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Research Article Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched Polyester Polyol Matrix O. I. Medvedeva, S. S. Kambulova, O. V. Bondar, A. R. Gataulina, N. A. Ulakhovich, A. V. Gerasimov, V. G. Evtugyn, I. F. Gilmutdinov, and M. P. Kutyreva Department of Inorganic Chemistry, Kazan Federal University, 18 Kremlyovskaya St., Kazan 420008, Russia Correspondence should be addressed to M. P. Kutyreva; [email protected] Received 28 May 2017; Accepted 16 July 2017; Published 20 August 2017 Academic Editor: Enkeleda Dervishi Copyright © 2017 O. I. Medvedeva et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A series of cobalt (Co) and its oxides based nanoparticles were synthesized by using hyperbranched polyester polyol Boltorn H20 as a platform and sodium borohydride as a reducing agent. UV, FT-IR, XRD, NTA, and TEM methods were employed to obtain physicochemical characteristics of the products. e average diameter of Co nanoparticles was approximately 8.2 ± 3.4 nm. eir magnetic properties, including hysteresis loop, field-cooled, and zero field-cooled curves were investigated. e nanoparticles exhibit superparamagnetism at room temperature, accompanied by magnetic hysteresis below the blocking temperature. 1. Introduction Magnetic nanoparticles exhibit specific physical properties and are of great interest because of their prospective appli- cations in biology and medicine [1–5] for magnetic cell separation [6], magnetically controlled delivery of anticancer drugs [7, 8], magnetic resonance imaging (MRI) contrast enhancement [9, 10], and hypothermia treatment [11]. Most of these applications require chemically stable, well-dispersed, and uniform sized particles. e magnetic properties of nanoparticles are determined by many factors. e chemical composition, crystal structure and the degree of its defectiveness, morphology, and the interaction of particles with the surrounding matrix and neighboring particles play crucial role [12, 13]. It is possible to control the magnetic characteristics of materials by changing the morphology of such nanoparticles [12]. Among numer- ous magnetic nanomaterials, cobalt (Co) and its oxides based nanoparticles have attracted particular attention because of their excellent optical [14, 15], magnetic [12, 13, 16], and catalytic properties [17, 18]. For the synthesis of such compounds, the most common methods are solvent-thermal [19–21], thermolysis of the carbonyl [22] or other cobalt complexes [23], and chemical reduction of cobalt salts [24, 25]. e strong magnetic interaction between cobalt nanopar- ticles and their propensity for oxidation make it difficult to obtain stable colloids. erefore, in most cases, organic stabilizers are used to control the growth of nanoparticles and prevent the occurrence of adverse reactions [1, 26]. e nature of the stabilizer oſten determines the morphol- ogy of nanoparticles and the properties of the hybrid material. e use of polymer matrix for stabilization makes it possible to combine the unique properties of metal nanoparticles with useful properties of polymers [1]. e molecules of den- drimers and hyperbranched polymers (HBPs) with core-shell structure in comparison with linear polymers have a number of advantages [27–30]. ey have a three-dimensional struc- ture, large number of heteroatoms, functional groups, and cavities [31, 32]. Usage of HBP as a platform for cluster growth, both cluster stability and full control over size, and size distribution were achieved by simultaneously allowing access of substrates to the cluster surface. An additional advantage of HBP matrix in the synthesis of practically useful metal nanoparticles is their biosimilar topological structure and simplicity of synthesis [33, 34]. Earlier it was shown by some authors how series of magnetic cobalt (Co) nanoparticles could be stabilized by a poly-amidoamine (PAMAM) dendrimer [28], polyamine dendrimers with a trimesyl core [29], and Hindawi Journal of Nanotechnology Volume 2017, Article ID 7607658, 9 pages https://doi.org/10.1155/2017/7607658
Transcript
Page 1: Magnetic Cobalt and Cobalt Oxide Nanoparticles in ...downloads.hindawi.com/journals/jnt/2017/7607658.pdf · ResearchArticle Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched

Research ArticleMagnetic Cobalt and Cobalt Oxide Nanoparticles inHyperbranched Polyester Polyol Matrix

O I Medvedeva S S Kambulova O V Bondar A R Gataulina N A UlakhovichA V Gerasimov V G Evtugyn I F Gilmutdinov andM P Kutyreva

Department of Inorganic Chemistry Kazan Federal University 18 Kremlyovskaya St Kazan 420008 Russia

Correspondence should be addressed to M P Kutyreva mkutyrevamailru

Received 28 May 2017 Accepted 16 July 2017 Published 20 August 2017

Academic Editor Enkeleda Dervishi

Copyright copy 2017 O I Medvedeva et alThis is an open access article distributed under theCreativeCommonsAttribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

A series of cobalt (Co) and its oxides based nanoparticles were synthesized by using hyperbranched polyester polyol BoltornH20 as a platform and sodium borohydride as a reducing agent UV FT-IR XRD NTA and TEM methods were employed toobtain physicochemical characteristics of the products The average diameter of Co nanoparticles was approximately 82 plusmn 34 nmTheirmagnetic properties including hysteresis loop field-cooled and zero field-cooled curves were investigatedThe nanoparticlesexhibit superparamagnetism at room temperature accompanied by magnetic hysteresis below the blocking temperature

1 Introduction

Magnetic nanoparticles exhibit specific physical propertiesand are of great interest because of their prospective appli-cations in biology and medicine [1ndash5] for magnetic cellseparation [6] magnetically controlled delivery of anticancerdrugs [7 8] magnetic resonance imaging (MRI) contrastenhancement [9 10] andhypothermia treatment [11]Most ofthese applications require chemically stable well-dispersedand uniform sized particles

The magnetic properties of nanoparticles are determinedby many factorsThe chemical composition crystal structureand the degree of its defectiveness morphology and theinteraction of particles with the surrounding matrix andneighboring particles play crucial role [12 13] It is possible tocontrol the magnetic characteristics of materials by changingthe morphology of such nanoparticles [12] Among numer-ous magnetic nanomaterials cobalt (Co) and its oxides basednanoparticles have attracted particular attention becauseof their excellent optical [14 15] magnetic [12 13 16]and catalytic properties [17 18] For the synthesis of suchcompounds the most commonmethods are solvent-thermal[19ndash21] thermolysis of the carbonyl [22] or other cobaltcomplexes [23] and chemical reduction of cobalt salts [2425]

The strongmagnetic interaction between cobalt nanopar-ticles and their propensity for oxidation make it difficultto obtain stable colloids Therefore in most cases organicstabilizers are used to control the growth of nanoparticles andprevent the occurrence of adverse reactions [1 26]

Thenature of the stabilizer oftendetermines themorphol-ogy of nanoparticles and the properties of the hybridmaterialThe use of polymer matrix for stabilization makes it possibleto combine the unique properties of metal nanoparticles withuseful properties of polymers [1] The molecules of den-drimers and hyperbranched polymers (HBPs) with core-shellstructure in comparison with linear polymers have a numberof advantages [27ndash30] They have a three-dimensional struc-ture large number of heteroatoms functional groups andcavities [31 32]

Usage of HBP as a platform for cluster growth bothcluster stability and full control over size and size distributionwere achieved by simultaneously allowing access of substratesto the cluster surface An additional advantage of HBPmatrixin the synthesis of practically useful metal nanoparticlesis their biosimilar topological structure and simplicity ofsynthesis [33 34] Earlier it was shown by some authorshow series of magnetic cobalt (Co) nanoparticles couldbe stabilized by a poly-amidoamine (PAMAM) dendrimer[28] polyamine dendrimers with a trimesyl core [29] and

HindawiJournal of NanotechnologyVolume 2017 Article ID 7607658 9 pageshttpsdoiorg10115520177607658

2 Journal of Nanotechnology

hydroxyl-terminated PAMAM dendrimers [30] PAMAM isa highly branched macromolecule which contains interiortertiary amine groups which can effectively coordinate metalions Such metal ions may then be reduced to the encapsu-lated metal particles that are highly stable in solution Sincethe same number of chelating sites is present in all dendrimermolecules this process can yield to monodisperse metalparticles [28] However the presence of primary aminesresults in a high cytotoxicity for many cellular systems [35]Therefore for the purposes of cell sorting medical diagnosisand controlled drug delivery the strategy for the synthesisof magnetic cobalt nanoparticles is based on the use of non-toxic biosimilar and biodegradable hyperbranched polymersand dendrimers Such compounds include hyperbranchedpolyester polyols (HBPO) of various generations [36]

In this study we describe the synthesis of Co nanopar-ticles via the matrix of nontoxic hyperbranched polyesterpolyol based on 22-bis-hydroxymethyl-propionic acid

2 Materials and Methods

21 Materials The initial reagent was anhydrous salt cobalt(II) chloride (b]Cl2) (97 Alfa Aesar) Stabilizer washyperbranched polyester polyol BoltornH20 (BH20) (Sigma-Aldrich theoretically having 16 hydroxyl end groups permolecule and the average molecular weight of 1749 gmol)Sodium borohydride NaBH4 (98 Alfa Aesar) was used asa reducing agent The organic solvents such as ethanol anddiethyl ether were used as solvents for the synthesis andisolation of nanoparticles

22 Characterization Theelectronic absorption spectra wererecorded on Lambda 750 (Perkin Elmer) in the wavelengthrange from 200 to 1000 nm at 119879 = 25 plusmn 001C using atemperature-maintaining system including a cell holder flowthermostat laquoJulabo MB-5Araquo and a Peltier PTP-1 thermostatQuartz cells with a thickness of 1 cm were used for themeasurements The measurement accuracy for absorbance(119860) was plusmn1

The size concentration and movement of nanoparti-cles were determined using the NanoSight LM-10 (MalvernInstruments Ltd UK) equipped with a CMOS cameraC11440-50B with scientific image sensor FL-280 HamamatsuPhotonics (Japan) as a detector Measurements were carriedout in a special cell for organic solvents having a modifiedentry angle for the laser beam into the solution a 405 nm laser(version cd SN 2990491) and Kalrez sealing ring Contactthermometer OMEGA HH804 (Engineering IncStamfordCT USA) was used to determine the temperature in thecell during the experiment The NanoSight NTA 23 software(build 0033) was used to process the results

ATR-FT-IR spectra were recorded over the range from4000 to 400 cmminus1 using a FT-IR spectrometer Spectrum 400(Perkin Elmer) with a universal ATR accessory and a ZnSeprismThe resolution of the spectra was 1 cmminus1 and scanningwas repeated 16 times

X-ray powder diffraction (XRPD) studies of nanoparti-cles samples were made using a MiniFlex 600 diffractometer(Rigaku Japan) equipped with a DteX Ultra detector In this

experiment Cu K120572 radiation (40 kV 15mA) was used anddata was collected at room temperature in the range of 2120579from 3 to 100∘ with a step of 002∘ and exposure time at eachpoint of 024 s without sample rotation

Magnetic properties were measured by PPMS-9 (Quan-tum Design USA) equipped with vibrating sample magne-tometer (VSM) Zero field-cooled (ZFC) and field-cooled(FC) measurements were performed in 100 Oe Field depen-dencies of magnetization were measured at 5ndash300K at fieldrange from minus1 T to 1 T

Analysis of samples was carried out in a transmissionelectronmicroscopeHitachi HT7700 Exalens Sample prepa-ration was as follows 10 microliters of the suspension wasplaced on a formvarcarbon lacey 3mm copper grid anddrying was performed at room temperature After dryinggrid was placed in a transmission electron microscopeusing special holder for microanalysis Analysis was held atan accelerating voltage of 100 kV in TEM mode and theelemental analysis was carried out in STEM mode at thesame parameters using Oxford Instruments X-Max 80 TdetectorThe size and shape of hybrid NPs were estimated viaAxioVision rel48 soft

The size distribution of cobalt nanoparticles was obtainedby TEM images processing using AxioVision program ver-sion 482The size distribution curve was constructed on thebase of fivefold sampling of 400 treated nanoparticles

23 The Synthesis of Co Nanoparticles Stabilized by HBPHBP BH20 was dissolved in 30ml of 50 water-ethanolsolution (119888HBPO = 01mV) then 10ml of b]Cl2 dissolved indeionizedwater was addedThemolar ratio of Co2+ toHBPwas 4 1 8 1 10 1 12 1 and 16 1 The solution was stirredfor 12 hours and then was cooled to 4∘b After that 10mLof 03mol times Lminus1 NaBH4 solution was added dropwise withconstant stirringThe solidwas separated andwashed 2 timesby deionized water first then by ethyl alcohol dried undervacuum without heating

3 Results and Discussion

Synthesis of organic-inorganic nanocomposites was carriedout in the following way the first stage is the formation ofcomplex forms of Co2+ HBPO the second stage was thesynthesis of polymer-metal nanocomposites by the chemicalreduction method [37]

HBPO BH20 was used to stabilize cobalt nanoparticlesThe molecule of HBPO BH20 contains ester and hydroxylgroups (Figure 1) Molecules of hyperbranched polymers oflow generation (119866 = 2) as well as dendrimermolecules of lowgeneration exist in a relatively open structure [34] The stageof metal ions organization on a polymer matrix can deter-mine the morphology of organic-inorganic nanomaterialtherefore at the first stage of the work the interaction of Co2+ions with a polymer platform of HBPO was studied Featuresof the HBPO structure suggest the associates formation insolution due to intermolecular and intramolecular hydrogenbonds [34] The NTA method showed that in BH20 solutionwith a concentration of 87times 10minus5mgml there were two types

Journal of Nanotechnology 3

O

O

O

O

O

O O

O

O OH

OH

O

OHOH

O O

O

O O

OH

OHO

OH OH

O

OO

HO

O

HO

O

OHO

HO

O

OOH

O

O

OH

O

O

HO

HO

Figure 1 Structure of HBP G20 (BH20)

Con

ml E

6

152

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle size (nm)concentration

Figure 2 Concentration and size distribution from NTA measure-ments of BH20 aqueous solution

of closely related associates with a hydrodynamic diameter of150 plusmn 8 nm (Figure 2)

In the absorption spectra of the HBPO BH20 solutionthere were no absorption bands in the visible region ofthe spectrum (Figure 3) In the absorption spectrum of theaqueous solution of cobalt chloride there was an intenseabsorption band in the region of 510 nm due to the d-dtransitions of 4T1 g (F)rarr 4T1 g (P) in the [Co (H2O)6]

2+ aquaions Absorption at 290 nm was assigned to charge transferfrom the nonbonding orbital of chloride ions to half-filledd-orbitals of cobalt (II) [38] In solutions of CoCl2 BH20at different molar ratios of 119888co2+119888BH20 from 4 1 to 16 1the absorption bands intensity and the shift of the maximato 518 nm were observed for both absorption bands which

250 300 350 400 450 500 550 60000

01

02

03

04

05

2 4 6 8 10 12 14 16000001002003004005006007008

Abso

rban

ce

Abso

rban

ce

Wavenumber (nm)

(a) (b)

I2+ BH20 molar ratio

[I((2)6]2+

I4(BH20)I8(BH20)

I10(BH20)I12(BH20)I16(BH20)

Figure 3 (a) UV-vis absorption spectra of b]2+-BH20 complexwith different b]2+ BH20 molar ratio in aqueous solution (b)Spectrophotometric titration solution of BH20 by CoCl2 solution(119888BH20 = 01mM 119888CoCl2 = 01ndash16mM and 120582 = 518 nm) (b)

corresponds to the interaction of Co2+ ions with the terminalhydroxyl groups of HBPO and the formation of Co2+ BH20Spectrophotometric titration plot (Figure 3(b)) absorbanceat the maximum of 518 nm 5 levels was observed accordingto the formation of the five main complex forms (Table 1)

Nf0 analysis showed that the increase in the molarratio 119888co2+119888BH20 in aqua solution from 4 1 to 16 1leads to the increase of hydrodynamic diameter of

4 Journal of Nanotechnology

Con

ml E

6105

318

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle size (nm)concentration

(a)

Con

ml E

6

56

263

140

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle size (nm)concentration

(b)

Figure 4 Concentration and size distribution from NTA measurements of complexes Co8(BH20) (a) and Co10(BH20) (b) in aqueoussolution

Table 1 Stability constants (lg120573) hydrodynamic diameter (119889ℎ) andconcentration of complexes Co119899(BH20) in aqueous solution

Complex lg 120573 119889ℎ nmCo4(BH20) 62 96 plusmn 17

Co8(BH20) 104 105 plusmn 10

Co10(BH20) 177 140 plusmn 18263 plusmn 10

Co12(BH20) 262 123 plusmn 15168 plusmn 20

Co16(BH20) 31174 plusmn 5124 plusmn 10210 plusmn 17

associates from 96 plusmn 17 nm to 210 plusmn 17 nm and theirpolydispersity (Table 1 Figure 4 Supplementary FiguresS1 S2 see Supplementary Material available online athttpsdoiorg10115520177607658)

It can be assumed that the introduction of cobalt ionsinto the BH20 solution leads to a violation of the hydrogenbonding system followed by the destruction of the BH20associates and the formation of associates of complex formsCo119899(BH20) (119899 = 4 8 and 10) of smaller size

Comparing the data of UV-vis spectroscopy and NTAanalysis it can be assumed that an increase in the molarratio b]2+ jH20 from 4 1 to 16 1 leads to a decrease inthe proportion of coordinated hydroxylic groups of HBPOin the inner sphere of the Co2+ ion that could be indicatedby a decrease in the ldquored shiftrdquo value and an increase in thehydrodynamic diameter of Co119899(BH20) associates

Synthesis of cobalt nanoparticles (CoNPs)was carried outby the reduction of Co119899(BH20) complex forms (119899 = 4 8 1012 and 16) by sodium borohydride

2b]2+ + BH4minus + 4Xminus

997888rarr 2Co∙0 + 3B (OH)4minus + 2H2

(1)

During the reduction process for all ratios the color ofthe solution has changed from light pink (Figures 5(a) and5(d)) to black (Figures 5(b) and 5(e))

After the reduction of all complex forms according to theUVvis spectroscopy data the absorption bands disappearat 120582 = 510 nm and 302 nm characteristic for aqua ions[Co(H2O)6]

2+ During the reduction of Co8(BH20) andCo10(BH20) forms a weak absorption peak of the PPR in theregion of 260 nm appeared (Figure 6) After the reduction ofCo12(BH20) an absorption maximum appears in the regionof 274 nm characteristic of cobalt nanoparticles b]0 [3039 40] After the reduction of Co16(BH20) complex formCoNPs have appeared which had two maxima in the regionof 268 nmand 385 nm characteristic for nanoparticlesb]34[41 42]

boNPs (Co2+ HBPO= 4 1 8 1 and 10 1) samples failedto isolate quantitivelyboNPs (Co2+ HBPO = 12 1 and 16 1)samples were isolated from the solution as the black powderHoweverboNPs (16 1) have possessed less stability andwereeasily oxidized by air oxygen and the color of the powderchanged to green indicating the presence of CoO

The FR-IR spectra of BH20 boNPs (12 1) and boNPs(16 1) solids (oxidized forms) were shown in Figure 7 It wasfound that during the synthesis of CoNPs nanocomposites(12 1) the polymer matrix of HBPO did not degrade anddid not undergo significant changes The peaks at 3356 cmminus1belong to H-bonded OH 2945 cmminus1 and 2859 cmminus1 ascribedto antisymmetric and symmetric CndashH 1728 cmminus1 ascribedto H-bonded carbonyl (]bondedC=O) 1440 cm

minus1 symmetricCOO-stretching 1400 cmminus1 and 1375 cmminus1 CH2 deformationantisymmetric and symmetric 1305 cmminus1 deformation H-bonded 1220 cmminus1 and 1120 cmminus1 C-O and O-C stretchingester and 1040 cmminus1 CO(-OH) stretching hydroxyl in BH20[34] At FR-IR spectra boNPs (12 1) and boNPs (16 1) aband at 1645 cmminus1 appeared which could be associated withthe formation and crystallization of a by-product NaBO3 incavities ofHBPO [43] An increase in the absorption intensity

Journal of Nanotechnology 5

(a) (b) (c) (d) (e) (f)

Figure 5 Color transformation of Co2+-BH20 solution before (a d) and after (b e) reduction the collection of CoNPs by a magnet (c f)

300 400 500 600 700

02

04

06

08

10

12

14

16

18

Wavenumber (nm)

Abso

rban

ce

(a)

(b)

(c)

(d)

Figure 6 UVvis spectra of aqueous solutions containing CoNPsafter Co8(BH20) reduction (a) CoNPs after Co10(BH20) reduction(b) CoNPs after Co12(BH20) reduction (c) and CoNPs afterCo16(BH20) reduction (d)

3500 3000 2500 2000 1500 10000002040608101214161820

Abso

rban

ce

(a)

(b)

(c)

Wavenumber (=Gminus1

)

Figure 7 FT-IR spectra of HBP BH20 (a) boNPs (12 1) (b) andboNPs (16 1) (c)

0 20 40 60 80 100

Rela

tive i

nten

sity

2 (degree)

(a)

(b)

Figure 8 XRD powder pattern of CoNPs (12 1) (a) and CoNPs(16 1) (b)

at 3356 cmminus1 could be associated with the increasing numberof hydrogen bonds Moreover during the synthesis of boNPs(16 1) a partial destruction of ester bonds took place Thatfact was indicated by a decrease in signal strength at 17201305 1220 and 1120 cmminus1 and increase of peak intensity at2878 cmminus1 [35 43]

XRD pattern indicated the amorphous structure of prod-uctsThe broadening of the diffraction peaks ofboNPs (12 1)(Figure 8(a)) and boNPs (16 1) (Figure 8(b)) suggests thepresence of small particles [28 29] The diffraction peaks at2120579 = 194∘ and 21∘ refer to reflections of the HBPO matrixand a maximum at 479∘ and a wide reflex with a maximumat 7960 can be attributed to the metallic Co∘ in which thealternatingmicrodomainswith cubic andhexagonal packingswere observed

The magnetic curves field dependence of magnetizationof CoNPs (12 1) wasmeasured at 5 10 50 100 200 and 360K(Figure 9) The magnetization curves of the sample CoNPs(12 1)measured at 5 10 and 50K had visible hysteresis loops[2 3]The loops are closed and symmetrical versus the originof the coordinate system formThemagnetization under fieldof 10 kOe was 587 emugminus1 The remanence magnetization

6 Journal of NanotechnologyM

(em

ugr

)

H (kOe)

6

3

0

minus3

minus6minus10 minus5 0 5 10

5 +

300 +

Figure 9 Hysteresis loops obtained at 5 K and 300K for CoNPs(12 1)

M(e

mu

g)

T (K)

FCZFC

10

08

06

04

02

000 100 200 300

H = 100

Figure 10 ZFCndashFC curves measured in an applied field of 100Oefor CoNPs (12 1)

value (Mr) was 206 emugminus1 and the coercivity was 323OeThemagnetization curves showedneither hysteresis nor coer-civity The saturated magnetization values (Ms) measuredat 100 200 and 300K were 456 416 and 362 emugminus1respectively

The temperature dependence of the magnetization wasmeasured under magnetic field of 100Oe from 5 to 300Kusing zero field-cooled (ZFC) and field-cooled (FC) proce-dure This measurement allowed determining the blockingtemperature of CoNPs The obtained ZFCndashFC curves ofCoNPs (12 1) nanocomposite are displayed in Figure 10Magnetization of CoNPs increased with the increase of thetemperature that is shown at the ZFC curve The wide

Table 2 Hydrodynamic diameter (119889ℎ) from NTAmeasurements ofnanoparticles boNPs in aqueous solution

boNPs 119889ℎ nmboNPs (8 1) 106 plusmn 15

boNPs (10 1) 107 plusmn 20

boNPs (12 1) 112 plusmn 10

boNPs (16 1) 123 plusmn 18

peak was observed at 100ndash170P with maximum at 140KThe maximum temperature is called blocking temperatureTb The thermal energy becomes comparable to the energybarrier of magnetic anisotropy for spin reorientation atblocking temperature

At a temperature of 300K discrepancy between the ZFCand FC curves was observed A sufficiently high temper-ature which characterizes the temperature of irreversiblemagnetic changes is associated with a wide size distributionof nanoparticles in the sample and strong interaction betweenthe particles [2]

The variations in size determined by different methodswere due to the fact that thesemethods rely ondifferent physi-cal principles andor detectionmethods In addition electronmicroscopy probes dry particles that is the metallic coreonly whereas the NTA probe the hydrodynamic diameterwhich is always larger The size predicted by TEM analysiswas found to be smaller than predicted by NTA analysis

According to the NTA method hydrodynamic diameterof CoNPs nanocomposite rose from 106 plusmn 15 to 123 plusmn 18 nm(Figure 11 Supplementary Figures S3 S4) with increase ofmolar ratio Co2+ BH20 however it was smaller than thediameter of respective complex forms of Co119899(BH20) (Table 2Supplementary Table S5)

The successful formation of CoNPswas first confirmed byTEM studies Figure 12 shows the TEMmicrographs and sizedistributions of CoNPs nanoparticles (12 1) obtained usingHBPO BH20 as a stabilizer The nanoparticles CoNPs (12 1)were approximately spherical with size about 82 plusmn 34 nmParticles have aggregated easily probably because of the highmobility of the particles as well as the magnetic interactionbetween the particles

4 Conclusions

Thus for the first time the process of preorganization of Co2+ions on the platform of a hyperbranched polyester polyolof the second generation was studied and the significantcomplex forms of Co119899(BH20) existing in an aqueous solutionwere determined The cobalt nanoparticles were synthesizedby the chemical reduction method in solution at variousmolar ratios of CoCl2 HBPO It is shown that an increase inthe concentration of Co2+ ions in the polymer matrix at thepreorganization stage leads to an increase in the proportion ofoxide forms in the composition of the nanoparticles CoNPssynthesized at the CoCl2 HBPO molar ratio of 12 1 havepossessed the highest stability They had spherical shapemoreover metallic nanoclusters of cobalt with a diameterof 82 plusmn 34 nm were in the polymer shell of the stabilizer

Journal of Nanotechnology 7

Con

ml E

6

162

57

79

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(a)

Con

ml E

6

43

57

9867

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(b)

Figure 11 Concentration and size distribution from NTA measurements of CoNPs (8 1) (a) and CoNPs (12 1) (b) in aqueous solution

500 HG

(a)

100 HG

(b)

3-4 5-6 7-8 9-10 11-12 13-14 15-160

5

10

15

20

25

30

Freq

uenc

y (

)

Particle size (nm)

Average particle size 82 plusmn 34 HG

(c)

Cps (

eV)

(keV)2 4 6 8

C

Co

Co

Co

Cu

Cu

Na

O

CuCl

04

03

02

01

0

(d)

Figure 12 TEM images CoNPs (12 1) (a b) corresponding particle-size distribution of CoNPs (c) and EDS spectrum (d) for the areacorresponding to (a) The Cu signals come from TEM grids

8 Journal of Nanotechnology

It has been proved that the polymer-composite nanoparti-cles CoBH20 (12 1) exhibit magnetic properties includingsuperparamagnetic properties at room temperature whichwill allow them to be used for further development of MRIdiagnostic systems as well as targeted drug delivery system

Conflicts of Interest

The authors O I Medvedeva S S Kambulova O V BondarA R Gataulina N A Ulakhovich A V Gerasimov V GEvtugyn I F Gilmutdinov and M P Kutyreva declare thatthere are no conflicts of interest regarding the publication ofthis paper

Acknowledgments

The magnetic measurements were carried out at the FederalCenter of Shared Facilities of Kazan Federal UniversityMicroscopy studies were carried out at the InterdisciplinaryCenter of AnalyticalMicroscopy of Kazan Federal UniversityThework is performed according to the Russian GovernmentProgram of Competitive Growth of Kazan Federal Univer-sity

References

[1] L Merhari Hybrid Nanocomposites for Nanotechnology Elec-tronic Optical Magnetic and Biomedical Applications SpringerBoston MA USA 2009

[2] S Gubin Magnetic Nanoparticles WILEY-VCH Verlag GmbHamp Co KGaA 2009

[3] Q A Pankhurst J Connolly S K Jones and J Dobson ldquoAppli-cations of magnetic nanoparticles in biomedicinerdquo Journal ofPhysics D Applied Physics vol 36 no 13 pp R167ndashR181 2003

[4] W H Suh Y H Suh and G D Stucky Nano Today vol 4 pp27ndash36 2009

[5] T K Indira and R K Lakshmi International Journal of Phar-maceutical Sciences and Nanotechnology vol 3 pp 1035ndash10422010

[6] P P Waifalkar S B Parit A D Chougale S C Sahoo P SPatil and P B Patil ldquoImmobilization of invertase on chitosancoated 120574-Fe2O3 magnetic nanoparticles to facilitate magneticseparationrdquo Journal of Colloid and Interface Science vol 482 pp159ndash164 2016

[7] J Chomoucka J Drbohlavova D Huska V Adam R Kizekand J Hubalek ldquoMagnetic nanoparticles and targeted drugdeliveringrdquo Pharmacological Research vol 62 no 2 pp 144ndash149 2010

[8] A M Nystrom and B Fadeel ldquoSafety assessment of nanoma-terials implications for nanomedicinerdquo Journal of ControlledRelease vol 161 no 2 pp 403ndash408 2012

[9] P Padmanabhan A Kumar S Kumar R K Chaudhary and BGulyas ldquoNanoparticles in practice formolecular-imaging appli-cations An overviewrdquoActa Biomaterialia vol 41 pp 1ndash16 2016

[10] R S Chaughule S Purushotham and R V Ramanujan ldquoMag-netic Nanoparticles as Contrast Agents forMagnetic ResonanceImagingrdquo Proceedings of the National Academy of Sciences IndiaSection A Physical Sciences vol 82 no 3 pp 257ndash268 2012

[11] J Verma S Lal and C J F van Noorden ldquoNanoparticles forhyperthermic therapy synthesis strategies and applications in

glioblastomardquo International Journal of Nanomedicine vol 9 no1 pp 2863ndash2877 2014

[12] N Shatrova A Yudin V Levina et al ldquoElaboration char-acterization and magnetic properties of cobalt nanoparticlessynthesized by ultrasonic spray pyrolysis followed by hydrogenreductionrdquoMaterials Research Bulletin vol 86 pp 80ndash87 2017

[13] H Shokrollahi and L Avazpour ldquoInfluence of intrinsic param-eters on the particle size of magnetic spinel nanoparticlessynthesized by wet chemical methodsrdquo Particuology vol 26 pp32ndash39 2016

[14] S Gopinath K Sivakumar B Karthikeyen C Ragupathi andR Sundaram ldquoStructural morphological optical and magneticproperties of Co3O4 nanoparticles prepared by conventionalmethodrdquo Physica E Low-Dimensional Systems and Nanostruc-tures vol 81 pp 66ndash70 2016

[15] L Pan L Li and C Yo ldquoSynthesis of hexagonal Co3O4 and Ag

Co3O4 composite nanosheets and their electrocatalytic perfor-mancesrdquo Journal of Cluster Science vol 24 no 4 pp 1001ndash10102013

[16] H T Yang Y K Su C M Shen T Z Yang and H J GaoldquoSynthesis and magnetic properties of 120576-cobalt nanoparticlesrdquoSurface and Interface Analysis vol 36 no 2 pp 155ndash160 2004

[17] Y Dong G Wang P Jiang A Zhang L Yue and X ZhangldquoCatalytic ozonation of phenol in aqueous solution by Co3O4nanoparticlesrdquo Bulletin of the Korean Chemical Society vol 31no 10 pp 2830ndash2834 2010

[18] Y Liang Y Li HWang et al ldquoCo3O4 nanocrystals on grapheneas a synergistic catalyst for oxygen reduction reactionrdquo NatureMaterials vol 10 no 10 pp 780ndash786 2011

[19] F Moro S V Tang F Tuna and E Lester ldquoDetection ofparandashantiferromagnetic transition in Bi2Fe4O9 powders bymeans of microwave absorption measurementsrdquo Journal ofMagnetism and Magnetic Materials vol 348 pp 17ndash21 2013

[20] J Park X Shen and GWang ldquoSolvothermal synthesis and gas-sensing performance of Co3O4 hollow nanospheresrdquo Sensorsand Actuators B Chemical vol 136 no 2 pp 494ndash498 2009

[21] Y Xu CWang Y Sun G Zhang and D Gao ldquoFabrication andcharacterization of nearly monodisperse Co3O4 nanospheresrdquoMaterials Letters vol 64 no 11 pp 1275ndash1278 2010

[22] H Bonnemann W Brijoux R Brinkmann et al ldquoA size-selective synthesis of air stable colloidal magnetic cobalt nano-particlesrdquo Inorganica Chimica Acta vol 350 pp 617ndash624 2003

[23] M Edrissi and A R Keshavarz ldquoSynthesis of cobalt chromitenanoparticles by thermolysis of mixed Cr3+ and Co2+ chelatesof 2-mercaptopyridin N-Oxiderdquo Nano-Micro Letters vol 4 no2 pp 83ndash89 2012

[24] S A Novopashin M A Serebryakova and S Y Khmel ldquoMeth-ods of magnetic fluid synthesis (review)rdquo Thermophysics andAeromechanics vol 22 no 4 pp 397ndash412 2015

[25] S A Usami ldquoSynthesis and Characterization of Cobalt Nano-particlesUsingHydrazine andCitricAcidrdquo Journal of Nanotech-nology vol 2014 Article ID 525193 6 pages 2014

[26] J P Rao P Gruenberg and K E Geckeler ldquoMagnetic zero-valent metal polymer nanoparticles Current trends scope andperspectivesrdquo Progress in Polymer Science vol 40 pp 138ndash1472015

[27] M Zhao L Sun and R M Crooks ldquoPreparation of Cu nan-oclusters within dendrimer templatesrdquo Journal of the AmericanChemical Society vol 120 no 19 pp 4877-4878 1998

Journal of Nanotechnology 9

[28] H Kavas Z Durmus E Tanriverdi M Senel H Sozeri andA Baykal ldquoFabrication and characterization of dendrimer-encapsulated monometallic Co nanoparticlesrdquo Journal of Alloysand Compounds vol 509 no 17 pp 5341ndash5348 2011

[29] H-X Wu C-X Zhang L Jin H Yang and S-P YangldquoPreparation and magnetic properties of cobalt nanoparticleswith dendrimers as templatesrdquoMaterials Chemistry and Physicsvol 121 no 1-2 pp 342ndash348 2010

[30] K Aranishi Q-L Zhu and Q Xu ldquoDendrimer-EncapsulatedCobalt Nanoparticles as High-Performance Catalysts for theHydrolysis of Ammonia Boranerdquo Chem Cat Chem vol 6 no5 pp 1375ndash1379 2014

[31] K InoueK Prog Polym Sci vol 25 pp 453ndash571 2000[32] B I Voit and A Lederer ldquoHyperbranched and highly branched

polymer architectures-synthetic strategies andmajor character-ization aspectsrdquo Chemical Reviews vol 109 no 11 pp 5924ndash5973 2009

[33] E Zagar and J Grdadolnik ldquoAn infrared spectroscopic study ofH-bond network in hyperbranched polyester polyolrdquo Journal ofMolecular Structure vol 658 no 3 pp 143ndash152 2003

[34] E Zagar and M Zigon ldquoAliphatic hyperbranched polyestersbased on 22-bis(methylol)propionic acidmdashDetermination ofstructure solution and bulk propertiesrdquo Progress in PolymerScience vol 36 no 1 pp 53ndash88 2011

[35] R Arote T-H Kim Y-K Hwang et al ldquoA biodegradablepoly(ester amine) based on polycaprolactone and polyethylen-imine as a gene carrierrdquo Biomaterials vol 28 pp 735ndash744 2007

[36] L M Bronstein and Z B Shifrina ldquoNanoparticles in den-drimers From synthesis to applicationrdquo Nanotechnologies inRussia vol 4 no 9-10 pp 576ndash608 2009

[37] R A Ahmadi F Hasanvand G Bruno H A Rudbari SAmani and J Beilstein ldquoSynthesis Spectroscopy andMagneticCharacterization of Copper(II) and Cobalt(II) Complexes with2-Amino-5-bromopyridine as Ligandrdquo ISRN Inorganic Chem-istry vol 2013 Article ID 426712 7 pages 2013

[38] P Petkova and V Nedkov ldquoBehavior of Co2+ cations in theaqueous and alcoholic solution of CoCl26H2Ordquo Acta PhysicaPolonica A vol 123 no 2 pp 207-208 2013

[39] O Metin and S Ozkar ldquoWater soluble nickel(0) and cobalt(0)nanoclusters stabilized by poly(4-styrenesulfonic acid-co-maleic acid) Highly active durable and cost effective catalystsin hydrogen generation from the hydrolysis of ammoniaboranerdquo International Journal of Hydrogen Energy vol 36 no2 pp 1424ndash1432 2011

[40] S Karahan and S Ozkar ldquoPoly(4-styrenesulfonic acid-co-maleic acid) stabilized cobalt(0) nanoparticles A cost-effectiveand magnetically recoverable catalyst in hydrogen generationfrom the hydrolysis of hydrazine boranerdquo International Journalof Hydrogen Energy vol 40 no 5 pp 2255ndash2265 2015

[41] LMAlrehaily JM JosephMC BiesingerDAGuzonas andJ CWren ldquoGamma-radiolysis-assisted cobalt oxide nanoparti-cle formationrdquo Physical Chemistry Chemical Physics vol 15 no3 pp 1014ndash1024 2013

[42] M Yarestani A D Khalaji A Rohani and D Das ldquoHydrother-mal synthesis of cobalt oxide nanoparticles Its optical andmagnetic propertiesrdquo Journal of Sciences Islamic Republic ofIran vol 25 no 4 pp 339ndash343 2014

[43] F A Miller and C H Wilkins ldquoInfrared spectra and charac-teristic frequencies of inorganic ions their use in qualitativeanalysisrdquo Analytical Chemistry vol 24 no 8 pp 1253ndash12941952

Submit your manuscripts athttpswwwhindawicom

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Page 2: Magnetic Cobalt and Cobalt Oxide Nanoparticles in ...downloads.hindawi.com/journals/jnt/2017/7607658.pdf · ResearchArticle Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched

2 Journal of Nanotechnology

hydroxyl-terminated PAMAM dendrimers [30] PAMAM isa highly branched macromolecule which contains interiortertiary amine groups which can effectively coordinate metalions Such metal ions may then be reduced to the encapsu-lated metal particles that are highly stable in solution Sincethe same number of chelating sites is present in all dendrimermolecules this process can yield to monodisperse metalparticles [28] However the presence of primary aminesresults in a high cytotoxicity for many cellular systems [35]Therefore for the purposes of cell sorting medical diagnosisand controlled drug delivery the strategy for the synthesisof magnetic cobalt nanoparticles is based on the use of non-toxic biosimilar and biodegradable hyperbranched polymersand dendrimers Such compounds include hyperbranchedpolyester polyols (HBPO) of various generations [36]

In this study we describe the synthesis of Co nanopar-ticles via the matrix of nontoxic hyperbranched polyesterpolyol based on 22-bis-hydroxymethyl-propionic acid

2 Materials and Methods

21 Materials The initial reagent was anhydrous salt cobalt(II) chloride (b]Cl2) (97 Alfa Aesar) Stabilizer washyperbranched polyester polyol BoltornH20 (BH20) (Sigma-Aldrich theoretically having 16 hydroxyl end groups permolecule and the average molecular weight of 1749 gmol)Sodium borohydride NaBH4 (98 Alfa Aesar) was used asa reducing agent The organic solvents such as ethanol anddiethyl ether were used as solvents for the synthesis andisolation of nanoparticles

22 Characterization Theelectronic absorption spectra wererecorded on Lambda 750 (Perkin Elmer) in the wavelengthrange from 200 to 1000 nm at 119879 = 25 plusmn 001C using atemperature-maintaining system including a cell holder flowthermostat laquoJulabo MB-5Araquo and a Peltier PTP-1 thermostatQuartz cells with a thickness of 1 cm were used for themeasurements The measurement accuracy for absorbance(119860) was plusmn1

The size concentration and movement of nanoparti-cles were determined using the NanoSight LM-10 (MalvernInstruments Ltd UK) equipped with a CMOS cameraC11440-50B with scientific image sensor FL-280 HamamatsuPhotonics (Japan) as a detector Measurements were carriedout in a special cell for organic solvents having a modifiedentry angle for the laser beam into the solution a 405 nm laser(version cd SN 2990491) and Kalrez sealing ring Contactthermometer OMEGA HH804 (Engineering IncStamfordCT USA) was used to determine the temperature in thecell during the experiment The NanoSight NTA 23 software(build 0033) was used to process the results

ATR-FT-IR spectra were recorded over the range from4000 to 400 cmminus1 using a FT-IR spectrometer Spectrum 400(Perkin Elmer) with a universal ATR accessory and a ZnSeprismThe resolution of the spectra was 1 cmminus1 and scanningwas repeated 16 times

X-ray powder diffraction (XRPD) studies of nanoparti-cles samples were made using a MiniFlex 600 diffractometer(Rigaku Japan) equipped with a DteX Ultra detector In this

experiment Cu K120572 radiation (40 kV 15mA) was used anddata was collected at room temperature in the range of 2120579from 3 to 100∘ with a step of 002∘ and exposure time at eachpoint of 024 s without sample rotation

Magnetic properties were measured by PPMS-9 (Quan-tum Design USA) equipped with vibrating sample magne-tometer (VSM) Zero field-cooled (ZFC) and field-cooled(FC) measurements were performed in 100 Oe Field depen-dencies of magnetization were measured at 5ndash300K at fieldrange from minus1 T to 1 T

Analysis of samples was carried out in a transmissionelectronmicroscopeHitachi HT7700 Exalens Sample prepa-ration was as follows 10 microliters of the suspension wasplaced on a formvarcarbon lacey 3mm copper grid anddrying was performed at room temperature After dryinggrid was placed in a transmission electron microscopeusing special holder for microanalysis Analysis was held atan accelerating voltage of 100 kV in TEM mode and theelemental analysis was carried out in STEM mode at thesame parameters using Oxford Instruments X-Max 80 TdetectorThe size and shape of hybrid NPs were estimated viaAxioVision rel48 soft

The size distribution of cobalt nanoparticles was obtainedby TEM images processing using AxioVision program ver-sion 482The size distribution curve was constructed on thebase of fivefold sampling of 400 treated nanoparticles

23 The Synthesis of Co Nanoparticles Stabilized by HBPHBP BH20 was dissolved in 30ml of 50 water-ethanolsolution (119888HBPO = 01mV) then 10ml of b]Cl2 dissolved indeionizedwater was addedThemolar ratio of Co2+ toHBPwas 4 1 8 1 10 1 12 1 and 16 1 The solution was stirredfor 12 hours and then was cooled to 4∘b After that 10mLof 03mol times Lminus1 NaBH4 solution was added dropwise withconstant stirringThe solidwas separated andwashed 2 timesby deionized water first then by ethyl alcohol dried undervacuum without heating

3 Results and Discussion

Synthesis of organic-inorganic nanocomposites was carriedout in the following way the first stage is the formation ofcomplex forms of Co2+ HBPO the second stage was thesynthesis of polymer-metal nanocomposites by the chemicalreduction method [37]

HBPO BH20 was used to stabilize cobalt nanoparticlesThe molecule of HBPO BH20 contains ester and hydroxylgroups (Figure 1) Molecules of hyperbranched polymers oflow generation (119866 = 2) as well as dendrimermolecules of lowgeneration exist in a relatively open structure [34] The stageof metal ions organization on a polymer matrix can deter-mine the morphology of organic-inorganic nanomaterialtherefore at the first stage of the work the interaction of Co2+ions with a polymer platform of HBPO was studied Featuresof the HBPO structure suggest the associates formation insolution due to intermolecular and intramolecular hydrogenbonds [34] The NTA method showed that in BH20 solutionwith a concentration of 87times 10minus5mgml there were two types

Journal of Nanotechnology 3

O

O

O

O

O

O O

O

O OH

OH

O

OHOH

O O

O

O O

OH

OHO

OH OH

O

OO

HO

O

HO

O

OHO

HO

O

OOH

O

O

OH

O

O

HO

HO

Figure 1 Structure of HBP G20 (BH20)

Con

ml E

6

152

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle size (nm)concentration

Figure 2 Concentration and size distribution from NTA measure-ments of BH20 aqueous solution

of closely related associates with a hydrodynamic diameter of150 plusmn 8 nm (Figure 2)

In the absorption spectra of the HBPO BH20 solutionthere were no absorption bands in the visible region ofthe spectrum (Figure 3) In the absorption spectrum of theaqueous solution of cobalt chloride there was an intenseabsorption band in the region of 510 nm due to the d-dtransitions of 4T1 g (F)rarr 4T1 g (P) in the [Co (H2O)6]

2+ aquaions Absorption at 290 nm was assigned to charge transferfrom the nonbonding orbital of chloride ions to half-filledd-orbitals of cobalt (II) [38] In solutions of CoCl2 BH20at different molar ratios of 119888co2+119888BH20 from 4 1 to 16 1the absorption bands intensity and the shift of the maximato 518 nm were observed for both absorption bands which

250 300 350 400 450 500 550 60000

01

02

03

04

05

2 4 6 8 10 12 14 16000001002003004005006007008

Abso

rban

ce

Abso

rban

ce

Wavenumber (nm)

(a) (b)

I2+ BH20 molar ratio

[I((2)6]2+

I4(BH20)I8(BH20)

I10(BH20)I12(BH20)I16(BH20)

Figure 3 (a) UV-vis absorption spectra of b]2+-BH20 complexwith different b]2+ BH20 molar ratio in aqueous solution (b)Spectrophotometric titration solution of BH20 by CoCl2 solution(119888BH20 = 01mM 119888CoCl2 = 01ndash16mM and 120582 = 518 nm) (b)

corresponds to the interaction of Co2+ ions with the terminalhydroxyl groups of HBPO and the formation of Co2+ BH20Spectrophotometric titration plot (Figure 3(b)) absorbanceat the maximum of 518 nm 5 levels was observed accordingto the formation of the five main complex forms (Table 1)

Nf0 analysis showed that the increase in the molarratio 119888co2+119888BH20 in aqua solution from 4 1 to 16 1leads to the increase of hydrodynamic diameter of

4 Journal of Nanotechnology

Con

ml E

6105

318

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle size (nm)concentration

(a)

Con

ml E

6

56

263

140

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle size (nm)concentration

(b)

Figure 4 Concentration and size distribution from NTA measurements of complexes Co8(BH20) (a) and Co10(BH20) (b) in aqueoussolution

Table 1 Stability constants (lg120573) hydrodynamic diameter (119889ℎ) andconcentration of complexes Co119899(BH20) in aqueous solution

Complex lg 120573 119889ℎ nmCo4(BH20) 62 96 plusmn 17

Co8(BH20) 104 105 plusmn 10

Co10(BH20) 177 140 plusmn 18263 plusmn 10

Co12(BH20) 262 123 plusmn 15168 plusmn 20

Co16(BH20) 31174 plusmn 5124 plusmn 10210 plusmn 17

associates from 96 plusmn 17 nm to 210 plusmn 17 nm and theirpolydispersity (Table 1 Figure 4 Supplementary FiguresS1 S2 see Supplementary Material available online athttpsdoiorg10115520177607658)

It can be assumed that the introduction of cobalt ionsinto the BH20 solution leads to a violation of the hydrogenbonding system followed by the destruction of the BH20associates and the formation of associates of complex formsCo119899(BH20) (119899 = 4 8 and 10) of smaller size

Comparing the data of UV-vis spectroscopy and NTAanalysis it can be assumed that an increase in the molarratio b]2+ jH20 from 4 1 to 16 1 leads to a decrease inthe proportion of coordinated hydroxylic groups of HBPOin the inner sphere of the Co2+ ion that could be indicatedby a decrease in the ldquored shiftrdquo value and an increase in thehydrodynamic diameter of Co119899(BH20) associates

Synthesis of cobalt nanoparticles (CoNPs)was carried outby the reduction of Co119899(BH20) complex forms (119899 = 4 8 1012 and 16) by sodium borohydride

2b]2+ + BH4minus + 4Xminus

997888rarr 2Co∙0 + 3B (OH)4minus + 2H2

(1)

During the reduction process for all ratios the color ofthe solution has changed from light pink (Figures 5(a) and5(d)) to black (Figures 5(b) and 5(e))

After the reduction of all complex forms according to theUVvis spectroscopy data the absorption bands disappearat 120582 = 510 nm and 302 nm characteristic for aqua ions[Co(H2O)6]

2+ During the reduction of Co8(BH20) andCo10(BH20) forms a weak absorption peak of the PPR in theregion of 260 nm appeared (Figure 6) After the reduction ofCo12(BH20) an absorption maximum appears in the regionof 274 nm characteristic of cobalt nanoparticles b]0 [3039 40] After the reduction of Co16(BH20) complex formCoNPs have appeared which had two maxima in the regionof 268 nmand 385 nm characteristic for nanoparticlesb]34[41 42]

boNPs (Co2+ HBPO= 4 1 8 1 and 10 1) samples failedto isolate quantitivelyboNPs (Co2+ HBPO = 12 1 and 16 1)samples were isolated from the solution as the black powderHoweverboNPs (16 1) have possessed less stability andwereeasily oxidized by air oxygen and the color of the powderchanged to green indicating the presence of CoO

The FR-IR spectra of BH20 boNPs (12 1) and boNPs(16 1) solids (oxidized forms) were shown in Figure 7 It wasfound that during the synthesis of CoNPs nanocomposites(12 1) the polymer matrix of HBPO did not degrade anddid not undergo significant changes The peaks at 3356 cmminus1belong to H-bonded OH 2945 cmminus1 and 2859 cmminus1 ascribedto antisymmetric and symmetric CndashH 1728 cmminus1 ascribedto H-bonded carbonyl (]bondedC=O) 1440 cm

minus1 symmetricCOO-stretching 1400 cmminus1 and 1375 cmminus1 CH2 deformationantisymmetric and symmetric 1305 cmminus1 deformation H-bonded 1220 cmminus1 and 1120 cmminus1 C-O and O-C stretchingester and 1040 cmminus1 CO(-OH) stretching hydroxyl in BH20[34] At FR-IR spectra boNPs (12 1) and boNPs (16 1) aband at 1645 cmminus1 appeared which could be associated withthe formation and crystallization of a by-product NaBO3 incavities ofHBPO [43] An increase in the absorption intensity

Journal of Nanotechnology 5

(a) (b) (c) (d) (e) (f)

Figure 5 Color transformation of Co2+-BH20 solution before (a d) and after (b e) reduction the collection of CoNPs by a magnet (c f)

300 400 500 600 700

02

04

06

08

10

12

14

16

18

Wavenumber (nm)

Abso

rban

ce

(a)

(b)

(c)

(d)

Figure 6 UVvis spectra of aqueous solutions containing CoNPsafter Co8(BH20) reduction (a) CoNPs after Co10(BH20) reduction(b) CoNPs after Co12(BH20) reduction (c) and CoNPs afterCo16(BH20) reduction (d)

3500 3000 2500 2000 1500 10000002040608101214161820

Abso

rban

ce

(a)

(b)

(c)

Wavenumber (=Gminus1

)

Figure 7 FT-IR spectra of HBP BH20 (a) boNPs (12 1) (b) andboNPs (16 1) (c)

0 20 40 60 80 100

Rela

tive i

nten

sity

2 (degree)

(a)

(b)

Figure 8 XRD powder pattern of CoNPs (12 1) (a) and CoNPs(16 1) (b)

at 3356 cmminus1 could be associated with the increasing numberof hydrogen bonds Moreover during the synthesis of boNPs(16 1) a partial destruction of ester bonds took place Thatfact was indicated by a decrease in signal strength at 17201305 1220 and 1120 cmminus1 and increase of peak intensity at2878 cmminus1 [35 43]

XRD pattern indicated the amorphous structure of prod-uctsThe broadening of the diffraction peaks ofboNPs (12 1)(Figure 8(a)) and boNPs (16 1) (Figure 8(b)) suggests thepresence of small particles [28 29] The diffraction peaks at2120579 = 194∘ and 21∘ refer to reflections of the HBPO matrixand a maximum at 479∘ and a wide reflex with a maximumat 7960 can be attributed to the metallic Co∘ in which thealternatingmicrodomainswith cubic andhexagonal packingswere observed

The magnetic curves field dependence of magnetizationof CoNPs (12 1) wasmeasured at 5 10 50 100 200 and 360K(Figure 9) The magnetization curves of the sample CoNPs(12 1)measured at 5 10 and 50K had visible hysteresis loops[2 3]The loops are closed and symmetrical versus the originof the coordinate system formThemagnetization under fieldof 10 kOe was 587 emugminus1 The remanence magnetization

6 Journal of NanotechnologyM

(em

ugr

)

H (kOe)

6

3

0

minus3

minus6minus10 minus5 0 5 10

5 +

300 +

Figure 9 Hysteresis loops obtained at 5 K and 300K for CoNPs(12 1)

M(e

mu

g)

T (K)

FCZFC

10

08

06

04

02

000 100 200 300

H = 100

Figure 10 ZFCndashFC curves measured in an applied field of 100Oefor CoNPs (12 1)

value (Mr) was 206 emugminus1 and the coercivity was 323OeThemagnetization curves showedneither hysteresis nor coer-civity The saturated magnetization values (Ms) measuredat 100 200 and 300K were 456 416 and 362 emugminus1respectively

The temperature dependence of the magnetization wasmeasured under magnetic field of 100Oe from 5 to 300Kusing zero field-cooled (ZFC) and field-cooled (FC) proce-dure This measurement allowed determining the blockingtemperature of CoNPs The obtained ZFCndashFC curves ofCoNPs (12 1) nanocomposite are displayed in Figure 10Magnetization of CoNPs increased with the increase of thetemperature that is shown at the ZFC curve The wide

Table 2 Hydrodynamic diameter (119889ℎ) from NTAmeasurements ofnanoparticles boNPs in aqueous solution

boNPs 119889ℎ nmboNPs (8 1) 106 plusmn 15

boNPs (10 1) 107 plusmn 20

boNPs (12 1) 112 plusmn 10

boNPs (16 1) 123 plusmn 18

peak was observed at 100ndash170P with maximum at 140KThe maximum temperature is called blocking temperatureTb The thermal energy becomes comparable to the energybarrier of magnetic anisotropy for spin reorientation atblocking temperature

At a temperature of 300K discrepancy between the ZFCand FC curves was observed A sufficiently high temper-ature which characterizes the temperature of irreversiblemagnetic changes is associated with a wide size distributionof nanoparticles in the sample and strong interaction betweenthe particles [2]

The variations in size determined by different methodswere due to the fact that thesemethods rely ondifferent physi-cal principles andor detectionmethods In addition electronmicroscopy probes dry particles that is the metallic coreonly whereas the NTA probe the hydrodynamic diameterwhich is always larger The size predicted by TEM analysiswas found to be smaller than predicted by NTA analysis

According to the NTA method hydrodynamic diameterof CoNPs nanocomposite rose from 106 plusmn 15 to 123 plusmn 18 nm(Figure 11 Supplementary Figures S3 S4) with increase ofmolar ratio Co2+ BH20 however it was smaller than thediameter of respective complex forms of Co119899(BH20) (Table 2Supplementary Table S5)

The successful formation of CoNPswas first confirmed byTEM studies Figure 12 shows the TEMmicrographs and sizedistributions of CoNPs nanoparticles (12 1) obtained usingHBPO BH20 as a stabilizer The nanoparticles CoNPs (12 1)were approximately spherical with size about 82 plusmn 34 nmParticles have aggregated easily probably because of the highmobility of the particles as well as the magnetic interactionbetween the particles

4 Conclusions

Thus for the first time the process of preorganization of Co2+ions on the platform of a hyperbranched polyester polyolof the second generation was studied and the significantcomplex forms of Co119899(BH20) existing in an aqueous solutionwere determined The cobalt nanoparticles were synthesizedby the chemical reduction method in solution at variousmolar ratios of CoCl2 HBPO It is shown that an increase inthe concentration of Co2+ ions in the polymer matrix at thepreorganization stage leads to an increase in the proportion ofoxide forms in the composition of the nanoparticles CoNPssynthesized at the CoCl2 HBPO molar ratio of 12 1 havepossessed the highest stability They had spherical shapemoreover metallic nanoclusters of cobalt with a diameterof 82 plusmn 34 nm were in the polymer shell of the stabilizer

Journal of Nanotechnology 7

Con

ml E

6

162

57

79

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(a)

Con

ml E

6

43

57

9867

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(b)

Figure 11 Concentration and size distribution from NTA measurements of CoNPs (8 1) (a) and CoNPs (12 1) (b) in aqueous solution

500 HG

(a)

100 HG

(b)

3-4 5-6 7-8 9-10 11-12 13-14 15-160

5

10

15

20

25

30

Freq

uenc

y (

)

Particle size (nm)

Average particle size 82 plusmn 34 HG

(c)

Cps (

eV)

(keV)2 4 6 8

C

Co

Co

Co

Cu

Cu

Na

O

CuCl

04

03

02

01

0

(d)

Figure 12 TEM images CoNPs (12 1) (a b) corresponding particle-size distribution of CoNPs (c) and EDS spectrum (d) for the areacorresponding to (a) The Cu signals come from TEM grids

8 Journal of Nanotechnology

It has been proved that the polymer-composite nanoparti-cles CoBH20 (12 1) exhibit magnetic properties includingsuperparamagnetic properties at room temperature whichwill allow them to be used for further development of MRIdiagnostic systems as well as targeted drug delivery system

Conflicts of Interest

The authors O I Medvedeva S S Kambulova O V BondarA R Gataulina N A Ulakhovich A V Gerasimov V GEvtugyn I F Gilmutdinov and M P Kutyreva declare thatthere are no conflicts of interest regarding the publication ofthis paper

Acknowledgments

The magnetic measurements were carried out at the FederalCenter of Shared Facilities of Kazan Federal UniversityMicroscopy studies were carried out at the InterdisciplinaryCenter of AnalyticalMicroscopy of Kazan Federal UniversityThework is performed according to the Russian GovernmentProgram of Competitive Growth of Kazan Federal Univer-sity

References

[1] L Merhari Hybrid Nanocomposites for Nanotechnology Elec-tronic Optical Magnetic and Biomedical Applications SpringerBoston MA USA 2009

[2] S Gubin Magnetic Nanoparticles WILEY-VCH Verlag GmbHamp Co KGaA 2009

[3] Q A Pankhurst J Connolly S K Jones and J Dobson ldquoAppli-cations of magnetic nanoparticles in biomedicinerdquo Journal ofPhysics D Applied Physics vol 36 no 13 pp R167ndashR181 2003

[4] W H Suh Y H Suh and G D Stucky Nano Today vol 4 pp27ndash36 2009

[5] T K Indira and R K Lakshmi International Journal of Phar-maceutical Sciences and Nanotechnology vol 3 pp 1035ndash10422010

[6] P P Waifalkar S B Parit A D Chougale S C Sahoo P SPatil and P B Patil ldquoImmobilization of invertase on chitosancoated 120574-Fe2O3 magnetic nanoparticles to facilitate magneticseparationrdquo Journal of Colloid and Interface Science vol 482 pp159ndash164 2016

[7] J Chomoucka J Drbohlavova D Huska V Adam R Kizekand J Hubalek ldquoMagnetic nanoparticles and targeted drugdeliveringrdquo Pharmacological Research vol 62 no 2 pp 144ndash149 2010

[8] A M Nystrom and B Fadeel ldquoSafety assessment of nanoma-terials implications for nanomedicinerdquo Journal of ControlledRelease vol 161 no 2 pp 403ndash408 2012

[9] P Padmanabhan A Kumar S Kumar R K Chaudhary and BGulyas ldquoNanoparticles in practice formolecular-imaging appli-cations An overviewrdquoActa Biomaterialia vol 41 pp 1ndash16 2016

[10] R S Chaughule S Purushotham and R V Ramanujan ldquoMag-netic Nanoparticles as Contrast Agents forMagnetic ResonanceImagingrdquo Proceedings of the National Academy of Sciences IndiaSection A Physical Sciences vol 82 no 3 pp 257ndash268 2012

[11] J Verma S Lal and C J F van Noorden ldquoNanoparticles forhyperthermic therapy synthesis strategies and applications in

glioblastomardquo International Journal of Nanomedicine vol 9 no1 pp 2863ndash2877 2014

[12] N Shatrova A Yudin V Levina et al ldquoElaboration char-acterization and magnetic properties of cobalt nanoparticlessynthesized by ultrasonic spray pyrolysis followed by hydrogenreductionrdquoMaterials Research Bulletin vol 86 pp 80ndash87 2017

[13] H Shokrollahi and L Avazpour ldquoInfluence of intrinsic param-eters on the particle size of magnetic spinel nanoparticlessynthesized by wet chemical methodsrdquo Particuology vol 26 pp32ndash39 2016

[14] S Gopinath K Sivakumar B Karthikeyen C Ragupathi andR Sundaram ldquoStructural morphological optical and magneticproperties of Co3O4 nanoparticles prepared by conventionalmethodrdquo Physica E Low-Dimensional Systems and Nanostruc-tures vol 81 pp 66ndash70 2016

[15] L Pan L Li and C Yo ldquoSynthesis of hexagonal Co3O4 and Ag

Co3O4 composite nanosheets and their electrocatalytic perfor-mancesrdquo Journal of Cluster Science vol 24 no 4 pp 1001ndash10102013

[16] H T Yang Y K Su C M Shen T Z Yang and H J GaoldquoSynthesis and magnetic properties of 120576-cobalt nanoparticlesrdquoSurface and Interface Analysis vol 36 no 2 pp 155ndash160 2004

[17] Y Dong G Wang P Jiang A Zhang L Yue and X ZhangldquoCatalytic ozonation of phenol in aqueous solution by Co3O4nanoparticlesrdquo Bulletin of the Korean Chemical Society vol 31no 10 pp 2830ndash2834 2010

[18] Y Liang Y Li HWang et al ldquoCo3O4 nanocrystals on grapheneas a synergistic catalyst for oxygen reduction reactionrdquo NatureMaterials vol 10 no 10 pp 780ndash786 2011

[19] F Moro S V Tang F Tuna and E Lester ldquoDetection ofparandashantiferromagnetic transition in Bi2Fe4O9 powders bymeans of microwave absorption measurementsrdquo Journal ofMagnetism and Magnetic Materials vol 348 pp 17ndash21 2013

[20] J Park X Shen and GWang ldquoSolvothermal synthesis and gas-sensing performance of Co3O4 hollow nanospheresrdquo Sensorsand Actuators B Chemical vol 136 no 2 pp 494ndash498 2009

[21] Y Xu CWang Y Sun G Zhang and D Gao ldquoFabrication andcharacterization of nearly monodisperse Co3O4 nanospheresrdquoMaterials Letters vol 64 no 11 pp 1275ndash1278 2010

[22] H Bonnemann W Brijoux R Brinkmann et al ldquoA size-selective synthesis of air stable colloidal magnetic cobalt nano-particlesrdquo Inorganica Chimica Acta vol 350 pp 617ndash624 2003

[23] M Edrissi and A R Keshavarz ldquoSynthesis of cobalt chromitenanoparticles by thermolysis of mixed Cr3+ and Co2+ chelatesof 2-mercaptopyridin N-Oxiderdquo Nano-Micro Letters vol 4 no2 pp 83ndash89 2012

[24] S A Novopashin M A Serebryakova and S Y Khmel ldquoMeth-ods of magnetic fluid synthesis (review)rdquo Thermophysics andAeromechanics vol 22 no 4 pp 397ndash412 2015

[25] S A Usami ldquoSynthesis and Characterization of Cobalt Nano-particlesUsingHydrazine andCitricAcidrdquo Journal of Nanotech-nology vol 2014 Article ID 525193 6 pages 2014

[26] J P Rao P Gruenberg and K E Geckeler ldquoMagnetic zero-valent metal polymer nanoparticles Current trends scope andperspectivesrdquo Progress in Polymer Science vol 40 pp 138ndash1472015

[27] M Zhao L Sun and R M Crooks ldquoPreparation of Cu nan-oclusters within dendrimer templatesrdquo Journal of the AmericanChemical Society vol 120 no 19 pp 4877-4878 1998

Journal of Nanotechnology 9

[28] H Kavas Z Durmus E Tanriverdi M Senel H Sozeri andA Baykal ldquoFabrication and characterization of dendrimer-encapsulated monometallic Co nanoparticlesrdquo Journal of Alloysand Compounds vol 509 no 17 pp 5341ndash5348 2011

[29] H-X Wu C-X Zhang L Jin H Yang and S-P YangldquoPreparation and magnetic properties of cobalt nanoparticleswith dendrimers as templatesrdquoMaterials Chemistry and Physicsvol 121 no 1-2 pp 342ndash348 2010

[30] K Aranishi Q-L Zhu and Q Xu ldquoDendrimer-EncapsulatedCobalt Nanoparticles as High-Performance Catalysts for theHydrolysis of Ammonia Boranerdquo Chem Cat Chem vol 6 no5 pp 1375ndash1379 2014

[31] K InoueK Prog Polym Sci vol 25 pp 453ndash571 2000[32] B I Voit and A Lederer ldquoHyperbranched and highly branched

polymer architectures-synthetic strategies andmajor character-ization aspectsrdquo Chemical Reviews vol 109 no 11 pp 5924ndash5973 2009

[33] E Zagar and J Grdadolnik ldquoAn infrared spectroscopic study ofH-bond network in hyperbranched polyester polyolrdquo Journal ofMolecular Structure vol 658 no 3 pp 143ndash152 2003

[34] E Zagar and M Zigon ldquoAliphatic hyperbranched polyestersbased on 22-bis(methylol)propionic acidmdashDetermination ofstructure solution and bulk propertiesrdquo Progress in PolymerScience vol 36 no 1 pp 53ndash88 2011

[35] R Arote T-H Kim Y-K Hwang et al ldquoA biodegradablepoly(ester amine) based on polycaprolactone and polyethylen-imine as a gene carrierrdquo Biomaterials vol 28 pp 735ndash744 2007

[36] L M Bronstein and Z B Shifrina ldquoNanoparticles in den-drimers From synthesis to applicationrdquo Nanotechnologies inRussia vol 4 no 9-10 pp 576ndash608 2009

[37] R A Ahmadi F Hasanvand G Bruno H A Rudbari SAmani and J Beilstein ldquoSynthesis Spectroscopy andMagneticCharacterization of Copper(II) and Cobalt(II) Complexes with2-Amino-5-bromopyridine as Ligandrdquo ISRN Inorganic Chem-istry vol 2013 Article ID 426712 7 pages 2013

[38] P Petkova and V Nedkov ldquoBehavior of Co2+ cations in theaqueous and alcoholic solution of CoCl26H2Ordquo Acta PhysicaPolonica A vol 123 no 2 pp 207-208 2013

[39] O Metin and S Ozkar ldquoWater soluble nickel(0) and cobalt(0)nanoclusters stabilized by poly(4-styrenesulfonic acid-co-maleic acid) Highly active durable and cost effective catalystsin hydrogen generation from the hydrolysis of ammoniaboranerdquo International Journal of Hydrogen Energy vol 36 no2 pp 1424ndash1432 2011

[40] S Karahan and S Ozkar ldquoPoly(4-styrenesulfonic acid-co-maleic acid) stabilized cobalt(0) nanoparticles A cost-effectiveand magnetically recoverable catalyst in hydrogen generationfrom the hydrolysis of hydrazine boranerdquo International Journalof Hydrogen Energy vol 40 no 5 pp 2255ndash2265 2015

[41] LMAlrehaily JM JosephMC BiesingerDAGuzonas andJ CWren ldquoGamma-radiolysis-assisted cobalt oxide nanoparti-cle formationrdquo Physical Chemistry Chemical Physics vol 15 no3 pp 1014ndash1024 2013

[42] M Yarestani A D Khalaji A Rohani and D Das ldquoHydrother-mal synthesis of cobalt oxide nanoparticles Its optical andmagnetic propertiesrdquo Journal of Sciences Islamic Republic ofIran vol 25 no 4 pp 339ndash343 2014

[43] F A Miller and C H Wilkins ldquoInfrared spectra and charac-teristic frequencies of inorganic ions their use in qualitativeanalysisrdquo Analytical Chemistry vol 24 no 8 pp 1253ndash12941952

Submit your manuscripts athttpswwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

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Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Page 3: Magnetic Cobalt and Cobalt Oxide Nanoparticles in ...downloads.hindawi.com/journals/jnt/2017/7607658.pdf · ResearchArticle Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched

Journal of Nanotechnology 3

O

O

O

O

O

O O

O

O OH

OH

O

OHOH

O O

O

O O

OH

OHO

OH OH

O

OO

HO

O

HO

O

OHO

HO

O

OOH

O

O

OH

O

O

HO

HO

Figure 1 Structure of HBP G20 (BH20)

Con

ml E

6

152

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle size (nm)concentration

Figure 2 Concentration and size distribution from NTA measure-ments of BH20 aqueous solution

of closely related associates with a hydrodynamic diameter of150 plusmn 8 nm (Figure 2)

In the absorption spectra of the HBPO BH20 solutionthere were no absorption bands in the visible region ofthe spectrum (Figure 3) In the absorption spectrum of theaqueous solution of cobalt chloride there was an intenseabsorption band in the region of 510 nm due to the d-dtransitions of 4T1 g (F)rarr 4T1 g (P) in the [Co (H2O)6]

2+ aquaions Absorption at 290 nm was assigned to charge transferfrom the nonbonding orbital of chloride ions to half-filledd-orbitals of cobalt (II) [38] In solutions of CoCl2 BH20at different molar ratios of 119888co2+119888BH20 from 4 1 to 16 1the absorption bands intensity and the shift of the maximato 518 nm were observed for both absorption bands which

250 300 350 400 450 500 550 60000

01

02

03

04

05

2 4 6 8 10 12 14 16000001002003004005006007008

Abso

rban

ce

Abso

rban

ce

Wavenumber (nm)

(a) (b)

I2+ BH20 molar ratio

[I((2)6]2+

I4(BH20)I8(BH20)

I10(BH20)I12(BH20)I16(BH20)

Figure 3 (a) UV-vis absorption spectra of b]2+-BH20 complexwith different b]2+ BH20 molar ratio in aqueous solution (b)Spectrophotometric titration solution of BH20 by CoCl2 solution(119888BH20 = 01mM 119888CoCl2 = 01ndash16mM and 120582 = 518 nm) (b)

corresponds to the interaction of Co2+ ions with the terminalhydroxyl groups of HBPO and the formation of Co2+ BH20Spectrophotometric titration plot (Figure 3(b)) absorbanceat the maximum of 518 nm 5 levels was observed accordingto the formation of the five main complex forms (Table 1)

Nf0 analysis showed that the increase in the molarratio 119888co2+119888BH20 in aqua solution from 4 1 to 16 1leads to the increase of hydrodynamic diameter of

4 Journal of Nanotechnology

Con

ml E

6105

318

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle size (nm)concentration

(a)

Con

ml E

6

56

263

140

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle size (nm)concentration

(b)

Figure 4 Concentration and size distribution from NTA measurements of complexes Co8(BH20) (a) and Co10(BH20) (b) in aqueoussolution

Table 1 Stability constants (lg120573) hydrodynamic diameter (119889ℎ) andconcentration of complexes Co119899(BH20) in aqueous solution

Complex lg 120573 119889ℎ nmCo4(BH20) 62 96 plusmn 17

Co8(BH20) 104 105 plusmn 10

Co10(BH20) 177 140 plusmn 18263 plusmn 10

Co12(BH20) 262 123 plusmn 15168 plusmn 20

Co16(BH20) 31174 plusmn 5124 plusmn 10210 plusmn 17

associates from 96 plusmn 17 nm to 210 plusmn 17 nm and theirpolydispersity (Table 1 Figure 4 Supplementary FiguresS1 S2 see Supplementary Material available online athttpsdoiorg10115520177607658)

It can be assumed that the introduction of cobalt ionsinto the BH20 solution leads to a violation of the hydrogenbonding system followed by the destruction of the BH20associates and the formation of associates of complex formsCo119899(BH20) (119899 = 4 8 and 10) of smaller size

Comparing the data of UV-vis spectroscopy and NTAanalysis it can be assumed that an increase in the molarratio b]2+ jH20 from 4 1 to 16 1 leads to a decrease inthe proportion of coordinated hydroxylic groups of HBPOin the inner sphere of the Co2+ ion that could be indicatedby a decrease in the ldquored shiftrdquo value and an increase in thehydrodynamic diameter of Co119899(BH20) associates

Synthesis of cobalt nanoparticles (CoNPs)was carried outby the reduction of Co119899(BH20) complex forms (119899 = 4 8 1012 and 16) by sodium borohydride

2b]2+ + BH4minus + 4Xminus

997888rarr 2Co∙0 + 3B (OH)4minus + 2H2

(1)

During the reduction process for all ratios the color ofthe solution has changed from light pink (Figures 5(a) and5(d)) to black (Figures 5(b) and 5(e))

After the reduction of all complex forms according to theUVvis spectroscopy data the absorption bands disappearat 120582 = 510 nm and 302 nm characteristic for aqua ions[Co(H2O)6]

2+ During the reduction of Co8(BH20) andCo10(BH20) forms a weak absorption peak of the PPR in theregion of 260 nm appeared (Figure 6) After the reduction ofCo12(BH20) an absorption maximum appears in the regionof 274 nm characteristic of cobalt nanoparticles b]0 [3039 40] After the reduction of Co16(BH20) complex formCoNPs have appeared which had two maxima in the regionof 268 nmand 385 nm characteristic for nanoparticlesb]34[41 42]

boNPs (Co2+ HBPO= 4 1 8 1 and 10 1) samples failedto isolate quantitivelyboNPs (Co2+ HBPO = 12 1 and 16 1)samples were isolated from the solution as the black powderHoweverboNPs (16 1) have possessed less stability andwereeasily oxidized by air oxygen and the color of the powderchanged to green indicating the presence of CoO

The FR-IR spectra of BH20 boNPs (12 1) and boNPs(16 1) solids (oxidized forms) were shown in Figure 7 It wasfound that during the synthesis of CoNPs nanocomposites(12 1) the polymer matrix of HBPO did not degrade anddid not undergo significant changes The peaks at 3356 cmminus1belong to H-bonded OH 2945 cmminus1 and 2859 cmminus1 ascribedto antisymmetric and symmetric CndashH 1728 cmminus1 ascribedto H-bonded carbonyl (]bondedC=O) 1440 cm

minus1 symmetricCOO-stretching 1400 cmminus1 and 1375 cmminus1 CH2 deformationantisymmetric and symmetric 1305 cmminus1 deformation H-bonded 1220 cmminus1 and 1120 cmminus1 C-O and O-C stretchingester and 1040 cmminus1 CO(-OH) stretching hydroxyl in BH20[34] At FR-IR spectra boNPs (12 1) and boNPs (16 1) aband at 1645 cmminus1 appeared which could be associated withthe formation and crystallization of a by-product NaBO3 incavities ofHBPO [43] An increase in the absorption intensity

Journal of Nanotechnology 5

(a) (b) (c) (d) (e) (f)

Figure 5 Color transformation of Co2+-BH20 solution before (a d) and after (b e) reduction the collection of CoNPs by a magnet (c f)

300 400 500 600 700

02

04

06

08

10

12

14

16

18

Wavenumber (nm)

Abso

rban

ce

(a)

(b)

(c)

(d)

Figure 6 UVvis spectra of aqueous solutions containing CoNPsafter Co8(BH20) reduction (a) CoNPs after Co10(BH20) reduction(b) CoNPs after Co12(BH20) reduction (c) and CoNPs afterCo16(BH20) reduction (d)

3500 3000 2500 2000 1500 10000002040608101214161820

Abso

rban

ce

(a)

(b)

(c)

Wavenumber (=Gminus1

)

Figure 7 FT-IR spectra of HBP BH20 (a) boNPs (12 1) (b) andboNPs (16 1) (c)

0 20 40 60 80 100

Rela

tive i

nten

sity

2 (degree)

(a)

(b)

Figure 8 XRD powder pattern of CoNPs (12 1) (a) and CoNPs(16 1) (b)

at 3356 cmminus1 could be associated with the increasing numberof hydrogen bonds Moreover during the synthesis of boNPs(16 1) a partial destruction of ester bonds took place Thatfact was indicated by a decrease in signal strength at 17201305 1220 and 1120 cmminus1 and increase of peak intensity at2878 cmminus1 [35 43]

XRD pattern indicated the amorphous structure of prod-uctsThe broadening of the diffraction peaks ofboNPs (12 1)(Figure 8(a)) and boNPs (16 1) (Figure 8(b)) suggests thepresence of small particles [28 29] The diffraction peaks at2120579 = 194∘ and 21∘ refer to reflections of the HBPO matrixand a maximum at 479∘ and a wide reflex with a maximumat 7960 can be attributed to the metallic Co∘ in which thealternatingmicrodomainswith cubic andhexagonal packingswere observed

The magnetic curves field dependence of magnetizationof CoNPs (12 1) wasmeasured at 5 10 50 100 200 and 360K(Figure 9) The magnetization curves of the sample CoNPs(12 1)measured at 5 10 and 50K had visible hysteresis loops[2 3]The loops are closed and symmetrical versus the originof the coordinate system formThemagnetization under fieldof 10 kOe was 587 emugminus1 The remanence magnetization

6 Journal of NanotechnologyM

(em

ugr

)

H (kOe)

6

3

0

minus3

minus6minus10 minus5 0 5 10

5 +

300 +

Figure 9 Hysteresis loops obtained at 5 K and 300K for CoNPs(12 1)

M(e

mu

g)

T (K)

FCZFC

10

08

06

04

02

000 100 200 300

H = 100

Figure 10 ZFCndashFC curves measured in an applied field of 100Oefor CoNPs (12 1)

value (Mr) was 206 emugminus1 and the coercivity was 323OeThemagnetization curves showedneither hysteresis nor coer-civity The saturated magnetization values (Ms) measuredat 100 200 and 300K were 456 416 and 362 emugminus1respectively

The temperature dependence of the magnetization wasmeasured under magnetic field of 100Oe from 5 to 300Kusing zero field-cooled (ZFC) and field-cooled (FC) proce-dure This measurement allowed determining the blockingtemperature of CoNPs The obtained ZFCndashFC curves ofCoNPs (12 1) nanocomposite are displayed in Figure 10Magnetization of CoNPs increased with the increase of thetemperature that is shown at the ZFC curve The wide

Table 2 Hydrodynamic diameter (119889ℎ) from NTAmeasurements ofnanoparticles boNPs in aqueous solution

boNPs 119889ℎ nmboNPs (8 1) 106 plusmn 15

boNPs (10 1) 107 plusmn 20

boNPs (12 1) 112 plusmn 10

boNPs (16 1) 123 plusmn 18

peak was observed at 100ndash170P with maximum at 140KThe maximum temperature is called blocking temperatureTb The thermal energy becomes comparable to the energybarrier of magnetic anisotropy for spin reorientation atblocking temperature

At a temperature of 300K discrepancy between the ZFCand FC curves was observed A sufficiently high temper-ature which characterizes the temperature of irreversiblemagnetic changes is associated with a wide size distributionof nanoparticles in the sample and strong interaction betweenthe particles [2]

The variations in size determined by different methodswere due to the fact that thesemethods rely ondifferent physi-cal principles andor detectionmethods In addition electronmicroscopy probes dry particles that is the metallic coreonly whereas the NTA probe the hydrodynamic diameterwhich is always larger The size predicted by TEM analysiswas found to be smaller than predicted by NTA analysis

According to the NTA method hydrodynamic diameterof CoNPs nanocomposite rose from 106 plusmn 15 to 123 plusmn 18 nm(Figure 11 Supplementary Figures S3 S4) with increase ofmolar ratio Co2+ BH20 however it was smaller than thediameter of respective complex forms of Co119899(BH20) (Table 2Supplementary Table S5)

The successful formation of CoNPswas first confirmed byTEM studies Figure 12 shows the TEMmicrographs and sizedistributions of CoNPs nanoparticles (12 1) obtained usingHBPO BH20 as a stabilizer The nanoparticles CoNPs (12 1)were approximately spherical with size about 82 plusmn 34 nmParticles have aggregated easily probably because of the highmobility of the particles as well as the magnetic interactionbetween the particles

4 Conclusions

Thus for the first time the process of preorganization of Co2+ions on the platform of a hyperbranched polyester polyolof the second generation was studied and the significantcomplex forms of Co119899(BH20) existing in an aqueous solutionwere determined The cobalt nanoparticles were synthesizedby the chemical reduction method in solution at variousmolar ratios of CoCl2 HBPO It is shown that an increase inthe concentration of Co2+ ions in the polymer matrix at thepreorganization stage leads to an increase in the proportion ofoxide forms in the composition of the nanoparticles CoNPssynthesized at the CoCl2 HBPO molar ratio of 12 1 havepossessed the highest stability They had spherical shapemoreover metallic nanoclusters of cobalt with a diameterof 82 plusmn 34 nm were in the polymer shell of the stabilizer

Journal of Nanotechnology 7

Con

ml E

6

162

57

79

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(a)

Con

ml E

6

43

57

9867

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(b)

Figure 11 Concentration and size distribution from NTA measurements of CoNPs (8 1) (a) and CoNPs (12 1) (b) in aqueous solution

500 HG

(a)

100 HG

(b)

3-4 5-6 7-8 9-10 11-12 13-14 15-160

5

10

15

20

25

30

Freq

uenc

y (

)

Particle size (nm)

Average particle size 82 plusmn 34 HG

(c)

Cps (

eV)

(keV)2 4 6 8

C

Co

Co

Co

Cu

Cu

Na

O

CuCl

04

03

02

01

0

(d)

Figure 12 TEM images CoNPs (12 1) (a b) corresponding particle-size distribution of CoNPs (c) and EDS spectrum (d) for the areacorresponding to (a) The Cu signals come from TEM grids

8 Journal of Nanotechnology

It has been proved that the polymer-composite nanoparti-cles CoBH20 (12 1) exhibit magnetic properties includingsuperparamagnetic properties at room temperature whichwill allow them to be used for further development of MRIdiagnostic systems as well as targeted drug delivery system

Conflicts of Interest

The authors O I Medvedeva S S Kambulova O V BondarA R Gataulina N A Ulakhovich A V Gerasimov V GEvtugyn I F Gilmutdinov and M P Kutyreva declare thatthere are no conflicts of interest regarding the publication ofthis paper

Acknowledgments

The magnetic measurements were carried out at the FederalCenter of Shared Facilities of Kazan Federal UniversityMicroscopy studies were carried out at the InterdisciplinaryCenter of AnalyticalMicroscopy of Kazan Federal UniversityThework is performed according to the Russian GovernmentProgram of Competitive Growth of Kazan Federal Univer-sity

References

[1] L Merhari Hybrid Nanocomposites for Nanotechnology Elec-tronic Optical Magnetic and Biomedical Applications SpringerBoston MA USA 2009

[2] S Gubin Magnetic Nanoparticles WILEY-VCH Verlag GmbHamp Co KGaA 2009

[3] Q A Pankhurst J Connolly S K Jones and J Dobson ldquoAppli-cations of magnetic nanoparticles in biomedicinerdquo Journal ofPhysics D Applied Physics vol 36 no 13 pp R167ndashR181 2003

[4] W H Suh Y H Suh and G D Stucky Nano Today vol 4 pp27ndash36 2009

[5] T K Indira and R K Lakshmi International Journal of Phar-maceutical Sciences and Nanotechnology vol 3 pp 1035ndash10422010

[6] P P Waifalkar S B Parit A D Chougale S C Sahoo P SPatil and P B Patil ldquoImmobilization of invertase on chitosancoated 120574-Fe2O3 magnetic nanoparticles to facilitate magneticseparationrdquo Journal of Colloid and Interface Science vol 482 pp159ndash164 2016

[7] J Chomoucka J Drbohlavova D Huska V Adam R Kizekand J Hubalek ldquoMagnetic nanoparticles and targeted drugdeliveringrdquo Pharmacological Research vol 62 no 2 pp 144ndash149 2010

[8] A M Nystrom and B Fadeel ldquoSafety assessment of nanoma-terials implications for nanomedicinerdquo Journal of ControlledRelease vol 161 no 2 pp 403ndash408 2012

[9] P Padmanabhan A Kumar S Kumar R K Chaudhary and BGulyas ldquoNanoparticles in practice formolecular-imaging appli-cations An overviewrdquoActa Biomaterialia vol 41 pp 1ndash16 2016

[10] R S Chaughule S Purushotham and R V Ramanujan ldquoMag-netic Nanoparticles as Contrast Agents forMagnetic ResonanceImagingrdquo Proceedings of the National Academy of Sciences IndiaSection A Physical Sciences vol 82 no 3 pp 257ndash268 2012

[11] J Verma S Lal and C J F van Noorden ldquoNanoparticles forhyperthermic therapy synthesis strategies and applications in

glioblastomardquo International Journal of Nanomedicine vol 9 no1 pp 2863ndash2877 2014

[12] N Shatrova A Yudin V Levina et al ldquoElaboration char-acterization and magnetic properties of cobalt nanoparticlessynthesized by ultrasonic spray pyrolysis followed by hydrogenreductionrdquoMaterials Research Bulletin vol 86 pp 80ndash87 2017

[13] H Shokrollahi and L Avazpour ldquoInfluence of intrinsic param-eters on the particle size of magnetic spinel nanoparticlessynthesized by wet chemical methodsrdquo Particuology vol 26 pp32ndash39 2016

[14] S Gopinath K Sivakumar B Karthikeyen C Ragupathi andR Sundaram ldquoStructural morphological optical and magneticproperties of Co3O4 nanoparticles prepared by conventionalmethodrdquo Physica E Low-Dimensional Systems and Nanostruc-tures vol 81 pp 66ndash70 2016

[15] L Pan L Li and C Yo ldquoSynthesis of hexagonal Co3O4 and Ag

Co3O4 composite nanosheets and their electrocatalytic perfor-mancesrdquo Journal of Cluster Science vol 24 no 4 pp 1001ndash10102013

[16] H T Yang Y K Su C M Shen T Z Yang and H J GaoldquoSynthesis and magnetic properties of 120576-cobalt nanoparticlesrdquoSurface and Interface Analysis vol 36 no 2 pp 155ndash160 2004

[17] Y Dong G Wang P Jiang A Zhang L Yue and X ZhangldquoCatalytic ozonation of phenol in aqueous solution by Co3O4nanoparticlesrdquo Bulletin of the Korean Chemical Society vol 31no 10 pp 2830ndash2834 2010

[18] Y Liang Y Li HWang et al ldquoCo3O4 nanocrystals on grapheneas a synergistic catalyst for oxygen reduction reactionrdquo NatureMaterials vol 10 no 10 pp 780ndash786 2011

[19] F Moro S V Tang F Tuna and E Lester ldquoDetection ofparandashantiferromagnetic transition in Bi2Fe4O9 powders bymeans of microwave absorption measurementsrdquo Journal ofMagnetism and Magnetic Materials vol 348 pp 17ndash21 2013

[20] J Park X Shen and GWang ldquoSolvothermal synthesis and gas-sensing performance of Co3O4 hollow nanospheresrdquo Sensorsand Actuators B Chemical vol 136 no 2 pp 494ndash498 2009

[21] Y Xu CWang Y Sun G Zhang and D Gao ldquoFabrication andcharacterization of nearly monodisperse Co3O4 nanospheresrdquoMaterials Letters vol 64 no 11 pp 1275ndash1278 2010

[22] H Bonnemann W Brijoux R Brinkmann et al ldquoA size-selective synthesis of air stable colloidal magnetic cobalt nano-particlesrdquo Inorganica Chimica Acta vol 350 pp 617ndash624 2003

[23] M Edrissi and A R Keshavarz ldquoSynthesis of cobalt chromitenanoparticles by thermolysis of mixed Cr3+ and Co2+ chelatesof 2-mercaptopyridin N-Oxiderdquo Nano-Micro Letters vol 4 no2 pp 83ndash89 2012

[24] S A Novopashin M A Serebryakova and S Y Khmel ldquoMeth-ods of magnetic fluid synthesis (review)rdquo Thermophysics andAeromechanics vol 22 no 4 pp 397ndash412 2015

[25] S A Usami ldquoSynthesis and Characterization of Cobalt Nano-particlesUsingHydrazine andCitricAcidrdquo Journal of Nanotech-nology vol 2014 Article ID 525193 6 pages 2014

[26] J P Rao P Gruenberg and K E Geckeler ldquoMagnetic zero-valent metal polymer nanoparticles Current trends scope andperspectivesrdquo Progress in Polymer Science vol 40 pp 138ndash1472015

[27] M Zhao L Sun and R M Crooks ldquoPreparation of Cu nan-oclusters within dendrimer templatesrdquo Journal of the AmericanChemical Society vol 120 no 19 pp 4877-4878 1998

Journal of Nanotechnology 9

[28] H Kavas Z Durmus E Tanriverdi M Senel H Sozeri andA Baykal ldquoFabrication and characterization of dendrimer-encapsulated monometallic Co nanoparticlesrdquo Journal of Alloysand Compounds vol 509 no 17 pp 5341ndash5348 2011

[29] H-X Wu C-X Zhang L Jin H Yang and S-P YangldquoPreparation and magnetic properties of cobalt nanoparticleswith dendrimers as templatesrdquoMaterials Chemistry and Physicsvol 121 no 1-2 pp 342ndash348 2010

[30] K Aranishi Q-L Zhu and Q Xu ldquoDendrimer-EncapsulatedCobalt Nanoparticles as High-Performance Catalysts for theHydrolysis of Ammonia Boranerdquo Chem Cat Chem vol 6 no5 pp 1375ndash1379 2014

[31] K InoueK Prog Polym Sci vol 25 pp 453ndash571 2000[32] B I Voit and A Lederer ldquoHyperbranched and highly branched

polymer architectures-synthetic strategies andmajor character-ization aspectsrdquo Chemical Reviews vol 109 no 11 pp 5924ndash5973 2009

[33] E Zagar and J Grdadolnik ldquoAn infrared spectroscopic study ofH-bond network in hyperbranched polyester polyolrdquo Journal ofMolecular Structure vol 658 no 3 pp 143ndash152 2003

[34] E Zagar and M Zigon ldquoAliphatic hyperbranched polyestersbased on 22-bis(methylol)propionic acidmdashDetermination ofstructure solution and bulk propertiesrdquo Progress in PolymerScience vol 36 no 1 pp 53ndash88 2011

[35] R Arote T-H Kim Y-K Hwang et al ldquoA biodegradablepoly(ester amine) based on polycaprolactone and polyethylen-imine as a gene carrierrdquo Biomaterials vol 28 pp 735ndash744 2007

[36] L M Bronstein and Z B Shifrina ldquoNanoparticles in den-drimers From synthesis to applicationrdquo Nanotechnologies inRussia vol 4 no 9-10 pp 576ndash608 2009

[37] R A Ahmadi F Hasanvand G Bruno H A Rudbari SAmani and J Beilstein ldquoSynthesis Spectroscopy andMagneticCharacterization of Copper(II) and Cobalt(II) Complexes with2-Amino-5-bromopyridine as Ligandrdquo ISRN Inorganic Chem-istry vol 2013 Article ID 426712 7 pages 2013

[38] P Petkova and V Nedkov ldquoBehavior of Co2+ cations in theaqueous and alcoholic solution of CoCl26H2Ordquo Acta PhysicaPolonica A vol 123 no 2 pp 207-208 2013

[39] O Metin and S Ozkar ldquoWater soluble nickel(0) and cobalt(0)nanoclusters stabilized by poly(4-styrenesulfonic acid-co-maleic acid) Highly active durable and cost effective catalystsin hydrogen generation from the hydrolysis of ammoniaboranerdquo International Journal of Hydrogen Energy vol 36 no2 pp 1424ndash1432 2011

[40] S Karahan and S Ozkar ldquoPoly(4-styrenesulfonic acid-co-maleic acid) stabilized cobalt(0) nanoparticles A cost-effectiveand magnetically recoverable catalyst in hydrogen generationfrom the hydrolysis of hydrazine boranerdquo International Journalof Hydrogen Energy vol 40 no 5 pp 2255ndash2265 2015

[41] LMAlrehaily JM JosephMC BiesingerDAGuzonas andJ CWren ldquoGamma-radiolysis-assisted cobalt oxide nanoparti-cle formationrdquo Physical Chemistry Chemical Physics vol 15 no3 pp 1014ndash1024 2013

[42] M Yarestani A D Khalaji A Rohani and D Das ldquoHydrother-mal synthesis of cobalt oxide nanoparticles Its optical andmagnetic propertiesrdquo Journal of Sciences Islamic Republic ofIran vol 25 no 4 pp 339ndash343 2014

[43] F A Miller and C H Wilkins ldquoInfrared spectra and charac-teristic frequencies of inorganic ions their use in qualitativeanalysisrdquo Analytical Chemistry vol 24 no 8 pp 1253ndash12941952

Submit your manuscripts athttpswwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Page 4: Magnetic Cobalt and Cobalt Oxide Nanoparticles in ...downloads.hindawi.com/journals/jnt/2017/7607658.pdf · ResearchArticle Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched

4 Journal of Nanotechnology

Con

ml E

6105

318

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle size (nm)concentration

(a)

Con

ml E

6

56

263

140

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle size (nm)concentration

(b)

Figure 4 Concentration and size distribution from NTA measurements of complexes Co8(BH20) (a) and Co10(BH20) (b) in aqueoussolution

Table 1 Stability constants (lg120573) hydrodynamic diameter (119889ℎ) andconcentration of complexes Co119899(BH20) in aqueous solution

Complex lg 120573 119889ℎ nmCo4(BH20) 62 96 plusmn 17

Co8(BH20) 104 105 plusmn 10

Co10(BH20) 177 140 plusmn 18263 plusmn 10

Co12(BH20) 262 123 plusmn 15168 plusmn 20

Co16(BH20) 31174 plusmn 5124 plusmn 10210 plusmn 17

associates from 96 plusmn 17 nm to 210 plusmn 17 nm and theirpolydispersity (Table 1 Figure 4 Supplementary FiguresS1 S2 see Supplementary Material available online athttpsdoiorg10115520177607658)

It can be assumed that the introduction of cobalt ionsinto the BH20 solution leads to a violation of the hydrogenbonding system followed by the destruction of the BH20associates and the formation of associates of complex formsCo119899(BH20) (119899 = 4 8 and 10) of smaller size

Comparing the data of UV-vis spectroscopy and NTAanalysis it can be assumed that an increase in the molarratio b]2+ jH20 from 4 1 to 16 1 leads to a decrease inthe proportion of coordinated hydroxylic groups of HBPOin the inner sphere of the Co2+ ion that could be indicatedby a decrease in the ldquored shiftrdquo value and an increase in thehydrodynamic diameter of Co119899(BH20) associates

Synthesis of cobalt nanoparticles (CoNPs)was carried outby the reduction of Co119899(BH20) complex forms (119899 = 4 8 1012 and 16) by sodium borohydride

2b]2+ + BH4minus + 4Xminus

997888rarr 2Co∙0 + 3B (OH)4minus + 2H2

(1)

During the reduction process for all ratios the color ofthe solution has changed from light pink (Figures 5(a) and5(d)) to black (Figures 5(b) and 5(e))

After the reduction of all complex forms according to theUVvis spectroscopy data the absorption bands disappearat 120582 = 510 nm and 302 nm characteristic for aqua ions[Co(H2O)6]

2+ During the reduction of Co8(BH20) andCo10(BH20) forms a weak absorption peak of the PPR in theregion of 260 nm appeared (Figure 6) After the reduction ofCo12(BH20) an absorption maximum appears in the regionof 274 nm characteristic of cobalt nanoparticles b]0 [3039 40] After the reduction of Co16(BH20) complex formCoNPs have appeared which had two maxima in the regionof 268 nmand 385 nm characteristic for nanoparticlesb]34[41 42]

boNPs (Co2+ HBPO= 4 1 8 1 and 10 1) samples failedto isolate quantitivelyboNPs (Co2+ HBPO = 12 1 and 16 1)samples were isolated from the solution as the black powderHoweverboNPs (16 1) have possessed less stability andwereeasily oxidized by air oxygen and the color of the powderchanged to green indicating the presence of CoO

The FR-IR spectra of BH20 boNPs (12 1) and boNPs(16 1) solids (oxidized forms) were shown in Figure 7 It wasfound that during the synthesis of CoNPs nanocomposites(12 1) the polymer matrix of HBPO did not degrade anddid not undergo significant changes The peaks at 3356 cmminus1belong to H-bonded OH 2945 cmminus1 and 2859 cmminus1 ascribedto antisymmetric and symmetric CndashH 1728 cmminus1 ascribedto H-bonded carbonyl (]bondedC=O) 1440 cm

minus1 symmetricCOO-stretching 1400 cmminus1 and 1375 cmminus1 CH2 deformationantisymmetric and symmetric 1305 cmminus1 deformation H-bonded 1220 cmminus1 and 1120 cmminus1 C-O and O-C stretchingester and 1040 cmminus1 CO(-OH) stretching hydroxyl in BH20[34] At FR-IR spectra boNPs (12 1) and boNPs (16 1) aband at 1645 cmminus1 appeared which could be associated withthe formation and crystallization of a by-product NaBO3 incavities ofHBPO [43] An increase in the absorption intensity

Journal of Nanotechnology 5

(a) (b) (c) (d) (e) (f)

Figure 5 Color transformation of Co2+-BH20 solution before (a d) and after (b e) reduction the collection of CoNPs by a magnet (c f)

300 400 500 600 700

02

04

06

08

10

12

14

16

18

Wavenumber (nm)

Abso

rban

ce

(a)

(b)

(c)

(d)

Figure 6 UVvis spectra of aqueous solutions containing CoNPsafter Co8(BH20) reduction (a) CoNPs after Co10(BH20) reduction(b) CoNPs after Co12(BH20) reduction (c) and CoNPs afterCo16(BH20) reduction (d)

3500 3000 2500 2000 1500 10000002040608101214161820

Abso

rban

ce

(a)

(b)

(c)

Wavenumber (=Gminus1

)

Figure 7 FT-IR spectra of HBP BH20 (a) boNPs (12 1) (b) andboNPs (16 1) (c)

0 20 40 60 80 100

Rela

tive i

nten

sity

2 (degree)

(a)

(b)

Figure 8 XRD powder pattern of CoNPs (12 1) (a) and CoNPs(16 1) (b)

at 3356 cmminus1 could be associated with the increasing numberof hydrogen bonds Moreover during the synthesis of boNPs(16 1) a partial destruction of ester bonds took place Thatfact was indicated by a decrease in signal strength at 17201305 1220 and 1120 cmminus1 and increase of peak intensity at2878 cmminus1 [35 43]

XRD pattern indicated the amorphous structure of prod-uctsThe broadening of the diffraction peaks ofboNPs (12 1)(Figure 8(a)) and boNPs (16 1) (Figure 8(b)) suggests thepresence of small particles [28 29] The diffraction peaks at2120579 = 194∘ and 21∘ refer to reflections of the HBPO matrixand a maximum at 479∘ and a wide reflex with a maximumat 7960 can be attributed to the metallic Co∘ in which thealternatingmicrodomainswith cubic andhexagonal packingswere observed

The magnetic curves field dependence of magnetizationof CoNPs (12 1) wasmeasured at 5 10 50 100 200 and 360K(Figure 9) The magnetization curves of the sample CoNPs(12 1)measured at 5 10 and 50K had visible hysteresis loops[2 3]The loops are closed and symmetrical versus the originof the coordinate system formThemagnetization under fieldof 10 kOe was 587 emugminus1 The remanence magnetization

6 Journal of NanotechnologyM

(em

ugr

)

H (kOe)

6

3

0

minus3

minus6minus10 minus5 0 5 10

5 +

300 +

Figure 9 Hysteresis loops obtained at 5 K and 300K for CoNPs(12 1)

M(e

mu

g)

T (K)

FCZFC

10

08

06

04

02

000 100 200 300

H = 100

Figure 10 ZFCndashFC curves measured in an applied field of 100Oefor CoNPs (12 1)

value (Mr) was 206 emugminus1 and the coercivity was 323OeThemagnetization curves showedneither hysteresis nor coer-civity The saturated magnetization values (Ms) measuredat 100 200 and 300K were 456 416 and 362 emugminus1respectively

The temperature dependence of the magnetization wasmeasured under magnetic field of 100Oe from 5 to 300Kusing zero field-cooled (ZFC) and field-cooled (FC) proce-dure This measurement allowed determining the blockingtemperature of CoNPs The obtained ZFCndashFC curves ofCoNPs (12 1) nanocomposite are displayed in Figure 10Magnetization of CoNPs increased with the increase of thetemperature that is shown at the ZFC curve The wide

Table 2 Hydrodynamic diameter (119889ℎ) from NTAmeasurements ofnanoparticles boNPs in aqueous solution

boNPs 119889ℎ nmboNPs (8 1) 106 plusmn 15

boNPs (10 1) 107 plusmn 20

boNPs (12 1) 112 plusmn 10

boNPs (16 1) 123 plusmn 18

peak was observed at 100ndash170P with maximum at 140KThe maximum temperature is called blocking temperatureTb The thermal energy becomes comparable to the energybarrier of magnetic anisotropy for spin reorientation atblocking temperature

At a temperature of 300K discrepancy between the ZFCand FC curves was observed A sufficiently high temper-ature which characterizes the temperature of irreversiblemagnetic changes is associated with a wide size distributionof nanoparticles in the sample and strong interaction betweenthe particles [2]

The variations in size determined by different methodswere due to the fact that thesemethods rely ondifferent physi-cal principles andor detectionmethods In addition electronmicroscopy probes dry particles that is the metallic coreonly whereas the NTA probe the hydrodynamic diameterwhich is always larger The size predicted by TEM analysiswas found to be smaller than predicted by NTA analysis

According to the NTA method hydrodynamic diameterof CoNPs nanocomposite rose from 106 plusmn 15 to 123 plusmn 18 nm(Figure 11 Supplementary Figures S3 S4) with increase ofmolar ratio Co2+ BH20 however it was smaller than thediameter of respective complex forms of Co119899(BH20) (Table 2Supplementary Table S5)

The successful formation of CoNPswas first confirmed byTEM studies Figure 12 shows the TEMmicrographs and sizedistributions of CoNPs nanoparticles (12 1) obtained usingHBPO BH20 as a stabilizer The nanoparticles CoNPs (12 1)were approximately spherical with size about 82 plusmn 34 nmParticles have aggregated easily probably because of the highmobility of the particles as well as the magnetic interactionbetween the particles

4 Conclusions

Thus for the first time the process of preorganization of Co2+ions on the platform of a hyperbranched polyester polyolof the second generation was studied and the significantcomplex forms of Co119899(BH20) existing in an aqueous solutionwere determined The cobalt nanoparticles were synthesizedby the chemical reduction method in solution at variousmolar ratios of CoCl2 HBPO It is shown that an increase inthe concentration of Co2+ ions in the polymer matrix at thepreorganization stage leads to an increase in the proportion ofoxide forms in the composition of the nanoparticles CoNPssynthesized at the CoCl2 HBPO molar ratio of 12 1 havepossessed the highest stability They had spherical shapemoreover metallic nanoclusters of cobalt with a diameterof 82 plusmn 34 nm were in the polymer shell of the stabilizer

Journal of Nanotechnology 7

Con

ml E

6

162

57

79

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(a)

Con

ml E

6

43

57

9867

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(b)

Figure 11 Concentration and size distribution from NTA measurements of CoNPs (8 1) (a) and CoNPs (12 1) (b) in aqueous solution

500 HG

(a)

100 HG

(b)

3-4 5-6 7-8 9-10 11-12 13-14 15-160

5

10

15

20

25

30

Freq

uenc

y (

)

Particle size (nm)

Average particle size 82 plusmn 34 HG

(c)

Cps (

eV)

(keV)2 4 6 8

C

Co

Co

Co

Cu

Cu

Na

O

CuCl

04

03

02

01

0

(d)

Figure 12 TEM images CoNPs (12 1) (a b) corresponding particle-size distribution of CoNPs (c) and EDS spectrum (d) for the areacorresponding to (a) The Cu signals come from TEM grids

8 Journal of Nanotechnology

It has been proved that the polymer-composite nanoparti-cles CoBH20 (12 1) exhibit magnetic properties includingsuperparamagnetic properties at room temperature whichwill allow them to be used for further development of MRIdiagnostic systems as well as targeted drug delivery system

Conflicts of Interest

The authors O I Medvedeva S S Kambulova O V BondarA R Gataulina N A Ulakhovich A V Gerasimov V GEvtugyn I F Gilmutdinov and M P Kutyreva declare thatthere are no conflicts of interest regarding the publication ofthis paper

Acknowledgments

The magnetic measurements were carried out at the FederalCenter of Shared Facilities of Kazan Federal UniversityMicroscopy studies were carried out at the InterdisciplinaryCenter of AnalyticalMicroscopy of Kazan Federal UniversityThework is performed according to the Russian GovernmentProgram of Competitive Growth of Kazan Federal Univer-sity

References

[1] L Merhari Hybrid Nanocomposites for Nanotechnology Elec-tronic Optical Magnetic and Biomedical Applications SpringerBoston MA USA 2009

[2] S Gubin Magnetic Nanoparticles WILEY-VCH Verlag GmbHamp Co KGaA 2009

[3] Q A Pankhurst J Connolly S K Jones and J Dobson ldquoAppli-cations of magnetic nanoparticles in biomedicinerdquo Journal ofPhysics D Applied Physics vol 36 no 13 pp R167ndashR181 2003

[4] W H Suh Y H Suh and G D Stucky Nano Today vol 4 pp27ndash36 2009

[5] T K Indira and R K Lakshmi International Journal of Phar-maceutical Sciences and Nanotechnology vol 3 pp 1035ndash10422010

[6] P P Waifalkar S B Parit A D Chougale S C Sahoo P SPatil and P B Patil ldquoImmobilization of invertase on chitosancoated 120574-Fe2O3 magnetic nanoparticles to facilitate magneticseparationrdquo Journal of Colloid and Interface Science vol 482 pp159ndash164 2016

[7] J Chomoucka J Drbohlavova D Huska V Adam R Kizekand J Hubalek ldquoMagnetic nanoparticles and targeted drugdeliveringrdquo Pharmacological Research vol 62 no 2 pp 144ndash149 2010

[8] A M Nystrom and B Fadeel ldquoSafety assessment of nanoma-terials implications for nanomedicinerdquo Journal of ControlledRelease vol 161 no 2 pp 403ndash408 2012

[9] P Padmanabhan A Kumar S Kumar R K Chaudhary and BGulyas ldquoNanoparticles in practice formolecular-imaging appli-cations An overviewrdquoActa Biomaterialia vol 41 pp 1ndash16 2016

[10] R S Chaughule S Purushotham and R V Ramanujan ldquoMag-netic Nanoparticles as Contrast Agents forMagnetic ResonanceImagingrdquo Proceedings of the National Academy of Sciences IndiaSection A Physical Sciences vol 82 no 3 pp 257ndash268 2012

[11] J Verma S Lal and C J F van Noorden ldquoNanoparticles forhyperthermic therapy synthesis strategies and applications in

glioblastomardquo International Journal of Nanomedicine vol 9 no1 pp 2863ndash2877 2014

[12] N Shatrova A Yudin V Levina et al ldquoElaboration char-acterization and magnetic properties of cobalt nanoparticlessynthesized by ultrasonic spray pyrolysis followed by hydrogenreductionrdquoMaterials Research Bulletin vol 86 pp 80ndash87 2017

[13] H Shokrollahi and L Avazpour ldquoInfluence of intrinsic param-eters on the particle size of magnetic spinel nanoparticlessynthesized by wet chemical methodsrdquo Particuology vol 26 pp32ndash39 2016

[14] S Gopinath K Sivakumar B Karthikeyen C Ragupathi andR Sundaram ldquoStructural morphological optical and magneticproperties of Co3O4 nanoparticles prepared by conventionalmethodrdquo Physica E Low-Dimensional Systems and Nanostruc-tures vol 81 pp 66ndash70 2016

[15] L Pan L Li and C Yo ldquoSynthesis of hexagonal Co3O4 and Ag

Co3O4 composite nanosheets and their electrocatalytic perfor-mancesrdquo Journal of Cluster Science vol 24 no 4 pp 1001ndash10102013

[16] H T Yang Y K Su C M Shen T Z Yang and H J GaoldquoSynthesis and magnetic properties of 120576-cobalt nanoparticlesrdquoSurface and Interface Analysis vol 36 no 2 pp 155ndash160 2004

[17] Y Dong G Wang P Jiang A Zhang L Yue and X ZhangldquoCatalytic ozonation of phenol in aqueous solution by Co3O4nanoparticlesrdquo Bulletin of the Korean Chemical Society vol 31no 10 pp 2830ndash2834 2010

[18] Y Liang Y Li HWang et al ldquoCo3O4 nanocrystals on grapheneas a synergistic catalyst for oxygen reduction reactionrdquo NatureMaterials vol 10 no 10 pp 780ndash786 2011

[19] F Moro S V Tang F Tuna and E Lester ldquoDetection ofparandashantiferromagnetic transition in Bi2Fe4O9 powders bymeans of microwave absorption measurementsrdquo Journal ofMagnetism and Magnetic Materials vol 348 pp 17ndash21 2013

[20] J Park X Shen and GWang ldquoSolvothermal synthesis and gas-sensing performance of Co3O4 hollow nanospheresrdquo Sensorsand Actuators B Chemical vol 136 no 2 pp 494ndash498 2009

[21] Y Xu CWang Y Sun G Zhang and D Gao ldquoFabrication andcharacterization of nearly monodisperse Co3O4 nanospheresrdquoMaterials Letters vol 64 no 11 pp 1275ndash1278 2010

[22] H Bonnemann W Brijoux R Brinkmann et al ldquoA size-selective synthesis of air stable colloidal magnetic cobalt nano-particlesrdquo Inorganica Chimica Acta vol 350 pp 617ndash624 2003

[23] M Edrissi and A R Keshavarz ldquoSynthesis of cobalt chromitenanoparticles by thermolysis of mixed Cr3+ and Co2+ chelatesof 2-mercaptopyridin N-Oxiderdquo Nano-Micro Letters vol 4 no2 pp 83ndash89 2012

[24] S A Novopashin M A Serebryakova and S Y Khmel ldquoMeth-ods of magnetic fluid synthesis (review)rdquo Thermophysics andAeromechanics vol 22 no 4 pp 397ndash412 2015

[25] S A Usami ldquoSynthesis and Characterization of Cobalt Nano-particlesUsingHydrazine andCitricAcidrdquo Journal of Nanotech-nology vol 2014 Article ID 525193 6 pages 2014

[26] J P Rao P Gruenberg and K E Geckeler ldquoMagnetic zero-valent metal polymer nanoparticles Current trends scope andperspectivesrdquo Progress in Polymer Science vol 40 pp 138ndash1472015

[27] M Zhao L Sun and R M Crooks ldquoPreparation of Cu nan-oclusters within dendrimer templatesrdquo Journal of the AmericanChemical Society vol 120 no 19 pp 4877-4878 1998

Journal of Nanotechnology 9

[28] H Kavas Z Durmus E Tanriverdi M Senel H Sozeri andA Baykal ldquoFabrication and characterization of dendrimer-encapsulated monometallic Co nanoparticlesrdquo Journal of Alloysand Compounds vol 509 no 17 pp 5341ndash5348 2011

[29] H-X Wu C-X Zhang L Jin H Yang and S-P YangldquoPreparation and magnetic properties of cobalt nanoparticleswith dendrimers as templatesrdquoMaterials Chemistry and Physicsvol 121 no 1-2 pp 342ndash348 2010

[30] K Aranishi Q-L Zhu and Q Xu ldquoDendrimer-EncapsulatedCobalt Nanoparticles as High-Performance Catalysts for theHydrolysis of Ammonia Boranerdquo Chem Cat Chem vol 6 no5 pp 1375ndash1379 2014

[31] K InoueK Prog Polym Sci vol 25 pp 453ndash571 2000[32] B I Voit and A Lederer ldquoHyperbranched and highly branched

polymer architectures-synthetic strategies andmajor character-ization aspectsrdquo Chemical Reviews vol 109 no 11 pp 5924ndash5973 2009

[33] E Zagar and J Grdadolnik ldquoAn infrared spectroscopic study ofH-bond network in hyperbranched polyester polyolrdquo Journal ofMolecular Structure vol 658 no 3 pp 143ndash152 2003

[34] E Zagar and M Zigon ldquoAliphatic hyperbranched polyestersbased on 22-bis(methylol)propionic acidmdashDetermination ofstructure solution and bulk propertiesrdquo Progress in PolymerScience vol 36 no 1 pp 53ndash88 2011

[35] R Arote T-H Kim Y-K Hwang et al ldquoA biodegradablepoly(ester amine) based on polycaprolactone and polyethylen-imine as a gene carrierrdquo Biomaterials vol 28 pp 735ndash744 2007

[36] L M Bronstein and Z B Shifrina ldquoNanoparticles in den-drimers From synthesis to applicationrdquo Nanotechnologies inRussia vol 4 no 9-10 pp 576ndash608 2009

[37] R A Ahmadi F Hasanvand G Bruno H A Rudbari SAmani and J Beilstein ldquoSynthesis Spectroscopy andMagneticCharacterization of Copper(II) and Cobalt(II) Complexes with2-Amino-5-bromopyridine as Ligandrdquo ISRN Inorganic Chem-istry vol 2013 Article ID 426712 7 pages 2013

[38] P Petkova and V Nedkov ldquoBehavior of Co2+ cations in theaqueous and alcoholic solution of CoCl26H2Ordquo Acta PhysicaPolonica A vol 123 no 2 pp 207-208 2013

[39] O Metin and S Ozkar ldquoWater soluble nickel(0) and cobalt(0)nanoclusters stabilized by poly(4-styrenesulfonic acid-co-maleic acid) Highly active durable and cost effective catalystsin hydrogen generation from the hydrolysis of ammoniaboranerdquo International Journal of Hydrogen Energy vol 36 no2 pp 1424ndash1432 2011

[40] S Karahan and S Ozkar ldquoPoly(4-styrenesulfonic acid-co-maleic acid) stabilized cobalt(0) nanoparticles A cost-effectiveand magnetically recoverable catalyst in hydrogen generationfrom the hydrolysis of hydrazine boranerdquo International Journalof Hydrogen Energy vol 40 no 5 pp 2255ndash2265 2015

[41] LMAlrehaily JM JosephMC BiesingerDAGuzonas andJ CWren ldquoGamma-radiolysis-assisted cobalt oxide nanoparti-cle formationrdquo Physical Chemistry Chemical Physics vol 15 no3 pp 1014ndash1024 2013

[42] M Yarestani A D Khalaji A Rohani and D Das ldquoHydrother-mal synthesis of cobalt oxide nanoparticles Its optical andmagnetic propertiesrdquo Journal of Sciences Islamic Republic ofIran vol 25 no 4 pp 339ndash343 2014

[43] F A Miller and C H Wilkins ldquoInfrared spectra and charac-teristic frequencies of inorganic ions their use in qualitativeanalysisrdquo Analytical Chemistry vol 24 no 8 pp 1253ndash12941952

Submit your manuscripts athttpswwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Page 5: Magnetic Cobalt and Cobalt Oxide Nanoparticles in ...downloads.hindawi.com/journals/jnt/2017/7607658.pdf · ResearchArticle Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched

Journal of Nanotechnology 5

(a) (b) (c) (d) (e) (f)

Figure 5 Color transformation of Co2+-BH20 solution before (a d) and after (b e) reduction the collection of CoNPs by a magnet (c f)

300 400 500 600 700

02

04

06

08

10

12

14

16

18

Wavenumber (nm)

Abso

rban

ce

(a)

(b)

(c)

(d)

Figure 6 UVvis spectra of aqueous solutions containing CoNPsafter Co8(BH20) reduction (a) CoNPs after Co10(BH20) reduction(b) CoNPs after Co12(BH20) reduction (c) and CoNPs afterCo16(BH20) reduction (d)

3500 3000 2500 2000 1500 10000002040608101214161820

Abso

rban

ce

(a)

(b)

(c)

Wavenumber (=Gminus1

)

Figure 7 FT-IR spectra of HBP BH20 (a) boNPs (12 1) (b) andboNPs (16 1) (c)

0 20 40 60 80 100

Rela

tive i

nten

sity

2 (degree)

(a)

(b)

Figure 8 XRD powder pattern of CoNPs (12 1) (a) and CoNPs(16 1) (b)

at 3356 cmminus1 could be associated with the increasing numberof hydrogen bonds Moreover during the synthesis of boNPs(16 1) a partial destruction of ester bonds took place Thatfact was indicated by a decrease in signal strength at 17201305 1220 and 1120 cmminus1 and increase of peak intensity at2878 cmminus1 [35 43]

XRD pattern indicated the amorphous structure of prod-uctsThe broadening of the diffraction peaks ofboNPs (12 1)(Figure 8(a)) and boNPs (16 1) (Figure 8(b)) suggests thepresence of small particles [28 29] The diffraction peaks at2120579 = 194∘ and 21∘ refer to reflections of the HBPO matrixand a maximum at 479∘ and a wide reflex with a maximumat 7960 can be attributed to the metallic Co∘ in which thealternatingmicrodomainswith cubic andhexagonal packingswere observed

The magnetic curves field dependence of magnetizationof CoNPs (12 1) wasmeasured at 5 10 50 100 200 and 360K(Figure 9) The magnetization curves of the sample CoNPs(12 1)measured at 5 10 and 50K had visible hysteresis loops[2 3]The loops are closed and symmetrical versus the originof the coordinate system formThemagnetization under fieldof 10 kOe was 587 emugminus1 The remanence magnetization

6 Journal of NanotechnologyM

(em

ugr

)

H (kOe)

6

3

0

minus3

minus6minus10 minus5 0 5 10

5 +

300 +

Figure 9 Hysteresis loops obtained at 5 K and 300K for CoNPs(12 1)

M(e

mu

g)

T (K)

FCZFC

10

08

06

04

02

000 100 200 300

H = 100

Figure 10 ZFCndashFC curves measured in an applied field of 100Oefor CoNPs (12 1)

value (Mr) was 206 emugminus1 and the coercivity was 323OeThemagnetization curves showedneither hysteresis nor coer-civity The saturated magnetization values (Ms) measuredat 100 200 and 300K were 456 416 and 362 emugminus1respectively

The temperature dependence of the magnetization wasmeasured under magnetic field of 100Oe from 5 to 300Kusing zero field-cooled (ZFC) and field-cooled (FC) proce-dure This measurement allowed determining the blockingtemperature of CoNPs The obtained ZFCndashFC curves ofCoNPs (12 1) nanocomposite are displayed in Figure 10Magnetization of CoNPs increased with the increase of thetemperature that is shown at the ZFC curve The wide

Table 2 Hydrodynamic diameter (119889ℎ) from NTAmeasurements ofnanoparticles boNPs in aqueous solution

boNPs 119889ℎ nmboNPs (8 1) 106 plusmn 15

boNPs (10 1) 107 plusmn 20

boNPs (12 1) 112 plusmn 10

boNPs (16 1) 123 plusmn 18

peak was observed at 100ndash170P with maximum at 140KThe maximum temperature is called blocking temperatureTb The thermal energy becomes comparable to the energybarrier of magnetic anisotropy for spin reorientation atblocking temperature

At a temperature of 300K discrepancy between the ZFCand FC curves was observed A sufficiently high temper-ature which characterizes the temperature of irreversiblemagnetic changes is associated with a wide size distributionof nanoparticles in the sample and strong interaction betweenthe particles [2]

The variations in size determined by different methodswere due to the fact that thesemethods rely ondifferent physi-cal principles andor detectionmethods In addition electronmicroscopy probes dry particles that is the metallic coreonly whereas the NTA probe the hydrodynamic diameterwhich is always larger The size predicted by TEM analysiswas found to be smaller than predicted by NTA analysis

According to the NTA method hydrodynamic diameterof CoNPs nanocomposite rose from 106 plusmn 15 to 123 plusmn 18 nm(Figure 11 Supplementary Figures S3 S4) with increase ofmolar ratio Co2+ BH20 however it was smaller than thediameter of respective complex forms of Co119899(BH20) (Table 2Supplementary Table S5)

The successful formation of CoNPswas first confirmed byTEM studies Figure 12 shows the TEMmicrographs and sizedistributions of CoNPs nanoparticles (12 1) obtained usingHBPO BH20 as a stabilizer The nanoparticles CoNPs (12 1)were approximately spherical with size about 82 plusmn 34 nmParticles have aggregated easily probably because of the highmobility of the particles as well as the magnetic interactionbetween the particles

4 Conclusions

Thus for the first time the process of preorganization of Co2+ions on the platform of a hyperbranched polyester polyolof the second generation was studied and the significantcomplex forms of Co119899(BH20) existing in an aqueous solutionwere determined The cobalt nanoparticles were synthesizedby the chemical reduction method in solution at variousmolar ratios of CoCl2 HBPO It is shown that an increase inthe concentration of Co2+ ions in the polymer matrix at thepreorganization stage leads to an increase in the proportion ofoxide forms in the composition of the nanoparticles CoNPssynthesized at the CoCl2 HBPO molar ratio of 12 1 havepossessed the highest stability They had spherical shapemoreover metallic nanoclusters of cobalt with a diameterof 82 plusmn 34 nm were in the polymer shell of the stabilizer

Journal of Nanotechnology 7

Con

ml E

6

162

57

79

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(a)

Con

ml E

6

43

57

9867

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(b)

Figure 11 Concentration and size distribution from NTA measurements of CoNPs (8 1) (a) and CoNPs (12 1) (b) in aqueous solution

500 HG

(a)

100 HG

(b)

3-4 5-6 7-8 9-10 11-12 13-14 15-160

5

10

15

20

25

30

Freq

uenc

y (

)

Particle size (nm)

Average particle size 82 plusmn 34 HG

(c)

Cps (

eV)

(keV)2 4 6 8

C

Co

Co

Co

Cu

Cu

Na

O

CuCl

04

03

02

01

0

(d)

Figure 12 TEM images CoNPs (12 1) (a b) corresponding particle-size distribution of CoNPs (c) and EDS spectrum (d) for the areacorresponding to (a) The Cu signals come from TEM grids

8 Journal of Nanotechnology

It has been proved that the polymer-composite nanoparti-cles CoBH20 (12 1) exhibit magnetic properties includingsuperparamagnetic properties at room temperature whichwill allow them to be used for further development of MRIdiagnostic systems as well as targeted drug delivery system

Conflicts of Interest

The authors O I Medvedeva S S Kambulova O V BondarA R Gataulina N A Ulakhovich A V Gerasimov V GEvtugyn I F Gilmutdinov and M P Kutyreva declare thatthere are no conflicts of interest regarding the publication ofthis paper

Acknowledgments

The magnetic measurements were carried out at the FederalCenter of Shared Facilities of Kazan Federal UniversityMicroscopy studies were carried out at the InterdisciplinaryCenter of AnalyticalMicroscopy of Kazan Federal UniversityThework is performed according to the Russian GovernmentProgram of Competitive Growth of Kazan Federal Univer-sity

References

[1] L Merhari Hybrid Nanocomposites for Nanotechnology Elec-tronic Optical Magnetic and Biomedical Applications SpringerBoston MA USA 2009

[2] S Gubin Magnetic Nanoparticles WILEY-VCH Verlag GmbHamp Co KGaA 2009

[3] Q A Pankhurst J Connolly S K Jones and J Dobson ldquoAppli-cations of magnetic nanoparticles in biomedicinerdquo Journal ofPhysics D Applied Physics vol 36 no 13 pp R167ndashR181 2003

[4] W H Suh Y H Suh and G D Stucky Nano Today vol 4 pp27ndash36 2009

[5] T K Indira and R K Lakshmi International Journal of Phar-maceutical Sciences and Nanotechnology vol 3 pp 1035ndash10422010

[6] P P Waifalkar S B Parit A D Chougale S C Sahoo P SPatil and P B Patil ldquoImmobilization of invertase on chitosancoated 120574-Fe2O3 magnetic nanoparticles to facilitate magneticseparationrdquo Journal of Colloid and Interface Science vol 482 pp159ndash164 2016

[7] J Chomoucka J Drbohlavova D Huska V Adam R Kizekand J Hubalek ldquoMagnetic nanoparticles and targeted drugdeliveringrdquo Pharmacological Research vol 62 no 2 pp 144ndash149 2010

[8] A M Nystrom and B Fadeel ldquoSafety assessment of nanoma-terials implications for nanomedicinerdquo Journal of ControlledRelease vol 161 no 2 pp 403ndash408 2012

[9] P Padmanabhan A Kumar S Kumar R K Chaudhary and BGulyas ldquoNanoparticles in practice formolecular-imaging appli-cations An overviewrdquoActa Biomaterialia vol 41 pp 1ndash16 2016

[10] R S Chaughule S Purushotham and R V Ramanujan ldquoMag-netic Nanoparticles as Contrast Agents forMagnetic ResonanceImagingrdquo Proceedings of the National Academy of Sciences IndiaSection A Physical Sciences vol 82 no 3 pp 257ndash268 2012

[11] J Verma S Lal and C J F van Noorden ldquoNanoparticles forhyperthermic therapy synthesis strategies and applications in

glioblastomardquo International Journal of Nanomedicine vol 9 no1 pp 2863ndash2877 2014

[12] N Shatrova A Yudin V Levina et al ldquoElaboration char-acterization and magnetic properties of cobalt nanoparticlessynthesized by ultrasonic spray pyrolysis followed by hydrogenreductionrdquoMaterials Research Bulletin vol 86 pp 80ndash87 2017

[13] H Shokrollahi and L Avazpour ldquoInfluence of intrinsic param-eters on the particle size of magnetic spinel nanoparticlessynthesized by wet chemical methodsrdquo Particuology vol 26 pp32ndash39 2016

[14] S Gopinath K Sivakumar B Karthikeyen C Ragupathi andR Sundaram ldquoStructural morphological optical and magneticproperties of Co3O4 nanoparticles prepared by conventionalmethodrdquo Physica E Low-Dimensional Systems and Nanostruc-tures vol 81 pp 66ndash70 2016

[15] L Pan L Li and C Yo ldquoSynthesis of hexagonal Co3O4 and Ag

Co3O4 composite nanosheets and their electrocatalytic perfor-mancesrdquo Journal of Cluster Science vol 24 no 4 pp 1001ndash10102013

[16] H T Yang Y K Su C M Shen T Z Yang and H J GaoldquoSynthesis and magnetic properties of 120576-cobalt nanoparticlesrdquoSurface and Interface Analysis vol 36 no 2 pp 155ndash160 2004

[17] Y Dong G Wang P Jiang A Zhang L Yue and X ZhangldquoCatalytic ozonation of phenol in aqueous solution by Co3O4nanoparticlesrdquo Bulletin of the Korean Chemical Society vol 31no 10 pp 2830ndash2834 2010

[18] Y Liang Y Li HWang et al ldquoCo3O4 nanocrystals on grapheneas a synergistic catalyst for oxygen reduction reactionrdquo NatureMaterials vol 10 no 10 pp 780ndash786 2011

[19] F Moro S V Tang F Tuna and E Lester ldquoDetection ofparandashantiferromagnetic transition in Bi2Fe4O9 powders bymeans of microwave absorption measurementsrdquo Journal ofMagnetism and Magnetic Materials vol 348 pp 17ndash21 2013

[20] J Park X Shen and GWang ldquoSolvothermal synthesis and gas-sensing performance of Co3O4 hollow nanospheresrdquo Sensorsand Actuators B Chemical vol 136 no 2 pp 494ndash498 2009

[21] Y Xu CWang Y Sun G Zhang and D Gao ldquoFabrication andcharacterization of nearly monodisperse Co3O4 nanospheresrdquoMaterials Letters vol 64 no 11 pp 1275ndash1278 2010

[22] H Bonnemann W Brijoux R Brinkmann et al ldquoA size-selective synthesis of air stable colloidal magnetic cobalt nano-particlesrdquo Inorganica Chimica Acta vol 350 pp 617ndash624 2003

[23] M Edrissi and A R Keshavarz ldquoSynthesis of cobalt chromitenanoparticles by thermolysis of mixed Cr3+ and Co2+ chelatesof 2-mercaptopyridin N-Oxiderdquo Nano-Micro Letters vol 4 no2 pp 83ndash89 2012

[24] S A Novopashin M A Serebryakova and S Y Khmel ldquoMeth-ods of magnetic fluid synthesis (review)rdquo Thermophysics andAeromechanics vol 22 no 4 pp 397ndash412 2015

[25] S A Usami ldquoSynthesis and Characterization of Cobalt Nano-particlesUsingHydrazine andCitricAcidrdquo Journal of Nanotech-nology vol 2014 Article ID 525193 6 pages 2014

[26] J P Rao P Gruenberg and K E Geckeler ldquoMagnetic zero-valent metal polymer nanoparticles Current trends scope andperspectivesrdquo Progress in Polymer Science vol 40 pp 138ndash1472015

[27] M Zhao L Sun and R M Crooks ldquoPreparation of Cu nan-oclusters within dendrimer templatesrdquo Journal of the AmericanChemical Society vol 120 no 19 pp 4877-4878 1998

Journal of Nanotechnology 9

[28] H Kavas Z Durmus E Tanriverdi M Senel H Sozeri andA Baykal ldquoFabrication and characterization of dendrimer-encapsulated monometallic Co nanoparticlesrdquo Journal of Alloysand Compounds vol 509 no 17 pp 5341ndash5348 2011

[29] H-X Wu C-X Zhang L Jin H Yang and S-P YangldquoPreparation and magnetic properties of cobalt nanoparticleswith dendrimers as templatesrdquoMaterials Chemistry and Physicsvol 121 no 1-2 pp 342ndash348 2010

[30] K Aranishi Q-L Zhu and Q Xu ldquoDendrimer-EncapsulatedCobalt Nanoparticles as High-Performance Catalysts for theHydrolysis of Ammonia Boranerdquo Chem Cat Chem vol 6 no5 pp 1375ndash1379 2014

[31] K InoueK Prog Polym Sci vol 25 pp 453ndash571 2000[32] B I Voit and A Lederer ldquoHyperbranched and highly branched

polymer architectures-synthetic strategies andmajor character-ization aspectsrdquo Chemical Reviews vol 109 no 11 pp 5924ndash5973 2009

[33] E Zagar and J Grdadolnik ldquoAn infrared spectroscopic study ofH-bond network in hyperbranched polyester polyolrdquo Journal ofMolecular Structure vol 658 no 3 pp 143ndash152 2003

[34] E Zagar and M Zigon ldquoAliphatic hyperbranched polyestersbased on 22-bis(methylol)propionic acidmdashDetermination ofstructure solution and bulk propertiesrdquo Progress in PolymerScience vol 36 no 1 pp 53ndash88 2011

[35] R Arote T-H Kim Y-K Hwang et al ldquoA biodegradablepoly(ester amine) based on polycaprolactone and polyethylen-imine as a gene carrierrdquo Biomaterials vol 28 pp 735ndash744 2007

[36] L M Bronstein and Z B Shifrina ldquoNanoparticles in den-drimers From synthesis to applicationrdquo Nanotechnologies inRussia vol 4 no 9-10 pp 576ndash608 2009

[37] R A Ahmadi F Hasanvand G Bruno H A Rudbari SAmani and J Beilstein ldquoSynthesis Spectroscopy andMagneticCharacterization of Copper(II) and Cobalt(II) Complexes with2-Amino-5-bromopyridine as Ligandrdquo ISRN Inorganic Chem-istry vol 2013 Article ID 426712 7 pages 2013

[38] P Petkova and V Nedkov ldquoBehavior of Co2+ cations in theaqueous and alcoholic solution of CoCl26H2Ordquo Acta PhysicaPolonica A vol 123 no 2 pp 207-208 2013

[39] O Metin and S Ozkar ldquoWater soluble nickel(0) and cobalt(0)nanoclusters stabilized by poly(4-styrenesulfonic acid-co-maleic acid) Highly active durable and cost effective catalystsin hydrogen generation from the hydrolysis of ammoniaboranerdquo International Journal of Hydrogen Energy vol 36 no2 pp 1424ndash1432 2011

[40] S Karahan and S Ozkar ldquoPoly(4-styrenesulfonic acid-co-maleic acid) stabilized cobalt(0) nanoparticles A cost-effectiveand magnetically recoverable catalyst in hydrogen generationfrom the hydrolysis of hydrazine boranerdquo International Journalof Hydrogen Energy vol 40 no 5 pp 2255ndash2265 2015

[41] LMAlrehaily JM JosephMC BiesingerDAGuzonas andJ CWren ldquoGamma-radiolysis-assisted cobalt oxide nanoparti-cle formationrdquo Physical Chemistry Chemical Physics vol 15 no3 pp 1014ndash1024 2013

[42] M Yarestani A D Khalaji A Rohani and D Das ldquoHydrother-mal synthesis of cobalt oxide nanoparticles Its optical andmagnetic propertiesrdquo Journal of Sciences Islamic Republic ofIran vol 25 no 4 pp 339ndash343 2014

[43] F A Miller and C H Wilkins ldquoInfrared spectra and charac-teristic frequencies of inorganic ions their use in qualitativeanalysisrdquo Analytical Chemistry vol 24 no 8 pp 1253ndash12941952

Submit your manuscripts athttpswwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Page 6: Magnetic Cobalt and Cobalt Oxide Nanoparticles in ...downloads.hindawi.com/journals/jnt/2017/7607658.pdf · ResearchArticle Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched

6 Journal of NanotechnologyM

(em

ugr

)

H (kOe)

6

3

0

minus3

minus6minus10 minus5 0 5 10

5 +

300 +

Figure 9 Hysteresis loops obtained at 5 K and 300K for CoNPs(12 1)

M(e

mu

g)

T (K)

FCZFC

10

08

06

04

02

000 100 200 300

H = 100

Figure 10 ZFCndashFC curves measured in an applied field of 100Oefor CoNPs (12 1)

value (Mr) was 206 emugminus1 and the coercivity was 323OeThemagnetization curves showedneither hysteresis nor coer-civity The saturated magnetization values (Ms) measuredat 100 200 and 300K were 456 416 and 362 emugminus1respectively

The temperature dependence of the magnetization wasmeasured under magnetic field of 100Oe from 5 to 300Kusing zero field-cooled (ZFC) and field-cooled (FC) proce-dure This measurement allowed determining the blockingtemperature of CoNPs The obtained ZFCndashFC curves ofCoNPs (12 1) nanocomposite are displayed in Figure 10Magnetization of CoNPs increased with the increase of thetemperature that is shown at the ZFC curve The wide

Table 2 Hydrodynamic diameter (119889ℎ) from NTAmeasurements ofnanoparticles boNPs in aqueous solution

boNPs 119889ℎ nmboNPs (8 1) 106 plusmn 15

boNPs (10 1) 107 plusmn 20

boNPs (12 1) 112 plusmn 10

boNPs (16 1) 123 plusmn 18

peak was observed at 100ndash170P with maximum at 140KThe maximum temperature is called blocking temperatureTb The thermal energy becomes comparable to the energybarrier of magnetic anisotropy for spin reorientation atblocking temperature

At a temperature of 300K discrepancy between the ZFCand FC curves was observed A sufficiently high temper-ature which characterizes the temperature of irreversiblemagnetic changes is associated with a wide size distributionof nanoparticles in the sample and strong interaction betweenthe particles [2]

The variations in size determined by different methodswere due to the fact that thesemethods rely ondifferent physi-cal principles andor detectionmethods In addition electronmicroscopy probes dry particles that is the metallic coreonly whereas the NTA probe the hydrodynamic diameterwhich is always larger The size predicted by TEM analysiswas found to be smaller than predicted by NTA analysis

According to the NTA method hydrodynamic diameterof CoNPs nanocomposite rose from 106 plusmn 15 to 123 plusmn 18 nm(Figure 11 Supplementary Figures S3 S4) with increase ofmolar ratio Co2+ BH20 however it was smaller than thediameter of respective complex forms of Co119899(BH20) (Table 2Supplementary Table S5)

The successful formation of CoNPswas first confirmed byTEM studies Figure 12 shows the TEMmicrographs and sizedistributions of CoNPs nanoparticles (12 1) obtained usingHBPO BH20 as a stabilizer The nanoparticles CoNPs (12 1)were approximately spherical with size about 82 plusmn 34 nmParticles have aggregated easily probably because of the highmobility of the particles as well as the magnetic interactionbetween the particles

4 Conclusions

Thus for the first time the process of preorganization of Co2+ions on the platform of a hyperbranched polyester polyolof the second generation was studied and the significantcomplex forms of Co119899(BH20) existing in an aqueous solutionwere determined The cobalt nanoparticles were synthesizedby the chemical reduction method in solution at variousmolar ratios of CoCl2 HBPO It is shown that an increase inthe concentration of Co2+ ions in the polymer matrix at thepreorganization stage leads to an increase in the proportion ofoxide forms in the composition of the nanoparticles CoNPssynthesized at the CoCl2 HBPO molar ratio of 12 1 havepossessed the highest stability They had spherical shapemoreover metallic nanoclusters of cobalt with a diameterof 82 plusmn 34 nm were in the polymer shell of the stabilizer

Journal of Nanotechnology 7

Con

ml E

6

162

57

79

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(a)

Con

ml E

6

43

57

9867

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(b)

Figure 11 Concentration and size distribution from NTA measurements of CoNPs (8 1) (a) and CoNPs (12 1) (b) in aqueous solution

500 HG

(a)

100 HG

(b)

3-4 5-6 7-8 9-10 11-12 13-14 15-160

5

10

15

20

25

30

Freq

uenc

y (

)

Particle size (nm)

Average particle size 82 plusmn 34 HG

(c)

Cps (

eV)

(keV)2 4 6 8

C

Co

Co

Co

Cu

Cu

Na

O

CuCl

04

03

02

01

0

(d)

Figure 12 TEM images CoNPs (12 1) (a b) corresponding particle-size distribution of CoNPs (c) and EDS spectrum (d) for the areacorresponding to (a) The Cu signals come from TEM grids

8 Journal of Nanotechnology

It has been proved that the polymer-composite nanoparti-cles CoBH20 (12 1) exhibit magnetic properties includingsuperparamagnetic properties at room temperature whichwill allow them to be used for further development of MRIdiagnostic systems as well as targeted drug delivery system

Conflicts of Interest

The authors O I Medvedeva S S Kambulova O V BondarA R Gataulina N A Ulakhovich A V Gerasimov V GEvtugyn I F Gilmutdinov and M P Kutyreva declare thatthere are no conflicts of interest regarding the publication ofthis paper

Acknowledgments

The magnetic measurements were carried out at the FederalCenter of Shared Facilities of Kazan Federal UniversityMicroscopy studies were carried out at the InterdisciplinaryCenter of AnalyticalMicroscopy of Kazan Federal UniversityThework is performed according to the Russian GovernmentProgram of Competitive Growth of Kazan Federal Univer-sity

References

[1] L Merhari Hybrid Nanocomposites for Nanotechnology Elec-tronic Optical Magnetic and Biomedical Applications SpringerBoston MA USA 2009

[2] S Gubin Magnetic Nanoparticles WILEY-VCH Verlag GmbHamp Co KGaA 2009

[3] Q A Pankhurst J Connolly S K Jones and J Dobson ldquoAppli-cations of magnetic nanoparticles in biomedicinerdquo Journal ofPhysics D Applied Physics vol 36 no 13 pp R167ndashR181 2003

[4] W H Suh Y H Suh and G D Stucky Nano Today vol 4 pp27ndash36 2009

[5] T K Indira and R K Lakshmi International Journal of Phar-maceutical Sciences and Nanotechnology vol 3 pp 1035ndash10422010

[6] P P Waifalkar S B Parit A D Chougale S C Sahoo P SPatil and P B Patil ldquoImmobilization of invertase on chitosancoated 120574-Fe2O3 magnetic nanoparticles to facilitate magneticseparationrdquo Journal of Colloid and Interface Science vol 482 pp159ndash164 2016

[7] J Chomoucka J Drbohlavova D Huska V Adam R Kizekand J Hubalek ldquoMagnetic nanoparticles and targeted drugdeliveringrdquo Pharmacological Research vol 62 no 2 pp 144ndash149 2010

[8] A M Nystrom and B Fadeel ldquoSafety assessment of nanoma-terials implications for nanomedicinerdquo Journal of ControlledRelease vol 161 no 2 pp 403ndash408 2012

[9] P Padmanabhan A Kumar S Kumar R K Chaudhary and BGulyas ldquoNanoparticles in practice formolecular-imaging appli-cations An overviewrdquoActa Biomaterialia vol 41 pp 1ndash16 2016

[10] R S Chaughule S Purushotham and R V Ramanujan ldquoMag-netic Nanoparticles as Contrast Agents forMagnetic ResonanceImagingrdquo Proceedings of the National Academy of Sciences IndiaSection A Physical Sciences vol 82 no 3 pp 257ndash268 2012

[11] J Verma S Lal and C J F van Noorden ldquoNanoparticles forhyperthermic therapy synthesis strategies and applications in

glioblastomardquo International Journal of Nanomedicine vol 9 no1 pp 2863ndash2877 2014

[12] N Shatrova A Yudin V Levina et al ldquoElaboration char-acterization and magnetic properties of cobalt nanoparticlessynthesized by ultrasonic spray pyrolysis followed by hydrogenreductionrdquoMaterials Research Bulletin vol 86 pp 80ndash87 2017

[13] H Shokrollahi and L Avazpour ldquoInfluence of intrinsic param-eters on the particle size of magnetic spinel nanoparticlessynthesized by wet chemical methodsrdquo Particuology vol 26 pp32ndash39 2016

[14] S Gopinath K Sivakumar B Karthikeyen C Ragupathi andR Sundaram ldquoStructural morphological optical and magneticproperties of Co3O4 nanoparticles prepared by conventionalmethodrdquo Physica E Low-Dimensional Systems and Nanostruc-tures vol 81 pp 66ndash70 2016

[15] L Pan L Li and C Yo ldquoSynthesis of hexagonal Co3O4 and Ag

Co3O4 composite nanosheets and their electrocatalytic perfor-mancesrdquo Journal of Cluster Science vol 24 no 4 pp 1001ndash10102013

[16] H T Yang Y K Su C M Shen T Z Yang and H J GaoldquoSynthesis and magnetic properties of 120576-cobalt nanoparticlesrdquoSurface and Interface Analysis vol 36 no 2 pp 155ndash160 2004

[17] Y Dong G Wang P Jiang A Zhang L Yue and X ZhangldquoCatalytic ozonation of phenol in aqueous solution by Co3O4nanoparticlesrdquo Bulletin of the Korean Chemical Society vol 31no 10 pp 2830ndash2834 2010

[18] Y Liang Y Li HWang et al ldquoCo3O4 nanocrystals on grapheneas a synergistic catalyst for oxygen reduction reactionrdquo NatureMaterials vol 10 no 10 pp 780ndash786 2011

[19] F Moro S V Tang F Tuna and E Lester ldquoDetection ofparandashantiferromagnetic transition in Bi2Fe4O9 powders bymeans of microwave absorption measurementsrdquo Journal ofMagnetism and Magnetic Materials vol 348 pp 17ndash21 2013

[20] J Park X Shen and GWang ldquoSolvothermal synthesis and gas-sensing performance of Co3O4 hollow nanospheresrdquo Sensorsand Actuators B Chemical vol 136 no 2 pp 494ndash498 2009

[21] Y Xu CWang Y Sun G Zhang and D Gao ldquoFabrication andcharacterization of nearly monodisperse Co3O4 nanospheresrdquoMaterials Letters vol 64 no 11 pp 1275ndash1278 2010

[22] H Bonnemann W Brijoux R Brinkmann et al ldquoA size-selective synthesis of air stable colloidal magnetic cobalt nano-particlesrdquo Inorganica Chimica Acta vol 350 pp 617ndash624 2003

[23] M Edrissi and A R Keshavarz ldquoSynthesis of cobalt chromitenanoparticles by thermolysis of mixed Cr3+ and Co2+ chelatesof 2-mercaptopyridin N-Oxiderdquo Nano-Micro Letters vol 4 no2 pp 83ndash89 2012

[24] S A Novopashin M A Serebryakova and S Y Khmel ldquoMeth-ods of magnetic fluid synthesis (review)rdquo Thermophysics andAeromechanics vol 22 no 4 pp 397ndash412 2015

[25] S A Usami ldquoSynthesis and Characterization of Cobalt Nano-particlesUsingHydrazine andCitricAcidrdquo Journal of Nanotech-nology vol 2014 Article ID 525193 6 pages 2014

[26] J P Rao P Gruenberg and K E Geckeler ldquoMagnetic zero-valent metal polymer nanoparticles Current trends scope andperspectivesrdquo Progress in Polymer Science vol 40 pp 138ndash1472015

[27] M Zhao L Sun and R M Crooks ldquoPreparation of Cu nan-oclusters within dendrimer templatesrdquo Journal of the AmericanChemical Society vol 120 no 19 pp 4877-4878 1998

Journal of Nanotechnology 9

[28] H Kavas Z Durmus E Tanriverdi M Senel H Sozeri andA Baykal ldquoFabrication and characterization of dendrimer-encapsulated monometallic Co nanoparticlesrdquo Journal of Alloysand Compounds vol 509 no 17 pp 5341ndash5348 2011

[29] H-X Wu C-X Zhang L Jin H Yang and S-P YangldquoPreparation and magnetic properties of cobalt nanoparticleswith dendrimers as templatesrdquoMaterials Chemistry and Physicsvol 121 no 1-2 pp 342ndash348 2010

[30] K Aranishi Q-L Zhu and Q Xu ldquoDendrimer-EncapsulatedCobalt Nanoparticles as High-Performance Catalysts for theHydrolysis of Ammonia Boranerdquo Chem Cat Chem vol 6 no5 pp 1375ndash1379 2014

[31] K InoueK Prog Polym Sci vol 25 pp 453ndash571 2000[32] B I Voit and A Lederer ldquoHyperbranched and highly branched

polymer architectures-synthetic strategies andmajor character-ization aspectsrdquo Chemical Reviews vol 109 no 11 pp 5924ndash5973 2009

[33] E Zagar and J Grdadolnik ldquoAn infrared spectroscopic study ofH-bond network in hyperbranched polyester polyolrdquo Journal ofMolecular Structure vol 658 no 3 pp 143ndash152 2003

[34] E Zagar and M Zigon ldquoAliphatic hyperbranched polyestersbased on 22-bis(methylol)propionic acidmdashDetermination ofstructure solution and bulk propertiesrdquo Progress in PolymerScience vol 36 no 1 pp 53ndash88 2011

[35] R Arote T-H Kim Y-K Hwang et al ldquoA biodegradablepoly(ester amine) based on polycaprolactone and polyethylen-imine as a gene carrierrdquo Biomaterials vol 28 pp 735ndash744 2007

[36] L M Bronstein and Z B Shifrina ldquoNanoparticles in den-drimers From synthesis to applicationrdquo Nanotechnologies inRussia vol 4 no 9-10 pp 576ndash608 2009

[37] R A Ahmadi F Hasanvand G Bruno H A Rudbari SAmani and J Beilstein ldquoSynthesis Spectroscopy andMagneticCharacterization of Copper(II) and Cobalt(II) Complexes with2-Amino-5-bromopyridine as Ligandrdquo ISRN Inorganic Chem-istry vol 2013 Article ID 426712 7 pages 2013

[38] P Petkova and V Nedkov ldquoBehavior of Co2+ cations in theaqueous and alcoholic solution of CoCl26H2Ordquo Acta PhysicaPolonica A vol 123 no 2 pp 207-208 2013

[39] O Metin and S Ozkar ldquoWater soluble nickel(0) and cobalt(0)nanoclusters stabilized by poly(4-styrenesulfonic acid-co-maleic acid) Highly active durable and cost effective catalystsin hydrogen generation from the hydrolysis of ammoniaboranerdquo International Journal of Hydrogen Energy vol 36 no2 pp 1424ndash1432 2011

[40] S Karahan and S Ozkar ldquoPoly(4-styrenesulfonic acid-co-maleic acid) stabilized cobalt(0) nanoparticles A cost-effectiveand magnetically recoverable catalyst in hydrogen generationfrom the hydrolysis of hydrazine boranerdquo International Journalof Hydrogen Energy vol 40 no 5 pp 2255ndash2265 2015

[41] LMAlrehaily JM JosephMC BiesingerDAGuzonas andJ CWren ldquoGamma-radiolysis-assisted cobalt oxide nanoparti-cle formationrdquo Physical Chemistry Chemical Physics vol 15 no3 pp 1014ndash1024 2013

[42] M Yarestani A D Khalaji A Rohani and D Das ldquoHydrother-mal synthesis of cobalt oxide nanoparticles Its optical andmagnetic propertiesrdquo Journal of Sciences Islamic Republic ofIran vol 25 no 4 pp 339ndash343 2014

[43] F A Miller and C H Wilkins ldquoInfrared spectra and charac-teristic frequencies of inorganic ions their use in qualitativeanalysisrdquo Analytical Chemistry vol 24 no 8 pp 1253ndash12941952

Submit your manuscripts athttpswwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Page 7: Magnetic Cobalt and Cobalt Oxide Nanoparticles in ...downloads.hindawi.com/journals/jnt/2017/7607658.pdf · ResearchArticle Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched

Journal of Nanotechnology 7

Con

ml E

6

162

57

79

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(a)

Con

ml E

6

43

57

9867

0 100 200 300 400 500 600 700 800 900

(nm)

100

90

80

70

60

50

40

30

20

10

Cum

()

Con

par

ticle

sm

l E6

Particle sizeconcentration(b)

Figure 11 Concentration and size distribution from NTA measurements of CoNPs (8 1) (a) and CoNPs (12 1) (b) in aqueous solution

500 HG

(a)

100 HG

(b)

3-4 5-6 7-8 9-10 11-12 13-14 15-160

5

10

15

20

25

30

Freq

uenc

y (

)

Particle size (nm)

Average particle size 82 plusmn 34 HG

(c)

Cps (

eV)

(keV)2 4 6 8

C

Co

Co

Co

Cu

Cu

Na

O

CuCl

04

03

02

01

0

(d)

Figure 12 TEM images CoNPs (12 1) (a b) corresponding particle-size distribution of CoNPs (c) and EDS spectrum (d) for the areacorresponding to (a) The Cu signals come from TEM grids

8 Journal of Nanotechnology

It has been proved that the polymer-composite nanoparti-cles CoBH20 (12 1) exhibit magnetic properties includingsuperparamagnetic properties at room temperature whichwill allow them to be used for further development of MRIdiagnostic systems as well as targeted drug delivery system

Conflicts of Interest

The authors O I Medvedeva S S Kambulova O V BondarA R Gataulina N A Ulakhovich A V Gerasimov V GEvtugyn I F Gilmutdinov and M P Kutyreva declare thatthere are no conflicts of interest regarding the publication ofthis paper

Acknowledgments

The magnetic measurements were carried out at the FederalCenter of Shared Facilities of Kazan Federal UniversityMicroscopy studies were carried out at the InterdisciplinaryCenter of AnalyticalMicroscopy of Kazan Federal UniversityThework is performed according to the Russian GovernmentProgram of Competitive Growth of Kazan Federal Univer-sity

References

[1] L Merhari Hybrid Nanocomposites for Nanotechnology Elec-tronic Optical Magnetic and Biomedical Applications SpringerBoston MA USA 2009

[2] S Gubin Magnetic Nanoparticles WILEY-VCH Verlag GmbHamp Co KGaA 2009

[3] Q A Pankhurst J Connolly S K Jones and J Dobson ldquoAppli-cations of magnetic nanoparticles in biomedicinerdquo Journal ofPhysics D Applied Physics vol 36 no 13 pp R167ndashR181 2003

[4] W H Suh Y H Suh and G D Stucky Nano Today vol 4 pp27ndash36 2009

[5] T K Indira and R K Lakshmi International Journal of Phar-maceutical Sciences and Nanotechnology vol 3 pp 1035ndash10422010

[6] P P Waifalkar S B Parit A D Chougale S C Sahoo P SPatil and P B Patil ldquoImmobilization of invertase on chitosancoated 120574-Fe2O3 magnetic nanoparticles to facilitate magneticseparationrdquo Journal of Colloid and Interface Science vol 482 pp159ndash164 2016

[7] J Chomoucka J Drbohlavova D Huska V Adam R Kizekand J Hubalek ldquoMagnetic nanoparticles and targeted drugdeliveringrdquo Pharmacological Research vol 62 no 2 pp 144ndash149 2010

[8] A M Nystrom and B Fadeel ldquoSafety assessment of nanoma-terials implications for nanomedicinerdquo Journal of ControlledRelease vol 161 no 2 pp 403ndash408 2012

[9] P Padmanabhan A Kumar S Kumar R K Chaudhary and BGulyas ldquoNanoparticles in practice formolecular-imaging appli-cations An overviewrdquoActa Biomaterialia vol 41 pp 1ndash16 2016

[10] R S Chaughule S Purushotham and R V Ramanujan ldquoMag-netic Nanoparticles as Contrast Agents forMagnetic ResonanceImagingrdquo Proceedings of the National Academy of Sciences IndiaSection A Physical Sciences vol 82 no 3 pp 257ndash268 2012

[11] J Verma S Lal and C J F van Noorden ldquoNanoparticles forhyperthermic therapy synthesis strategies and applications in

glioblastomardquo International Journal of Nanomedicine vol 9 no1 pp 2863ndash2877 2014

[12] N Shatrova A Yudin V Levina et al ldquoElaboration char-acterization and magnetic properties of cobalt nanoparticlessynthesized by ultrasonic spray pyrolysis followed by hydrogenreductionrdquoMaterials Research Bulletin vol 86 pp 80ndash87 2017

[13] H Shokrollahi and L Avazpour ldquoInfluence of intrinsic param-eters on the particle size of magnetic spinel nanoparticlessynthesized by wet chemical methodsrdquo Particuology vol 26 pp32ndash39 2016

[14] S Gopinath K Sivakumar B Karthikeyen C Ragupathi andR Sundaram ldquoStructural morphological optical and magneticproperties of Co3O4 nanoparticles prepared by conventionalmethodrdquo Physica E Low-Dimensional Systems and Nanostruc-tures vol 81 pp 66ndash70 2016

[15] L Pan L Li and C Yo ldquoSynthesis of hexagonal Co3O4 and Ag

Co3O4 composite nanosheets and their electrocatalytic perfor-mancesrdquo Journal of Cluster Science vol 24 no 4 pp 1001ndash10102013

[16] H T Yang Y K Su C M Shen T Z Yang and H J GaoldquoSynthesis and magnetic properties of 120576-cobalt nanoparticlesrdquoSurface and Interface Analysis vol 36 no 2 pp 155ndash160 2004

[17] Y Dong G Wang P Jiang A Zhang L Yue and X ZhangldquoCatalytic ozonation of phenol in aqueous solution by Co3O4nanoparticlesrdquo Bulletin of the Korean Chemical Society vol 31no 10 pp 2830ndash2834 2010

[18] Y Liang Y Li HWang et al ldquoCo3O4 nanocrystals on grapheneas a synergistic catalyst for oxygen reduction reactionrdquo NatureMaterials vol 10 no 10 pp 780ndash786 2011

[19] F Moro S V Tang F Tuna and E Lester ldquoDetection ofparandashantiferromagnetic transition in Bi2Fe4O9 powders bymeans of microwave absorption measurementsrdquo Journal ofMagnetism and Magnetic Materials vol 348 pp 17ndash21 2013

[20] J Park X Shen and GWang ldquoSolvothermal synthesis and gas-sensing performance of Co3O4 hollow nanospheresrdquo Sensorsand Actuators B Chemical vol 136 no 2 pp 494ndash498 2009

[21] Y Xu CWang Y Sun G Zhang and D Gao ldquoFabrication andcharacterization of nearly monodisperse Co3O4 nanospheresrdquoMaterials Letters vol 64 no 11 pp 1275ndash1278 2010

[22] H Bonnemann W Brijoux R Brinkmann et al ldquoA size-selective synthesis of air stable colloidal magnetic cobalt nano-particlesrdquo Inorganica Chimica Acta vol 350 pp 617ndash624 2003

[23] M Edrissi and A R Keshavarz ldquoSynthesis of cobalt chromitenanoparticles by thermolysis of mixed Cr3+ and Co2+ chelatesof 2-mercaptopyridin N-Oxiderdquo Nano-Micro Letters vol 4 no2 pp 83ndash89 2012

[24] S A Novopashin M A Serebryakova and S Y Khmel ldquoMeth-ods of magnetic fluid synthesis (review)rdquo Thermophysics andAeromechanics vol 22 no 4 pp 397ndash412 2015

[25] S A Usami ldquoSynthesis and Characterization of Cobalt Nano-particlesUsingHydrazine andCitricAcidrdquo Journal of Nanotech-nology vol 2014 Article ID 525193 6 pages 2014

[26] J P Rao P Gruenberg and K E Geckeler ldquoMagnetic zero-valent metal polymer nanoparticles Current trends scope andperspectivesrdquo Progress in Polymer Science vol 40 pp 138ndash1472015

[27] M Zhao L Sun and R M Crooks ldquoPreparation of Cu nan-oclusters within dendrimer templatesrdquo Journal of the AmericanChemical Society vol 120 no 19 pp 4877-4878 1998

Journal of Nanotechnology 9

[28] H Kavas Z Durmus E Tanriverdi M Senel H Sozeri andA Baykal ldquoFabrication and characterization of dendrimer-encapsulated monometallic Co nanoparticlesrdquo Journal of Alloysand Compounds vol 509 no 17 pp 5341ndash5348 2011

[29] H-X Wu C-X Zhang L Jin H Yang and S-P YangldquoPreparation and magnetic properties of cobalt nanoparticleswith dendrimers as templatesrdquoMaterials Chemistry and Physicsvol 121 no 1-2 pp 342ndash348 2010

[30] K Aranishi Q-L Zhu and Q Xu ldquoDendrimer-EncapsulatedCobalt Nanoparticles as High-Performance Catalysts for theHydrolysis of Ammonia Boranerdquo Chem Cat Chem vol 6 no5 pp 1375ndash1379 2014

[31] K InoueK Prog Polym Sci vol 25 pp 453ndash571 2000[32] B I Voit and A Lederer ldquoHyperbranched and highly branched

polymer architectures-synthetic strategies andmajor character-ization aspectsrdquo Chemical Reviews vol 109 no 11 pp 5924ndash5973 2009

[33] E Zagar and J Grdadolnik ldquoAn infrared spectroscopic study ofH-bond network in hyperbranched polyester polyolrdquo Journal ofMolecular Structure vol 658 no 3 pp 143ndash152 2003

[34] E Zagar and M Zigon ldquoAliphatic hyperbranched polyestersbased on 22-bis(methylol)propionic acidmdashDetermination ofstructure solution and bulk propertiesrdquo Progress in PolymerScience vol 36 no 1 pp 53ndash88 2011

[35] R Arote T-H Kim Y-K Hwang et al ldquoA biodegradablepoly(ester amine) based on polycaprolactone and polyethylen-imine as a gene carrierrdquo Biomaterials vol 28 pp 735ndash744 2007

[36] L M Bronstein and Z B Shifrina ldquoNanoparticles in den-drimers From synthesis to applicationrdquo Nanotechnologies inRussia vol 4 no 9-10 pp 576ndash608 2009

[37] R A Ahmadi F Hasanvand G Bruno H A Rudbari SAmani and J Beilstein ldquoSynthesis Spectroscopy andMagneticCharacterization of Copper(II) and Cobalt(II) Complexes with2-Amino-5-bromopyridine as Ligandrdquo ISRN Inorganic Chem-istry vol 2013 Article ID 426712 7 pages 2013

[38] P Petkova and V Nedkov ldquoBehavior of Co2+ cations in theaqueous and alcoholic solution of CoCl26H2Ordquo Acta PhysicaPolonica A vol 123 no 2 pp 207-208 2013

[39] O Metin and S Ozkar ldquoWater soluble nickel(0) and cobalt(0)nanoclusters stabilized by poly(4-styrenesulfonic acid-co-maleic acid) Highly active durable and cost effective catalystsin hydrogen generation from the hydrolysis of ammoniaboranerdquo International Journal of Hydrogen Energy vol 36 no2 pp 1424ndash1432 2011

[40] S Karahan and S Ozkar ldquoPoly(4-styrenesulfonic acid-co-maleic acid) stabilized cobalt(0) nanoparticles A cost-effectiveand magnetically recoverable catalyst in hydrogen generationfrom the hydrolysis of hydrazine boranerdquo International Journalof Hydrogen Energy vol 40 no 5 pp 2255ndash2265 2015

[41] LMAlrehaily JM JosephMC BiesingerDAGuzonas andJ CWren ldquoGamma-radiolysis-assisted cobalt oxide nanoparti-cle formationrdquo Physical Chemistry Chemical Physics vol 15 no3 pp 1014ndash1024 2013

[42] M Yarestani A D Khalaji A Rohani and D Das ldquoHydrother-mal synthesis of cobalt oxide nanoparticles Its optical andmagnetic propertiesrdquo Journal of Sciences Islamic Republic ofIran vol 25 no 4 pp 339ndash343 2014

[43] F A Miller and C H Wilkins ldquoInfrared spectra and charac-teristic frequencies of inorganic ions their use in qualitativeanalysisrdquo Analytical Chemistry vol 24 no 8 pp 1253ndash12941952

Submit your manuscripts athttpswwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Page 8: Magnetic Cobalt and Cobalt Oxide Nanoparticles in ...downloads.hindawi.com/journals/jnt/2017/7607658.pdf · ResearchArticle Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched

8 Journal of Nanotechnology

It has been proved that the polymer-composite nanoparti-cles CoBH20 (12 1) exhibit magnetic properties includingsuperparamagnetic properties at room temperature whichwill allow them to be used for further development of MRIdiagnostic systems as well as targeted drug delivery system

Conflicts of Interest

The authors O I Medvedeva S S Kambulova O V BondarA R Gataulina N A Ulakhovich A V Gerasimov V GEvtugyn I F Gilmutdinov and M P Kutyreva declare thatthere are no conflicts of interest regarding the publication ofthis paper

Acknowledgments

The magnetic measurements were carried out at the FederalCenter of Shared Facilities of Kazan Federal UniversityMicroscopy studies were carried out at the InterdisciplinaryCenter of AnalyticalMicroscopy of Kazan Federal UniversityThework is performed according to the Russian GovernmentProgram of Competitive Growth of Kazan Federal Univer-sity

References

[1] L Merhari Hybrid Nanocomposites for Nanotechnology Elec-tronic Optical Magnetic and Biomedical Applications SpringerBoston MA USA 2009

[2] S Gubin Magnetic Nanoparticles WILEY-VCH Verlag GmbHamp Co KGaA 2009

[3] Q A Pankhurst J Connolly S K Jones and J Dobson ldquoAppli-cations of magnetic nanoparticles in biomedicinerdquo Journal ofPhysics D Applied Physics vol 36 no 13 pp R167ndashR181 2003

[4] W H Suh Y H Suh and G D Stucky Nano Today vol 4 pp27ndash36 2009

[5] T K Indira and R K Lakshmi International Journal of Phar-maceutical Sciences and Nanotechnology vol 3 pp 1035ndash10422010

[6] P P Waifalkar S B Parit A D Chougale S C Sahoo P SPatil and P B Patil ldquoImmobilization of invertase on chitosancoated 120574-Fe2O3 magnetic nanoparticles to facilitate magneticseparationrdquo Journal of Colloid and Interface Science vol 482 pp159ndash164 2016

[7] J Chomoucka J Drbohlavova D Huska V Adam R Kizekand J Hubalek ldquoMagnetic nanoparticles and targeted drugdeliveringrdquo Pharmacological Research vol 62 no 2 pp 144ndash149 2010

[8] A M Nystrom and B Fadeel ldquoSafety assessment of nanoma-terials implications for nanomedicinerdquo Journal of ControlledRelease vol 161 no 2 pp 403ndash408 2012

[9] P Padmanabhan A Kumar S Kumar R K Chaudhary and BGulyas ldquoNanoparticles in practice formolecular-imaging appli-cations An overviewrdquoActa Biomaterialia vol 41 pp 1ndash16 2016

[10] R S Chaughule S Purushotham and R V Ramanujan ldquoMag-netic Nanoparticles as Contrast Agents forMagnetic ResonanceImagingrdquo Proceedings of the National Academy of Sciences IndiaSection A Physical Sciences vol 82 no 3 pp 257ndash268 2012

[11] J Verma S Lal and C J F van Noorden ldquoNanoparticles forhyperthermic therapy synthesis strategies and applications in

glioblastomardquo International Journal of Nanomedicine vol 9 no1 pp 2863ndash2877 2014

[12] N Shatrova A Yudin V Levina et al ldquoElaboration char-acterization and magnetic properties of cobalt nanoparticlessynthesized by ultrasonic spray pyrolysis followed by hydrogenreductionrdquoMaterials Research Bulletin vol 86 pp 80ndash87 2017

[13] H Shokrollahi and L Avazpour ldquoInfluence of intrinsic param-eters on the particle size of magnetic spinel nanoparticlessynthesized by wet chemical methodsrdquo Particuology vol 26 pp32ndash39 2016

[14] S Gopinath K Sivakumar B Karthikeyen C Ragupathi andR Sundaram ldquoStructural morphological optical and magneticproperties of Co3O4 nanoparticles prepared by conventionalmethodrdquo Physica E Low-Dimensional Systems and Nanostruc-tures vol 81 pp 66ndash70 2016

[15] L Pan L Li and C Yo ldquoSynthesis of hexagonal Co3O4 and Ag

Co3O4 composite nanosheets and their electrocatalytic perfor-mancesrdquo Journal of Cluster Science vol 24 no 4 pp 1001ndash10102013

[16] H T Yang Y K Su C M Shen T Z Yang and H J GaoldquoSynthesis and magnetic properties of 120576-cobalt nanoparticlesrdquoSurface and Interface Analysis vol 36 no 2 pp 155ndash160 2004

[17] Y Dong G Wang P Jiang A Zhang L Yue and X ZhangldquoCatalytic ozonation of phenol in aqueous solution by Co3O4nanoparticlesrdquo Bulletin of the Korean Chemical Society vol 31no 10 pp 2830ndash2834 2010

[18] Y Liang Y Li HWang et al ldquoCo3O4 nanocrystals on grapheneas a synergistic catalyst for oxygen reduction reactionrdquo NatureMaterials vol 10 no 10 pp 780ndash786 2011

[19] F Moro S V Tang F Tuna and E Lester ldquoDetection ofparandashantiferromagnetic transition in Bi2Fe4O9 powders bymeans of microwave absorption measurementsrdquo Journal ofMagnetism and Magnetic Materials vol 348 pp 17ndash21 2013

[20] J Park X Shen and GWang ldquoSolvothermal synthesis and gas-sensing performance of Co3O4 hollow nanospheresrdquo Sensorsand Actuators B Chemical vol 136 no 2 pp 494ndash498 2009

[21] Y Xu CWang Y Sun G Zhang and D Gao ldquoFabrication andcharacterization of nearly monodisperse Co3O4 nanospheresrdquoMaterials Letters vol 64 no 11 pp 1275ndash1278 2010

[22] H Bonnemann W Brijoux R Brinkmann et al ldquoA size-selective synthesis of air stable colloidal magnetic cobalt nano-particlesrdquo Inorganica Chimica Acta vol 350 pp 617ndash624 2003

[23] M Edrissi and A R Keshavarz ldquoSynthesis of cobalt chromitenanoparticles by thermolysis of mixed Cr3+ and Co2+ chelatesof 2-mercaptopyridin N-Oxiderdquo Nano-Micro Letters vol 4 no2 pp 83ndash89 2012

[24] S A Novopashin M A Serebryakova and S Y Khmel ldquoMeth-ods of magnetic fluid synthesis (review)rdquo Thermophysics andAeromechanics vol 22 no 4 pp 397ndash412 2015

[25] S A Usami ldquoSynthesis and Characterization of Cobalt Nano-particlesUsingHydrazine andCitricAcidrdquo Journal of Nanotech-nology vol 2014 Article ID 525193 6 pages 2014

[26] J P Rao P Gruenberg and K E Geckeler ldquoMagnetic zero-valent metal polymer nanoparticles Current trends scope andperspectivesrdquo Progress in Polymer Science vol 40 pp 138ndash1472015

[27] M Zhao L Sun and R M Crooks ldquoPreparation of Cu nan-oclusters within dendrimer templatesrdquo Journal of the AmericanChemical Society vol 120 no 19 pp 4877-4878 1998

Journal of Nanotechnology 9

[28] H Kavas Z Durmus E Tanriverdi M Senel H Sozeri andA Baykal ldquoFabrication and characterization of dendrimer-encapsulated monometallic Co nanoparticlesrdquo Journal of Alloysand Compounds vol 509 no 17 pp 5341ndash5348 2011

[29] H-X Wu C-X Zhang L Jin H Yang and S-P YangldquoPreparation and magnetic properties of cobalt nanoparticleswith dendrimers as templatesrdquoMaterials Chemistry and Physicsvol 121 no 1-2 pp 342ndash348 2010

[30] K Aranishi Q-L Zhu and Q Xu ldquoDendrimer-EncapsulatedCobalt Nanoparticles as High-Performance Catalysts for theHydrolysis of Ammonia Boranerdquo Chem Cat Chem vol 6 no5 pp 1375ndash1379 2014

[31] K InoueK Prog Polym Sci vol 25 pp 453ndash571 2000[32] B I Voit and A Lederer ldquoHyperbranched and highly branched

polymer architectures-synthetic strategies andmajor character-ization aspectsrdquo Chemical Reviews vol 109 no 11 pp 5924ndash5973 2009

[33] E Zagar and J Grdadolnik ldquoAn infrared spectroscopic study ofH-bond network in hyperbranched polyester polyolrdquo Journal ofMolecular Structure vol 658 no 3 pp 143ndash152 2003

[34] E Zagar and M Zigon ldquoAliphatic hyperbranched polyestersbased on 22-bis(methylol)propionic acidmdashDetermination ofstructure solution and bulk propertiesrdquo Progress in PolymerScience vol 36 no 1 pp 53ndash88 2011

[35] R Arote T-H Kim Y-K Hwang et al ldquoA biodegradablepoly(ester amine) based on polycaprolactone and polyethylen-imine as a gene carrierrdquo Biomaterials vol 28 pp 735ndash744 2007

[36] L M Bronstein and Z B Shifrina ldquoNanoparticles in den-drimers From synthesis to applicationrdquo Nanotechnologies inRussia vol 4 no 9-10 pp 576ndash608 2009

[37] R A Ahmadi F Hasanvand G Bruno H A Rudbari SAmani and J Beilstein ldquoSynthesis Spectroscopy andMagneticCharacterization of Copper(II) and Cobalt(II) Complexes with2-Amino-5-bromopyridine as Ligandrdquo ISRN Inorganic Chem-istry vol 2013 Article ID 426712 7 pages 2013

[38] P Petkova and V Nedkov ldquoBehavior of Co2+ cations in theaqueous and alcoholic solution of CoCl26H2Ordquo Acta PhysicaPolonica A vol 123 no 2 pp 207-208 2013

[39] O Metin and S Ozkar ldquoWater soluble nickel(0) and cobalt(0)nanoclusters stabilized by poly(4-styrenesulfonic acid-co-maleic acid) Highly active durable and cost effective catalystsin hydrogen generation from the hydrolysis of ammoniaboranerdquo International Journal of Hydrogen Energy vol 36 no2 pp 1424ndash1432 2011

[40] S Karahan and S Ozkar ldquoPoly(4-styrenesulfonic acid-co-maleic acid) stabilized cobalt(0) nanoparticles A cost-effectiveand magnetically recoverable catalyst in hydrogen generationfrom the hydrolysis of hydrazine boranerdquo International Journalof Hydrogen Energy vol 40 no 5 pp 2255ndash2265 2015

[41] LMAlrehaily JM JosephMC BiesingerDAGuzonas andJ CWren ldquoGamma-radiolysis-assisted cobalt oxide nanoparti-cle formationrdquo Physical Chemistry Chemical Physics vol 15 no3 pp 1014ndash1024 2013

[42] M Yarestani A D Khalaji A Rohani and D Das ldquoHydrother-mal synthesis of cobalt oxide nanoparticles Its optical andmagnetic propertiesrdquo Journal of Sciences Islamic Republic ofIran vol 25 no 4 pp 339ndash343 2014

[43] F A Miller and C H Wilkins ldquoInfrared spectra and charac-teristic frequencies of inorganic ions their use in qualitativeanalysisrdquo Analytical Chemistry vol 24 no 8 pp 1253ndash12941952

Submit your manuscripts athttpswwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Page 9: Magnetic Cobalt and Cobalt Oxide Nanoparticles in ...downloads.hindawi.com/journals/jnt/2017/7607658.pdf · ResearchArticle Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched

Journal of Nanotechnology 9

[28] H Kavas Z Durmus E Tanriverdi M Senel H Sozeri andA Baykal ldquoFabrication and characterization of dendrimer-encapsulated monometallic Co nanoparticlesrdquo Journal of Alloysand Compounds vol 509 no 17 pp 5341ndash5348 2011

[29] H-X Wu C-X Zhang L Jin H Yang and S-P YangldquoPreparation and magnetic properties of cobalt nanoparticleswith dendrimers as templatesrdquoMaterials Chemistry and Physicsvol 121 no 1-2 pp 342ndash348 2010

[30] K Aranishi Q-L Zhu and Q Xu ldquoDendrimer-EncapsulatedCobalt Nanoparticles as High-Performance Catalysts for theHydrolysis of Ammonia Boranerdquo Chem Cat Chem vol 6 no5 pp 1375ndash1379 2014

[31] K InoueK Prog Polym Sci vol 25 pp 453ndash571 2000[32] B I Voit and A Lederer ldquoHyperbranched and highly branched

polymer architectures-synthetic strategies andmajor character-ization aspectsrdquo Chemical Reviews vol 109 no 11 pp 5924ndash5973 2009

[33] E Zagar and J Grdadolnik ldquoAn infrared spectroscopic study ofH-bond network in hyperbranched polyester polyolrdquo Journal ofMolecular Structure vol 658 no 3 pp 143ndash152 2003

[34] E Zagar and M Zigon ldquoAliphatic hyperbranched polyestersbased on 22-bis(methylol)propionic acidmdashDetermination ofstructure solution and bulk propertiesrdquo Progress in PolymerScience vol 36 no 1 pp 53ndash88 2011

[35] R Arote T-H Kim Y-K Hwang et al ldquoA biodegradablepoly(ester amine) based on polycaprolactone and polyethylen-imine as a gene carrierrdquo Biomaterials vol 28 pp 735ndash744 2007

[36] L M Bronstein and Z B Shifrina ldquoNanoparticles in den-drimers From synthesis to applicationrdquo Nanotechnologies inRussia vol 4 no 9-10 pp 576ndash608 2009

[37] R A Ahmadi F Hasanvand G Bruno H A Rudbari SAmani and J Beilstein ldquoSynthesis Spectroscopy andMagneticCharacterization of Copper(II) and Cobalt(II) Complexes with2-Amino-5-bromopyridine as Ligandrdquo ISRN Inorganic Chem-istry vol 2013 Article ID 426712 7 pages 2013

[38] P Petkova and V Nedkov ldquoBehavior of Co2+ cations in theaqueous and alcoholic solution of CoCl26H2Ordquo Acta PhysicaPolonica A vol 123 no 2 pp 207-208 2013

[39] O Metin and S Ozkar ldquoWater soluble nickel(0) and cobalt(0)nanoclusters stabilized by poly(4-styrenesulfonic acid-co-maleic acid) Highly active durable and cost effective catalystsin hydrogen generation from the hydrolysis of ammoniaboranerdquo International Journal of Hydrogen Energy vol 36 no2 pp 1424ndash1432 2011

[40] S Karahan and S Ozkar ldquoPoly(4-styrenesulfonic acid-co-maleic acid) stabilized cobalt(0) nanoparticles A cost-effectiveand magnetically recoverable catalyst in hydrogen generationfrom the hydrolysis of hydrazine boranerdquo International Journalof Hydrogen Energy vol 40 no 5 pp 2255ndash2265 2015

[41] LMAlrehaily JM JosephMC BiesingerDAGuzonas andJ CWren ldquoGamma-radiolysis-assisted cobalt oxide nanoparti-cle formationrdquo Physical Chemistry Chemical Physics vol 15 no3 pp 1014ndash1024 2013

[42] M Yarestani A D Khalaji A Rohani and D Das ldquoHydrother-mal synthesis of cobalt oxide nanoparticles Its optical andmagnetic propertiesrdquo Journal of Sciences Islamic Republic ofIran vol 25 no 4 pp 339ndash343 2014

[43] F A Miller and C H Wilkins ldquoInfrared spectra and charac-teristic frequencies of inorganic ions their use in qualitativeanalysisrdquo Analytical Chemistry vol 24 no 8 pp 1253ndash12941952

Submit your manuscripts athttpswwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Page 10: Magnetic Cobalt and Cobalt Oxide Nanoparticles in ...downloads.hindawi.com/journals/jnt/2017/7607658.pdf · ResearchArticle Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched

Submit your manuscripts athttpswwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


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