steel in acidicmedium experimental and theoretical approachrdquo Journal ofBio- and Tribo-Corrosion vol 4 no 4 p 61 2018
[7] T K Bhuvaneswari V S Vasantha and C JeyaprabhaldquoPongamia pinnata as a green corrosion inhibitor for mildsteel in 1N sulfuric acid mediumrdquo Silicon vol 10 no 5pp 1793ndash1807 2018
[8] M P Rai A Khanra S Rai M Srivastava and R PrakashldquoPivotal role of levoglucosenone and hexadecanoic acid frommicroalgae Chlorococcum sp for corrosion resistance on mildsteel electrochemical microstructural and theoretical anal-ysisrdquo Journal of Molecular Liquids vol 266 pp 279ndash2902018
[9] A Saxena D Prasad and R Haldhar ldquoInvestigation ofcorrosion inhibition effect and adsorption activities of Cus-cuta reflexa extract for mild steel in 05 M H2SO4rdquo Bio-electrochemistry vol 124 pp 156ndash164 2018
[10] X Zheng M Gong Q Li and L Guo ldquoCorrosion inhibitionof mild steel in sulfuric acid solution by loquat (Eriobotryajaponica Lindl) leaves extractrdquo Scientific Report vol 8p 9140 2018
[11] A Bouoidina F El-Hajjaji M Drissi et al ldquoTowards a deeperunderstanding of the anticorrosive properties of hydrazinederivatives in acid medium experimental DFT and MDsimulation assessmentrdquo Metallurgical and Materials Trans-actions A vol 49 no 10 pp 5180ndash5191 2018
[12] A Chaouiki H Lgaz I-M Chung et al ldquoUnderstandingcorrosion inhibition of mild steel in acid medium by newbenzonitriles insights from experimental and computationalstudiesrdquo Journal of Molecular Liquids vol 266 pp 603ndash6162018
[13] Y Guo Z Chen Y Zuo Y Chen W Yang and B Xu ldquoIonicliquids with two typical hydrophobic anions as acidic cor-rosion inhibitorsrdquo Journal of Molecular Liquids vol 269pp 886ndash895 2018
[14] E Naseri M Hajisafari A Kosari M Talari S Hosseinpourand A Davoodi ldquoInhibitive effect of Clopidogrel as a green
corrosion inhibitor for mild steel statistical modeling andquantum Monte Carlo simulation studiesrdquo Journal of Mo-lecular Liquids vol 269 pp 193ndash202 2018
[15] R Geethanjali and S Subhashini ldquoSynthesis and kinetics ofcorrosion inhibition of water-soluble terpolymer of polyvinylalcohol functionalized with vinyl sulfonate and p-vinyl ben-zene sulfonate in molar HClrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4 p 60 2018
[16] P Han W Li H Tian et al ldquoDesigning and fabricating oftime-depend self-strengthening inhibitor film synergisticinhibition of sodium dodecyl sulfate and 4-mercaptopyridinefor mild steelrdquo Journal of Molecular Liquids vol 268pp 425ndash437 2018
[17] X He J Mao Q Ma and Y Tang ldquoCorrosion inhibition ofperimidine derivatives for mild steel in acidic media elec-trochemical and computational studiesrdquo Journal of MolecularLiquids vol 269 pp 260ndash268 2018
[18] A A Mahmmod I A Kazarinov A A Khadom andH B Mahood ldquoExperimental and theoretical studies of mildsteel corrosion inhibition in phosphoric acid using tetrazolesderivativesrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4p 58 2018
[19] M Messali M Larouj H Lgaz et al ldquoA new schiff basederivative as an effective corrosion inhibitor for mild steel inacidic media experimental and computer simulations stud-iesrdquo Journal of Molecular Structure vol 1168 pp 39ndash48 2018
[20] A Mishra C Verma S Chauhan et al ldquoCharacterizationand corrosion inhibition performance of 5-aminopyrazolecarbonitriles towards mild steel acidic corrosionrdquo Journal ofBio- and Tribo-Corrosion vol 4 p 53 2018
[21] N Saini R Kumar H Lgaz et al ldquoMinified dose of urispasdrug as better corrosion constraint for soft steel in sulphuricacid solutionrdquo Journal of Molecular Liquids vol 269pp 371ndash380 2018
[22] K Zhang W Yang Y Chen et al ldquoEnhanced inhibitiveperformance of fluoro-substituted imidazolium-based ionicliquid for mild steel corrosion in hydrochloric acid at elevatedtemperaturerdquo Journal of Materials Science vol 53 no 20pp 14666ndash14680 2018
[23] K R Ansari M A Quraishi and A Singh ldquoCorrosion in-hibition of mild steel in hydrochloric acid by some pyridinederivatives an experimental and quantum chemical studyrdquoJournal of Industrial and Engineering Chemistry vol 25pp 89ndash98 2015
[24] L O Olasunkanmi I B Obot M M Kabanda andE E Ebenso ldquoSome quinoxalin-6-yl derivatives as corrosioninhibitors for mild steel in hydrochloric acid experimentaland theoretical studiesrdquo Journal of Physical Chemistry Cvol 119 no 28 pp 16004ndash16019 2015
[25] M Ewis S S Elkholy and M Z Esabee ldquoAntifungal efficacyof chitosan and its thiourea derivatives upon the growth ofsome sugar-beet pathogensrdquo International Journal of Bi-ological Macromolecules vol 38 no 1 pp 1ndash8 2006
[26] Z-X Tang J-Q Qian and L-E Shi ldquoCharacterizations ofimmobilized neutral lipase on chitosan nano-particlesrdquoMaterials Letters vol 61 no 1 pp 37ndash40 2007
[27] M N El-Haddad ldquoChitosan as a green inhibitor for coppercorrosion in acidic mediumrdquo International Journal of Bi-ological Macromolecules vol 55 pp 142ndash149 2013
[28] S Cheng S Chen T Liu X Chang and Y Yin ldquoCarbox-ymenthylchitosan as an ecofriendly inhibitor for mild steel in1 MHClrdquoMaterials Letters vol 61 no 14-15 pp 3276ndash32802007
International Journal of Chemical Engineering 11
[29] K Wan P Feng B Hou and Y Li ldquoEnhanced corrosioninhibition properties of carboxymethyl hydroxypropyl chi-tosan for mild steel in 10 M HCl solutionrdquo RSC Advancesvol 6 no 81 pp 77515ndash77524 2016
[30] M M Solomon H Gerengi T Kaya and S A UmorenldquoEnhanced corrosion inhibition effect of chitosan for St37 in15 H2SO4 environment by silver nanoparticlesrdquo In-ternational Journal of Biological Macromolecules vol 104pp 638ndash649 2017
[31] A M Alsabagh M Z Elsabee Y M Moustafa A Elfky andR E Morsi ldquoCorrosion inhibition efficiency of somehydrophobically modified chitosan surfactants in relation totheir surface active propertiesrdquo Egyptian Journal of Petroleumvol 23 no 4 pp 349ndash359 2014
[32] S A Umoren M J Banera T Alonso-Garcia C A Gervasiand M V Mirıfico ldquoInhibition of mild steel corrosion in HClsolution using chitosanrdquo Cellulose vol 20 no 5 pp 2529ndash2545 2013
[33] M Erna Y Eryanti and A Dahliaty ldquoModifikasi amilosa daripati tapioka dan garut menjadi amilosa asetatrdquo Jurnal PilarSains vol 7 pp 28ndash30 2008
[34] H T Pang X G Chen H J Park D S Cha andJ F Kennedy ldquoPreparation and rheological properties ofdeoxycholate-chitosan and carboxymethyl-chitosan inaqueous systemsrdquo Carbohydrate Polymers vol 69 no 3pp 419ndash425 2007
[35] K K Anupama and J Abraham ldquoElectroanalytical studies onthe corrosion inhibition behavior of guava (Psidium guajava)leaves extract on mild steel in hydrochloric acidrdquo Research onChemical Intermediates vol 39 no 9 pp 4067ndash4080 2012
[36] M E Al-Dokheily H M Kredy and R N Al-Jabery ldquoIn-hibition of copper corrosion in H2SO4 NaCl and NaOHsolutions by Citrullus colocynthis fruits extractrdquo Journal ofNatural Sciences Research vol 4 pp 60ndash73 2014
[37] M H Hussin andM J Kassim ldquoe corrosion inhibition andadsorption behavior ofUncaria gambir extract onmild steel in1M HClrdquo Materials Chemistry and Physics vol 125 no 3pp 461ndash468 2011
[38] K R Ansari M A Quraishi and A Singh ldquoIsatin derivativesas a non-toxic corrosion inhibitor for mild steel in 20H2SO4rdquo Corrosion Science vol 95 pp 62ndash70 2015
[39] B Zerga A Attayibat M Sfaira et al ldquoEffect of some tripodalbipyrazolic compounds on C38 steel corrosion in hydro-chloric acid solutionrdquo Journal of Applied Electrochemistryvol 40 no 9 pp 1575ndash1582 2010
[40] H Ashassi-Sorkhabi and S A Nabavi-Amri ldquoCorrosioninhibition of carbon steel in petroleumwater mixtures byn-containing compoundsrdquo Acta Chimica Slovenica vol 47pp 507ndash517 2000
where i0corr and icorrprime represent the corrosion current densitieswithout and with the addition of inhibitors respectivelyeresults conrmed that the inhibition eciency responseincreased while the corrosion current density decreasedwhen the addition of inhibitors concentration increasedis implies that the inhibitor adsorption on the mild steelrsquossurface and the adsorption process is enhanced and in-creased inhibition eciency
36 Surface Characterization SEM and EDX In order todetermine the eiexclectiveness of the formatted thin layer of theinhibitor on the mild steelrsquos surface the treated mild steelwas imaged using an SEM SEM images of the mild steelsurface in the presenceabsence of CMCh in HCl and H2SO4solutions are shown in Figures 7 and 8 In the presence of AAat their respective optimum concentrations (400 ppm) inHCl (Figure 7(a)) and H2SO4 solutions (Figure 8(a)) asmooth surface of mild steel can be seen (Figures 7(a) and
8(a)) In the presence of AA-CMCh in HCl (Figure 7(b)) andH2SO4 solution (Figure 8(b)) a smoother surface of the mildspecimen can be seen (Figures 7(b) and 8(b)) is impliesthat the AA-CMCh is more eiexclective in inhibiting corrosionon mild steelrsquos surface compared to the AA inhibitor isfeature probably contributed to the homogeneity and bio-compatibility of the AA-CMCh composites on the mildsteelrsquos surface Generally a smoother surface of themild steelspecimen denote that the AA-CMCh has adsorbed onto themild steelrsquos surface and protected specimens from direct acidattacks
e EDX spectra of the mild steel and control specimenin HCl solution is shown in Figure 9 e surface of mildsteels as a control specimen before treatment (Figure 9(c))and the presence of AA-CMCh (Figure 9(b)) exhibit asmooth and uniform surface e morphology in thepresence AA was slightly damaged and rough (Figure 9(a))is conrmed that the mild steel surface is well protectedfrom acidic attacks and prevented from corroding Table 2shows the percentage of atomic contents in the inhibitor andcontrol specimens e EDX spectrum in the presence ofAA-CMCh conrmed that the concentration of the Cl ion is
Figure 6 Potentiodynamic polarization curves of mild steel in 10MHCl solutionmeasured in the absence (a) and presence of (b) 100 ppm(c) 200 ppm (d) 300 ppm and (e) 400 ppm of amylose-acetatecarboxymethyl chitosan (AA-CMCh)
Table 1 Electrochemical parameters obtained from polarization measurement in 10M HCl in the presence and absence of a diiexclerentconcentration of AA-CMCh
Figure 8 SEM micrographs of the mild steel surface in 025M H2SO4 with AA (a) and AA-CMCh (b)
(a) (b)
Figure 7 SEM images of mild steel surfaces in 1M HCl with AA (a) and AA-CMCh (b)
(a) (b)
Figure 9 Continued
International Journal of Chemical Engineering 9
higher than that of the presence of AA whilst the con-centration of C in the control specimen prior to treatmentwas lower than that of the treated specimen due to theinhibitor absorbed onto the mild steelrsquos surface e con-centration of Fe and O from the inhibitor of AA is notsignificantly different than the inhibitor of AA-CMCh(Table 2) Generally both AA and AA-CMCh inhibitorsare able to inhibit the mild steel specimen from a directattack by the Cl ion which protects the mild steel surfacefrom an aggressive environment
37Mechanismof Inhibition e adsorption of AA-blendedCMCh on mild steel can be clearly defined by consideringthe chemisorption processes e specific mechanism ofcorrosion inhibition of AA-CMCh to the surface of mildsteel coupons is detailed in the following equations
Fe + AA-CMCh⟷ Fe(AA-CMCh)ads (9)
Fe(AA-CMCh)ads⟷ Fe2++ AA-CMCh + neminus (10)
AA-CMChaq + H2Oads⟷AA-CMChads + H2Oaq
(11)
e chemisorption of AA-CMCh on mild steel isdenoted by the donor-acceptor interactions between thelone pair of the electron from the carbonyl and amine groupsof AA-CMCh with the d-orbitals of Fe e value of freeenergy from the AA-CMCh adsorption was minus33 kJmiddotmolminus1 ormore negative is confirms that the adsorption mecha-nism of the AA-CMCh on the surface of the mild steelcoupon was chemically adsorbed e inhibition of
corrosion begins by the displacement of water molecules bythe inhibitorrsquos capacity toward specific adsorption of theinhibitor on the metalrsquos surface [40]
4 Conclusions
e corrosion inhibition mechanism based on carbox-ymethyl chitosanamylose-acetate composites used to pro-tect mild steel in an acidic medium was successfullyinvestigatede AA-CMCh base inhibitor showed excellentinhibition performance in the case of mild steel in a 1MHClsolution e inhibiting efficiencies decreased in the order ofAA-CMChgtAA e inhibitor adsorptions on the mildsteelrsquos surface are chemically adsorbed while the corrosioninhibition mechanism on the mild steelrsquos surface wasspontaneous exothermal and irregular and took place dueto the formation of the Fe-chelate compound on the surfaceof the mild steel specimen e adsorption of the inhibitorson the mild steel specimen in acidic media solution com-ports with that of the Langmuir adsorption isotherm enegative values of the ∆Gads and ∆H indicated that theadsorption reaction took place spontaneously andexothermally
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this work
Acknowledgments
e authors gratefully acknowledge financial support fromthe Directorate General of Higher Education of Ministry(DIKTI) the Ministry of Research Technology and HigherEducation through a fundamental grant of the UniversitasRiau Indonesia
(c)
Figure 9 SEMEDX spectra of the mild steel surface in 1M HCl (a) AA (b) AA-CMCh blended (c) control
Table 2 Percentage atomic contents of elements measured usingthe EDX technique
Inhibitors Fe O S Cl CControl 9664 197 mdash 012 027AA 7769 2226 mdash 006 1346AA-CMCh 7761 2223 mdash 015 1649
10 International Journal of Chemical Engineering
References
[1] B Xu W Yang Y Liu X Yin W Gong and Y ChenldquoExperimental and theoretical evaluation of two pyr-idinecarboxaldehyde thiosemicarbazone compounds as cor-rosion inhibitors for mild steel in hydrochloric acid solutionrdquoCorrosion Science vol 78 pp 260ndash268 2014
[2] S A Umoren and U M Eduok ldquoApplication of carbohydratepolymers as corrosion inhibitors for metal substrates indifferent media a reviewrdquo Carbohydrate Polymers vol 140pp 314ndash341 2016
[3] S E Karekar U D Bagale S H Sonawane B A Bhanvaseand D V Pinjari ldquoA smart coating established with encap-sulation of Zinc Molybdate centred nanocontainer for activecorrosion protection of mild steel release kinetics of corro-sion inhibitorrdquo Composite Interfaces vol 25 no 9 pp 785ndash808 2018
[4] S Abrishami R Naderi and B Ramezanzadeh ldquoFabricationand characterization of zinc acetylacetonateUrtica dioicaleaves extract complex as an effective organicinorganic hy-brid corrosion inhibitive pigment for mild steel protection inchloride solutionrdquo Applied Surface Science vol 457pp 487ndash496 2018
[5] M Krishnan H Subramanian H-U Dahms et al ldquoBiogeniccorrosion inhibitor on mild steel protection in concentratedHCl mediumrdquo Scientific Report vol 8 p 2609 2018
[6] N Bhardwaj D Prasad and R Haldhar ldquoStudy of the Aeglemarmelos as a green corrosion inhibitor for mild steel in acidicmedium experimental and theoretical approachrdquo Journal ofBio- and Tribo-Corrosion vol 4 no 4 p 61 2018
[7] T K Bhuvaneswari V S Vasantha and C JeyaprabhaldquoPongamia pinnata as a green corrosion inhibitor for mildsteel in 1N sulfuric acid mediumrdquo Silicon vol 10 no 5pp 1793ndash1807 2018
[8] M P Rai A Khanra S Rai M Srivastava and R PrakashldquoPivotal role of levoglucosenone and hexadecanoic acid frommicroalgae Chlorococcum sp for corrosion resistance on mildsteel electrochemical microstructural and theoretical anal-ysisrdquo Journal of Molecular Liquids vol 266 pp 279ndash2902018
[9] A Saxena D Prasad and R Haldhar ldquoInvestigation ofcorrosion inhibition effect and adsorption activities of Cus-cuta reflexa extract for mild steel in 05 M H2SO4rdquo Bio-electrochemistry vol 124 pp 156ndash164 2018
[10] X Zheng M Gong Q Li and L Guo ldquoCorrosion inhibitionof mild steel in sulfuric acid solution by loquat (Eriobotryajaponica Lindl) leaves extractrdquo Scientific Report vol 8p 9140 2018
[11] A Bouoidina F El-Hajjaji M Drissi et al ldquoTowards a deeperunderstanding of the anticorrosive properties of hydrazinederivatives in acid medium experimental DFT and MDsimulation assessmentrdquo Metallurgical and Materials Trans-actions A vol 49 no 10 pp 5180ndash5191 2018
[12] A Chaouiki H Lgaz I-M Chung et al ldquoUnderstandingcorrosion inhibition of mild steel in acid medium by newbenzonitriles insights from experimental and computationalstudiesrdquo Journal of Molecular Liquids vol 266 pp 603ndash6162018
[13] Y Guo Z Chen Y Zuo Y Chen W Yang and B Xu ldquoIonicliquids with two typical hydrophobic anions as acidic cor-rosion inhibitorsrdquo Journal of Molecular Liquids vol 269pp 886ndash895 2018
[14] E Naseri M Hajisafari A Kosari M Talari S Hosseinpourand A Davoodi ldquoInhibitive effect of Clopidogrel as a green
corrosion inhibitor for mild steel statistical modeling andquantum Monte Carlo simulation studiesrdquo Journal of Mo-lecular Liquids vol 269 pp 193ndash202 2018
[15] R Geethanjali and S Subhashini ldquoSynthesis and kinetics ofcorrosion inhibition of water-soluble terpolymer of polyvinylalcohol functionalized with vinyl sulfonate and p-vinyl ben-zene sulfonate in molar HClrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4 p 60 2018
[16] P Han W Li H Tian et al ldquoDesigning and fabricating oftime-depend self-strengthening inhibitor film synergisticinhibition of sodium dodecyl sulfate and 4-mercaptopyridinefor mild steelrdquo Journal of Molecular Liquids vol 268pp 425ndash437 2018
[17] X He J Mao Q Ma and Y Tang ldquoCorrosion inhibition ofperimidine derivatives for mild steel in acidic media elec-trochemical and computational studiesrdquo Journal of MolecularLiquids vol 269 pp 260ndash268 2018
[18] A A Mahmmod I A Kazarinov A A Khadom andH B Mahood ldquoExperimental and theoretical studies of mildsteel corrosion inhibition in phosphoric acid using tetrazolesderivativesrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4p 58 2018
[19] M Messali M Larouj H Lgaz et al ldquoA new schiff basederivative as an effective corrosion inhibitor for mild steel inacidic media experimental and computer simulations stud-iesrdquo Journal of Molecular Structure vol 1168 pp 39ndash48 2018
[20] A Mishra C Verma S Chauhan et al ldquoCharacterizationand corrosion inhibition performance of 5-aminopyrazolecarbonitriles towards mild steel acidic corrosionrdquo Journal ofBio- and Tribo-Corrosion vol 4 p 53 2018
[21] N Saini R Kumar H Lgaz et al ldquoMinified dose of urispasdrug as better corrosion constraint for soft steel in sulphuricacid solutionrdquo Journal of Molecular Liquids vol 269pp 371ndash380 2018
[22] K Zhang W Yang Y Chen et al ldquoEnhanced inhibitiveperformance of fluoro-substituted imidazolium-based ionicliquid for mild steel corrosion in hydrochloric acid at elevatedtemperaturerdquo Journal of Materials Science vol 53 no 20pp 14666ndash14680 2018
[23] K R Ansari M A Quraishi and A Singh ldquoCorrosion in-hibition of mild steel in hydrochloric acid by some pyridinederivatives an experimental and quantum chemical studyrdquoJournal of Industrial and Engineering Chemistry vol 25pp 89ndash98 2015
[24] L O Olasunkanmi I B Obot M M Kabanda andE E Ebenso ldquoSome quinoxalin-6-yl derivatives as corrosioninhibitors for mild steel in hydrochloric acid experimentaland theoretical studiesrdquo Journal of Physical Chemistry Cvol 119 no 28 pp 16004ndash16019 2015
[25] M Ewis S S Elkholy and M Z Esabee ldquoAntifungal efficacyof chitosan and its thiourea derivatives upon the growth ofsome sugar-beet pathogensrdquo International Journal of Bi-ological Macromolecules vol 38 no 1 pp 1ndash8 2006
[26] Z-X Tang J-Q Qian and L-E Shi ldquoCharacterizations ofimmobilized neutral lipase on chitosan nano-particlesrdquoMaterials Letters vol 61 no 1 pp 37ndash40 2007
[27] M N El-Haddad ldquoChitosan as a green inhibitor for coppercorrosion in acidic mediumrdquo International Journal of Bi-ological Macromolecules vol 55 pp 142ndash149 2013
[28] S Cheng S Chen T Liu X Chang and Y Yin ldquoCarbox-ymenthylchitosan as an ecofriendly inhibitor for mild steel in1 MHClrdquoMaterials Letters vol 61 no 14-15 pp 3276ndash32802007
International Journal of Chemical Engineering 11
[29] K Wan P Feng B Hou and Y Li ldquoEnhanced corrosioninhibition properties of carboxymethyl hydroxypropyl chi-tosan for mild steel in 10 M HCl solutionrdquo RSC Advancesvol 6 no 81 pp 77515ndash77524 2016
[30] M M Solomon H Gerengi T Kaya and S A UmorenldquoEnhanced corrosion inhibition effect of chitosan for St37 in15 H2SO4 environment by silver nanoparticlesrdquo In-ternational Journal of Biological Macromolecules vol 104pp 638ndash649 2017
[31] A M Alsabagh M Z Elsabee Y M Moustafa A Elfky andR E Morsi ldquoCorrosion inhibition efficiency of somehydrophobically modified chitosan surfactants in relation totheir surface active propertiesrdquo Egyptian Journal of Petroleumvol 23 no 4 pp 349ndash359 2014
[32] S A Umoren M J Banera T Alonso-Garcia C A Gervasiand M V Mirıfico ldquoInhibition of mild steel corrosion in HClsolution using chitosanrdquo Cellulose vol 20 no 5 pp 2529ndash2545 2013
[33] M Erna Y Eryanti and A Dahliaty ldquoModifikasi amilosa daripati tapioka dan garut menjadi amilosa asetatrdquo Jurnal PilarSains vol 7 pp 28ndash30 2008
[34] H T Pang X G Chen H J Park D S Cha andJ F Kennedy ldquoPreparation and rheological properties ofdeoxycholate-chitosan and carboxymethyl-chitosan inaqueous systemsrdquo Carbohydrate Polymers vol 69 no 3pp 419ndash425 2007
[35] K K Anupama and J Abraham ldquoElectroanalytical studies onthe corrosion inhibition behavior of guava (Psidium guajava)leaves extract on mild steel in hydrochloric acidrdquo Research onChemical Intermediates vol 39 no 9 pp 4067ndash4080 2012
[36] M E Al-Dokheily H M Kredy and R N Al-Jabery ldquoIn-hibition of copper corrosion in H2SO4 NaCl and NaOHsolutions by Citrullus colocynthis fruits extractrdquo Journal ofNatural Sciences Research vol 4 pp 60ndash73 2014
[37] M H Hussin andM J Kassim ldquoe corrosion inhibition andadsorption behavior ofUncaria gambir extract onmild steel in1M HClrdquo Materials Chemistry and Physics vol 125 no 3pp 461ndash468 2011
[38] K R Ansari M A Quraishi and A Singh ldquoIsatin derivativesas a non-toxic corrosion inhibitor for mild steel in 20H2SO4rdquo Corrosion Science vol 95 pp 62ndash70 2015
[39] B Zerga A Attayibat M Sfaira et al ldquoEffect of some tripodalbipyrazolic compounds on C38 steel corrosion in hydro-chloric acid solutionrdquo Journal of Applied Electrochemistryvol 40 no 9 pp 1575ndash1582 2010
[40] H Ashassi-Sorkhabi and S A Nabavi-Amri ldquoCorrosioninhibition of carbon steel in petroleumwater mixtures byn-containing compoundsrdquo Acta Chimica Slovenica vol 47pp 507ndash517 2000
where i0corr and icorrprime represent the corrosion current densitieswithout and with the addition of inhibitors respectivelyeresults conrmed that the inhibition eciency responseincreased while the corrosion current density decreasedwhen the addition of inhibitors concentration increasedis implies that the inhibitor adsorption on the mild steelrsquossurface and the adsorption process is enhanced and in-creased inhibition eciency
36 Surface Characterization SEM and EDX In order todetermine the eiexclectiveness of the formatted thin layer of theinhibitor on the mild steelrsquos surface the treated mild steelwas imaged using an SEM SEM images of the mild steelsurface in the presenceabsence of CMCh in HCl and H2SO4solutions are shown in Figures 7 and 8 In the presence of AAat their respective optimum concentrations (400 ppm) inHCl (Figure 7(a)) and H2SO4 solutions (Figure 8(a)) asmooth surface of mild steel can be seen (Figures 7(a) and
8(a)) In the presence of AA-CMCh in HCl (Figure 7(b)) andH2SO4 solution (Figure 8(b)) a smoother surface of the mildspecimen can be seen (Figures 7(b) and 8(b)) is impliesthat the AA-CMCh is more eiexclective in inhibiting corrosionon mild steelrsquos surface compared to the AA inhibitor isfeature probably contributed to the homogeneity and bio-compatibility of the AA-CMCh composites on the mildsteelrsquos surface Generally a smoother surface of themild steelspecimen denote that the AA-CMCh has adsorbed onto themild steelrsquos surface and protected specimens from direct acidattacks
e EDX spectra of the mild steel and control specimenin HCl solution is shown in Figure 9 e surface of mildsteels as a control specimen before treatment (Figure 9(c))and the presence of AA-CMCh (Figure 9(b)) exhibit asmooth and uniform surface e morphology in thepresence AA was slightly damaged and rough (Figure 9(a))is conrmed that the mild steel surface is well protectedfrom acidic attacks and prevented from corroding Table 2shows the percentage of atomic contents in the inhibitor andcontrol specimens e EDX spectrum in the presence ofAA-CMCh conrmed that the concentration of the Cl ion is
Figure 6 Potentiodynamic polarization curves of mild steel in 10MHCl solutionmeasured in the absence (a) and presence of (b) 100 ppm(c) 200 ppm (d) 300 ppm and (e) 400 ppm of amylose-acetatecarboxymethyl chitosan (AA-CMCh)
Table 1 Electrochemical parameters obtained from polarization measurement in 10M HCl in the presence and absence of a diiexclerentconcentration of AA-CMCh
Figure 8 SEM micrographs of the mild steel surface in 025M H2SO4 with AA (a) and AA-CMCh (b)
(a) (b)
Figure 7 SEM images of mild steel surfaces in 1M HCl with AA (a) and AA-CMCh (b)
(a) (b)
Figure 9 Continued
International Journal of Chemical Engineering 9
higher than that of the presence of AA whilst the con-centration of C in the control specimen prior to treatmentwas lower than that of the treated specimen due to theinhibitor absorbed onto the mild steelrsquos surface e con-centration of Fe and O from the inhibitor of AA is notsignificantly different than the inhibitor of AA-CMCh(Table 2) Generally both AA and AA-CMCh inhibitorsare able to inhibit the mild steel specimen from a directattack by the Cl ion which protects the mild steel surfacefrom an aggressive environment
37Mechanismof Inhibition e adsorption of AA-blendedCMCh on mild steel can be clearly defined by consideringthe chemisorption processes e specific mechanism ofcorrosion inhibition of AA-CMCh to the surface of mildsteel coupons is detailed in the following equations
Fe + AA-CMCh⟷ Fe(AA-CMCh)ads (9)
Fe(AA-CMCh)ads⟷ Fe2++ AA-CMCh + neminus (10)
AA-CMChaq + H2Oads⟷AA-CMChads + H2Oaq
(11)
e chemisorption of AA-CMCh on mild steel isdenoted by the donor-acceptor interactions between thelone pair of the electron from the carbonyl and amine groupsof AA-CMCh with the d-orbitals of Fe e value of freeenergy from the AA-CMCh adsorption was minus33 kJmiddotmolminus1 ormore negative is confirms that the adsorption mecha-nism of the AA-CMCh on the surface of the mild steelcoupon was chemically adsorbed e inhibition of
corrosion begins by the displacement of water molecules bythe inhibitorrsquos capacity toward specific adsorption of theinhibitor on the metalrsquos surface [40]
4 Conclusions
e corrosion inhibition mechanism based on carbox-ymethyl chitosanamylose-acetate composites used to pro-tect mild steel in an acidic medium was successfullyinvestigatede AA-CMCh base inhibitor showed excellentinhibition performance in the case of mild steel in a 1MHClsolution e inhibiting efficiencies decreased in the order ofAA-CMChgtAA e inhibitor adsorptions on the mildsteelrsquos surface are chemically adsorbed while the corrosioninhibition mechanism on the mild steelrsquos surface wasspontaneous exothermal and irregular and took place dueto the formation of the Fe-chelate compound on the surfaceof the mild steel specimen e adsorption of the inhibitorson the mild steel specimen in acidic media solution com-ports with that of the Langmuir adsorption isotherm enegative values of the ∆Gads and ∆H indicated that theadsorption reaction took place spontaneously andexothermally
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this work
Acknowledgments
e authors gratefully acknowledge financial support fromthe Directorate General of Higher Education of Ministry(DIKTI) the Ministry of Research Technology and HigherEducation through a fundamental grant of the UniversitasRiau Indonesia
(c)
Figure 9 SEMEDX spectra of the mild steel surface in 1M HCl (a) AA (b) AA-CMCh blended (c) control
Table 2 Percentage atomic contents of elements measured usingthe EDX technique
Inhibitors Fe O S Cl CControl 9664 197 mdash 012 027AA 7769 2226 mdash 006 1346AA-CMCh 7761 2223 mdash 015 1649
10 International Journal of Chemical Engineering
References
[1] B Xu W Yang Y Liu X Yin W Gong and Y ChenldquoExperimental and theoretical evaluation of two pyr-idinecarboxaldehyde thiosemicarbazone compounds as cor-rosion inhibitors for mild steel in hydrochloric acid solutionrdquoCorrosion Science vol 78 pp 260ndash268 2014
[2] S A Umoren and U M Eduok ldquoApplication of carbohydratepolymers as corrosion inhibitors for metal substrates indifferent media a reviewrdquo Carbohydrate Polymers vol 140pp 314ndash341 2016
[3] S E Karekar U D Bagale S H Sonawane B A Bhanvaseand D V Pinjari ldquoA smart coating established with encap-sulation of Zinc Molybdate centred nanocontainer for activecorrosion protection of mild steel release kinetics of corro-sion inhibitorrdquo Composite Interfaces vol 25 no 9 pp 785ndash808 2018
[4] S Abrishami R Naderi and B Ramezanzadeh ldquoFabricationand characterization of zinc acetylacetonateUrtica dioicaleaves extract complex as an effective organicinorganic hy-brid corrosion inhibitive pigment for mild steel protection inchloride solutionrdquo Applied Surface Science vol 457pp 487ndash496 2018
[5] M Krishnan H Subramanian H-U Dahms et al ldquoBiogeniccorrosion inhibitor on mild steel protection in concentratedHCl mediumrdquo Scientific Report vol 8 p 2609 2018
[6] N Bhardwaj D Prasad and R Haldhar ldquoStudy of the Aeglemarmelos as a green corrosion inhibitor for mild steel in acidicmedium experimental and theoretical approachrdquo Journal ofBio- and Tribo-Corrosion vol 4 no 4 p 61 2018
[7] T K Bhuvaneswari V S Vasantha and C JeyaprabhaldquoPongamia pinnata as a green corrosion inhibitor for mildsteel in 1N sulfuric acid mediumrdquo Silicon vol 10 no 5pp 1793ndash1807 2018
[8] M P Rai A Khanra S Rai M Srivastava and R PrakashldquoPivotal role of levoglucosenone and hexadecanoic acid frommicroalgae Chlorococcum sp for corrosion resistance on mildsteel electrochemical microstructural and theoretical anal-ysisrdquo Journal of Molecular Liquids vol 266 pp 279ndash2902018
[9] A Saxena D Prasad and R Haldhar ldquoInvestigation ofcorrosion inhibition effect and adsorption activities of Cus-cuta reflexa extract for mild steel in 05 M H2SO4rdquo Bio-electrochemistry vol 124 pp 156ndash164 2018
[10] X Zheng M Gong Q Li and L Guo ldquoCorrosion inhibitionof mild steel in sulfuric acid solution by loquat (Eriobotryajaponica Lindl) leaves extractrdquo Scientific Report vol 8p 9140 2018
[11] A Bouoidina F El-Hajjaji M Drissi et al ldquoTowards a deeperunderstanding of the anticorrosive properties of hydrazinederivatives in acid medium experimental DFT and MDsimulation assessmentrdquo Metallurgical and Materials Trans-actions A vol 49 no 10 pp 5180ndash5191 2018
[12] A Chaouiki H Lgaz I-M Chung et al ldquoUnderstandingcorrosion inhibition of mild steel in acid medium by newbenzonitriles insights from experimental and computationalstudiesrdquo Journal of Molecular Liquids vol 266 pp 603ndash6162018
[13] Y Guo Z Chen Y Zuo Y Chen W Yang and B Xu ldquoIonicliquids with two typical hydrophobic anions as acidic cor-rosion inhibitorsrdquo Journal of Molecular Liquids vol 269pp 886ndash895 2018
[14] E Naseri M Hajisafari A Kosari M Talari S Hosseinpourand A Davoodi ldquoInhibitive effect of Clopidogrel as a green
corrosion inhibitor for mild steel statistical modeling andquantum Monte Carlo simulation studiesrdquo Journal of Mo-lecular Liquids vol 269 pp 193ndash202 2018
[15] R Geethanjali and S Subhashini ldquoSynthesis and kinetics ofcorrosion inhibition of water-soluble terpolymer of polyvinylalcohol functionalized with vinyl sulfonate and p-vinyl ben-zene sulfonate in molar HClrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4 p 60 2018
[16] P Han W Li H Tian et al ldquoDesigning and fabricating oftime-depend self-strengthening inhibitor film synergisticinhibition of sodium dodecyl sulfate and 4-mercaptopyridinefor mild steelrdquo Journal of Molecular Liquids vol 268pp 425ndash437 2018
[17] X He J Mao Q Ma and Y Tang ldquoCorrosion inhibition ofperimidine derivatives for mild steel in acidic media elec-trochemical and computational studiesrdquo Journal of MolecularLiquids vol 269 pp 260ndash268 2018
[18] A A Mahmmod I A Kazarinov A A Khadom andH B Mahood ldquoExperimental and theoretical studies of mildsteel corrosion inhibition in phosphoric acid using tetrazolesderivativesrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4p 58 2018
[19] M Messali M Larouj H Lgaz et al ldquoA new schiff basederivative as an effective corrosion inhibitor for mild steel inacidic media experimental and computer simulations stud-iesrdquo Journal of Molecular Structure vol 1168 pp 39ndash48 2018
[20] A Mishra C Verma S Chauhan et al ldquoCharacterizationand corrosion inhibition performance of 5-aminopyrazolecarbonitriles towards mild steel acidic corrosionrdquo Journal ofBio- and Tribo-Corrosion vol 4 p 53 2018
[21] N Saini R Kumar H Lgaz et al ldquoMinified dose of urispasdrug as better corrosion constraint for soft steel in sulphuricacid solutionrdquo Journal of Molecular Liquids vol 269pp 371ndash380 2018
[22] K Zhang W Yang Y Chen et al ldquoEnhanced inhibitiveperformance of fluoro-substituted imidazolium-based ionicliquid for mild steel corrosion in hydrochloric acid at elevatedtemperaturerdquo Journal of Materials Science vol 53 no 20pp 14666ndash14680 2018
[23] K R Ansari M A Quraishi and A Singh ldquoCorrosion in-hibition of mild steel in hydrochloric acid by some pyridinederivatives an experimental and quantum chemical studyrdquoJournal of Industrial and Engineering Chemistry vol 25pp 89ndash98 2015
[24] L O Olasunkanmi I B Obot M M Kabanda andE E Ebenso ldquoSome quinoxalin-6-yl derivatives as corrosioninhibitors for mild steel in hydrochloric acid experimentaland theoretical studiesrdquo Journal of Physical Chemistry Cvol 119 no 28 pp 16004ndash16019 2015
[25] M Ewis S S Elkholy and M Z Esabee ldquoAntifungal efficacyof chitosan and its thiourea derivatives upon the growth ofsome sugar-beet pathogensrdquo International Journal of Bi-ological Macromolecules vol 38 no 1 pp 1ndash8 2006
[26] Z-X Tang J-Q Qian and L-E Shi ldquoCharacterizations ofimmobilized neutral lipase on chitosan nano-particlesrdquoMaterials Letters vol 61 no 1 pp 37ndash40 2007
[27] M N El-Haddad ldquoChitosan as a green inhibitor for coppercorrosion in acidic mediumrdquo International Journal of Bi-ological Macromolecules vol 55 pp 142ndash149 2013
[28] S Cheng S Chen T Liu X Chang and Y Yin ldquoCarbox-ymenthylchitosan as an ecofriendly inhibitor for mild steel in1 MHClrdquoMaterials Letters vol 61 no 14-15 pp 3276ndash32802007
International Journal of Chemical Engineering 11
[29] K Wan P Feng B Hou and Y Li ldquoEnhanced corrosioninhibition properties of carboxymethyl hydroxypropyl chi-tosan for mild steel in 10 M HCl solutionrdquo RSC Advancesvol 6 no 81 pp 77515ndash77524 2016
[30] M M Solomon H Gerengi T Kaya and S A UmorenldquoEnhanced corrosion inhibition effect of chitosan for St37 in15 H2SO4 environment by silver nanoparticlesrdquo In-ternational Journal of Biological Macromolecules vol 104pp 638ndash649 2017
[31] A M Alsabagh M Z Elsabee Y M Moustafa A Elfky andR E Morsi ldquoCorrosion inhibition efficiency of somehydrophobically modified chitosan surfactants in relation totheir surface active propertiesrdquo Egyptian Journal of Petroleumvol 23 no 4 pp 349ndash359 2014
[32] S A Umoren M J Banera T Alonso-Garcia C A Gervasiand M V Mirıfico ldquoInhibition of mild steel corrosion in HClsolution using chitosanrdquo Cellulose vol 20 no 5 pp 2529ndash2545 2013
[33] M Erna Y Eryanti and A Dahliaty ldquoModifikasi amilosa daripati tapioka dan garut menjadi amilosa asetatrdquo Jurnal PilarSains vol 7 pp 28ndash30 2008
[34] H T Pang X G Chen H J Park D S Cha andJ F Kennedy ldquoPreparation and rheological properties ofdeoxycholate-chitosan and carboxymethyl-chitosan inaqueous systemsrdquo Carbohydrate Polymers vol 69 no 3pp 419ndash425 2007
[35] K K Anupama and J Abraham ldquoElectroanalytical studies onthe corrosion inhibition behavior of guava (Psidium guajava)leaves extract on mild steel in hydrochloric acidrdquo Research onChemical Intermediates vol 39 no 9 pp 4067ndash4080 2012
[36] M E Al-Dokheily H M Kredy and R N Al-Jabery ldquoIn-hibition of copper corrosion in H2SO4 NaCl and NaOHsolutions by Citrullus colocynthis fruits extractrdquo Journal ofNatural Sciences Research vol 4 pp 60ndash73 2014
[37] M H Hussin andM J Kassim ldquoe corrosion inhibition andadsorption behavior ofUncaria gambir extract onmild steel in1M HClrdquo Materials Chemistry and Physics vol 125 no 3pp 461ndash468 2011
[38] K R Ansari M A Quraishi and A Singh ldquoIsatin derivativesas a non-toxic corrosion inhibitor for mild steel in 20H2SO4rdquo Corrosion Science vol 95 pp 62ndash70 2015
[39] B Zerga A Attayibat M Sfaira et al ldquoEffect of some tripodalbipyrazolic compounds on C38 steel corrosion in hydro-chloric acid solutionrdquo Journal of Applied Electrochemistryvol 40 no 9 pp 1575ndash1582 2010
[40] H Ashassi-Sorkhabi and S A Nabavi-Amri ldquoCorrosioninhibition of carbon steel in petroleumwater mixtures byn-containing compoundsrdquo Acta Chimica Slovenica vol 47pp 507ndash517 2000
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
(a) (b)
Figure 8 SEM micrographs of the mild steel surface in 025M H2SO4 with AA (a) and AA-CMCh (b)
(a) (b)
Figure 7 SEM images of mild steel surfaces in 1M HCl with AA (a) and AA-CMCh (b)
(a) (b)
Figure 9 Continued
International Journal of Chemical Engineering 9
higher than that of the presence of AA whilst the con-centration of C in the control specimen prior to treatmentwas lower than that of the treated specimen due to theinhibitor absorbed onto the mild steelrsquos surface e con-centration of Fe and O from the inhibitor of AA is notsignificantly different than the inhibitor of AA-CMCh(Table 2) Generally both AA and AA-CMCh inhibitorsare able to inhibit the mild steel specimen from a directattack by the Cl ion which protects the mild steel surfacefrom an aggressive environment
37Mechanismof Inhibition e adsorption of AA-blendedCMCh on mild steel can be clearly defined by consideringthe chemisorption processes e specific mechanism ofcorrosion inhibition of AA-CMCh to the surface of mildsteel coupons is detailed in the following equations
Fe + AA-CMCh⟷ Fe(AA-CMCh)ads (9)
Fe(AA-CMCh)ads⟷ Fe2++ AA-CMCh + neminus (10)
AA-CMChaq + H2Oads⟷AA-CMChads + H2Oaq
(11)
e chemisorption of AA-CMCh on mild steel isdenoted by the donor-acceptor interactions between thelone pair of the electron from the carbonyl and amine groupsof AA-CMCh with the d-orbitals of Fe e value of freeenergy from the AA-CMCh adsorption was minus33 kJmiddotmolminus1 ormore negative is confirms that the adsorption mecha-nism of the AA-CMCh on the surface of the mild steelcoupon was chemically adsorbed e inhibition of
corrosion begins by the displacement of water molecules bythe inhibitorrsquos capacity toward specific adsorption of theinhibitor on the metalrsquos surface [40]
4 Conclusions
e corrosion inhibition mechanism based on carbox-ymethyl chitosanamylose-acetate composites used to pro-tect mild steel in an acidic medium was successfullyinvestigatede AA-CMCh base inhibitor showed excellentinhibition performance in the case of mild steel in a 1MHClsolution e inhibiting efficiencies decreased in the order ofAA-CMChgtAA e inhibitor adsorptions on the mildsteelrsquos surface are chemically adsorbed while the corrosioninhibition mechanism on the mild steelrsquos surface wasspontaneous exothermal and irregular and took place dueto the formation of the Fe-chelate compound on the surfaceof the mild steel specimen e adsorption of the inhibitorson the mild steel specimen in acidic media solution com-ports with that of the Langmuir adsorption isotherm enegative values of the ∆Gads and ∆H indicated that theadsorption reaction took place spontaneously andexothermally
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this work
Acknowledgments
e authors gratefully acknowledge financial support fromthe Directorate General of Higher Education of Ministry(DIKTI) the Ministry of Research Technology and HigherEducation through a fundamental grant of the UniversitasRiau Indonesia
(c)
Figure 9 SEMEDX spectra of the mild steel surface in 1M HCl (a) AA (b) AA-CMCh blended (c) control
Table 2 Percentage atomic contents of elements measured usingthe EDX technique
Inhibitors Fe O S Cl CControl 9664 197 mdash 012 027AA 7769 2226 mdash 006 1346AA-CMCh 7761 2223 mdash 015 1649
10 International Journal of Chemical Engineering
References
[1] B Xu W Yang Y Liu X Yin W Gong and Y ChenldquoExperimental and theoretical evaluation of two pyr-idinecarboxaldehyde thiosemicarbazone compounds as cor-rosion inhibitors for mild steel in hydrochloric acid solutionrdquoCorrosion Science vol 78 pp 260ndash268 2014
[2] S A Umoren and U M Eduok ldquoApplication of carbohydratepolymers as corrosion inhibitors for metal substrates indifferent media a reviewrdquo Carbohydrate Polymers vol 140pp 314ndash341 2016
[3] S E Karekar U D Bagale S H Sonawane B A Bhanvaseand D V Pinjari ldquoA smart coating established with encap-sulation of Zinc Molybdate centred nanocontainer for activecorrosion protection of mild steel release kinetics of corro-sion inhibitorrdquo Composite Interfaces vol 25 no 9 pp 785ndash808 2018
[4] S Abrishami R Naderi and B Ramezanzadeh ldquoFabricationand characterization of zinc acetylacetonateUrtica dioicaleaves extract complex as an effective organicinorganic hy-brid corrosion inhibitive pigment for mild steel protection inchloride solutionrdquo Applied Surface Science vol 457pp 487ndash496 2018
[5] M Krishnan H Subramanian H-U Dahms et al ldquoBiogeniccorrosion inhibitor on mild steel protection in concentratedHCl mediumrdquo Scientific Report vol 8 p 2609 2018
[6] N Bhardwaj D Prasad and R Haldhar ldquoStudy of the Aeglemarmelos as a green corrosion inhibitor for mild steel in acidicmedium experimental and theoretical approachrdquo Journal ofBio- and Tribo-Corrosion vol 4 no 4 p 61 2018
[7] T K Bhuvaneswari V S Vasantha and C JeyaprabhaldquoPongamia pinnata as a green corrosion inhibitor for mildsteel in 1N sulfuric acid mediumrdquo Silicon vol 10 no 5pp 1793ndash1807 2018
[8] M P Rai A Khanra S Rai M Srivastava and R PrakashldquoPivotal role of levoglucosenone and hexadecanoic acid frommicroalgae Chlorococcum sp for corrosion resistance on mildsteel electrochemical microstructural and theoretical anal-ysisrdquo Journal of Molecular Liquids vol 266 pp 279ndash2902018
[9] A Saxena D Prasad and R Haldhar ldquoInvestigation ofcorrosion inhibition effect and adsorption activities of Cus-cuta reflexa extract for mild steel in 05 M H2SO4rdquo Bio-electrochemistry vol 124 pp 156ndash164 2018
[10] X Zheng M Gong Q Li and L Guo ldquoCorrosion inhibitionof mild steel in sulfuric acid solution by loquat (Eriobotryajaponica Lindl) leaves extractrdquo Scientific Report vol 8p 9140 2018
[11] A Bouoidina F El-Hajjaji M Drissi et al ldquoTowards a deeperunderstanding of the anticorrosive properties of hydrazinederivatives in acid medium experimental DFT and MDsimulation assessmentrdquo Metallurgical and Materials Trans-actions A vol 49 no 10 pp 5180ndash5191 2018
[12] A Chaouiki H Lgaz I-M Chung et al ldquoUnderstandingcorrosion inhibition of mild steel in acid medium by newbenzonitriles insights from experimental and computationalstudiesrdquo Journal of Molecular Liquids vol 266 pp 603ndash6162018
[13] Y Guo Z Chen Y Zuo Y Chen W Yang and B Xu ldquoIonicliquids with two typical hydrophobic anions as acidic cor-rosion inhibitorsrdquo Journal of Molecular Liquids vol 269pp 886ndash895 2018
[14] E Naseri M Hajisafari A Kosari M Talari S Hosseinpourand A Davoodi ldquoInhibitive effect of Clopidogrel as a green
corrosion inhibitor for mild steel statistical modeling andquantum Monte Carlo simulation studiesrdquo Journal of Mo-lecular Liquids vol 269 pp 193ndash202 2018
[15] R Geethanjali and S Subhashini ldquoSynthesis and kinetics ofcorrosion inhibition of water-soluble terpolymer of polyvinylalcohol functionalized with vinyl sulfonate and p-vinyl ben-zene sulfonate in molar HClrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4 p 60 2018
[16] P Han W Li H Tian et al ldquoDesigning and fabricating oftime-depend self-strengthening inhibitor film synergisticinhibition of sodium dodecyl sulfate and 4-mercaptopyridinefor mild steelrdquo Journal of Molecular Liquids vol 268pp 425ndash437 2018
[17] X He J Mao Q Ma and Y Tang ldquoCorrosion inhibition ofperimidine derivatives for mild steel in acidic media elec-trochemical and computational studiesrdquo Journal of MolecularLiquids vol 269 pp 260ndash268 2018
[18] A A Mahmmod I A Kazarinov A A Khadom andH B Mahood ldquoExperimental and theoretical studies of mildsteel corrosion inhibition in phosphoric acid using tetrazolesderivativesrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4p 58 2018
[19] M Messali M Larouj H Lgaz et al ldquoA new schiff basederivative as an effective corrosion inhibitor for mild steel inacidic media experimental and computer simulations stud-iesrdquo Journal of Molecular Structure vol 1168 pp 39ndash48 2018
[20] A Mishra C Verma S Chauhan et al ldquoCharacterizationand corrosion inhibition performance of 5-aminopyrazolecarbonitriles towards mild steel acidic corrosionrdquo Journal ofBio- and Tribo-Corrosion vol 4 p 53 2018
[21] N Saini R Kumar H Lgaz et al ldquoMinified dose of urispasdrug as better corrosion constraint for soft steel in sulphuricacid solutionrdquo Journal of Molecular Liquids vol 269pp 371ndash380 2018
[22] K Zhang W Yang Y Chen et al ldquoEnhanced inhibitiveperformance of fluoro-substituted imidazolium-based ionicliquid for mild steel corrosion in hydrochloric acid at elevatedtemperaturerdquo Journal of Materials Science vol 53 no 20pp 14666ndash14680 2018
[23] K R Ansari M A Quraishi and A Singh ldquoCorrosion in-hibition of mild steel in hydrochloric acid by some pyridinederivatives an experimental and quantum chemical studyrdquoJournal of Industrial and Engineering Chemistry vol 25pp 89ndash98 2015
[24] L O Olasunkanmi I B Obot M M Kabanda andE E Ebenso ldquoSome quinoxalin-6-yl derivatives as corrosioninhibitors for mild steel in hydrochloric acid experimentaland theoretical studiesrdquo Journal of Physical Chemistry Cvol 119 no 28 pp 16004ndash16019 2015
[25] M Ewis S S Elkholy and M Z Esabee ldquoAntifungal efficacyof chitosan and its thiourea derivatives upon the growth ofsome sugar-beet pathogensrdquo International Journal of Bi-ological Macromolecules vol 38 no 1 pp 1ndash8 2006
[26] Z-X Tang J-Q Qian and L-E Shi ldquoCharacterizations ofimmobilized neutral lipase on chitosan nano-particlesrdquoMaterials Letters vol 61 no 1 pp 37ndash40 2007
[27] M N El-Haddad ldquoChitosan as a green inhibitor for coppercorrosion in acidic mediumrdquo International Journal of Bi-ological Macromolecules vol 55 pp 142ndash149 2013
[28] S Cheng S Chen T Liu X Chang and Y Yin ldquoCarbox-ymenthylchitosan as an ecofriendly inhibitor for mild steel in1 MHClrdquoMaterials Letters vol 61 no 14-15 pp 3276ndash32802007
International Journal of Chemical Engineering 11
[29] K Wan P Feng B Hou and Y Li ldquoEnhanced corrosioninhibition properties of carboxymethyl hydroxypropyl chi-tosan for mild steel in 10 M HCl solutionrdquo RSC Advancesvol 6 no 81 pp 77515ndash77524 2016
[30] M M Solomon H Gerengi T Kaya and S A UmorenldquoEnhanced corrosion inhibition effect of chitosan for St37 in15 H2SO4 environment by silver nanoparticlesrdquo In-ternational Journal of Biological Macromolecules vol 104pp 638ndash649 2017
[31] A M Alsabagh M Z Elsabee Y M Moustafa A Elfky andR E Morsi ldquoCorrosion inhibition efficiency of somehydrophobically modified chitosan surfactants in relation totheir surface active propertiesrdquo Egyptian Journal of Petroleumvol 23 no 4 pp 349ndash359 2014
[32] S A Umoren M J Banera T Alonso-Garcia C A Gervasiand M V Mirıfico ldquoInhibition of mild steel corrosion in HClsolution using chitosanrdquo Cellulose vol 20 no 5 pp 2529ndash2545 2013
[33] M Erna Y Eryanti and A Dahliaty ldquoModifikasi amilosa daripati tapioka dan garut menjadi amilosa asetatrdquo Jurnal PilarSains vol 7 pp 28ndash30 2008
[34] H T Pang X G Chen H J Park D S Cha andJ F Kennedy ldquoPreparation and rheological properties ofdeoxycholate-chitosan and carboxymethyl-chitosan inaqueous systemsrdquo Carbohydrate Polymers vol 69 no 3pp 419ndash425 2007
[35] K K Anupama and J Abraham ldquoElectroanalytical studies onthe corrosion inhibition behavior of guava (Psidium guajava)leaves extract on mild steel in hydrochloric acidrdquo Research onChemical Intermediates vol 39 no 9 pp 4067ndash4080 2012
[36] M E Al-Dokheily H M Kredy and R N Al-Jabery ldquoIn-hibition of copper corrosion in H2SO4 NaCl and NaOHsolutions by Citrullus colocynthis fruits extractrdquo Journal ofNatural Sciences Research vol 4 pp 60ndash73 2014
[37] M H Hussin andM J Kassim ldquoe corrosion inhibition andadsorption behavior ofUncaria gambir extract onmild steel in1M HClrdquo Materials Chemistry and Physics vol 125 no 3pp 461ndash468 2011
[38] K R Ansari M A Quraishi and A Singh ldquoIsatin derivativesas a non-toxic corrosion inhibitor for mild steel in 20H2SO4rdquo Corrosion Science vol 95 pp 62ndash70 2015
[39] B Zerga A Attayibat M Sfaira et al ldquoEffect of some tripodalbipyrazolic compounds on C38 steel corrosion in hydro-chloric acid solutionrdquo Journal of Applied Electrochemistryvol 40 no 9 pp 1575ndash1582 2010
[40] H Ashassi-Sorkhabi and S A Nabavi-Amri ldquoCorrosioninhibition of carbon steel in petroleumwater mixtures byn-containing compoundsrdquo Acta Chimica Slovenica vol 47pp 507ndash517 2000
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
higher than that of the presence of AA whilst the con-centration of C in the control specimen prior to treatmentwas lower than that of the treated specimen due to theinhibitor absorbed onto the mild steelrsquos surface e con-centration of Fe and O from the inhibitor of AA is notsignificantly different than the inhibitor of AA-CMCh(Table 2) Generally both AA and AA-CMCh inhibitorsare able to inhibit the mild steel specimen from a directattack by the Cl ion which protects the mild steel surfacefrom an aggressive environment
37Mechanismof Inhibition e adsorption of AA-blendedCMCh on mild steel can be clearly defined by consideringthe chemisorption processes e specific mechanism ofcorrosion inhibition of AA-CMCh to the surface of mildsteel coupons is detailed in the following equations
Fe + AA-CMCh⟷ Fe(AA-CMCh)ads (9)
Fe(AA-CMCh)ads⟷ Fe2++ AA-CMCh + neminus (10)
AA-CMChaq + H2Oads⟷AA-CMChads + H2Oaq
(11)
e chemisorption of AA-CMCh on mild steel isdenoted by the donor-acceptor interactions between thelone pair of the electron from the carbonyl and amine groupsof AA-CMCh with the d-orbitals of Fe e value of freeenergy from the AA-CMCh adsorption was minus33 kJmiddotmolminus1 ormore negative is confirms that the adsorption mecha-nism of the AA-CMCh on the surface of the mild steelcoupon was chemically adsorbed e inhibition of
corrosion begins by the displacement of water molecules bythe inhibitorrsquos capacity toward specific adsorption of theinhibitor on the metalrsquos surface [40]
4 Conclusions
e corrosion inhibition mechanism based on carbox-ymethyl chitosanamylose-acetate composites used to pro-tect mild steel in an acidic medium was successfullyinvestigatede AA-CMCh base inhibitor showed excellentinhibition performance in the case of mild steel in a 1MHClsolution e inhibiting efficiencies decreased in the order ofAA-CMChgtAA e inhibitor adsorptions on the mildsteelrsquos surface are chemically adsorbed while the corrosioninhibition mechanism on the mild steelrsquos surface wasspontaneous exothermal and irregular and took place dueto the formation of the Fe-chelate compound on the surfaceof the mild steel specimen e adsorption of the inhibitorson the mild steel specimen in acidic media solution com-ports with that of the Langmuir adsorption isotherm enegative values of the ∆Gads and ∆H indicated that theadsorption reaction took place spontaneously andexothermally
Data Availability
e data used to support the findings of this study areavailable from the corresponding author upon request
Conflicts of Interest
e authors declare that there are no conflicts of interestregarding the publication of this work
Acknowledgments
e authors gratefully acknowledge financial support fromthe Directorate General of Higher Education of Ministry(DIKTI) the Ministry of Research Technology and HigherEducation through a fundamental grant of the UniversitasRiau Indonesia
(c)
Figure 9 SEMEDX spectra of the mild steel surface in 1M HCl (a) AA (b) AA-CMCh blended (c) control
Table 2 Percentage atomic contents of elements measured usingthe EDX technique
Inhibitors Fe O S Cl CControl 9664 197 mdash 012 027AA 7769 2226 mdash 006 1346AA-CMCh 7761 2223 mdash 015 1649
10 International Journal of Chemical Engineering
References
[1] B Xu W Yang Y Liu X Yin W Gong and Y ChenldquoExperimental and theoretical evaluation of two pyr-idinecarboxaldehyde thiosemicarbazone compounds as cor-rosion inhibitors for mild steel in hydrochloric acid solutionrdquoCorrosion Science vol 78 pp 260ndash268 2014
[2] S A Umoren and U M Eduok ldquoApplication of carbohydratepolymers as corrosion inhibitors for metal substrates indifferent media a reviewrdquo Carbohydrate Polymers vol 140pp 314ndash341 2016
[3] S E Karekar U D Bagale S H Sonawane B A Bhanvaseand D V Pinjari ldquoA smart coating established with encap-sulation of Zinc Molybdate centred nanocontainer for activecorrosion protection of mild steel release kinetics of corro-sion inhibitorrdquo Composite Interfaces vol 25 no 9 pp 785ndash808 2018
[4] S Abrishami R Naderi and B Ramezanzadeh ldquoFabricationand characterization of zinc acetylacetonateUrtica dioicaleaves extract complex as an effective organicinorganic hy-brid corrosion inhibitive pigment for mild steel protection inchloride solutionrdquo Applied Surface Science vol 457pp 487ndash496 2018
[5] M Krishnan H Subramanian H-U Dahms et al ldquoBiogeniccorrosion inhibitor on mild steel protection in concentratedHCl mediumrdquo Scientific Report vol 8 p 2609 2018
[6] N Bhardwaj D Prasad and R Haldhar ldquoStudy of the Aeglemarmelos as a green corrosion inhibitor for mild steel in acidicmedium experimental and theoretical approachrdquo Journal ofBio- and Tribo-Corrosion vol 4 no 4 p 61 2018
[7] T K Bhuvaneswari V S Vasantha and C JeyaprabhaldquoPongamia pinnata as a green corrosion inhibitor for mildsteel in 1N sulfuric acid mediumrdquo Silicon vol 10 no 5pp 1793ndash1807 2018
[8] M P Rai A Khanra S Rai M Srivastava and R PrakashldquoPivotal role of levoglucosenone and hexadecanoic acid frommicroalgae Chlorococcum sp for corrosion resistance on mildsteel electrochemical microstructural and theoretical anal-ysisrdquo Journal of Molecular Liquids vol 266 pp 279ndash2902018
[9] A Saxena D Prasad and R Haldhar ldquoInvestigation ofcorrosion inhibition effect and adsorption activities of Cus-cuta reflexa extract for mild steel in 05 M H2SO4rdquo Bio-electrochemistry vol 124 pp 156ndash164 2018
[10] X Zheng M Gong Q Li and L Guo ldquoCorrosion inhibitionof mild steel in sulfuric acid solution by loquat (Eriobotryajaponica Lindl) leaves extractrdquo Scientific Report vol 8p 9140 2018
[11] A Bouoidina F El-Hajjaji M Drissi et al ldquoTowards a deeperunderstanding of the anticorrosive properties of hydrazinederivatives in acid medium experimental DFT and MDsimulation assessmentrdquo Metallurgical and Materials Trans-actions A vol 49 no 10 pp 5180ndash5191 2018
[12] A Chaouiki H Lgaz I-M Chung et al ldquoUnderstandingcorrosion inhibition of mild steel in acid medium by newbenzonitriles insights from experimental and computationalstudiesrdquo Journal of Molecular Liquids vol 266 pp 603ndash6162018
[13] Y Guo Z Chen Y Zuo Y Chen W Yang and B Xu ldquoIonicliquids with two typical hydrophobic anions as acidic cor-rosion inhibitorsrdquo Journal of Molecular Liquids vol 269pp 886ndash895 2018
[14] E Naseri M Hajisafari A Kosari M Talari S Hosseinpourand A Davoodi ldquoInhibitive effect of Clopidogrel as a green
corrosion inhibitor for mild steel statistical modeling andquantum Monte Carlo simulation studiesrdquo Journal of Mo-lecular Liquids vol 269 pp 193ndash202 2018
[15] R Geethanjali and S Subhashini ldquoSynthesis and kinetics ofcorrosion inhibition of water-soluble terpolymer of polyvinylalcohol functionalized with vinyl sulfonate and p-vinyl ben-zene sulfonate in molar HClrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4 p 60 2018
[16] P Han W Li H Tian et al ldquoDesigning and fabricating oftime-depend self-strengthening inhibitor film synergisticinhibition of sodium dodecyl sulfate and 4-mercaptopyridinefor mild steelrdquo Journal of Molecular Liquids vol 268pp 425ndash437 2018
[17] X He J Mao Q Ma and Y Tang ldquoCorrosion inhibition ofperimidine derivatives for mild steel in acidic media elec-trochemical and computational studiesrdquo Journal of MolecularLiquids vol 269 pp 260ndash268 2018
[18] A A Mahmmod I A Kazarinov A A Khadom andH B Mahood ldquoExperimental and theoretical studies of mildsteel corrosion inhibition in phosphoric acid using tetrazolesderivativesrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4p 58 2018
[19] M Messali M Larouj H Lgaz et al ldquoA new schiff basederivative as an effective corrosion inhibitor for mild steel inacidic media experimental and computer simulations stud-iesrdquo Journal of Molecular Structure vol 1168 pp 39ndash48 2018
[20] A Mishra C Verma S Chauhan et al ldquoCharacterizationand corrosion inhibition performance of 5-aminopyrazolecarbonitriles towards mild steel acidic corrosionrdquo Journal ofBio- and Tribo-Corrosion vol 4 p 53 2018
[21] N Saini R Kumar H Lgaz et al ldquoMinified dose of urispasdrug as better corrosion constraint for soft steel in sulphuricacid solutionrdquo Journal of Molecular Liquids vol 269pp 371ndash380 2018
[22] K Zhang W Yang Y Chen et al ldquoEnhanced inhibitiveperformance of fluoro-substituted imidazolium-based ionicliquid for mild steel corrosion in hydrochloric acid at elevatedtemperaturerdquo Journal of Materials Science vol 53 no 20pp 14666ndash14680 2018
[23] K R Ansari M A Quraishi and A Singh ldquoCorrosion in-hibition of mild steel in hydrochloric acid by some pyridinederivatives an experimental and quantum chemical studyrdquoJournal of Industrial and Engineering Chemistry vol 25pp 89ndash98 2015
[24] L O Olasunkanmi I B Obot M M Kabanda andE E Ebenso ldquoSome quinoxalin-6-yl derivatives as corrosioninhibitors for mild steel in hydrochloric acid experimentaland theoretical studiesrdquo Journal of Physical Chemistry Cvol 119 no 28 pp 16004ndash16019 2015
[25] M Ewis S S Elkholy and M Z Esabee ldquoAntifungal efficacyof chitosan and its thiourea derivatives upon the growth ofsome sugar-beet pathogensrdquo International Journal of Bi-ological Macromolecules vol 38 no 1 pp 1ndash8 2006
[26] Z-X Tang J-Q Qian and L-E Shi ldquoCharacterizations ofimmobilized neutral lipase on chitosan nano-particlesrdquoMaterials Letters vol 61 no 1 pp 37ndash40 2007
[27] M N El-Haddad ldquoChitosan as a green inhibitor for coppercorrosion in acidic mediumrdquo International Journal of Bi-ological Macromolecules vol 55 pp 142ndash149 2013
[28] S Cheng S Chen T Liu X Chang and Y Yin ldquoCarbox-ymenthylchitosan as an ecofriendly inhibitor for mild steel in1 MHClrdquoMaterials Letters vol 61 no 14-15 pp 3276ndash32802007
International Journal of Chemical Engineering 11
[29] K Wan P Feng B Hou and Y Li ldquoEnhanced corrosioninhibition properties of carboxymethyl hydroxypropyl chi-tosan for mild steel in 10 M HCl solutionrdquo RSC Advancesvol 6 no 81 pp 77515ndash77524 2016
[30] M M Solomon H Gerengi T Kaya and S A UmorenldquoEnhanced corrosion inhibition effect of chitosan for St37 in15 H2SO4 environment by silver nanoparticlesrdquo In-ternational Journal of Biological Macromolecules vol 104pp 638ndash649 2017
[31] A M Alsabagh M Z Elsabee Y M Moustafa A Elfky andR E Morsi ldquoCorrosion inhibition efficiency of somehydrophobically modified chitosan surfactants in relation totheir surface active propertiesrdquo Egyptian Journal of Petroleumvol 23 no 4 pp 349ndash359 2014
[32] S A Umoren M J Banera T Alonso-Garcia C A Gervasiand M V Mirıfico ldquoInhibition of mild steel corrosion in HClsolution using chitosanrdquo Cellulose vol 20 no 5 pp 2529ndash2545 2013
[33] M Erna Y Eryanti and A Dahliaty ldquoModifikasi amilosa daripati tapioka dan garut menjadi amilosa asetatrdquo Jurnal PilarSains vol 7 pp 28ndash30 2008
[34] H T Pang X G Chen H J Park D S Cha andJ F Kennedy ldquoPreparation and rheological properties ofdeoxycholate-chitosan and carboxymethyl-chitosan inaqueous systemsrdquo Carbohydrate Polymers vol 69 no 3pp 419ndash425 2007
[35] K K Anupama and J Abraham ldquoElectroanalytical studies onthe corrosion inhibition behavior of guava (Psidium guajava)leaves extract on mild steel in hydrochloric acidrdquo Research onChemical Intermediates vol 39 no 9 pp 4067ndash4080 2012
[36] M E Al-Dokheily H M Kredy and R N Al-Jabery ldquoIn-hibition of copper corrosion in H2SO4 NaCl and NaOHsolutions by Citrullus colocynthis fruits extractrdquo Journal ofNatural Sciences Research vol 4 pp 60ndash73 2014
[37] M H Hussin andM J Kassim ldquoe corrosion inhibition andadsorption behavior ofUncaria gambir extract onmild steel in1M HClrdquo Materials Chemistry and Physics vol 125 no 3pp 461ndash468 2011
[38] K R Ansari M A Quraishi and A Singh ldquoIsatin derivativesas a non-toxic corrosion inhibitor for mild steel in 20H2SO4rdquo Corrosion Science vol 95 pp 62ndash70 2015
[39] B Zerga A Attayibat M Sfaira et al ldquoEffect of some tripodalbipyrazolic compounds on C38 steel corrosion in hydro-chloric acid solutionrdquo Journal of Applied Electrochemistryvol 40 no 9 pp 1575ndash1582 2010
[40] H Ashassi-Sorkhabi and S A Nabavi-Amri ldquoCorrosioninhibition of carbon steel in petroleumwater mixtures byn-containing compoundsrdquo Acta Chimica Slovenica vol 47pp 507ndash517 2000
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
References
[1] B Xu W Yang Y Liu X Yin W Gong and Y ChenldquoExperimental and theoretical evaluation of two pyr-idinecarboxaldehyde thiosemicarbazone compounds as cor-rosion inhibitors for mild steel in hydrochloric acid solutionrdquoCorrosion Science vol 78 pp 260ndash268 2014
[2] S A Umoren and U M Eduok ldquoApplication of carbohydratepolymers as corrosion inhibitors for metal substrates indifferent media a reviewrdquo Carbohydrate Polymers vol 140pp 314ndash341 2016
[3] S E Karekar U D Bagale S H Sonawane B A Bhanvaseand D V Pinjari ldquoA smart coating established with encap-sulation of Zinc Molybdate centred nanocontainer for activecorrosion protection of mild steel release kinetics of corro-sion inhibitorrdquo Composite Interfaces vol 25 no 9 pp 785ndash808 2018
[4] S Abrishami R Naderi and B Ramezanzadeh ldquoFabricationand characterization of zinc acetylacetonateUrtica dioicaleaves extract complex as an effective organicinorganic hy-brid corrosion inhibitive pigment for mild steel protection inchloride solutionrdquo Applied Surface Science vol 457pp 487ndash496 2018
[5] M Krishnan H Subramanian H-U Dahms et al ldquoBiogeniccorrosion inhibitor on mild steel protection in concentratedHCl mediumrdquo Scientific Report vol 8 p 2609 2018
[6] N Bhardwaj D Prasad and R Haldhar ldquoStudy of the Aeglemarmelos as a green corrosion inhibitor for mild steel in acidicmedium experimental and theoretical approachrdquo Journal ofBio- and Tribo-Corrosion vol 4 no 4 p 61 2018
[7] T K Bhuvaneswari V S Vasantha and C JeyaprabhaldquoPongamia pinnata as a green corrosion inhibitor for mildsteel in 1N sulfuric acid mediumrdquo Silicon vol 10 no 5pp 1793ndash1807 2018
[8] M P Rai A Khanra S Rai M Srivastava and R PrakashldquoPivotal role of levoglucosenone and hexadecanoic acid frommicroalgae Chlorococcum sp for corrosion resistance on mildsteel electrochemical microstructural and theoretical anal-ysisrdquo Journal of Molecular Liquids vol 266 pp 279ndash2902018
[9] A Saxena D Prasad and R Haldhar ldquoInvestigation ofcorrosion inhibition effect and adsorption activities of Cus-cuta reflexa extract for mild steel in 05 M H2SO4rdquo Bio-electrochemistry vol 124 pp 156ndash164 2018
[10] X Zheng M Gong Q Li and L Guo ldquoCorrosion inhibitionof mild steel in sulfuric acid solution by loquat (Eriobotryajaponica Lindl) leaves extractrdquo Scientific Report vol 8p 9140 2018
[11] A Bouoidina F El-Hajjaji M Drissi et al ldquoTowards a deeperunderstanding of the anticorrosive properties of hydrazinederivatives in acid medium experimental DFT and MDsimulation assessmentrdquo Metallurgical and Materials Trans-actions A vol 49 no 10 pp 5180ndash5191 2018
[12] A Chaouiki H Lgaz I-M Chung et al ldquoUnderstandingcorrosion inhibition of mild steel in acid medium by newbenzonitriles insights from experimental and computationalstudiesrdquo Journal of Molecular Liquids vol 266 pp 603ndash6162018
[13] Y Guo Z Chen Y Zuo Y Chen W Yang and B Xu ldquoIonicliquids with two typical hydrophobic anions as acidic cor-rosion inhibitorsrdquo Journal of Molecular Liquids vol 269pp 886ndash895 2018
[14] E Naseri M Hajisafari A Kosari M Talari S Hosseinpourand A Davoodi ldquoInhibitive effect of Clopidogrel as a green
corrosion inhibitor for mild steel statistical modeling andquantum Monte Carlo simulation studiesrdquo Journal of Mo-lecular Liquids vol 269 pp 193ndash202 2018
[15] R Geethanjali and S Subhashini ldquoSynthesis and kinetics ofcorrosion inhibition of water-soluble terpolymer of polyvinylalcohol functionalized with vinyl sulfonate and p-vinyl ben-zene sulfonate in molar HClrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4 p 60 2018
[16] P Han W Li H Tian et al ldquoDesigning and fabricating oftime-depend self-strengthening inhibitor film synergisticinhibition of sodium dodecyl sulfate and 4-mercaptopyridinefor mild steelrdquo Journal of Molecular Liquids vol 268pp 425ndash437 2018
[17] X He J Mao Q Ma and Y Tang ldquoCorrosion inhibition ofperimidine derivatives for mild steel in acidic media elec-trochemical and computational studiesrdquo Journal of MolecularLiquids vol 269 pp 260ndash268 2018
[18] A A Mahmmod I A Kazarinov A A Khadom andH B Mahood ldquoExperimental and theoretical studies of mildsteel corrosion inhibition in phosphoric acid using tetrazolesderivativesrdquo Journal of Bio- and Tribo-Corrosion vol 4 no 4p 58 2018
[19] M Messali M Larouj H Lgaz et al ldquoA new schiff basederivative as an effective corrosion inhibitor for mild steel inacidic media experimental and computer simulations stud-iesrdquo Journal of Molecular Structure vol 1168 pp 39ndash48 2018
[20] A Mishra C Verma S Chauhan et al ldquoCharacterizationand corrosion inhibition performance of 5-aminopyrazolecarbonitriles towards mild steel acidic corrosionrdquo Journal ofBio- and Tribo-Corrosion vol 4 p 53 2018
[21] N Saini R Kumar H Lgaz et al ldquoMinified dose of urispasdrug as better corrosion constraint for soft steel in sulphuricacid solutionrdquo Journal of Molecular Liquids vol 269pp 371ndash380 2018
[22] K Zhang W Yang Y Chen et al ldquoEnhanced inhibitiveperformance of fluoro-substituted imidazolium-based ionicliquid for mild steel corrosion in hydrochloric acid at elevatedtemperaturerdquo Journal of Materials Science vol 53 no 20pp 14666ndash14680 2018
[23] K R Ansari M A Quraishi and A Singh ldquoCorrosion in-hibition of mild steel in hydrochloric acid by some pyridinederivatives an experimental and quantum chemical studyrdquoJournal of Industrial and Engineering Chemistry vol 25pp 89ndash98 2015
[24] L O Olasunkanmi I B Obot M M Kabanda andE E Ebenso ldquoSome quinoxalin-6-yl derivatives as corrosioninhibitors for mild steel in hydrochloric acid experimentaland theoretical studiesrdquo Journal of Physical Chemistry Cvol 119 no 28 pp 16004ndash16019 2015
[25] M Ewis S S Elkholy and M Z Esabee ldquoAntifungal efficacyof chitosan and its thiourea derivatives upon the growth ofsome sugar-beet pathogensrdquo International Journal of Bi-ological Macromolecules vol 38 no 1 pp 1ndash8 2006
[26] Z-X Tang J-Q Qian and L-E Shi ldquoCharacterizations ofimmobilized neutral lipase on chitosan nano-particlesrdquoMaterials Letters vol 61 no 1 pp 37ndash40 2007
[27] M N El-Haddad ldquoChitosan as a green inhibitor for coppercorrosion in acidic mediumrdquo International Journal of Bi-ological Macromolecules vol 55 pp 142ndash149 2013
[28] S Cheng S Chen T Liu X Chang and Y Yin ldquoCarbox-ymenthylchitosan as an ecofriendly inhibitor for mild steel in1 MHClrdquoMaterials Letters vol 61 no 14-15 pp 3276ndash32802007
International Journal of Chemical Engineering 11
[29] K Wan P Feng B Hou and Y Li ldquoEnhanced corrosioninhibition properties of carboxymethyl hydroxypropyl chi-tosan for mild steel in 10 M HCl solutionrdquo RSC Advancesvol 6 no 81 pp 77515ndash77524 2016
[30] M M Solomon H Gerengi T Kaya and S A UmorenldquoEnhanced corrosion inhibition effect of chitosan for St37 in15 H2SO4 environment by silver nanoparticlesrdquo In-ternational Journal of Biological Macromolecules vol 104pp 638ndash649 2017
[31] A M Alsabagh M Z Elsabee Y M Moustafa A Elfky andR E Morsi ldquoCorrosion inhibition efficiency of somehydrophobically modified chitosan surfactants in relation totheir surface active propertiesrdquo Egyptian Journal of Petroleumvol 23 no 4 pp 349ndash359 2014
[32] S A Umoren M J Banera T Alonso-Garcia C A Gervasiand M V Mirıfico ldquoInhibition of mild steel corrosion in HClsolution using chitosanrdquo Cellulose vol 20 no 5 pp 2529ndash2545 2013
[33] M Erna Y Eryanti and A Dahliaty ldquoModifikasi amilosa daripati tapioka dan garut menjadi amilosa asetatrdquo Jurnal PilarSains vol 7 pp 28ndash30 2008
[34] H T Pang X G Chen H J Park D S Cha andJ F Kennedy ldquoPreparation and rheological properties ofdeoxycholate-chitosan and carboxymethyl-chitosan inaqueous systemsrdquo Carbohydrate Polymers vol 69 no 3pp 419ndash425 2007
[35] K K Anupama and J Abraham ldquoElectroanalytical studies onthe corrosion inhibition behavior of guava (Psidium guajava)leaves extract on mild steel in hydrochloric acidrdquo Research onChemical Intermediates vol 39 no 9 pp 4067ndash4080 2012
[36] M E Al-Dokheily H M Kredy and R N Al-Jabery ldquoIn-hibition of copper corrosion in H2SO4 NaCl and NaOHsolutions by Citrullus colocynthis fruits extractrdquo Journal ofNatural Sciences Research vol 4 pp 60ndash73 2014
[37] M H Hussin andM J Kassim ldquoe corrosion inhibition andadsorption behavior ofUncaria gambir extract onmild steel in1M HClrdquo Materials Chemistry and Physics vol 125 no 3pp 461ndash468 2011
[38] K R Ansari M A Quraishi and A Singh ldquoIsatin derivativesas a non-toxic corrosion inhibitor for mild steel in 20H2SO4rdquo Corrosion Science vol 95 pp 62ndash70 2015
[39] B Zerga A Attayibat M Sfaira et al ldquoEffect of some tripodalbipyrazolic compounds on C38 steel corrosion in hydro-chloric acid solutionrdquo Journal of Applied Electrochemistryvol 40 no 9 pp 1575ndash1582 2010
[40] H Ashassi-Sorkhabi and S A Nabavi-Amri ldquoCorrosioninhibition of carbon steel in petroleumwater mixtures byn-containing compoundsrdquo Acta Chimica Slovenica vol 47pp 507ndash517 2000
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
[29] K Wan P Feng B Hou and Y Li ldquoEnhanced corrosioninhibition properties of carboxymethyl hydroxypropyl chi-tosan for mild steel in 10 M HCl solutionrdquo RSC Advancesvol 6 no 81 pp 77515ndash77524 2016
[30] M M Solomon H Gerengi T Kaya and S A UmorenldquoEnhanced corrosion inhibition effect of chitosan for St37 in15 H2SO4 environment by silver nanoparticlesrdquo In-ternational Journal of Biological Macromolecules vol 104pp 638ndash649 2017
[31] A M Alsabagh M Z Elsabee Y M Moustafa A Elfky andR E Morsi ldquoCorrosion inhibition efficiency of somehydrophobically modified chitosan surfactants in relation totheir surface active propertiesrdquo Egyptian Journal of Petroleumvol 23 no 4 pp 349ndash359 2014
[32] S A Umoren M J Banera T Alonso-Garcia C A Gervasiand M V Mirıfico ldquoInhibition of mild steel corrosion in HClsolution using chitosanrdquo Cellulose vol 20 no 5 pp 2529ndash2545 2013
[33] M Erna Y Eryanti and A Dahliaty ldquoModifikasi amilosa daripati tapioka dan garut menjadi amilosa asetatrdquo Jurnal PilarSains vol 7 pp 28ndash30 2008
[34] H T Pang X G Chen H J Park D S Cha andJ F Kennedy ldquoPreparation and rheological properties ofdeoxycholate-chitosan and carboxymethyl-chitosan inaqueous systemsrdquo Carbohydrate Polymers vol 69 no 3pp 419ndash425 2007
[35] K K Anupama and J Abraham ldquoElectroanalytical studies onthe corrosion inhibition behavior of guava (Psidium guajava)leaves extract on mild steel in hydrochloric acidrdquo Research onChemical Intermediates vol 39 no 9 pp 4067ndash4080 2012
[36] M E Al-Dokheily H M Kredy and R N Al-Jabery ldquoIn-hibition of copper corrosion in H2SO4 NaCl and NaOHsolutions by Citrullus colocynthis fruits extractrdquo Journal ofNatural Sciences Research vol 4 pp 60ndash73 2014
[37] M H Hussin andM J Kassim ldquoe corrosion inhibition andadsorption behavior ofUncaria gambir extract onmild steel in1M HClrdquo Materials Chemistry and Physics vol 125 no 3pp 461ndash468 2011
[38] K R Ansari M A Quraishi and A Singh ldquoIsatin derivativesas a non-toxic corrosion inhibitor for mild steel in 20H2SO4rdquo Corrosion Science vol 95 pp 62ndash70 2015
[39] B Zerga A Attayibat M Sfaira et al ldquoEffect of some tripodalbipyrazolic compounds on C38 steel corrosion in hydro-chloric acid solutionrdquo Journal of Applied Electrochemistryvol 40 no 9 pp 1575ndash1582 2010
[40] H Ashassi-Sorkhabi and S A Nabavi-Amri ldquoCorrosioninhibition of carbon steel in petroleumwater mixtures byn-containing compoundsrdquo Acta Chimica Slovenica vol 47pp 507ndash517 2000
