Chapters Phase II

7/29/2019 Chapters Phase II

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CHAPTER 1

INTRODUCTION

Paint is a viscous suspension containing binder, solvent, pigments, extenders and other

additives. The binder can be natural drying oil or resin. The solvent is added to the binder to

adjust its consistency so as to be convenient for application on a substrate in required thickness

depending upon the method of application used.

Most paints include at least four groups of components: binders, volatile substances,

pigments, and additives.

1.1 Pigments

Pigments are generally added in considerable proportion (360% by weight) to paint

formulations and are used to provide color, opacity, and sheen. They also affect the viscosity,

flow, toughness, durability, and other physical or chemical properties of the coating, such as

corrosion protection.

Pigments can be classified as either natural or synthetic types. Natural pigments include

various clays, calcium carbonate, mica, silica, talc etc. Synthetics would include engineered

molecules, calcined clays, precipitated calcium carbonate, and synthetic pyrogenic silica, etc.

The most important and established uses for organic pigments include the coloration of

coating compositions for interior, exterior, trade and automotive applications, including oil and

water emulsion paints and lacquers. Azo pigments are formed by successive diazotization of a

primary amine and coupling.

Inorganic pigments are an integral part of numerous decorative, protective and functional

coating systems, as found in automobile finishes, marine paints, industrial coatings, maintenance

paints, and exterior and interior oil, alkyd and latex house paints.

1.2 FillersFillers are a special type of materials that serves to thicken the film, support its structure

and simply increase the volume of the paint. Fillers are usually made of cheap and inert materials

like talc, lime, clay, etc. Floor paints that will be subjected to abrasion may even contain fine

quartz sand as filler. Not all paints include fillers. On the other hand some paints contain very

large proportions of filler.

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http://en.wikipedia.org/wiki/Clayhttp://en.wikipedia.org/wiki/Calcium_carbonatehttp://en.wikipedia.org/wiki/Micahttp://en.wikipedia.org/wiki/Micahttp://en.wikipedia.org/wiki/Silicahttp://en.wikipedia.org/wiki/Talchttp://en.wikipedia.org/wiki/Calcininghttp://en.wikipedia.org/wiki/Calcium_carbonatehttp://en.wikipedia.org/wiki/Talchttp://en.wikipedia.org/wiki/Talchttp://en.wikipedia.org/wiki/Lime_(mineral)http://en.wikipedia.org/wiki/Calcium_carbonatehttp://en.wikipedia.org/wiki/Micahttp://en.wikipedia.org/wiki/Silicahttp://en.wikipedia.org/wiki/Talchttp://en.wikipedia.org/wiki/Calcininghttp://en.wikipedia.org/wiki/Calcium_carbonatehttp://en.wikipedia.org/wiki/Talchttp://en.wikipedia.org/wiki/Lime_(mineral)http://en.wikipedia.org/wiki/Clay


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1.3 Binder/vehicle/resin

The binder, commonly referred to as the vehicle, is the actual film forming component of

paint. It is the only component that must be present; other components listed below are included

optionally, depending on the desired properties of the cured film. The binder imparts adhesion,

binds the pigments together, and strongly influences such properties as gloss potential, exterior

durability, flexibility, and toughness. Binders include synthetic or natural resins. They create

continuous coatings that stick to surfaces and remain in place indefinitely. In almost all cases,

these coatings are polymers. These molecules are interlock with one another like noodles.

Depending on the paint, these long molecules may already exist in the paint before application or

they may form as the paint "dries."

1.4 Solvent

The main purposes of the solvent are to adjust the curing properties and viscosityof the

paint. It is volatile and does not become part of the paint film. It also controls flow and

application properties, and affects the stability of the paint while in liquid state. Its main function

is as the carrier for the non volatile components. In order to spread heavier oils (i.e. linseed) as in

oil-based interior house paint, thinner oil is required. These volatile substances impart their

properties temporarily-once the solvent has evaporated or disintegrated, the remaining paint is

fixed to the surface.

Solvent-borne, also called oil-based, paints can have various combinations of solvents as

the diluent, including aliphatic, aromatics, alcohols, ketones and white spirit. These include

organic solvents such aspetroleum distillate,esters,glycol ethers.

1.5 Additives

Besides the four main categories of ingredients, paint can have a wide variety of

miscellaneous additives, which are usually added in very small amounts and yet give a very

significant effect on the product. Some of them include modification ofsurface tension, improve

flow properties, improve the finished appearance, increase wet edge and improve pigment

stability, etc.

1.6 Paint Manufacturing process General procedure

a. Mixing the pigment with sufficient vehicle to make a paste which has the correct

consistency for grinding

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http://en.wikipedia.org/wiki/Adhesionhttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Aliphatic_compoundhttp://en.wikipedia.org/wiki/Aromaticityhttp://en.wikipedia.org/wiki/Alcoholhttp://en.wikipedia.org/wiki/Alcoholhttp://en.wikipedia.org/wiki/Ketonehttp://en.wikipedia.org/wiki/White_spirithttp://en.wikipedia.org/wiki/White_spirithttp://en.wikipedia.org/wiki/Turpentine_substitutehttp://en.wikipedia.org/wiki/Turpentine_substitutehttp://en.wikipedia.org/wiki/Esterhttp://en.wikipedia.org/wiki/Glycolhttp://en.wikipedia.org/wiki/Glycolhttp://en.wikipedia.org/wiki/Surface_tensionhttp://en.wikipedia.org/wiki/Adhesionhttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Aliphatic_compoundhttp://en.wikipedia.org/wiki/Aromaticityhttp://en.wikipedia.org/wiki/Alcoholhttp://en.wikipedia.org/wiki/Ketonehttp://en.wikipedia.org/wiki/White_spirithttp://en.wikipedia.org/wiki/Turpentine_substitutehttp://en.wikipedia.org/wiki/Esterhttp://en.wikipedia.org/wiki/Glycolhttp://en.wikipedia.org/wiki/Surface_tension


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b. Grinding the paste on the mill until the aggregates is broken down as indicated by the

fineness of grinding test.

c. Letting down the ground paste with the remainder of the materials in formula.

d. Tinting the batch to the required color.

e. Testing physical properties and performance requirements.

1.7 Objectives of the study

The aim of the work is to prepare the nano formulated paint and compare the properties

of this nano formulated paint with conventional paint.

Synthesis of iron oxide, titanium dioxide, prussian blue and graphene oxide nano

particles by gel-combustion method, size reduction method, wet chemical method and

hummers method.

Characterization of the nano particles by FTIR, XRD, SEM, AFM etc.

The paint will be prepared by desired composition which can be assigned by trial

method. Prepared paint film was applied on the prepared mild steel by brush coating

method. On spreading sheet by draw down method at 150m.

The corrosion inhibition of nano formulated paint coated mild steel and commercial paint

coated mild steel in 1N HCl solution was studied at 24 hours at room temperature by

weight loss method. The corrosion rate and inhibition efficiency are calculated using

formula. The dry film property was studied for nano formulated and commercial paint by Hiding

power, spreading area, Glossing test, finishing test, solid content and drying time.

CHAPTER 2

LITERATURE SURVEY

Limited number of literatures are available since it is a commercially important product.

T. Mizutani et al (2006) studied the Application of Silica-containing Nano-composite

Emulsion to Wall Paint: A new environmentally safe paint of high performance. They

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prepared Nano Composite Emulsion (NCE) paint. It was prepared using silica

nanoparticle and nanosized polyacrylate. The various paint property has been studied.

Solvent resistance and anti- pollution property also studied.

Problem: Compare to the solvent type paints, emulsion type paint is not more

efficient. Drying of the film is very quick. Additives are needed to form a product.

Ashavani Kumar et al prepared (2008) Silver-nanoparticle-embedded antimicrobial

paints based on vegetable oil. They used metal nano particle like silver nano particle has

been dispersed in to vegetable oil. The vegetable oil was used as binder. Silver nano

particle possessed antibacterial property and it has been proved by testing method.

Characterization of the paint was studied by using TEM, SEM, AFM.

Problem: Some vegetable oils are having inflammable nature.

Susana Cabello reported (2010) Nano Scratch /Mar Testing of Paint on Metal Substrate

the scratching tests on the metal surface by using the Nanovea Mechanical Tester. The

process of scratching in a controlled manner to observe sample behaviour effects was

studied. In this application, nano scratch testing was performed on 7 year old 30-50m

thick paint sample on a metal substrate. A 2 m diamond tipped stylus has been used at a

progressive load ranging from 0.015 mN to 20.00 mN to scratch the coating. They

performed a pre and post scan of the paint with 0.2 mN load in order to determine the

value for the true depth of the scratch. The true depth analysis for plastic and elasticdeformation of the sample during testing had been done.

Problem: In this method the scratching test is studied by using Diamond Tip.

P.Patel et.al. (2011) analyzed the Surface Coating Studies of Polyurethane Derived from

Isocyanate Terminated Caster Oil Mixture. In this the Castor oil (C) had reacted with

commercial epoxy resin (E)). Isocyanides terminated castor oil polyurethane had

prepared by the reaction of caster oil and hexamethylene diisocyanate. Alkyd resin had

blended with various proportions of CEs and ICBPU. A unique solvent system, which

showed one phase clear solution and a clear coat of binder system had used. All the

blends had applied on mild steel panels and tested like drying time, adhesion, flexibility,

hardness, impact resistance and chemical resistance properties.

Problem: The chemicals are highly toxic and irritating and it is also hazardous to

human health.

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Kathrin studied the Innovative use of Ultrasound in the Manufacture of Paints and

Coatings (2011). He reported the addition of nano-sized particles in the prepared paint

coatings and thus found increased scratch resistance and UV stability. Novel colors and

coating has been produced by using titanium dioxide, zinc oxide, alumina, ceria, silica.

Conventional devices such as high shear or shear mixer, high-pressure homogenizers or

colloid and disk mills had not deliver sufficient power to separate nanomaterial into its

individual particles. Particularly for substances in the range of a few nanometers to a few

micron meters the high power ultra sound method was used.

Problem: The cost of production is more. At high speed the agglomarization of

particles takes place, heat is also generated.

Energy simulation of heat shield coating on the way to green building for a sustainable

development (2010) by Suresh Chandra Pattanaik reported as the project was purely

based on the green environment technology .The green coating was prepared by using bio

based polymers like methyl soyate, mineral spirit, ethyl locate & ethylene glycol and it

was mixed with suitable ingredients. The bio based coating was applied on the exterior

walls, roofs etc. The excellent heat shield property has been observed.

Problem: This is Conventional Method. The raw materials are in micron size and

above.

Silver nanoparticles: Protective paints (2008) by Gemma Moxham, studied theantibacterial property in the glass plate by coating with silver nanoparticle and also

studied the compression between the ordinary paint and silver nano particle implemented

paint.

Problem: It is studied in glass plate only.

Self-Sealing Crystalline Coating and Self-Cleaning Nano coating for the Concrete

Substrate for a Sustainable Development by Suresh Chandra Pattanaik they reported that

the self-cleaning property on the concrete structure by applying the self-sealing

crystalline coating; it includes the crack resistance surface at the concrete structure.

Problem: This method is studied in the concrete structure as coating.

Nanomaterials in the Construction Industry: A Review of Their Applications and

Environmental Health and Safety Considerations reported by LEE et al. they reported

the use of nano materials property in concrete structure .The nano materials like carbon

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based nano particle and metal based nanoparticle. The carbon based nanoparticle like

carbon nanotube enhanced mechanical durability of the concrete structure and prevent the

crack formation. Metal based nano particle like TiO2 increased degree of hydration in the

concrete structure and also improved the self-cleaning property.

Problem: These properties are studied in concrete structure as coating.

In this project work, it is proposed to prepare the oil paint by using the nano particle as a

pigment. The specialized pigment is also used to enhance the paint property which is applied on

the steel plate and the property of paint film will be studied. The metal based nanoparticles are

used to prepare the paint, it having less toxicity; the preparation of the metal based nanoparticle

is not a complicated process.

CHAPTER 3

METHODOLOGY

Preparing nano formulated paint i.e. Hybrid paint using inorganic pigments like Ironoxide (red), Titanium dioxide (white), Prussian Blue (blue) and Graphene oxide (Black),.

Inorganic nanoparticles are used as pigments.

The characterizations of the nanoparticles are carried out using AFM/SEM/XRD/FTIR.

The pigments dispersed in the alkyd resin binder.

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The mixing and milling process is carried out in the planetary ball mill.

Prepared paint is applied on the suitable substrate by using brush coating method.

Properties of paint film are studied.

PREPARATION OF NANOFORMULATED PAINT

3.1 Synthesis of nano particles

3.1.1 Iron oxide

Iron nitrate 4.0g and citric acid 4.2g was dissolved in 50ml of distilled water and stirred

vigorously, during stirring ammonia solution was added drop wise and pH of the solution was

raised to about 10. The obtained sol was heated at 80oC in a hot plate with continuous stirring.

After certain period of time, self-combustion took place. The ash was formed, it was collected

and calcined in furnace at 700-800oC for a period of 2hours.

3.1.2 Titanium Dioxide

The titanium dioxide pigment was prepared by size reduction method using planetary ball

mill. The ball and the vessel were cleaned using a toluene solvent then it allowed to dry in the

atmosphere. Ball to Powder ratio was maintained as 10:1 for the size reduction. Based on ball to

powder ratio 37g of TiO2 was taken and loaded in the container. The TiO2powder in nano range

has been obtained after milling the container in 9 hours.

Figure: 3.1.2 Ball Mill

3.1.3 Prussian blue

0.5 m mol of citric acid was (98 mg) added to a 20 mL of 1.0 mM aqueous FeCl 3 solutionunder stirring at room temperature. In that solution 20 mL of 1.0 m M aqueous K4[Fe(CN)6]

solution was added under vigorous stirring. It contained the same amount of citric acid. A clear

bright blue dispersion was formed immediately. After stirring for 10 minutes, the solution was

allowed to cool down to room temperature with the stirring continued for 5 more minutes. In

order to separate the nanoparticles an equal volume of acetone was added to the dispersion.

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Centrifugation was done at 10,000 rpm for about 15 minutes, resulted in the formation of a pellet

of nanoparticles. The later was re-dispersed in 20 mL distilled water by sonication and it was

separated again by the addition of equal volume of acetone and centrifugation. The purification

process was repeated for two more times.

3.1.4 Graphene Oxide

The graphene oxide (GO) was synthesized by modified Hummers method using graphite

powder as the starting material [1]. Graphite powder (2 g) was stirred in 98% H2SO4 (35 mL) for

2 h. KMnO4 (6 g) was gradually added to the above solution while keeping the temperature less

than 20 C. The mixture was then stirred at 35-40 C for 30 min. The resulting solution was

diluted by adding 90 mL of water under vigorous stirring and a dark brown color suspension was

obtained. The reaction was terminated by the addition of 150 mL of distilled water and 30%

H2O2 solution (10 mL). After continuously stirred for 2 hrs, the mixture was washed by repeated

centrifugation and filtration using 5% HCl aqueous solution in order to remove the residual metal

ions. Further, the centrifugation process was repeated with distilled water until the pH of the

solution becomes neutral. Finally, a brown colored precipitate of graphitic oxide was obtained by

filtration and was allowed to dry under vacuum. Then the dried graphite oxide is redispersed in

150 mL of doubly distilled water and exfoliated into graphene oxide by ultrasound irradiation for

1 hr. After centrifugation, the graphene oxide nanosheets were dried at 60 C and stored.

3.1.5 Silver

0.85g of Silver nitrate was dissolved in 25ml of distilled water. The coriander plant leafs

extract was slowly added to silver nitrate solution with constant stirring. Stirring process was

carried out for 30minutes. During the course of that time the color of the solution was turned

black due to reduction of Ag+ ions into silver nanoparticle. After stirring, the reaction mixture

was centrifuged in order to separate the silver nanoparticle. The residue obtained after

centrifugation was washed thoroughly with distilled water, filtered and vacuum dried.

3.1.6 Substrate preparation

1% sulphuric acid was prepared by dissolving 1ml of conc. sulphuric acid in 100ml

distilled water. This solution was heated in the water bath at 50oC for 10 min. The steel plate was

dipped in this solution for 1min to clean the surface. Then the steel plate was polished by using

emery paper and cleaned with thinner. Over this cleaned substrate the paint was coated.

3.2 Preparation of paint using nano particles as pigments

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Based on the standard weight ratio to solvent volume, the nano pigments are dispersed.

Uniform suspension can be achieved by taking the desired materials in proper composition. The

mixture is then being grinded in ball mill.

Table: 1 Composition of paint

Ingredients Weight %

Total solids(pigments + additives) 50-70

Vehicle or medium 30-40

Solvents 20-40

The pigments synthesized in the above process is mixed with paint forming constituents

like binder(linseed alkyd resin) and other additives.

Vehicle or binder - linseed alkyd resin

Pigments - Red - Fe2O3

Blue - Prussian blue, Prussian blue with Ag

White - TiO2

Black - Graphene oxide

Thinner - toluene, MTO

Drier - cobalt naphthenate

Stabilizers - zinc oxideAdditives - soya lecithin, aluminum stearate, zirconia, thickener

After characterizing the common property of prepared paint, the anticorrosion

study was done using weight-loss method.

Table: 2 Composition between conventional and nano formulated paint

Conventional paint Nano formulated paint

Pigments +Additives +extender 30% * Pigments+ additives 22.4%

Binder 53% Binder 60.6%Solvent 17% Solvent 17%Milling Hours 12hours Milling Hours 5hours

Based on the above (Table 2) composition nano formulated paint was prepared by trial

method. This process was repeated until the correct compositions of paint have been achieved.

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Table: 3 Various constituents present in the paint

Materials Weight in gram Percentage %

Pigment 10 20

Binder(Linseed Oil) 30.3 60.6

Stabilizer(ZnO) 0.25 0.5

Thickener & antisettling Agent 0.25 0.5

Wetting agent(Soya Lecithin) 0.25 0.5

Inner Coat Drier(Zirconia) 0.25 0.5

UpperCoat drier(Co.Naphthanate) 0.20 0.4

Thinner 8.5 17

Total 50 100

3.3 Properties of Paint film

3.3.1 Corrosion inhibition

The studies of mild steel corrosion in acidic media receive more and more attention both

of academics and industrials because of the wide applications. Corrosion is the destructive attack

to metal by chemical or electrochemical reaction with its environment. Mild steel was easilycorroded in acidic medium. To reduce this problem the corrosion inhibitor coating was done on

it. A corrosion inhibitor is the material which inhibits the corrosion reaction by providing a

protective barrier film which in turn stops the corrosive reaction. Paint is a material which

prevents the direct contact of corroding media like air and H2O over the metal surface. It forms a

uniform thin layer after drying and protects the base metal from the corrosion. The corrosion

inhibitors impregnated nanoformulated paint is applied over the steel plates which increases the

corrosion efficiency. Many researches provided the inhibition of corrosion by adsorption of

inhibitors on the metal surface. Then compounds can adsorb on metal surface and block the

active surface sites to reduce corrosion. It has been speculated that metal oxides inhibitors are

more effective with iron [2-3]. Due to the aggressiveness of hydrochloric acid and sulphuric acid

in the solution against structural materials such as mild steel, the use of corrosion inhibitor

impregnated nano formulated is usually required to minimize the corrosion attack. Therefore in

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this investigation, the corrosion inhibition of mild steel in 0.1N HCl solution was studied in the

presence of metal oxide nanoparticle impregnated nanoformulated paint coated substrate at 24

hours in ambient condition by weight loss method. Because metal oxide having a tendency to act

as corrosion inhibitor with alkyd resin medium

3.3.1. a Preparation of specimen

The mild steel strips were cut into pieces of l x b (5 2 cm) and are pickled in pickling

solution (1% H2SO4) for 3 minutes and washed with distilled water. After drying, the steel plates

were polished with various grades of emery papers and degreased using acetone. Three surface

cleaned substrate was weighed and one strip was taken as reference, another strip was coated

with nano formulated paint and third one was coated with commercially available paint of the

same colour. Each strip weight was noted after drying and immersed in 0.1N HCl solution for 24

hours at room temperature in three different beakers containing 0.1 N HCl solution After 24

hours strips were taken out from the beakers and dried in room temperature then the weight of

the each strips were noted. The corrosion rate was calculated by weight loss method using the

following equation [4].

(1)

Where

Wt. Loss = weight loss,

C.R unit = mg/dm2.day

Similarly, inhibition efficiency was calculated using the equation [4],

(2)

Where

IE % = Inhibition Efficiency

W0 and Wi are the values of the weight loss in (g) of mild steel (plain) and paint coated

respectively.

3.3.2 Solid content of the paint

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(W0- W

i)

IE% = X 100W

0

Wt.Loss X 372Corrosion rate (C.R) =

Area X Time


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Thoroughly cleaned watch glass was weighed in the balance noted as W1in gram. 1+ 0.1

gram amount of paint was added over it and its weight was noted as W 2. Then it has been heated

in hot air oven for 1hour at 110oC. Then it was allowed to cool for 10 minutes. After cooling the

weight was noted as W3 g. Solid content of the paint was calculated by using the following

formula.

(3)

Where W1 = weight of the empty watch glass

W2= weight of the watch glass with paint

W3 = weight of the watch glass with paint after 1 hour heating.

3.3.3 Gloss Test

Figure: 3.3.3 Gloss measurement and standards

MPI gloss and sheen standards

Gloss Level Description Gloss at 60 Sheen at 60

Gloss Level 1 a traditional matte finish, flat maximum 5 units maximum 10 units

Gloss Level 2 a high side sheen flat, a velvet-like finish maximum 10 units 10-35 units

Gloss Level 3 a traditional eggshell- like finish 10-25 units 10-35 units

Gloss Level 4 a satin-like finish 25-35 units minimum 35 units

Gloss Level 5a traditional

semi-gloss35-70 units

Gloss Level 6 a traditional gloss 70-85 units

Gloss Level 7 a high gloss more than 85 units

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W3-W

1

Solid content of paint in % = X 100W

2-W

1

Gloss Measurement


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Gloss meter is essential where an aesthetic appearance of the coating finish is required

and to ensure uniformity of the surface finish. The gloss value is determined by directing a light,

which has a similar wavelength to the human eye, at the test surface and measuring the amount

of specular reflection. Gloss is measured with angles of 60 and 20. The 60 angle is universal

for all applications. The 20 angle gives improved differentiation of measurement on high-gloss

coatings above 70 gloss units. For gloss measurement, the equipment requires is Gardner Gloss

meter. Primary working standard may be highly polished black surface, secondary standard shall

be of material having hard uniform surface such as ceramic tile, secondary standards must be

calibrated against primary standards on a gloss meter conforming to the geometric requirement

of this methods.

3.3.4. Opacity / Hiding Power and Spreading area

Opacity and hiding power measurement was done using quadruplex film applicator. It act

as Multifunctional film applicator with 4 application sides for applying paint-films of 4 different

pre-defined thicknesses, in film width 60 or 80 mm. One side of the applicator is supplied with a

removable guidance support for straight application. Applicators typically consist of a stainless

steel metal bar containing a gap of known depth or clearance on one or more faces. It is placed

near one end of a flat panel, like a test chart. A sufficient volume of paint/liquid is placed in front

of the applicator. The applicator is then "drawn down" the chart, either automatically or

manually, leaving a uniform film behind it.

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Figure: 3.3.4.a Multifunctional film applicator

with 8 pre-defined thickness sides for applyingpaint-films of: 25, 50, 75, 100, 125, 150, 175,

200 micron.

Figure: 3.3.4.b Multifunctional film

applicator with 4 pre-defined thickness sidesfor applying paint-films of: 50,100,150,200

micron.


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In this method the test chart weight was noted and placed 1gram of paint on it in

determined height fixed the chart on glass table. The paint was draw down by using film

applicator of 150micron thickness; again weight of the chart was noted and allowed to dry. The

weight difference of paint indicated the removal of paint during draw down method. This method

was used to identify the opacity property of paint and spreading area for the particular amount of

paint. The spreading area was calculated by graph method.

3.3.5 Drying time

During the drying of alkyd paints different stages were crossed. The first process is the

physical drying of the paint. In this process, the solvent evaporates and a closed film forms

through coalescence of the binder particles. Then chemical drying (also called oxidative drying)

occurs, a lipid autoxidation process, which means that the paint dries by oxidation of the binder

compound with molecular oxygen from the air. During the drying process

four overlapping phases can be discriminated:

Induction period

Hydroperoxide formation

Hydroperoxide decomposition into free radicals

Polymerisation / crosslinking

The induction period is the time between application of the paint to a surface and the start of

dioxygen uptake by the paint film. The induction period occurs because the effects of solvent,

anti-skinning agent and natural anti-oxidants that may be present in the alkyd resin must be

overcome before the drying process can begin. Autoxidation of the unsaturated fatty-acid chains

in the alkyd binder then gives rise to hydroperoxides with uptake of atmospheric oxygen.

Decomposition of these hydroperoxides results in the formation of peroxide and alkoxide

radicals. These radicals initiate the polymerisation of the unsaturated molecules of the bindingmedium. Polymerisation occurs through radical termination reactions forming cross-links,

causing gelling of the film, which is followed by drying and hardening. The number of cross-

linked sites that are formed determines the film hardness. Cross-link formation is irreversible;

hence when a paint layer has dried it.

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CHAPTER 4

CHARACTERIZATION TECHNIQUES USED

4.1 X-RAY DIFFRACTION

X-ray powder diffraction is a method used to determine the crystal structure and analyses

the phase of a particular material. Diffraction occurs as waves interact with a regular structure

whose repeat distance is about the same as the wavelength. X-rays have wavelengths on the

order of a few angstroms, the same as typical interatomic distances in crystalline solids, which

mean X-rays can be diffracted from minerals that, by definition, are crystalline and have

regularly repeating atomic structures. When certain geometric requirements are met, X-rays

scattered from a crystalline solid can constructively interfere, producing a diffracted beam, A

diffraction pattern appears, and this diffraction pattern can be analyzed to determine various

structural properties of a material. Bragg recognized a predictable relationship among several

factors:

1) The distance between similar atomic planes in a mineral (interatomic spacing) called

the d-spacing and measured in angstroms.

2) The angle of diffraction called the theta angle and measured in degrees. For

geometrical reasons the diffractometer measures an angle twice that of the angle 2.

3) The wave length of the incident X-radiation, Symbolized by and measured in

angstroms (equals 1.54 A for copper, which is commonly used).

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Figure: 4.1 Braggs reflection-The principle behind XRD.

These relationships are expressed in an equation defining Braggs law and can be written

as follows

n = 2d sin

Where is the angle of incidence or the Bragg angle and n is an integer number which is

customarily set to one. Now it is possible to determine the d-spacing of the crystal by measuring

the angle at which the intensity is maximized. The mean crystallite size can be calculated by the

Debye-Scherer equation.

Debye-Scherrer equation:

K

D= --------------------

cos

Where

D = Crystallite Size

K = Crystallite Shape factor=0.9

= X-ray wavelength, 1.5418 A for CuK

= Observed peak angle in degree

= X-ray diffraction broadening in radian

Here the instrument used is XPERT- PRO x-ray diffracto meter using CuK Radiation

(wavelength = 1.54016 A) at 40 keV over the range of 2=20- 80.

4.2 ATOMIC FORCE MICOSCOPY (AFM)

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The AFM is an instrument capable of imaging the topography of a given sample. A Nano

sized tip attached on a cantilever is traced over the sample and a 3D image of the sample

topography is generated on a computer. The advantage of the AFM over SEM is the ability to

make topographical measurements for detection and investigation of the size and shape of silver

nano particles in three dimensions at ambient condition. Thus, the AFM makes it possible to

determine the height of the particles also. The present studies were performed using XE 70,

SPM, Park Systems with a scan size of 20 m.

Figure: 4.2 Schematic representation of AFM

The AFM tip is held at the end of a thin, flexible beam, or "cantilever". This cantilever is

made just as the tip was, but its shape is usually triangular ("V" shaped) or long and rectangular

(an "I" beam). These are roughly 100 microns long (which is 0.1 millimeters, about the width ofa hair) and only a few microns thick. This makes them very flexible but strong enough to

securely hold the tips on their end.

Contact mode

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The first and foremost mode of operation, contact mode is widely used. As the tip is

raster-scanned across the surface, it is deflected as it moves over the surface corrugation. In

constant force mode, the tip is constantly adjusted to maintain a constant deflection, and

therefore constant height above the surface. It is this adjustment that is displayed as data.

However, the ability to track the surface in this manner is limited by the feedback circuit.

Sometimes the tip is allowed to scan without this adjustment, and one measures only the

deflection. This is useful for small, high-speed atomic resolution scans, and is known as variable-

deflection mode.

Noncontact mode

Noncontact mode belongs to a family of AC modes, which refers to the use of an

oscillating cantilever. A stiff cantilever is oscillated in the attractive regime, meaning that the tipis quite close to the sample, but not touching it (hence, noncontact). The forces between the tip

and sample are quite low, on the order of pN (10 -12 N). The detection scheme is based on

measuring changes to the resonant frequency or amplitude of the cantilever.

Advantages:

Highest resolution available: AFMs lateral resolution allows imaging and measurement

of features on the order of a few nano meters, the vertical (height) resolution is


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that are emitted after the impact with the specimen, which in turn are used to modulate the

cathode ray tube. Thus an image is formed on the video-display by scanning in synchronization

with the electron beam and a photographic record can be made.

By this technique, materials that are conducting can be imaged. If the conductivity is not

sufficient, it may be coated with conducting layers of gold, carbon etc., before the sample is

mounted in the specimen chamber. The images thus developed may be magnified to the extent of

200K, without any refocusing. It gives more three-dimensional details due to its greater depth of

focus, which is up to about 100 under the lightest voltage conditions (1KV). The main

advantages of SEM are the high lateral resolution (1-10nm) and the numerous types of electron-

specimen interaction that can be used for imaging or chemical analysis. The present studies were

performed on scanning microscopy (SEM) using Hitachi instrument.

Figure: 4.3 working principle of SEM

4.4 FOURIER TRANSFORM INFRA-RED SPECTROSCOPY (FTIR)

The FTIR (Fourier Transform Infrared) spectroscopy deals with the study of the

interaction of matter with Infrared (IR) radiation. FTIR Spectroscopy or simply FTIR Analysis

provides information about the chemical bonding or molecular structure of materials, whether

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organic or inorganic. It is used to identify unknown materials present in a specimen. The

technique works on the fact that bonds and groups of bonds vibrate at characteristic frequencies.

A molecule that is exposed to infrared rays absorbs infrared energy at frequencies which are

characteristic to that molecule. During FTIR analysis, a spot on the specimen is subjected to a

modulated IR beam. The specimens transmittance or absorbance of the infrared rays at different

frequencies is translated into an IR absorption plot consisting of reverse peaks. The resulting

FTIR spectral pattern is then analyzed and mated with known signatures of identified materials

in the FTIR library. The adsorption of radiation by a sample requires that the energy content of

radiation should correspond to the energy difference between the two vibrational states, there

should be strong coupling reaction between the sample and the radiation. This coupling

interaction takes place only if there is a change in dipole moment during the absorption process.

If there is no change in dipole moment during the absorption process, there will be no coupling

interaction between the sample molecules and radiation and therefore no absorption is possible,

even if the first condition is satisfied.

Infrared spectra are usually plotted as percentage transmittance (%T) or absorbance

(A) on a scale, linear in wave numbers (). Transmittance is the ratio of the intensity of radiation

transmitted by the sample (1) to that incident on the sample (I0), expressed as a percentage, so

that T=100(I/ I0) and T and A are related as:

A= log10 (I0/I)

= log10 (100/T)

= 2-log10T

The main advantage of FTIR is the rapid-scan capability, especially for the study of

short-lived species. Nowadays, computer controlled instruments are available which allow rapid

data manipulation, repetitive scanning, signal averaging, background subtraction, spectral

smoothing, fitting & scaling, and searching in digitized spectral libraries & databases, to identify

unknown samples. Among the applications of Infrared Spectroscopy, chemical analysis

(qualitative and quantitative) and the determination of molecular structure are important. The

present studies were performed on an Alpha model FTIR, Brucker, Germany.

4.5 UV-VISIBLE SPECTROSCOPY ANALYSIS

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Absorbance spectroscopy is used to determine the optical properties of a

solution. Light is send through the sample and the percentage of amount of absorbed light is

measured. When the wavelength is varied and the absorbance is measured (wavelength,

absorbance) graph can be drawn using computer software. The applications of this spectroscopy

were extensive. For example, the absorbance can be used to measure the concentration of a

solution by using Beer-Lamberts law. However for examination of nanoparticles, the optical

properties are much more complicated and require an individually developed theory. For

instance, the measured absorbance spectrum does not necessarily show the actual absorbance but

the extinction of light.

The extinction is both the absorbed and scattered light from the particles.

Spectrophotometry is used for both qualitative and quantitative investigations of samples. The

wavelength at the maximum of the absorption band will give information about the structure of

the molecule or ion and the extent of the absorption is proportional with the amount of the

species absorbing the light.

Fig: 4.5 Principle of UV-Visible spectroscopy

The quantitative determinations made by spectrophotometry could be divided in

two groups according to the number of substances to be measured. These are the analytical

measurements of systems that consist of only one absorbing component and systems that consist

of more than one absorbing component. In the case of systems containing one absorbing

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component we measure the absorption of light at a particular wavelength (which is usually

identical with the absorption maximum of the analyte).

We either calculate the concentration from the results by using the molar

absorptivity found in the literature or the unknown concentration can be determined by

comparing the results with a working curve of absorbance versus concentration (calibration

curve) derived using standard

CHAPTER 5

RESULTS AND DISCUSSION

5.1 Iron Oxide nano particle characterization

5.1.1.1FTIR ResultsFigure 5.1.1 shows the IR spectra of iron oxide nano particles. The strong peak found

between 400 and 700 cm-1 is attributed to the vibration band of metal-oxide. The bands at

415,440,473,526 are characteristic vibrations of Fe-O [5].

Figure: 5.1.1 IR spectra for Iron oxide

5.1.2 XRD Analysis

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Figure: 5.1.2 XRD pattern of Iron oxide

The structural feature of iron oxide is explored from XRD data. XRD of iron oxide is

shown in Figure 5.1.2. The XRD pattern of final powders revealed well developed reflections of

iron oxide (JCPDS PDF No. 871164). The XRD pattern of the sample exhibit the characteristic

peak at 2 = 24.5, which corresponds to the (0 1 2) plane. It also exhibits the 2 in 33.5o, 36.07o,

41.32o, 49.85o, 54.51o, 62.83o, 64.4o. The crystalline planes are indexed as (1 0 4), (2 0 1), (2 1 2),

(0 1 5), (0 0 9), (2 3 4) and (2 5 0) as per the JCPDS file no.871164. These peaks showed the

presence of -Fe2O3[6].

5.1.3 AFM studies

Atomic Force Microscopy (AFM) is one of the most powerful tools to study the surface

characteristics of nano phase materials. AFM image of the iron oxide nano particle shown in the

figure 5.1.3. The nano textured structure was well explored by this image and it shows 3D image

of iron oxide. The structural features of the nanoparticles have been explored by the XEI-image

processing software supplied by PARK system, South Korea. The particle size was found to be

around 40 nm.

Figure: 5.1.3 AFM Image of Fe2O3

5.1.4 SEM results

SEM is also used to determine the morphology of the nano particles. Figure 5.1.4

represents the SEM image of iron oxide nano particle. This figure reveals the presence and

uniformly distributed particles. The large particles are composed of small crystallites and show

particle aggregates of irregular shapes and large size. The average size of the particles was found

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to be in the range of 80 nm and undefined shape morphology was observed. Figure 5.1.4 image

was viewed at 3 m scale and 15k magnification at 10kV applied voltage. The SEM images of

this work were obtained using the Scanning Electron Microscope SU1510, Hitachi, Japan.

Figure: 5.1.4 SEM image of Iron oxide

5.2 Characterization of red paint (Iron oxide impregnated)

5.2.1 Composition of red color paint

Table: 4 Iron oxide nano particle impregnated paint

Materials Weight

in gram

Percentage %

Pigment(Fe2O3) 10.00 20.0

Binder(alkyd resin) 30.05 60.1Stabilizer(ZnO) 0.25 0.5Thickener & anti settling agent(Thickener &

Aluminum stearate)

0.50 1.0

Wetting agent(Soya lecithin) 0.25 0.5Inner coat drier(zirconia) 0.25 0.5Upper coat drier(Co. naphthenate) 0.20 0.4Thinner(toluene) 8.50 17.0

Total 50.00 100.0

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Quantity of each constituent present in the paint and its percentage are given in the table

4. Each component was weighed and mixed thoroughly in the ball mill for 1 hour and then the

liquid material was added in it. The ball mill was rotated at 300 rpm for 5 hours. The prepared

red color nano paint was applied on the suitable substrate.

5.2.2 FTIR image for red color nano paint film.

Figure: 5.2.2 IR spectra for iron oxide nano paint film

Figure 5.2.2 shows the IR spectra of iron oxide paint film. The strong peak found

between 400 and 700 cm-1, 1400 to1800 cm-1,1800 to 3000 cm-1 is attributed to the vibration

band of metal-oxide, methyl and methylene groups, linseed oil respectively. The band at 525

represence characteristic vibrations of Fe-O [5]. The band at 1413 cm-1 represence bending

vibration of C-H. The band at 1679, 1739, 3021 cm -1 represence stretching vibration of C=C,

C=O, C-H respectively [7-8].

5.2.3 Comparative study of the red color paint film

a. Corrosion rate and Inhibition efficiency of red color paint

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Prepared red color nano paint was applied on cleaned surface by brush coating method.

For corrosion studies three MS strip was taken such as uncoated, nano paint coated, commercial

paint coated and their weight also noted. Three substrate were separately immersed in 1N HCl

solution. This setup was kept as such as for 24 hours. Then it was removed and dried in air and

its weight was noted. Corrosion rate was calculated based on equation (1). Inhibition efficiency

was calculated based on the equation (2).

Table: 5 CR and IE values of red color paint coated MS plate

MS plate Initial

weight in g

Final weight

in g

Weight loss

in g

Corrosion rate

mg/dm2.day

Inhibition

efficiency %

Uncoated 4.6566 4.4778 0.1788 14.980 -

Nano paintcoated

4.5308 4.5298 1 X 10-03 0.0837 99.4412

Commercialpaint coated 4.6263 4.6230 3.3 X 10

-03

0.2764 98.1528b. Solid content of the red color paint

Solid content of the paint also calculated based on the equation (3).

Table: 6 Solid content of the red color paint

Paint Empty

watch glass

W1 in g

Weight of

watch glass

with paint

W2 (g)

Weight of

specimen

after dry W3(g)

W3-W1in g

W2-W1in g

(W3-W1 ) x 100

W2-W1

Nano paint 36.0389 36.918 36.5845 0.5456 0.8800 62%

Commercialpaint coated 36.0389 37.421 37.1660 1.1271 1.1382 99%

One gram red color paint was poured in the test sheet at a particular point then it was

draw down at 150 micron meter thickness. Same procedure was also followed to the

commercially available red oxide paint. Excess amount of paint was removed during testing. The

testing sheet was allowed to dry completely. Spreading area was calculated by graphical method.

The paint spreaded area was transferred into the graph sheet and area was measured in cm 2.

Gloss @60O was seemed using this sheet. Drying time was also noted.

c. Hiding power and spreading area

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d. Comparative Study between conventional paint and nano formulated red paint

Table: 7 Comparative study of paint property

Test Conventional Paint Nano formulated paint

Gloss @ 60 degree 1 90Solid Content % 99 62%

Hiding Power Background Whitecolor was observed

Good at 150mthickness

Spreading area 46 cm2 70cm2

Corrosion rate in mg/dm2.day 0.2764 0.0837Inhibition efficiency % 98.1528 99.4412Finishing Good Good and shiningRecommended no of coats 2-3 1-2

Drying time at room temperatureDry to touch 30 mins 1-2 hoursDry to handle 2 hour 6 hoursDry to overcoat 6 hours 12 hours

Compared to commercial paint, nano formulated iron oxide paint showed good glossy,

good corrosion resistance. But drying time was high for nano paint.

5.3 Titanium Oxide nano particle characterizations

5.3.1 FTIR Results

27

Figure: 5.2.3-a Commercially available Red

oxide paint

Figure: 5.2.3-b Nano formulated Red oxide

paint


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Figure: 5.3.1 IR spectra of titanium dioxide

Figure 5.3.1 shows the IR spectra of titanium dioxide nano particles. The strong peak

found between 400 and 700 cm-1 is attributed to the vibration band of metal-oxide. The band at

549 cm-1 showed the vibrations of Ti-O [9]. The bands at 620 and 726 cm-1 showed the vibrations

of Ti-O-Ti [10].

5.3.2 XRD Analysis

The structural feature of TiO2 is explored from XRD data. XRD of TiO2 is shown in

Figure 5.3.2. The XRD pattern revealed well developed reflections of TiO 2 (JCPDS PDF No.

896975). The XRD pattern of the sample exhibit the characteristic peak at 2 = 25.7, which

corresponds to the (1 0 1) plane. It also exhibits the 2 peaks at 27.8 o, 31.7o, 36.5o, 41.8o, 54.5o &

are indexed as (1 1 0), (2 1 1), (1 0 1), (1 1 1) and (2 1 1) etc. 25.7o

peak showed the differentdiffraction plane of anatase TiO2. 27.8o, 36.5o, 54.5o peaks showed the different diffraction

planes of rutile form of TiO2 [11].

Figure: 5.3.2 XRD Pattern of titanium dioxide

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5.3.3 AFM studies

Figure: 5.3.3 AFM image of titanium Dioxide

AFM image of the titanium dioxide nano particle shown in the figure 5.3.3. The nano

textured structure was well explored by this image. The particle size was found to be around 40nm.

5.3.4 SEM results

Figure 5.3.4 represents the SEM image of TiO2 nano particle. This figure reveals the

presence and uniformly distributed particles. The large particles are composed of small

crystallites and show particle aggregates of irregular shapes and large size. The average size of

the particles was found to be in the range of 90 nm. Figure 5.3.4 image was viewed at 3 m scale

and 17k magnification at 10kV applied voltage.

Figure: 5.3.4 SEM image of Titanium Dioxide

5.4 characterization of white paint (TiO2 based)

5.4.1 Constituent of white based paint

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Table: 8 Titanium dioxide nano particle impregnated paint

Quantity of each constituent present in the paint and its percentage are given in the table

8. Each component was weighed and mixed thoroughly in the ball mill for 1 hour along with

binder. The ball mill was rotated at 300 rpm for 5 hours. The prepared white color nano paint

was applied on the suitable substrate.

5.4.2 FTIR image of white color nano paint film.

Materials Weight in grams Percentage %

Pigment(TiO2) 10.00 20.0

Binder(alkyd resin) 30.00 60.0Stabilizer(ZnO) 0.25 0.5Thickener & anti settling agent(Thickener A

&Aluminum stearate)

0.25 0.5

Wetting agent(Soya lecithin) 0.30 0.6Inner coat drier(zirconia) 0.35 0.7Upper coat drier(Co.naphthenate) 0.35 0.7Thinner(toluene) 8.50 17.0Total 50.00 100.0

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Figure: 5.4.2 IR spectra for titanium dioxide nano paint film

FTIR spectra of TiO2 containing paint film is represented in the figure 5.4.2. It shows all

characteristics peaks corresponding to the linseed alkyd resin at 1413 cm -1 (bending C-H), 1679

cm-1 (stretching C=C), 1739 cm-1(stretching C=O). The stretching (C-H) vibration was observed

from methyl and methylene groups in the range from 2800 to 3000cm -1 and the strong vinyl

stretch vibration =C-H at 3021 cm-1 [7-8]. In addition to these peaks, the characteristic Ti-O

vibrations are found in the region 400-700 cm-1. The peak at 549 and 721 cm-1 are described to

the vibration modes of Ti-O [9].

5.4.3 Comparative study of the white color paint film

a. Corrosion rate (CR) and Inhibition efficiency (IE) for white color paintTable: 9 CR and IE values of white color paint coated mild steel (MS) plate

MS plate Initial

weight in g

Final weight

in g

Weight

loss in g

Corrosion rate

mg/dm2.day

Inhibition

efficiency %

Uncoated 4.6566 4.4778 0.1788 14.980 -

Nano paintcoated

4.5223 4.5039 0.0184 1.5416 89.7089

Commercialpaint coated

4.5506 4.5026 0.048 4.0216 73.1535

Nano paint was applied on cleaned surface by brush coating method. For corrosion studiesthree MS strip was taken such as uncoated, nano white paint coated, commercial white paint

coated and their weight also noted. Three substrate were separately immersed in 1N HCl solution

in different beakers. This setup was kept as such as for 24 hours. The steel substrates were then

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removed and dried in air and its weight was noted. Corrosion rate was calculated based on

equation (1). Inhibition efficiency was calculated based on the equation (2).

b. Solid content of the white color paint

Solid content of the paint was calculated based on the equation (3).

Table: 10 Solid content of the white color paint

Paint Empty

watch glass

W1 (g)

Weight of watch

glass with paint

W2 (g)

Weight of

specimen after

dry W3 (g)

W3-W1(g)

W2-W1 (

g)

100 x (W3-W1 ) /

( W2-W1)

Nano paint 36.0549 37.1253 36.8779 0.823 1.0794 76.2460Commercialpaint coated

43.9502 45.08 44.4958 0.5456 1.1298 48.29

One gram titanium dioxide paint was poured in the test sheet at a particular point then it

was draw down at 150 micron meter thickness. Same procedure was followed to thecommercially available white color paint. Excess amount of paint was removed during testing.

The testing sheet was allowed to dry completely. Spreading area was calculated by graph

method. The paint spreaded area was transferred into the graph sheet and area was measured in

cm2. Gloss @60O was measured using this dried sheet. Drying time was also noted.


Table: 11 Comparative studies between conventional paint and nano formulated white

paint

Test Conventional Paint Nano formulated paint

Gloss @ 60 degree 3 93Solid Content % 48.29% 76.24%

32

Figure: 5.4.3-a Commercially availablewhite color paint

Figure: 5.4.3-b Nano formulated Titaniumdioxide paint

Background Whitecolor was observed


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Hiding Power Background Whitecolor was observed

Good at 150mthickness


Corrosion rate in mg/dm2.day 4.0216 1.5416Inhibition efficiency % 73.1535 89.7089

Finishing Poor Good and shiningRecommended no of coats 2-3 1-2Drying time at room temperature

Dry to touch 30 mins 1-2 hoursDry to handle 2 hour 6 hoursDry to overcoat 6 hours 12 hours

Compared to commercial paint, nano formulated titanium dioxide paint showed good

glossy and corrosion resistance. But drying time was high for nano white paint.

5.5 Characterization of prussian blue nanoparticle

5.5.1 FTIR Results

Figure: 5.5.1 IR spectra of prussian blue

Figure 5.5.1 shows the IR spectra of prussian blue (PB) nano particles. The strong peak

found between 500 and 2500cm-1 is attributed to the vibration band of metal-CN links. The peak

at 2080 cm1 is the characteristic CN stretching absorption band of prussian blue and its

analogues, and the absorption band at 501 cm1 is due to the formation of MCNM structures

(M = metal); they indicate the presence of PB [12].

5.5.2 XRD Analysis

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The structural feature of PBis explored from XRD data. XRD of PB is shown in Figure

5.5.2. The XRD pattern of the particles revealed well developed reflections of PB (JCPDS PDF

No. 521907). The XRD pattern of the sample exhibit the characteristic peak at 2 = 17.93,

which corresponds to the (2 0 0) plane. It also exhibits the peaks at 25.3 o, 35.6o, 51.3o indexed as

(2 2 0), (4 0 0) and (4 4 0) planes [13].

Figure: 5.5.2 XRD pattern of Prussian Blue

5.5.3 AFM studies

Figure: 5.5.3 AFM image of PB

AFM image of the PB nano particle shown in the figure 5.5.3. The nano textured

structure is well explored by this image. The particle size was found to be around 120 nm.

5.5.4 SEM results

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Figure 5.5.4 represents the SEM image of prussian bluenano particle. This figure reveals

the presence and uniformly distributed particles. The large particles are composed of small

crystallites and show particle aggregates of irregular shapes and large size. The average size of

the particles was found to be in the range of 90 nm. Image was viewed at 5 m scale and 6.50k

magnification at 10kV applied voltage.

Figure: 5.5.4 SEM image of prussian blue

5.6. Characterization of silver nanoparticle

5.6.1 AFM studies

Figure: 5.6.1 AFM image of silver

AFM image of the Ag nano particle shown in the figure 5.6.1. The nano textured

structure is well explored by this image. The particle size was found to be around 30 nm.

5.6.2. UV-Visible spectrum analysis

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Figure: 5.6.2 UV-Visible spectrum of Ag nanoparticle

Figure 5.6.2 represents the UV-Visible spectrum of Ag nanoparticle prepared by bio-

reduction method using coriander leave extract. The aqueous suspension of the silver

nanoparticle exhibit a peak around 420 nm is a characteristic spectrum of silver nanoparticle in

the UV-Visible spectra [14].

5.7. Characterization of blue color paint film

5.7.1 Composition of prussian blue color paint with Ag and without Ag

Table: 12 property of prussian blue nano particle impregnated paint

Various constituent used for preparing blue color paint is given in the table 12. Each

component was weighed and mixed thoroughly in the ball mill for 1 hour along with binder. The

ball mill grounded the constituents at 300 rpm for 5 hours. The prepared blue color nano paint

was applied on the steel specimen for corrosion studies.

Materials Prussian blue alone Prussian blue with silver

Weight

in gram

Percentage

%

Weight in

gram

Percentage

%

Pigment(Prussian blue) 9.00 18.0 9.00+1.00 20.00

Binder(alkyd resin) 31.10 62.2 30.10 60.20Stabilizer(ZnO) 0.25 0.5 0.25 0.50Thickener & anti settlingagent(Thickener A&Aluminum stearate)

0.30 0.6 0.30 0.60

Wetting agent(Soya lecithin) 0.25 0.5 0.25 0.50Inner coat drier(zirconia) 0.30 0.6 0.30 0.60Upper coatdrier(Co.naphthenate)

0.30 0.6 0.30 0.60

Thinner(toluene) 8.50 17.0 8.50 17.00

Total 50.00 100.0 50.00 100.00

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5.7.2 FTIR image of blue color nano paint film.

Figure: 5.7.2 IR spectra for prussian blue nano paint film

Figure 5.7.2 shows the IR spectra of Prussian blue nano paint film. It shows all

characteristics peaks corresponding to the linseed alkyd resin at 1591 and 1454 cm-1

(Fundamental vibration of Pyrrole ring). The stretching (C-H) vibration is observed from methyl

and methylene groups in the range from 2800 to 3000cm -1 and the strong C-N stretching

vibration at 2071 cm-1.Stretching vibration of C-O-C, C=O is observed at 1255cm -1, 1726 cm-1

respectively. Band at 1120, 1062 cm-1 is observed due to = C-H plane in vibration [7-8]. Band at

738,701 cm-1 is observed due to the C-H out of plane bending vibration. The peak at 519 and 434

cm-1 are described to the vibration modes of M-CN-M [12].

5.7.3 Comparative study of the blue color paint film

a. Corrosion rate and Inhibition efficiency of blue color paint

Prepared blue color nano paint & Prussian blue with silver nano paint was applied on

cleaned surface by brush coating method. For corrosion studies four MS strip was taken such as

uncoated, nano paint coated, nano Prussian blue with silver nano paint, commercial paint coated

and their weight also noted. Four substrate were separately immersed in 1N HCl solution. This

setup was kept as such as for 24 hours. Then it was removed and dried in air and its weight was

noted. Corrosion rate calculated based on equation (1).Inhibition efficiency was calculated basedon the equation (2).

Table: 13 CR and IE values of blue color paint coated MS plate

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MS plate Initial

weight in g

Final weight

in g

Weight

loss in g

Corrosion rate

mg/dm2.day

Inhibition

efficiency %

Uncoated 4.6566 4.4778 0.1788 14.980 -Nano paintcoated

4.5818 4.5681 0.0137 1.1478 92.33

Nanopaintwith silver 4.5349 4.5342 7 X10-4

0.0586 99.61


4.3577 4.2704 0.0873 7.3142 51.17

b. Solid content of the blue color paint


Table: 14 Solid content of the blue color paint

Paint Empty

watch glassW1 in g

Weight of

watch glasswith paint

W2 (g)

Weight of

specimenafter dry W3(g)

W3-W1

in g

W2-W1

in g

(W3-W1 ) x 100

W2-W1

Nano paint 18.4097 19.5073 19.2393 0.8296 1.0976 75.58Nanopaintwith silver

43.9618 44.9789 44.7058 0.744 1.0082 73.7948


18.4017 19.4259 18.9372 0.5355 1.0242 52.2847

One gram blue color paint was poured in the test sheet at a particular point then it was

draw down at 150 micron meter thickness. Same procedure followed to the commerciallyavailable blue color paint. Excess amount of paint was removed during testing. The testing sheet

was allowed to dry completely. Spreading area was calculated by graph method. The paint

spreaded area was transferred into the graph sheet and area was measured approximately in terms

of cm2.Gloss @60O was measured using this sheet. Drying time was also noted.


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d. Comparative Study between conventional paint and nano formulated blue paint

Table: 15 Comparative study of blue paint property

Test Conventional Paint Nano formulated

paint

Nano formulated

paint with Ag

Gloss @ 60 degree 80 85 93Solid Content % 52.2847 75.58 73.7948Hiding Power Good at 150m thickness.

Peeling of material wasobserved if any materialtouches over it.

Good at 150mthickness. Nopeeling of paint film

Good at 150mthickness. Nopeeling of paint film

Spreading area 83 cm2 75cm2 80cm2Corrosion rate 7.3142 mg/dm2.day 1.1478 mg/dm2.day 0.0586 mg/dm2.dayIE % 51.17 92.33 99.61Finishing Good Good and shining Good and shiningAcid resistance Color changes occur No color changes No color changesRecommended noof coats

2-3 1-2 1-2

Drying time at room temperature

Dry to touch 2 mins 1 hours 1 hoursDry to handle 6 hour 3 hours 3 hoursDry to overcoat 12 hours 4 hours 6 hours

Compared to commercial paint, nanoformulated blue paint showed good glossy and

corrosion resistance and drying time was improved.

5.8 Characterization results of Graphene Oxide (GO) nanoparticle

5.8.1 FTIR results

39

Figure 5.7.3-a Commerciallyavailable blue color paint

Figure 5.7.3-b Nanoformulated Blue paint

Figure 5.7.3-c Nano formulatedBlue with silver paint


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Figure: 5.8.1 IR spectra of GO

Figure 5.8.1 shows the IR spectra of Graphene oxide (GO) nano particles. The FTIR

spectrum of GO clearly shows the presence of carboxyl, hydroxyl, epoxyl and carbonyl groups at1728 cm1, 1413 cm1, 1250 cm1 and 1050 cm1 respectively [15]. The peak due to the CC

vibrations from the graphitic domains is observed at 1600 cm1 [16]. The relatively broad peak at

3260 cm1 is due to the adsorbed water content in the surface of GO.

5.8.2 XRD analysis

Figure: 5.8.2 XRD pattern of graphene oxide

The structural feature of GOis explored from XRD data. XRD of GO is shown in Figure

5.8.2. The XRD pattern revealed well developed reflections of GO (JCPDS PDF No. 751621). In

general, the diffraction peak of pure graphite is found around 26 [17]. After successful

oxidation, the diffraction peak of GO shifted towards 2 = 10 which corresponds to the (2 0 0)

plane which is mainly due to the oxidation of graphite and the corresponding interlayer spacing

was 0.85 nm [15,17].

5.8.3 AFM studies

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Figure: 5.8.3 AFM image of GO

AFM image of the GO nano particle shown in the Figure 5.8.3. The nano texturedstructure is well explored by this image. The particle size was found to be around 80 nm.

5.8.4 SEM results

Figure: 5.8.4 SEM image of graphene oxide

Figure represents the SEM image of GO nano particle. The large particles are composed

of small crystallites and show particle aggregates of irregular shapes and large size. The average

size of the particles was found to be in the range of 90 nm and nano sheet shape morphology can

be observed. Figure 5.8.4 image was viewed at 1 m scale and 13000k magnification at 5kV

applied voltage.

5.9. Characterization results of black color paint film

5.9.1 Composition of graphene oxide paint

Table: 16 GO nano particle impregnated paint

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Composition of each component is given in the table 16. Each component was weighed

and mixed thoroughly in the ball mill for 1 hour with linseed alkyd resin. The ball mill wasrotated at 300 rpm for 5 hours. The prepared black color nano paint was applied on the suitable

substrate.

5.9.2 FTIR image of black color nano paint film.

Figure: 5.9.2 IR spectra for graphene oxide nano paint film

Figure 5.9.2 shows the IR spectra of graphene oxide nano paint film. It shows all

characteristics peaks corresponding to the linseed alkyd resin at 1648 cm-1

(Fundamentalvibration of Pyrrole ring) and 1725 cm-1 (C=O stretching vibration) [26-27]. The stretching (C-H)

vibration is observed from methyl and methylene groups in the range from 2800 to 3000 cm -1.

Stretching vibration of C-O-C is observed at 1250 cm-1 [7-8]. Band at 1108, 1054 cm-1 is

observed due to = C-H plane in vibration [15-16].

Materials Weight

in gram

Percentage

%

Pigment(Graphene oxide) 8.00 16.0Binder(alkyd resin) 32.10 64.2Stabilizer(ZnO) 0.25 0.5

Thickener & anti settling agent(Thickener A&Aluminum stearate)

0.27 0.54

Wetting agent(Soya lecithin) 0.28 0.56Inner coat drier(zirconia) 0.30 0.6Upper coat drier(Co.naphthenate) 0.30 0.6Thinner(toluene) 8.50 17.0Total 50.00 100.0

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5.9.3 Comparative study of the black color paint film

a. Corrosion rate and Inhibition efficiency for black color paint

Prepared black color nano paint was applied on cleaned surface by brush coating method.

For corrosion studies three MS strip was taken such as uncoated, nano paint coated, commercial

paint coated and their weight also noted. Three substrate were separately immersed in 1N HCl

solution. This setup was kept as such as for 24 hours. Then it was removed and dried in air and

its weight was noted. Corrosion rate calculated based on equation (1).Inhibition efficiency was

calculated based on the equation (2).

Table: 17 CR and IE values of black color paint coated MS plate

MS plate Initial

weight in g

Final weight

in g

Weight

loss in g

Corrosion rate

mg/dm2.day

Inhibition

efficiency %

Uncoated 4.6566 4.4778 0.1788 14.980 -

Nano paintcoated

4.8734 4.8532 0.0202 1.6924 88.70


4.9592 4.8741 0.0878 7.3562 50.89

b. Solid content of the black color paint


Table: 18 Solid content of the black color paint

Paint Empty

watch glass

W1 in g

Weight of

watch glass

with paint

W2 (g)

Weight of

specimen

after dry W3(g)

W3-W1in g

W2-W1in g

(W3-W1 ) x 100

W2-W1

Nano paint 36.0289 37.1365 36.7404 0.7115 1.1076 64.24Commercialpaint coated

36.1346 37.1200 36.5210 0.3864 0.9854 39.21

One gram black color paint was poured in the test sheet at a particular point then it was

draw down at 150 micron meter thickness. Same procedure was followed for the commercially

available black color paint. Excess amount of paint was removed during testing. The testing

sheet was allowed to dry completely. Spreading area was calculated by graph method. The paint

spreaded area was transferred into the graph sheet and area was measured f cm2.Gloss @60O was

measured using this sheet. Drying time was also noted.


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d. Comparative Study between conventional paint and nano formulated GO paint

Table: 19 Comparative study of paint property

Test Conventional Paint Nano formulated

paint

Gloss @ 60 degree 85 75Solid Content % 39.21 64.24Hiding Power Good at 150m thickness. Good at 150m

thickness.


Corrosion rate 7.3562 mg/dm2.day 1.6924mg/dm2.dayIE % 50.89 88.70Finishing Good and shining Good and shiningAcid resistance Peel off from the substrate No changesRecommended noof coats

2-3 1-2

Drying time at room temperature

Test Conventional paint Nano formulated

paint

Dry to touch 4hours 1 hoursDry to handle 8 hour 3 hoursDry to overcoat 24 hours 4 hours

Compared to commercial paint nanoformulated black paint showed good glossy and good

corrosion resistance and drying time was improved.

44

Figure 5.9.3-b commercially

available black color paint

Figure 5.9.3-a Graphene oxide

black color nanopaint


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SUMMARY

The nanoparticles used for the paint formulation have been prepared by Gel-Combustion

method, mechanical milling method, etc. The prepared nanoparticles have been characterized by

employing XRD, AFM, SEM, FTIR, UV etc. From the analytical parameters, the size of the iron

oxide, titanium dioxide, Prussian blue, Graphene oxide and silver nanoparticles has been

explored in the range of 70, 90, 40, 90, 30 nm respectively. The chemical nature, the metal-

oxygen vibrational modes etc, have been confirmed from the FTIR spectra.

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Nano formulated paint containing nano iron oxide, nano titanium dioxide, nano Prussian

blue, nano Prussian blue with nano silver and graphene oxide have been prepared with other

conventional additives by mechanical milling method. On the application of the prepared paint

over steel structure provides better surface finishes, high glossiness, increasing surface area,

improved hiding power and better corrosion inhibition efficiency compared with commercially

available paints. Compared to conventional paint the drying time was less for nano formulated

paint. Their performance behaviors have also been checked.

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