SYNTHESIS AND CHARACTERIZATION OF DIFFERENT PERCENTAGE OF CHROMIUM TRIOXIDE NANOCOMPOSITES BY EMULSION METHOD AND ITS ANTIBACTERIAL ACTIVITIES CHAPTER-I INTRODUCTION 1

SYNTHESIS AND CHARACTERIZATION OF DIFFERENT PERCENTAGE OF CHROMIUM TRIOXIDE NANOCOMPOSITES BY EMULSION METHOD AND ITS ANTIBACTERIAL ACTIVITIES
CHAPTER-I
INTRODUCTION
1.1. Polymer Nanocomposites
1.1.1. Introduction
The multiphase rock-solid substance where one of the phases has one, two, or three dimensions of less than 100 nanometers (<100nm) is called the nanocomposites or different phases that make up the substance becomes the structures having the nanoscale distance. There are designing the nanocomposites are used to the building blocks of dimensions with the nanometer range and due to the idea of new substance have been create the exceptional flexibility and their physical properties become improve. Also the properties should be differing the dissimilarities in structure and chemistry due to including the porous media,colloids gels and copolymers but the bulk matrix and phases of nano-dimensional which mean that to take the mixture of solid. They are many different from the element substance should be the mechanical, thermal, electrical, optical, electro, chemical, catalytic properties of the nanocomposites. Therefore <5nm for catalytic action,<20nm for manufacture a hard magnetic substance soft,<50nm for refractive index modify, and <100nm for achieving excellent paramagnetism,mechanical growth or restricting matrix disorder progress as below the dimension limits of this nanocomposites. Due to pattern of the structure in nanocomposites for abalone shell and bone should be found in nature. During investigated by the Jose-Yacaman et al due to the nanoparticle mechanism such that intensity of colour and conflict to acids and bio-corrosion of maya blue paint can be some mechanism.The nanoscale organo-clays have been used to control flow of polymer solution (e.g. for paint viscosifiers) or organization of gels (for example thickening substances in cosmetics, keeping the preparation in homogeneous form) as in the year of Mid-1950s.Nanocomposites do not used the commonly but the year of 1970s polymer/clay composites be the subject of text book. property of all over observed the maroscale property of the composites they are big quantity of strengthening surface areas such that logically small amount of nanoscale reinforcement. Examples are calculating electrical and thermal conductivity which can improve the carbon nanotubes. Another part of nanoparticles may be the consequences of optical properties, dielectric properties, heat resistances or mechanical properties such as strength, hardness and resistances to be dressed in and fracture. In case of universally nano reinforcement is discrete process of matrix.
1.1.2. Types of nanocomposites
According to the nanocomposites classify the terms of used to believe the substance to be reinforcement and matrix substance. Generally matrix substance nanocomposites are divided into the following three way in given below,
Polymer matrix nanocomposites
Ceramix matrix nanocomposites
Metal matrix nanocomposites
Polymer matrix nanocomposites
The matrix substance and nanoadditives should be the polymers they are used the reinforcement substance could be the polymer nanocompssites.They are above mentioned the word of nanoadditives can be
one dimensional(Nanotubes and fiber)
Two dimensional (Layered substance like clay)
Three dimensional (Spherical particle)
In this types of nanocomposites are extremely good quality mechanical properties and used to both academe and in industry, elastic hardness is high act and the nanoadditives with a strength of tiny attentiveness. They are variety of properties due to particular properties are stupendous properties of polymer nanocomposites should be the electrical and optical properties, dress in resistance, magnetic, barrier resistance, flame resistance, flame retardancy corresponding to companing the polymer as (matrix) and a filler as (reinforcement) of commonly with the polymer composite. Also the variety of substance usage of reinforcement substance can be carbon and glass fiber common part of substance.Many polymers substance like that particular substance is a polyamide as thermoplastic polymer. Another part of reinforcement substance should be used the aerospace industry and carbon fibers depending upon the reinforcement substance on the appliance. They are two types of intermolecular forces should be weak intermolecular forces are the polymer matrix and fillers can be bonding most universal part of this type. It can be exhibit the high aspect ratio with the 1nm thickness of silicate clay mineral layer and ~100nm width of the collected of platelets. It can be the size of 0.3mm length and 13 micrometer diameter of classic layer of silicate with comparison of ~ 4×109 times of glass fiber. In this types of matrix nanocomposit could be achieved the create with the chemical bonding of matrix substance and progress composite substance should be the mechanical properties can be some of the new and unanticipated or exotic properties. They are filler (reinforcement) substance can be used the clay minerals (montmorillonite, saponite, hectorite, etc), high strength get to be achieve. Even though in this case of employed the bonding of chemical as well successed the process. In the filler substance that means the reinforcement substance having the level of atomic or molecular is discrete the composite. Stupendous properties of polymer as low cost, essay processing, high durability, light weight ductility, corrosion resistance.
Metal matrix nanocomposites
Nanocomposites another one type of metal-matrix nanocomposites are the reinforced metal matrix composite. There are continuous and non-continuous reinforced substance of this types of composite carbon nanotube metal matrix composite. However carbon nanotube substance have been to take the new substance are being developed the usage of high tensile strength and electrical conductivity. They are metal matrix nanocomposites should be the research in new area being the addition of carbon nanotube metal matrix composites,boron nitride reinforced metal matrix composites and carbon nitride reinforced metal matrix composite. Corresponding to the part of CNT-MMC such that optical properties due to the area are new progress should be the effective techniques are given by the
Provide for a consistent dispersion of nanotubes in the metallic matrix.

Economically priducible
Lead to strong interfacial adhesion between the carbon nanotubes and metallic matrix.

Formation of superthermite substance such that the hybrid sol-gel with a silica base could be the energetic nanocomposite with combination of nano-scale aluminium powder and metal oxides. There are mechanical properties should be the single and multi-walled reinforced polymeric (polypropylene fumarate-PPF) nanocomposites to tungsten disulphide nanotubes reinforced PPF nano composites such that tungsten disulphide nano tubes reinforced PPF nanocomposites. Also than carbon nanotubes are better reinforcing agents are the tungsten disulphide nanotubes. There are mechanical properties has been increase the consistent dispersion of inorganic nanotubes in the polymer matrix and also the tungsten disulphide nanotubes are present in increases the cross linking density of the polymer. These effect should be the inorganic nanomaterials. In universal case may be better than to compare the reinforching agents to carbon nanotubes. Metal matrix nanocomposites(MMNC) are the substance having reinforced by considering the elastic metal or alloy matrix of which the nanoparticles are implanted. These are different with matrix substance correspond to believe the metal/alloy matrix filled with nanoparticles, display physical, chemical and mechanical properties.in this types of nanoparticles are used through the universal part of like that develop dress in resistance, damping characteristics, and mechanical properties. Metal matrix nanocomposites have been research to progress of explore the nanoparticle embedment the advanced properties and there are structural components due to the wide range of appliance.
Ceramic matrix nanocomposites
A ceramic is the one of the part of occupied in a volume due to the group of many composites substance. Example for the nitride, borides, silicates, group of oxides is the chemical compound etc,.. In case of second component is the metals such that encompass a ceramic- matrix nanocomposites. Mostly universal part of both components are the ceramic one, metallic one of the nanoscopic properties dispersed to finely in order to each other the educe. They are many properties due to progress the particular part of properties like magnetic, optical and electrical properties, as well as the protectic, corrosion- resistance and tribological properties. Believe the ceramic-matrix nanocomposites to design the binary phase diagram of the mixture and to take the chemical reaction should be avoid to measure the both components. However, important part of ceramic is easily react with component of ceramic is the high process temperature have been preparation and they do not having obey to constraint.The ceramic nanocomposites safety to measure the ceramic phases and immisible metal to choose. For example of each other component of Tio2 and Cu with the Gibbs triangles of Cu-o-Ti due to over the largeareas should be immiscible of the mixtures.In the type of matrix composites due to the application of thin film have been applied the thickness some tens of to few nm layer of solid to be deposited with substrate and the surface of function.

1.1.3. Classification of Polymer nanocomposites
The general class of nanocomposite organic/inorganic substance is a fast growing area of research. Important effort is focused on the ability to obtain control of the nano scale structure via innovative systamatic approaches. The properties of nanocomposite substance depend not only on the property of their morphology and interfacial characteristics.

cammarata(2006) point out the most nanocomposite that have been developed and that have demonstrated technically importance. That have been composite of two phases, and can be micro structurally classified in three principal types:
Nano layered composite composed of alternating layer of nano scale dimension
Nano filamentory composites are composed of a matrix with embedded and generally aligned nano scaledimeter filament.

Nano particulate composites composed of matrix with embedded nano scale particles.

There are essentially two moles of classification for nanocomposites. They are the organic and in organic and nanocomposites. So many efforts are taken by the researcher to take control over nano structure by synthetic approaches.

The properties of the nanocomposites not only depend upon the individual parent composition but also their morphology and interfacial characteristics. In the categorization of nanocomposites. The inorganic components can be three dimension structured systems such as zeolite; two dimensional layered substance such phosphate, chalcogenicles and even one dimensional and zero dimensional substance, such as (Mo3 Se3)n, chains and clusters experimental work has generally shown that practically all types and classes of nanocomposite substance lead to new and enhanced properties, when compared to their macrocomposite counterparts. Therefore, nanocomposites assure new appliance in many field such as mechanically- reinforced lightweight components, non-linear optics, battery cathodes and ionics, nanowires, sensors and other systems. The general case of organic/ inorganic nanocomposites may also be of importance to issue of bioceramics and biomineralization, in which in-situ growth and polymerization of biopolymer and inorganic matrix is occurring. Finally lamellar nanocomposites correspond to an extreme case of a composite in which interface interactions between the two phases are maximize.

1.1.4. Synthesis methods of Polymer nanocomposites
Melt intercalation
Melt intercalation is believe eco-friendly and a much better substitution for solution mixing permittable. However processing conditions surface modification of fillers, and compatibility of filler and polymer matrix all play important roles in determining how well the dispersion can be achieved. Discussed the relation between processing condition and morphologies obtained for CNT nanocomposites. Additionally the author explained the dispersion process by breaking it into three steps
1) Wetting of initial agglomerates by the polymer,
2) In filtration of polymer chain into the initial agglomerates to weaken them,
3) Dispersion of agglomerates by break and corrosion and distribution of individual nanotubes into the matrix.

The effects of multiple conditions on melt intercalation for polymer / layered silicates. The entropy loss associated with the confinement of a polymer melt is balanced with an entropy gain that is associated with layer separation and better conformational energy of aliphatic chains of alkylammonium cations. Therefore it is generally agreed that melt intercalation depends on the surface energies of polymer and modified layer silicates.

The synthesis of recycled high impact polystyrene (ps)/ organoclay nanocomposities by melt intercalation. The process was done in an interpenetrating corotating twin screw external with screw diameter of 20mm and L/D ratio of 36. Two different speeds and two types of clay fillers (viscogel S4 and S7 montmorillonite clays) each with different surfactant were used temperature varied between 150 and 190C in the processing zone. The high impact PS was crushed before mixing in order to increase the surface area and facilitate dispersion. It was reported that the higher mixing in order to increase the surface area and facilitate dispersion. It was reported with the higher mixing speed of 600 rpm yielded nanocomposites with better dispersion than they ones processed at 450 rpm. The preparation of PCL-multiwalled carbon nanotubes (MWCNT’S) mixture via melt blending followed by the synthesis of polycarbonate/ ?-pcL-MWCNT nanocomposites.

Exfoliation absorption
Solution intercalation method can be generally divided into several substeps
Dispersion of nanotubes in a solvent by agitation and mixing of nanotubes and polymer solution by agitation controlled evaporation of solvent are precipitation of nanocomposites. Unlike in melt intercalation the driving force behind exfoliation adsorption is the entropy of the confined intercalated chains. This method is considered good for the intercalation of polymer with little or no polarity.

Solution intercalation
Elastomer/ graphene nanocomposites were prepared by solution intercalation. Graphene platelets (3nm in thickness) were obtained from graphite-intercalated compound (GIC) by exposing them to thermal shock and treating them in tetrahydrofuran (THF) solvent while being ultrasonicated. The suspension was added to the SBR mixture and mechanically mixed at 200rpm followed by sonication for 1h below 30C.Evaporation of the solvent was done till 60C by mechanical stirring in which 60% was evaporated and at 60C. Ethanol was used to precipitate, collect, wash and dry the nanocomposite powder. According to XRD and TEM intercalated structure were obtained. Moreover the authors compared those results was obtained from melt mixing and better exfoliation and dispersion was achieved by earlier. This is because more interlayer spacing is available for polymer to intercalate. It was validated with the lower percolation threshold and higher mechanical properties are obtained.

Emulsion polymerization
PS/carbon black (CB) nanocomposite were prepared by emulsion polymerization. Synthesis was carried out by first manually mixing CB with styrene monomer at room temperature. A viscous paste was formed as carbon adsorbed the monomer. A surfactant was added to reduce the viscosity of the system. This is followed by the addition of Azobisbisobutyronitrile (AIBN) initiator to pre-pare emulsified monomer droplets. In order to disperse the system, a surfactant solution was added in the presence of ultrasound. Eventually, the dispersion was sent to the reactor for polymerization to take place. The conditions were set to be 60C, 350rpm mixing speed, and 120min reaction time. According to two main results were obtained particle diameter close to 50nm and high polydispersity and a layer of CB surrounding the polymer particles, which is because of carbon primary aggregates being modified during the dispersion stage.

In-situ polymerization
Several advantages are attributed to in- situ polymerization. First of all, thermo plastic- and thermoset –based nanocomposites can be synthesized via this route(3). In addition, it permits the grafting of polymers on filler surface, which can generally improve properties of the final composite. Partially exfoliated structures can be attainable with this method because of the good dispersion and intercalation of fillers in the polymer matrix. In-situ polymerization is the most suitable preparation method for polyolefin/ clay nanocomposites because of its lack of rigorous thermodynamic requirements compared to the other methods.

Non traditional method
In order to facilitate better dispersion of the filler in the polymer matrix for enhanced properties of final composites, researchers investigate different routes based on the traditional methods mentioned earlier. For instance, in-situ polymerization can be customized to be redox or catalytic microwave- induced synthesis, one-pot synthesis, template-directed synthesis, electro- chemical synthesis, self- assembly synthesis and intermatrix synthesis (IMS).

As the name imply, one-pot synthesis refers to a series of reactions being carried out in the same reactor. As it referes to a location, this mode can be inclusive of other synthesis methods .

1.1.5. Applications of Polymer Nanocomposites
The polymer nanocomposites are progress to used the new applications in many fields such that non-linear optics,mechanically reinforced lightweight components battery, cathods, ionics and nanowires, sensors and other system. Since numerous automotive and general industrial application. For including more general applications are given by
Packing
Fuel cell
Solar cell
Fuel tank
Plastic containers
Cover for portable electronic equipment such as mobile phones and pages
Impellers and blades for vaccum cleaners
Mirror housing on various types of vehicles
Door handles
Engine covers
Belt covers
1.2. Copolymer
1.2.1. Introduction
Copolymer other only the name of mixed polymer that means the polymer form of more than one kind of monomer unit.When two or more different monomers unit together to polymerize their result is called a copolymer and the process is called copolymerization. Monomers classically have a double bond that undergoes a linking reaction with another monomer molecule to form a single bond monomers. Double bond that participate in polymerization reactions include C=C double bond, C=N double bonds, and C=O double bonds.

For example : Copolymer
Buna-S rubber form of 1,3 butadiene (CH2= CH CH=CH2)
Styrene (C6H5CH=CH2)
1.2.2. Types of copolymer
If we believe the many types of copolymer and the reaction is copolymerization and present now the M and N are
Random type
MM MN NNN MM NMMMNN….

Alternating type
MN MN MN MN M……
Block polymerization
In this type of polymerization following together form block of straight polymerization can be using the multimers.

.MMM. NNNN. MM .NNNNN.

Graft polymerization
These type of polymerization having the section of graft (or) main chain reaction to form of the ? radiation (or) X radiation (or) Chemically reactive function group. The multimers are M and N to formed and the structure different from the block polymer .

1.3. Material Introduction
1.3.1. Aniline
Aniline C6H5NH2 is the chemical formula for the organic compound. It is consider the phenyl group due to the amino group. Manufacuring the mainly through the usage of polyurethane and it is also called the prototype aromatic amine. Its produce to manufacturing the various industrial chemicals. It’s like odour of rotten fish possesses the volatile amines.

Although its aromatic compound also can be the smoke flame characteristic. There was the process on going to the cumene prepared to form of ammonia and phenol from alternatively due to the aniline.

Aniline is distinguished in to three brands are derived the process of the step can be aniline oil for blue it is pure aniline. . A mixture of aniline is called the aniline oil for red and aniline oil for safranine its contain aniline and ortho-para- toluidines. Its fuchsine fusion of the distillate through the obtained from the aniline and the ortho-toluidine. The aromatic compound of aniline is the phenyl group of most universally through the further substitution amoung the compounds are chloroanilines, toluidines, xylidines, nitroaniline, aminobenzoic acids and many other include they are prepared from the reduction process of nitration due to substituted from the aromatic compound.
For example the process of convert toluene into toluidines and chlorobenzene into 4-chloroaniline usage of this approaches. It is also called the weak base. Generally weaker bases of the aromatic amines such as aniline, than aliphatic amines. Its can be the reaction of anilinium (or) phenyl ammonium ion (C6H5-NH3) to forming the strong acid. It was the methylene dianiline is the main application for prepared the compound. It is also the formaldehyde condensation of the related compounds.
Structure

Fig 1.1 Structure of Aniline
Properties
Chemical formulaC6H7N
Molar mass93.13 g·mol?1
Appearance Colorless to yellow liquid
Density1.0217 g/mol
Melting point?6.3 °C (20.7 °F; 266.8 K)
Boiling point184.13 °C(363.43 °F; 457.28 K)
Solubilityin water3.6 g/100 mol at 20 °C

Table 1.1 Physical properties of aniline
1.3.2. Polyaniline
Polyaniline (PANI) is a conducting polymer of the semi flexible rod polymer family. Although the compound itself was discovered over the 150 years ago, since the early 1980s has polyaniline captured the intense attention of the scientific community. The interest is due to the rediscovery of high electrical conductivity. Amongest the family of conducting polymers and organic semiconductors, polyaniline has many attractive processing properties.

Fig.1.2 Structure of polyaniline

Developed the first commercially successful route to the dye called Aniline Black. The first definition report of polyaniline did not occur until 1862, which include an electrochemical method for the determination of small quantities of aniline. Although the synthetic methods to produce polyaniline are quite simple, the mechanism of polymerization is probably complex. The synthesis of polyaniline nanostructure is facile.
Using special polymerization proceduces and surfactant dopants, the obtained polyaniline powder can be made dispersible and hence useful to practical application. Bulk synthesis of polyaniline nanofibers has lead to a highly scalable. Polyaniline and the other conducting polymers such as polythiophene, polypyrole and PEDOT/PSS have potential for application due to their lightweight, conductivity, mechanical flexibility and low cost. Polyaniline is especially attractive because it is relatively in expensive has three distinct oxidation states with different colours and has an acid/base doping response and attractive for acid/base chemical vapour sensor, supercapacitors and bio sensors. Currently the major application of printed circuit board manufacturing.

1.3.3 O- Toluidine
O-Toluidine is a colourless or light yellow liquid. It will become reddish brown while exposure to air and light. It is soluble in water, soluble in alcohol, ether and dilute acids and forms homogeneous mixture with carbon tetrachloride, diethylether, and ethanol. O-Toluidine emits toxic fumes of nitrogen oxides when heated. O-Toluidine is also combustible. The molecular formula of O-Toluidine is C7H9N.

O-Toluidine is used as an intermediate in the manufacture of dyes which are used in printing textile and as biological stains and in colour photography. It is also as an accelerator in vulcanization. O-Toluidine can be used as an alternative to tar produced by low temperature carbonization of coal. It is present in cigarette smoke. During thermal degradation of polyurethane products O-Toluidine is released into the environment.

The organic compounds o-toluidine, m-toluidine and p-toluidine are the three isomers of toluidine. In these compounds O- stands for ortho-,m-stands for meta-, and p-stands for para- all three are aryl amines. They have the chemical structure which is similar to aniline except that there is a methyl group substituted onto the benzene ring. There is a difference between these three isomers that is the position where the methyl group (-CH) is bonded to the ring relative to the amino functional group(-NH2).

Structure

Fig 1.3 Structure of O-Toluidine
Properties
Chemical formula C7H9N
Molar mass 107.16 g mol-1
Appearance Colourless to pale-yellow liquid
Odor Aromatic, aniline-like odor
Density 0.97759 g/cm3
Melting point 23.7C(-10.7F;249.5K)
Boiling point 200 to 202C
Vapour pressure 0.307531 mmHg (25C)
Table 1.2 Physical properties O-Toluidine
1.3.4. Poly O-Toluidine
Poly (O-Toluidine) (POT) is a derivative of PANI which contains the –CH3 group into the ortho position of the aromatic ring of the aniline monomer. Among the ring substituted PANI derivatives POT have widely studied in interesting of electro-optical properties. The improved for mechanical strength greater thermal and chemical stability and enhanced ion exchanged capacity electrochemical properties, optical and magnetic behavior.1.3.5. Chromium trioxide CrO3
Chromium trioxide with the chemical formula for CrO3. It is an inorganic compound of acidic anhydride of chromic acid and is called the sometimes are same name. It is the purpose of electroplating due to produce the millions of kilograms per annually. There was a powerful oxidizer and undergoing the carcinogen. There are suspended with a anhydrous conditions. It was a dark-purple soild and wet of which dissolves in water concomitant due to a hydrolysis condition of which soild is a bright orange. It was the main part of application can be chrome plating. This compound like that highly toxic,corrosive and carcinogenic. Example for an environmental hazard of hexavalent chromium. This compound which produce the sodium dichromate or corresponding to the sodium chromate with the solution of sulfuric acid due to the compound annually 100Mkg produced approximately or routes of the similar compound.
The solid of an chromium similar to overall ratio of stoichiometry is 1:3, there are believe in a reaction of tetrahedrally with the chains share vertices with the coordinates of this atoms. However chromium with the each point of center, and therefore two oxygen center with neighbours shares, given that not shared with the two oxygen atoms. The chromium Cro3 is the particular structure of monomeric and density functional theory calculated with this type of structure. Which that predicted to be valuable this compound of pyramidal can be like the shape which that planar .
Structure

Fig.1.4 Structure of CrO3
Properties
Chemical formula CrO3
Molar mass 99.99 g mol-1
Density 2.7 g/cm3 (20C)
Melting point 197C (387F;470K)
Boiling point 250C (482F;523K)
Solubility in water Decomposes, 164.8 g/100ml (0C)169 g/ 100ml (25C)
172.6 g/100ml (40C)
198.1 g/100ml (100C)
Solubility Soluble in H2SO4,HNO3, (C2H5)2O,CH3COOH,Acetone.

Appearance Dark red granular solid.

Table 1.3 Physical properties of Chromium trioxide
CHAPTER-II
REVIEW OF LITERATURE
Ashok.K.Sharmal et al.,1 synthesized PANI-CNTs and PANI-GNs nanocomposites by in-situ oxidative polymerization method and characterized to understand the nanocomposites formation of the substance. Nanocomposites are geared up in different molar ratioa on carbon nanotubes (CNTs) and Graphene (GNs)substrates, separately. Physicochemical characteristics of prepared nanocomposites are evaluated by means of UV- visible, FTIR and XRD techniques. The morphology of the nanocomposites are studied by SEM.

Yomen Atassi et al.,2 conductive polymers or ” organic metals” are highly engineered nanostructured substance made from organic building blocks. Present the synthesis of chloride doped polyaniline by bulk oxidative chemical polymerization using a solid aniline salt as a monomer instead of liquid aniline to diminish toxic hazards. The FTIR and UV- visible spectra confirmed the expected structure of the polymer. The electrical conductivity measured using a four probe method is measured using an HP impedance analyzer in the range 10kHz-13MHz. The influence of doping and the preparation.

Ana paula Grabina et al., 3 the polyaniline (PANI) can be overcome by preparing composites with high density polyethylene (HDPE). Pani nanofibers are synthesized in this research using a rapid mixing method, while HDPE/ PAni composites are prepared by in-situ polymerization using Cp2ZrC12/MAO as a catalyst system. Different experimental conditions for polymerization and an electrochemical study are performed. The findings confirmed that the addition of small amounts of Pani (up to 7%) and longer impregnation (120 min) with methylaluminoxane (MAO) before polymerization are important factors contributing to increased catalytic activity. Analysis by cyclic and differential pulse voltammetry indicates that MAO reacts with the PAni in the ethylene polymerization process and forms active species in the presence of the catalyst.
R. Ratheesh et al., 4 prepared polyaniline doped with hydrochloric acid (HCl) by chemical oxidative polymerization of aniline (ANI) in aqueous medium with ammonium peroxy disulphate as an oxidant. The prepared samples are characterized by Fourier transform – infrared (FT-IR) spectroscopy,Ultraviolet –Visible (UV- VIS) spectroscopy and X-ray diffraction technique. The prepared samples are pressed into pellets and DC electrical conductive is measured using four-probe method. The FT-IR peaks obtained in the samples are in good agreement with the reported peaks in literature. UV-VIS spectroscopy shows the various electron transition present in the polyaniline samples. The crystallinity of the samples is studied in detail by X-ray diffraction technique. The conductivity shows an increase with increase in temperature, for all the three samples.

Alireza Samzadeh-Kermani et al., 5 synthesized a new nanocomposite based on polyvinyl alcohol/Poly aniline/ Zinc oxide (PVA/PANI/Zno) is successfully. Zno powder is used to produce its nanoparticles (NPs) using conventional method. Morphology and the size of ZnO NPs in nanocomposites are studied by a Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) analysis and Infrared (IR) spectroscopy. According to XRD result the average size of prepared ZnO NPs is found to be at the range 22-34nm. SEM images are shown hexagonal shape for ZnO NPs, which is used for the investigation of antibacterial property.

M.V.N.Ambika prasad et al., 6 prepared polyaniline iron oxide nanocomposites are characterized by employing Fourier Transform infrared (FTIR), Scanning Electron Microscope (SEM), Thermal study by (TGA). The DC conductivity of prepared nanocomposites are measured as a function of temperature which shows the strong interaction between the polyaniline and iron oxide nanoparticles. They exhibits semiconducting behavior. Finally, the sensing properties of these nanocomposites are also studied at room temperature.

A.K.Barve et al., 7 synthesized nickel oxide (NiO) nanoparticles and its composite with polyaniline by sol-gel method. In this method ascorbic acid is used as a reducing reagent and ethylene glycol is used as a sol stabilizer and also served as a diffusion barrier. The synthesized samples are investigated by UV- Vis and FT-IR spectroscopy.
Ganesh R. Yerawar., 8 synthesized pure nanocrystalline zinc oxide compound by chemical co-precipitation method. The composite of polyaniline with nanosized zinc oxide is prepared by in-situ chemical oxidation polymerization method with ammonium per sulphate as an oxidant in aqueous hydrochloric acid under constant stirring at 0-4?C in presence of nitrogen atmosphere. The D.C. electrical conductivities as a function of temperature(298-423K) are measured by four probe technique. Electrical conductivity of composite with 20% weight of zinc oxide is found to be more among all other composites and even have been polyaniline. FTIR studies and showed that there is strong interaction between polyaniline and nanosized zinc oxide particle.

V.Sridevi et al., 9 synthesized doping plays a very important role to convert the polymer into conductive form. In this work, synthesize polyaniline chemically with various types of dopant acids such as inorganic acids like sulphuric acid, organic acids like p-Toluenesulfonic acid, Camphorsulfonic acid and metal Lewis acids like Auric acid which act as an oxidative agent as well as a secondary dopant to result in a polyaniline/Gold nanocomposite. Polyaniline (PANI) is chemically synthsized by oxidative polymerization of aniline in different acid dopants. The level of doping and nature of the polymer formed is studied using UV-Visible Spectroscopy. FTIR spectra show that the incorporation of Au seems to be effective for better conductivity of the polymer samples. XRD study confirm the presence of Au in the polymer sample in nanometer scale.

M.A. Sangamesha et al., 10 synthesized the copper selenide (Cu2Se)/poyaniline (PANI) nanocomposites by in-situ polymerization through a simple and harmless technique. The characteristic peaks in FT-IR and UV-Visible spectra are found shifted to higher wave numbers, which is attributed to the above said interaction. XRD pattern revealed the orderly arrangement of the polymer composite. Results obtained supports the prepared nanocompoiste may be used as a multifunctional substance for different nanoelectronic devices.

S.Raja et al., 11 synthesized polyaniline- copper (II) oxide (PAni-CuO) nano composite by chemical oxidation polymerization method with ammonium persulfate as an oxidant in aqueous hydrochloric acid under constant stirring at 0-2?C in presence of N2- atmorphere. CuO nanoparticle are synthesized by chemical co-precipitation method. Different weight percentage of CuO in PAni constitutes different PAni-CuO composite substance are synthesized and characterized by X- ray diffraction, infrared, ultraviolet, scanning electron microscopy, transmission electron microscopy, photoluminescence and electrical conductivity methods.

Sneh Lata Goyala et al., 12 in situ polymerization of aniline are carried out in presence of nickel oxide (NiO) to synthesize polyaniline /nickel oxide (PANI/NiO) composites using chemical oxidation method.PANI and PANI/nickel oxide composites are characterized by Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD),Thermal analysis and DC conductivity.FTIR and XRD results reveal the presence of NiO in the composites. Thermal stability of polymer composites has been analysed by TGA-DTG and corresponding thermal kinetic parameters are calculated.

Megha Sawarkar et al., 13 prepared ZnO-Pani and CdO-Pani nanocomposites by sol-gel method using their respective nitrates. The prepared samples are characterized by using Scanning Electron Microscope (SEM), X-ray diffraction (XRD) and Fourier Transform Spectroscopy (FTIR) to get surface morphology. The idea of getting particles of nanosized range so that further characterization can be done, to study the electrical properties of synthesized nanocomposite and measure the resistivity.

Tursun Abdiryim et al., 14 synthesized polyaniline / single-walled carbon nanotubes (PANI/SWNTs) composites with a content of SWNTs varying from 8wt% to 32 wt% using a solid-state synthesis method. The structure and morphology of the samples are characterized by Fourier transform infrared (FTIR) spectra, Ultraviolet-visible (UV-vis) absorption spectra, X-ray diffraction (XRD) and Transmission electron microscopy (TEM). The electrochemical performance of the composites are investigated by galvanostatic charge- discharge and cycling stability measurements.

J.Sebastian et al., 15 fabricated EVA/ZnO nanocomposites of 1%,2% and 4% Zno by direct probe sonicator method. The ZnO nanopowders are prepared by solvothermal method. The thermal analysis using TGA-DTA is also performed and it is found that the thermal stability of the nanocomposites increase with increasing the filler concentration. The thermal parameters such as thermal diffusivity () and thermal effusivity(e). The thermal conductivity (k) and heat capacity (Cp) are studied using photopyroelectric technique.

A khan et al., 16 polyaniline (PANI) is a well studied substance is the pre-eminent electrically conducting organic polymer with the potential for a variety of applications such as in batteries, microelectronics displays, antistatic coatings, electromagnetic shielding substance, sensors and actuators. The result of thermogravimetric, fourier transform infrared and UV-visble analysis indicated that the iron oxide nanoparticles could improve the composites thermal stability possibly due to the interaction between iron particles and PANI backbone.
A.katoch et al., 17 synthesized polyaniline/Tio2 hybrid nanoplates by sol-gel chemical method. The cyclic voltammetry to obtained hybrid substance revealed that the plate like structure is more advantages for the electrochemical stability. The chemical bonding estabilished between polyanpolyaniline and TiO2 confirmed by Fourier transformed infrared spectroscopy is likely to be responsible for the enhanced chemical stability.

Abdo Mohd Meftah et al., 18 synthesized polyaniline (PANI) and nickel (Ni) nanoparticles embedded in polyvinyl alcohol (PVA) film matrix by gamma radiolytic method. The effects of does and Ni ions concentration on structural, optical and electrical properties of the final PVA/PANI/Ni nanocomposities film are carefully examined. The structural and morphological studies show the presence of PANI with irregular granular microstructure and Ni nano particles with spherical shape and diameter less than 60 nm. The average particle size of Ni nanoparticles decreased with increasing does and decreasing of precursor concentration due to increase of nucleation process over aggregation process during gamma irradiation.

V.K.Gade et al., 19 the electrochemically synthesized Polypyrrole-Polyvinyl Sulphonate ( Ppy-PVS), Poly(N-methylpyrrole)- Polyvinyl Sulphonate (P(NMP)-PVS) and their co-polymer Polypyrrole-Poly(N-methylpyrrole)-Polyvinyl Sulphonate (Ppy-P(NMP)-PVS) films on indium tin oxide (ITO) coated glass electrode have been investigated by galvanostatic method. This study reveals that as compared to (P(NMP)-PVS) and (Ppy-P(NMP)-PVS) the Ppy-PVS film provide a polymer matrix with very good porosity, mechanical and environment stability, uniform surface morphology and higher conductivity, which is suitable for the immobilization of biocomponent. The synthesized films are characterized using electrochemical technique, electrical conductivity, Fourier-transform infrared (FTIR) spectroscopy and Scanning electron microscopy (SEM).

Jakeer Husain et al., 20 synthesized NiO Nanoparticls (NNP) by self- propagating high temperature synthesis from nickel nitrate. Synthesized NiO are used to prepare Polyaniline (PANI)- NiO nanocomposites by in-situ chemical oxidative polymerization at 0-5C. Different weight percentage of NiO (10%,20%,30%,40% and 50%) were added during the polymerization. The nanocomposites are characterized by X-ray diffraction (XRD), Surface morphology is studied using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). These nanocomposites have microwave, sensor and battery applications.

Shankarananda et al., 21 synthesized in-situ polymerization by chemical oxidation of aniline is carried out for Polyaniline (PANI) and Polyaniline – In2O3 (PANI-In2O3) composite substance. Different weight percentage of InO in PANI constitutes different PANI-In2O3 composite substance to know detailed changes.The structural changes of prepared composites substance are carried out by X-ray diffraction (XRD) tool. Morphology study of Indium oxide (PANI) and PANI-InO composites is studied by Scanning Electron Micrograph (SEM) tool. Bonding changes are observed by Infrared (IR) study.

Mahesh D. Bedre et al., 22 prepared polyaniline (PANI) and Polyaniline-Co3O4 nanocomposites (PCO) by employing interfacial polymerization using ammonium persulphate as an oxidizing agent. The formation of regular nanocomposite substance are studied by Fourier transform infrared (FTIR) spectroscopy and XRD techniques. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) images are conducted to characterize the morphology. Thermo- gravimetric (TG) and differential thermal analysis (DTA) are carried out study the thermal stability of the resulting composites.

Saima Sultana et al., 23 synthesized ZnO-ZrO2 nanocomposites by sol-gel method and in-situ polymerization is used to synthesis ZnO-ZrO2 nanocomposites doped polyaniline (PANI). The substance are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM),Scanning electron microscopy (SEM) , Energy dispersive X-ray spectroscopy (EDX) and (TGA) to ensure the crystalline size, functional groups, morphology, chemical composition and thermal stability of the polymer nanocomposites complex.

S.pramodini et al., 24 synthesized the results on the laser third order optical non linearity and optical limiting properties of polyaniline and poly(O-toludine) studied in N,N-dimethyl formaldehyde solution using a single-beam Z-scan technique. Experiments are performed using continuous wave He-Ne laser operating at 633 nm wavelength as an excitation source. The samples exhibit absorption and refraction nonlinearities. The negative sign of the nonlinear refractive index n2 indicates that both substance exhibit self-defocusing optical nonlinearity. The FTIR and UV-visible characterization spectra conform the expected molecular structure of the polymer.

G.B.V.S.Lakshmi et al., 25 prepared poly(O-toludine) (POT) a derivative of poly aniline by chemical oxidative polymerization method in aqueous media. The samples are characterized by X-ray diffraction and Fourier transform infrared spectroscopy(FTIR). The XRD pattern of the powder POT and their blend shows the semi-crystalline nature of the samples. FTIR studies show the information of changes in functional groups with doping and blending of POT with PVC.

CHAPTER-III
EXPERIMENTAL DETAILS
3.1. Experimental
3.1.1. Substance
The main reagents used for the synthesis of the substance are aniline (C6H5NH2) (molecular weight 93.13 g mol-1,density 1.02 kg) from Merck Ltd. O-Toluidine (C7H9N) (molecular weight 107.15 gmol-1, density 1.008 kg) from Merck Ltd. All the other chemicals and reagents are sulphuric acid (molecular weight 98.08 gmol-1,density 1.84 kg), potassium dichromate K2Cr2O7 (molecular weight 294.185 g mol-1, density 2.676 kg/cm3) and Chromium trioxide CrO3 (molecular weight 99.99 g mol-1,density 2.7 g/cm3), Acetone(C3H6O), Ammonium hydroxide also purchased from Merck Ltd. Demineralised water from nice was used throughout this work. Whatmann filter paper was used for filteration process. Substance listed as shown in Table 3.1.

Substance Molecular
Formula Action
Aniline C6H5NH2 Monomer
O-Toluidine C7H9N Monomer
Sulphuric acid H2So4 Dopant
Potassium dichromate K2Cr2O7 Oxidant
Chromium trioxide CrO3 Metal oxide
Acetone C3H6O Purifier
Ammonium hydroxide NH4OH Purifier

Table.3.1 Substance list-synthesis of CrO3 nanocomposites
3.2 Synthesis of nanocomposite CrO3 (25%)
CrO3 nanocomposites was synthesized by emulsion polymerization method with polymerization of aniline, O-toluidine in the presence of sulfuric acid as dopant and potassium dichromate as oxidant. For synthesis 3.6ml of aniline is mixed with 100ml of distilled water into the four necked round flask. The purpose of the flask is to maintain temperature is using thermometer to allow the inlet and outlet of gas because the whole experiment is carried out in nitrogen gas atmosphere and to add other reagents dropwise after 10 minutes 3.78ml O- toluidine is added to the aniline mixture the time and temperature are noted.

After 10 minutes the CrO3 2.5g added and remains the after 10minute Conc.H2SO4(5.3304ml) is added the mixture of solution. Exactly half an hour after the addition of potassium dichromate (2.9419)g mixed with 20ml of distilled water (0.5M) is added dropwise using an additional flask. The gas is passed from the nitrogen cylinder into the round flask through the condenser tube water is passed through the tube inorder to avoid evaporation due to heating. After the addition of few drops K2Cr2O7 the mixture becomes dark green to indicate the happening of polymerization. The temperature is maintained at 60C at a constant stirring of 500rpm.

The reaction takes place for 24 hours. The dark green precipitate of CrO3 resulting from polymerization is filtered using whatmann’s filter paper. Then the mixture is washed with 50ml of distilled water and 25ml of acetone to remove the excess acid and impurity. For deprotonation CrO3 was suspended in 25ml of ammonia solution. The resulting mixture was dried under vaccum at 70oC for 12 hour. The synthesized CrO3 was grinded using agate mortar and the product is obtained in the form of a fine powder.

Aniline
3.6ml
O-Toluidine
3.78ml

Distilled water 100ml

CrO3 2.5g
Constant stirring for 10mins

Constant stirring for 10 mins

Nitrogen gas ON
H2SO4 – 5.3304ml
( Added drop wise)

Constant stirring for half an hour
Pure PANI powder

K2Cr2O7-2.9419g+20ml distilled water
( Added drop wise under constant stirring)

Constant stirring for 24 hours

Green precipitate CrO3

Washed with 50mlDMW and filtered and treated with 25ml of acetone ; ammonia and filtered

Deep blue precipitate
CrO3

Dried under vaccum ( 70oC for 12 hours) and grinded in a agate mortar

CrO3 nanocomposites
powder

Fig.3.1. Schematic presentation of CrO3 (25%) nanocomposites preparation
3.3 Synthesis of nanocomposite CrO3 (50%)
CrO3 nanocomposites was synthesized by emulsion polymerization method with polymerization of aniline, O-toluidine in the presence of sulfuric acid as dopant and potassium dichromate as oxidant. For synthesis 2.355ml of aniline is mixed with 100ml of distilled water into the four necked round flask. The purpose of the flask is to maintain temperature is using thermometer to allow the inlet and outlet of gas because the whole experiment is carried out in nitrogen gas atmosphere and to add other reagents dropwise after 10 minutes 2.3565ml O- toluidine is added to the aniline mixture the time and temperature are noted.

After 10minutes the CrO34.99g added and remains the after 10minutes Conc.H2SO4(5.3304ml) is added the mixture of solution. Exactly half an hour after the addition of potassium dichromate (2.9419)g mixed with 20ml of distilled water (0.5M) is added dropwise using an additional flask. The gas is passed from the nitrogen cylinder into the round flask through the condenser tube water is passed through the tube inorder to avoid evaporation due to heating. After the addition of few drops K2Cr2O7 the mixture becomes dark green to indicate the happening of polymerization. The temperature is maintained at 60C at a constant stirring of 500rpm.

The reaction takes place for 24 hours. The dark green precipitate of CrO3 resulting from polymerization is filtered using whatmann’s filter paper. Then the mixture is washed with 50ml of distilled water and 25ml of acetone to remove the excess acid and impurity. For deprotonation CrO3 was suspended in 25ml of ammonia solution. The resulting mixture was dried under vaccum at 70oC for 12 hour. The synthesized CrO3 was grinded using agate mortar and the product is obtained in the form of a fine powder.

Aniline
2.355ml
O-Toluidine
2.3565ml

Distilled water 100ml

CrO3 4.99g
Constant stirring for 10mins

H2SO4 – 5.3304ml
( Added drop wise)
Nitrogen gas ON
Constant stirring for 10 mins

Constant stirring for half an hour
Pure PANI powder

K2Cr2O7-2.9419g+20ml distilled water
( Added drop wise under constant stirring)

Constant stirring for 24 hours

Green precipitate CrO3

Washed with 50ml DMW and filtered and treated with 25ml of acetone & ammonia and filtered

Deep blue precipitate
CrO3

Dried under vaccum ( 70oC for 12 hours) and grinded in a agate mortar

CrO3 nanocomposites
powder

Fig.3.2. Schematic presentation of CrO3 (50%) nanocomposites preparation
3.4 Synthesis of nanocomposite CrO3 (75%)
CrO3 nanocomposites was synthesized by emulsion polymerization method with polymerization of aniline, O-toluidine in the presence of sulfuric acid as dopant and potassium dichromate as oxidant. For synthesis 1.153ml of aniline is mixed with 100ml of distilled water into the four necked round flask. The purpose of the flask is to maintain temperature is using thermometer to allow the inlet and outlet of gas because the whole experiment is carried out in nitrogen gas atmosphere and to add other reagents dropwise after 10 minutes 1.305ml O- toluidine is added to the aniline mixture the time and temperature are noted.

After10minutes the CrO37.495g added and remains the after 10 minutes Conc.H2SO4 (5.3304ml) is added the mixture of solution. Exactly half an hour after the addition of potassium dichromate (2.9419)g mixed with 20ml of distilled water (0.5M) is added dropwise using an additional flask. The gas is passed from the nitrogen cylinder into the round flask through the condenser tube water is passed through the tube inorder to avoid evaporation due to heating. After the addition of few drops K2Cr2O7 the mixture becomes dark green to indicate the happening of polymerization. The temperature is maintained at 60C at a constant stirring of 500rpm.

The reaction takes place for 24 hours. The dark green precipitate of CrO3 resulting from polymerization is filtered using whatmann’s filter paper. Then the mixture is washed with 50ml of distilled water and 25ml of acetone to remove the excess acid and impurity. For deprotonation CrO3 was suspended in 25ml of ammonia solution. The resulting mixture was dried under vaccum at 70oC for 12 hour. The synthesized CrO3 was grinded using agate mortar and the product is obtained in the form of a fine powder.

Aniline
1.153ml
O-Toluidine
1.305ml

Distilled water 100ml

Constant stirring for 10mins

CrO3 7.495g

Nitrogen gas ON
Constant stirring for 10 mins

H2SO4 – 5.3304ml
( Added drop wise)

Constant stirring for half an hour
Pure PANI powder

K2Cr2O7-2.9419g+20ml distilled water
( Added drop wise under constant stirring)

Constant stirring for 24 hours

Green precipitate CrO3

Washed with 50ml DMW and filtered and treated with 25ml of acetone ; ammonia and filtered

Deep blue precipitate
CrO3

Dried under vaccum ( 70oC for 12 hours) and grinded in a agate mortar

CrO3 nanocomposites
powder

Fig.3.3. Schematic presentation of CrO3 (75%) nanocomposites preparation
CHAPTER-IV
CHARACTERIZATION TECHNIQUES
4.1. Fourier transform infrared (FTIR) spectroscopy
4.1.1. Introduction
FT-IR stands for Fourier transform infrared the prepared method of infrared spectroscopy. IR radiation is passed though a sample. Some of the infrared radiation is absorbed by the sample and some of it is passed through (transmitted) the resulting spectrum represent the molecular absorption and transmission creating a molecular finger print of the sample. Like a fingerprint no two unique molecular structures produce the same infrared spectrum. This makes infrared spectroscopy useful for several types of analysis it can be applied to the analysis of solids, liquids and gasses. The term Fourier transform infrared spectroscopy (FTIR) refers to a fairly recent progress in the manner in which the data is collected and converted from an interference pattern to a spectrum.

4.1.2. Instrumentation
The term Fourier transformation has originated from a mathematical operation demonstrated by ‘Jean Fourier’ which converts the frequency domain into time domain. Fourier transform infrared (FITR) spectrometers have almost entirely replaced dispersive instrument because of their enhanced performance in terms of speed and efficiency. The instruments consists of a interferometer, fixed mirror, a movable mirror, beam splitter.

A beam emitted by a source is split in to the beam splitter 50% of the incident radiation will be reflected to one of the mirror while 50% will be transmitted to the other mirror. The two beam are reflected from these mirror returning to the beam splitter where they recombine and interfere to give constructive interference or destructive interference, depending on the difference in the optical paths between two arms of interferometer.

The signal is then recorded by the detector the steps for recording an FTIR spectrum are to produce an interferogram with and without a sample in the beam then to transform these interferogram into spectra of the source with sample absorption and without sample absorption. The radio of the former to the latter is the IR transmission spectrum of the sample. In case of FTIR spectroscopy the sample placed between the interferometer and the detector Fig.4.1.The recent advance of IR are FTIR-ATR, FTIR-PAS, and FTIR- Micro spectrometry.

Fig 4.1 A simple spectrometer layout
4.1.3. The sample analysis process
The normal instrumental process is as follows
1.The source: Infrared energy is emitted from a glowing black-body source. This beam passes through an aperture which controls the amount of energy presented to the sample and ultimately to the detector.

2.The interferometer: The beam enters the interferometer were the ” spectral encoding” takes place.The resulting interferogram signal then exits the interferometer.

3.The sample: The beam enters the sample compartment where it is transmitted through or reflected off of the surface of the sample,depending on the type of analysis being accomplished. This is where specific frequencies of energy, which are uniquely characteristic of the sample are absorbed.

4.The detector: The beam finally passess to the detector for final measurement. The detectors used are specially designed to measure the special interferogram signal.

5.The computer: The measured signal is digitized and sent to the computer where the fourier transformation takes place. The final infrared spectrum is presented to the user for interpretation and any further manipulation.

Because there needs to be a relative scale for the absorption intensity a background spectrum must also be measured. This is normally a measurement with no sample in the beam. This can be compared to the measurement with the sample in the beam to determine the “percent transmittance”. This technique results in a spectrum which has all of the instrumental characteristics removed. Thus all spectral features which are present are strictly due to the sample. A single background measurement can be used for many sample measurements because this spectrum is characteristic of the instrument itself.

4.1.4. Applications
FTIR can be used in all applications. It finds extensive use in the identification and structural analysis of organic compounds, natural product, polymers, etc. The presence of particular functional group in a given organic compound can be identified. Since every functional group has unique vibrational energy. The IR spectra can be seen as their fingerprints. In addition, the multiplex and throughout advantages have opened up new areas of applications.
GC-IR(Gas chromatography-Infrared spectrometry)
A gas chromatograph can be used to separate the components of a mixture.The fractions containing single components are directed in to an FTIR spectrometer to provide the infrared spectrum of the sample. This technicque is complementary to GC-MS( Gas chromatography-mass spectrometry). The GC-IR method is particularly useful for identifying isomers, which by their nature have identical masses. The key to the successful use to GC-IR is that the interferogram can be captured in a very short time typically less than 1 second. FTIR has also been applied to the analysis of liquid chromatography fractions.

TG-IR(Thermo gravimetric-Infrared spectrometry)
IR spectra of the gases evolved during thermal decompositions are obtained as a function of temperature.

Micro samples
Tiny samples such as in forensic analysis can be examined with the aid of an infrared microscope in the sample chamber.An image of the surface can be obtained by scanning. Another example is the use of FTIR to characterize artistic substance in old-master paintings.

Emission spectra
Instead of recording the spectrum of light transmitted through the sample FTIR spectrometer can be used to acquire spectrum of light emitted by the sample. Such emission could be induced by various processes and the most universal ones are luminescence and Raman scattering. Little modification is required to an absorption FTIR spectrometer to record emission spectra and therefore many commercial FTIR spectrometers combine both absorption and emission/ Raman modes.

Photocurrent spectra
This mode uses a standard absorption FTIR spectrometer. The studied sample is instead of the FTIR detector and its photocurrent induced by the spectrometer broadband source is used to record the interferogram,which is then converted into the photoconductivity spectrum of the sample.

4.2. UV-Vis Spectroscopy
4.2.1. Introduction
Ultraviolet-Visible spectroscopy or Ultraviolet-Visible spectrophotometry (UV-Vis or UV/Vis) refers to absorption spectroscopy or reflectance spectroscopy in the ultraviolet-visible spectral region.This means it uses light in the visible and adjacent ranges. The absorption or reflectance in the visible range directly affects the perceived color of the chemicals involved. In this region of the electromagnetic spectrum atoms and molecules undergo electronic transitions. Absorption spectroscopy is complementary to fluorescence spectroscopy in that fluorescence deals with transition from the excited state to the ground state while absorption measures transitions from the ground state to the excited state.

Over a certain range of wavelength every chemical compound absorbs, transmits, or reflects light (electromagnetic radiation). Spectrophotometer is a measurement of how much a chemical substance absorbs or transmits and a spectrophotometer is an instruments that measures the amount of the intensity of light absorbed after it passes through sample solution with the spectrophotometer the concentrations of a substance (the amount of a know chemical substance ) can also the determined by measuring the intensity of light detected. It can be classified into two different types depending on the range of the wavelength of light source.

UV-visible spectrometer: Uses light over the ultra violet range (185-400 nm) and visible range (400-700 nm) of the electromagnetic radiation spectrum.

IR spectrophotometer: Uses light over infrared range (700-1500 nm) of electromagnetic radiation spectrum.

4.2.2. UV-Vis spectrometer
The basic structure of spectrometer is represented in Fig.4.2. It consists of a light source, a collimator, a monochromator , a wavelength selector, a cuvette for sample solution, a photoelectric detector, and a digital display or a meter . A spectrophotometer is general consists of two devices a spectrometer and photometer. A spectrometer is a device that produce typically disperses and measures light. A photometer indicates the photoelectric detector that measures the intensity of light .

Spectrometer : It produces a desired range of wavelength of light. First a collimator (lens) transmits a straight beam of light (photons) that passes through a monochromator (prism) to split it into several component wavelength (spectrum). Then a wavelength selector (slit) transmitted only the desired wavelength.

Fig 4.2 Diagram of UV spectrometer
Photometer: After the desired range of wavelength of light passes through the solution of a sample in curette the photometer detects. The amount of photons that is absorbed and then send a signal to a galvanometer or a digital display as a UV/Vis spectrometer measures the intensity of light passing through a sample and compares it to the intensity of light before it passes through the sample expressed in absorbance or transmittance. The ratio is called the reflectance and is usually expressed as a percentage (%R).

A beam of light from a visible or UV light source (colored red) is separated into its component wavelengths by prism or diffraction grating. Each monochromatic (single wavelength ) beam in turn to split into two equal intensity beams by a half-mirrored devices one beam the sample beam (colored magenta) passes through a small transparent container (curette) containing a solution of the compound being studied in a transparent solvent the other beam the reference (colored blue) passes through an identical curette containing only the solvent.
The intensities of these light beams are then measured by electronic detector and compared. The intensity of the reference beam which should have suffered little or no light absorption is defined as IO. The intensity of the sample beam is defined as I. over a short period of time the spectrometer automatically scans all the component wavelength in the manner described. The ultraviolet (UV) region scanned is normally from 200 to 400 nm and the visible portion is from 400 to 800 nm. The basic parts of a spectrometer are a light source, a holder for the sample, a diffraction grating in a monochromator or a prism to separate the different wavelength of light and a detector. The radiation source is often a tungsten filament (300-2500 nm), a deuterium are lamp, which is continuous over the ultraviolet region ( 190-400 nm ), xenon are lamp, which is continuous form 160-2,000 nm or more recently light emitted diodes (LED) for the visible wavelengths. The detector is typically a photomultimeter tube, a photodiode, a photodiode array or a charge-coupled device (CCD), single photodiode detector and photomultiplier tubes are used with scanning monochromators, which filter the light so that only light of a single wavelength reaches the detector at one time.

The scanning monochromator moves the diffraction grating to “step-through” each wavelength so that its intensity may be measured as a function of wavelength. Fixed monochromators are used with CCDs and photodiode arrays. As both of these devices consists of many detectors grouped into one or two dimensional arrays, they are able to collect light of different wavelengths on different pixels simultaneous.
4.2.3. Application
UV absorption spectroscopy is one of the best methods for determination of impurities in organic molecules.

UV spectroscopy is useful in the structure of organic molecules the presence and absence of unsaturation of molecules.

UV absorption spectroscopy can be used for the quantitative determination of compounds that absorb UV radiation.

This technique is used to detect the presence and absence of functional group in the compound.

4.3. X-ray diffraction
4.3.1. Introduction
In a crystalline solid the constituents (atoms, ions or molecules) are arranged in a regular order. An interaction of a particular crystalline solid with X-ray helps in investigating its actual structure. Crystals are found to act as diffraction gratings for X-rays and this indicates that the constituents particles in the crystals are arranged in planes at close distances in repeating patterns the phenonmenon of diffraction of X-rays by crystals was studied by W.L.Bragg and his father W.H.Bragg in 1913. They used crystals of zinc sulphide for this purpose.

4.3.2. Instrumentation
Diffractometer functions are the X-ray diffraction detecting from substance and the measuring of diffraction intensity. Fig.4.3 shows a real picture of a powder X-ray diffractometer. Demonstrates the geometrical arrangement of X-ray source, specimen and detector. The X-ray radiation generated by an X-ray tube passes through special slits , which collimator the X-ray beam. These solar slits are universally used in the diffractometer. They are made from a set of closely spaced thin metal plates parallel to plane. A divergent X-ray beam passing through the slits before they enter a detector. The diffracted X-ray beam needs to pass through a monochromatic filter (or a monochromator) before being received by a detector. Relative movements among the X-ray tube, specimen and the detector ensure the recording of diffraction intensity in a range of 2. Note that the angle is not the angle between the incident beam and specimen surface rather it is the angle between the incident beam and the crystallographic plane that generates diffraction. Diffractometers can have various types of geometric arrangements to enable collection of X-ray data. The majority of commercially available diffractometers use the Bragg-Brentano arrangement in which the X-ray incident beam is fixed but a sample stage around the axis perpendicular to the plane of a order to change the incident angle. The detector also rotates around the axis perpendicular to the plane but its angular speed is twice that of the sample stage in order to maintain the angular correlation between the sample and detector rotation. The Bragg-Brentano arrangement However, is not suitable for thin samples such as thin films and coating layers.
The technique of thin film X-ray diffractometry uses a special optical arrangement for detecting the crystal structure of thin films and coatings on a substrate. The incident beam is directed to the specimen at a small glancing angle (usually1) and the glancing angle is fixed during the operation and only the detector rotates to obtain the diffraction signals. Thin film X-ray diffractometry requires a parallel incident beam not a divergent beam as in regular diffractometry. Also a monochromator is placed in the optical path between the X-ray tube and the specimen not between the specimen and the detector. The small glancing angle of the incident beam ensures that sufficient diffraction signals come from a thin film or a coating layer instead of the substrate.

Fig 4.3 Diagram of a powder X-ray diffractometer
4.3.3. Applications
X- ray powder diffractions is most widely used for the identification of unknown crystalline substance (e.g.minerals, inorganic compounds).Determinations of unknown solids is critical to studies in geology, environmental science, material science, engineering and biology.Other applications include,
Characterization of crystalline substance
Identification of fine-grained minerals such as clays and mixed layers clays that are difficult to determine optically
Determination of unit cell dimensions
Measurement of sample purity with specialized
Techniques XRD can be used into
Determine crystal structures using rietveld refinement
Determine of modal amounds of minerals (quantitative analysis).

4.4. Scanning electron microscope
4.4.1.Introduction The SEM instrument is made up of two main components the electronic console and the electron console provides control knobs and switches that allow for instrument adjustments such as filament current, accelerating voltage, focus, magnification, brightness and constrast. The FEI quanta 200 is a state of the art electron microscope that uses a computer system in conjution with the electronic console making it unnecessary to have bulky console that houses control knobs , CRTs and an image capture device. All of the primary controls are accessed through the control system using the mouse and keyboard. The user need only be familiar with the GUI or software that controls the instrument rather than control knobs and switches typically found on older style scanning eletron microscopes. The image that is produced by the SEM is usually viewed on CRTs located on the electronic console but, instead with FEI the image can be seen on the computer monitor. Images that are captured can be saved in digital format or printed directly .

4.4.2. The components of SEM
The electron column is where the electron beam is generated under vaccum focused to a small diameter and scanned across the surface of a specimen by electromagnetic deflection coils the lower portion of the column is called the specimen chamber. The secondary electron detector is located above the sample stage inside the specimen chamber. Specimens are mounded and secured onto the stage which is controlled by a goniometer.The manual stage controls are found on the front side of the specimen chamber and allow for X-Y-Z movement 360 rotation and 90 tilt however only the tilt cannot be controlled through the computer system thus there is no need to use all of the manual controls manipulate the orientation of the sample inside the sample inside the sample chamber. Below is a diagram of the electron column and a description to each of the components of the electron column.

Electron gun: Located at the top of the column where free electrons are generated by thermionic emission from a tungsten filament at 2700K. The filament is inside the wehnelt which controls the number of electrons leaving the gun. Electrons are primarily accelerated towards an anode that is adjustable from 200v to 30 Kv (1KV=1000V).

Condenser lenses : After the beam passes the anode it is influenced by two condenser lenses that causes the beam to converge and pass through a focal point. What occurs that the electron beam is essentially focused down to 1000 times its original size. In conjunction with the selected accelerating voltage the condenser lenses are primarily responsible for determining the intensity of the electron beam when it strikes the specimen.

Apertures: Depending on the microscope one or more apertures may be found in the electron column. The function of these apertures is to reduce and exclude extraneous electrons in the lenses. The final lens aperture located below the scanning coils determines the diameter or spot size of the beam at specimen. The spot size on the specimen will in part determine the resolution and depth of filed decreasing the spot size will allow for an incease in resolution and depth of filed with loss of brightness.

Scanning system images are formed by mastering the electron beam across the specimen using deflication coils inside the objective lens. The stigma or astigmatisam correcter is located in the objective lens uses magnetic filed in order to reduce aberrations of the electron beam. The electron beam should have a circular cross section when it strikes the specimen however it is usually elliptical thus the stigma acts to control this problem.

Specimen champer: At the lower portion of the column the specimen stage and controls are located. The secondary electrons from the specimen are atteracted to the detector by a positive charge.

Fig 4.4 Scanning electron microscope
4.4.3. Working of SEM
In Scanning Electron Microscopy (SEM) the electron beam from the electron gun passes through the pair of deflection coils which deflect the beam in the X,Y axis. So that it scans the sample surface in a raster fashion over a rectangle area. When it interacts with the sample the energy transition takes place between the electron beam and the electrons of the sample surface. Hence secondary electrons are emitted by inelastic scattering. They are collected in a collector which is amplified then fed into CRT to display the image of the surface. The samples must be electrically conductive atleast surface are electrically grounded to prevent the accumulation of electrostatic charge at surface. Nonconductive specimen lean to charge when scanned by electrons. Therefore they are coated with an ultrathin coating of electrically conducting substance universally gold, alloy, platinum are used coating prevent the accumulation of static charge on specimen. Coating is made for the reasons to prevent charging and to increase the surface resolution of samples with low atomic number.

Fig.4.4 shows in a typical SEM an electron beam is emitted from an electron gun fitted with a tungsten filament cathode. Tungsten is normally used in thermionic electrons guns because it has the highest melting point and lowest vapour pressure of all metals Thereby, allowing it to be heated for electron emission and because of its low cost. Other types of electron emitters include
Cathodes which can be used in a standard tungsten filament SEM if the vacuum system is upgrateded and FEG which may be the cold-cathode type using tungsten single crystal emitters of Zirconium oxide. The beam passes through pairs of scanning coils or pairs of deflector plates in the electron column typically in the final lens, which deflect the beam in the X and Y axis so that it scans in a fashion over a rectangle area of the sample surface. When the primary electron beam interacts with the sample the electrons lose energy by repeated random scattering and absortion with in a droplet shaped volume of the specimen known as the interaction volume, which extends from less than 100 nm to around 5µm into the surface.

The size of the interaction volume depends on the electron’s landing energy the atomic number of the specimen and the specimen’s density. The energy between the electron beam and the samples results in the reflection of high energy electrons by elastic scattering emission of secondary electrons by inelastic scattering and the emission of electromagnetic radiation each of which can be detected by specialized detectors. The beam current absorbed by the specimen can also be detected and used to create images of the distribution of specimen can also be detected and used to create image of the distribution of specimen current. Electronic amplifiers of various types are used to amplify the signals, which is displayed as variations in brightness on a computer monitor. Each pixel of computer synchronized with the position of the beam on the specimen in the microscope and the resulting image is therefore a distribution map of the intensity of the signal being emitted from scanned area of the specimen. In older microscopes image may be captured by photography from a high resolution cathode ray tube but in modern machines image is saved to computer data storage.

4.4.4. Application
SEM is routinely used to generate high-resolution images of spaces of objects (SEI) and to show spatial variations in chemical compositions.

Acquiring elemental maps or spot chemical analysis using EDS
Discrimination of phases based on mean atomic number using BSE
Compositional maps based on difference in trace element “activators”(typically transition metal and rare earth elements) using CL
The SEM is also widely used to identify phases based on qualitative chemical analysis and /or crystalline structure precise measurement of very small features and objects down to 50nm in size is also accomplish using the SEM. Backscattered electron images (BSE)can be used for rapid discrimination of phase in multiphase samples. SEMs equipped with diffracted back scattered (EBSD) can be used to examine micro fabric and crystallographic orientation in many substance.

4.5. Energy dispersive X-ray analysis
4.5.1. Introduction
Energy –dispersive X-ray spectroscopy (EDS,EDX,EDXS or XEDS) sometimes called energy dispersive X-ray microanalysis (EDXMA) is an analytical technique used for the elemental analysis or chemical characterization of a sample. Its characterization capabilities are due in large part to the fundamental principle that each element has a unique atomic structure allowing a unique set of peaks on its electromagnetic emission spectrum which is main principle of spectroscopy.

To stimulate the emission of characteristic X-rays from a specimen high energy beam of charged particles such as electrons or protons (see PIXE) or a beam of X- rays is focused into the sample being studied. At rest, an atom with in the sample contains ground state (or unexcited) electrons in discrete energy levels or electron shells bound to the nucleus. The incident beam may excite an electron was. An electron from an outer higher- energy shell and the lower energy shell may be released in the form of an X-ray. The number and energy –dispersive spectrometer. As the energies of the X- rays are characteristic of the difference in energy between the two shells and of the atomic structure of the emitting element EDS allows the elemental composition of the specimen to be measured.

4.5.2. Equipment
Four primary components of the EDS setup are
1.The excitation source (electron beam or X-ray beam)
2.The X-ray detector
3.The pulse processor
4.The analyzer
Electron beam excitation is used in electron microscopes, scanning electron microscope (SEM) and scanning transmission electron microscopes (STEM). X-ray beam excitation is used in X-ray fluorescence (XRF) spectrometers. A detector is used to convert measures the signals and passes them onto an analyzer for data display and analysis.

The most common detector now is Si(Li) detector cooled to cryogenic temperatures with liquid nitrogen however, newer systems are often equipped with silicon drift detectors (SDD) with peltier cooling systems.

4.5.3. EDX spectrum
The output of an EDX analysis is an EDX spectrum. The EDX spectrum is just a plot of frequently an X-ray is received for each energy level. An EDX spectrum normally displays peaks consequent to the energy levels for which the most X-ray had been received. Each of these peaks are unique to atom and therefore correspond to a single element. The higher peak in a spectrum the more concentrated the element in the specimen.

An EDX spectrum plot not only identifies the element corresponding to each of its peaks but the type of X-ray to which it correspond as well. For example, a peaks corresponding to the amount of energy possessed by X-rays emitted by an electron in the L-shell going down to the K-shell is identified as a K-Alpha peak. The peak corresponding to X-rays emitted by M-shell electrons going to the K-shell is identified as a K-beta peak shown in the figure below.

Fig 4.5 EDX spectrum
4.5.4. Applications
Identification of metals and substance
Particle contamination identification and elimination
Classification of substance
Product and process failure and defect analysis
Examination of surface morphology(including stereo imaging)
Analysis and identification of surface and antiborne contamination
Powder morphology particle size and analysis
Cleaning problems and chemical etching
Welding and joining technology quality evaluation and failure investigation.

4.6. Antibacterial activity
4.6.1. Introduction
An antimicrobial is an agent that kills micro organisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria and antifungals are used against fungi. They can also be classified according to their function. Agents that kill microbes are called microbicidal, while those that merely inhibit their growth are called biostatic. The use of antimicrobial medicines to prevent infections is knows as antimicrobial prophylaxis.

The main classes of antimicrobial agents are disinfectants (“non selective antimicrobilas” such as bleach). Which kill a wide range of microbiles on non-living surfaces to prevent the spread of illenes. Antiseptics (which are applied to living tissue and help reduse infaction during surgery) and antibiotics (which destroy microorganisms with in the body) the term antibiotic originally described only those formulation derived from living organism but is no also applied to synthetic antimicrobials such as the sulphonamides or fluoroquinolones the term also used to be restribed to antibacterials (and is often u set as a synonym for tem by medical professionals and in medical literature.) but is context has broadened to include all antimicrobials. Antibacterial agents can be further subdivide in to bacterial agents which kill bacteria and bacteriostatic agents, which slow down or stall bacterial growth.in response further advances in antibacterial technologes have resulted in solutions that can go beyond simply inhibiting microbial growth. Instead, certain types of porous media have been developed to kill microbes on constant.

4.6.2 Chemical
Antibacterial
Antibacterials are used to treat bacterial infections . The drug toxicity to humans and other animals from antibacterial is generally consider low. Prolonged use of certain antibacterials can decrease the number of gut flora, which may have a negative impact on health. Consumption of probiotics and reasonable eating can help to replace destroyed get flora stool transplants may be considered for patients who are having difficulty recovering from prolonged antibiotic treatment, as for recurrent clostridium difficile infections.

Antifungals
Antifungles are used to kill or prevent further growth of fungi. In medicine they are used as a treatment for infeactions such as athlete’s foot, ringworm and thrushand work by exploiting difference between mammalian and fungals cells. They kill of the fungal organis with out dangerious effects on the host. Unlike bacteria, both fungi and humans are eukaryotes. Thus fungal and human cells are similer at the molecular level making it more difficult to find a target for an antifungal drug to attack that dose not also exit in the infected organism. Consequently there are often side effects to some of these drugs. Some of these side effects can be life-threatening if the drug is not used properly.

Antiparasitics
Antiparasitics are a class of medications indicated for the treatment of infection by parasites, such as nematodes, cestodes,trematodes, infections protozoa, and amoebae. Like all antimicrobials against intracellular microbes, they must kill the infecting pest without serious damage to the host.

Non-pharmaceutical
A wide range of chemical and natural compounds are used as antimicrobials. organic acids are used widely as antimicrobials in food products e.g. lactic acid, citric acid, acetic acid, and their salts, either as infections or disinfectants. For example, beef carcasses often are sprayed with acids, and then rinsed or steamed, to reduce the prevalence of E.coli.

Antimicrobial pesticides
According to the U.S.Environmental protection Agency (EPA) and defined by the Federal Insecticide, Fungicide and Rodenticide Act, antimicrobial pesticides are used in order to control growth of microbes through disinfection, sanitation, or systems, surface,water, or other chemical substance from contamination, fouling, or deterioration caused by bacteria, viruses, fungi,protozoa, algae, or slime.

Antimicrobial pesticide products the EPA monitors products, such as disinfectants/sanitizers for use in hospitals or homes, in order to ascertain efficiency. Products that are mean for public health are therefore under this monitoring systems-ones used for drinking water, swimming pools, food sanitation, and other environmental surfaces. These pesticide products are registered under the premise that when used properly they do not demonstrate unreasonable side effects to humans or the environment. Even once certain products are on the market the EPA continues to monitor public health products regulated by the EPA are divided in protecting public health.

Public health products regulated by the EPA are divided into three categories:
Sterilizers (Sporicides): Will eliminate all bacteria, fungi, spores and viruses. Disinfectants Destroy or inactivate micro organisms (Bacteria, fungi,viruses) but may not act as sporicides (as those are the most difficult form to destroy). According to efficacy data, the EPA will classify a disinfectant as limited, general/broad spectrum, or as a hospital disinfectant.

Sanitizers: Reduce the number of micro organisms, but may not kill or eliminate all them.

Antimicrobial pesticide safety according to a 2010 CDC report, health-care workers can take steps to improve their safety measusures against antimicrobial pesticide exposure. Workers are advised to minize exposure to these agents by wearing protective equipment, gloves, and safety glasses. Additionally, it is important to follow the handling instructions properly, as that is how the environmental protection agency has deemed it as sate to use. Employees should be educated about the health hazards and encouraged to seek medical care if exposure occurs.

4.6.3. Physical
Heat
Both dry and moist heat are effective in eliminating microbial life. For example jars used to store preserves such as jam can be sterilized by heating them in a conventional oven. Heat is also used in pasteurization, a method for slowing the spoilage of foods such as milk, cheese, juices, wines and vinegar. Such products are heated to a certain temperature for a set period of time, which greatly reduces the number of harmful micro organisms.

Radiation
Foods are often irradiated to kill harmful pathogens. Universal sources of radiation used in food sterilization include cobalt-60 (a gamma emitter), electron beams and X-rays ultraviolet light is also used to disinfect drinking water, both in small scale personal use systems and large scale community water purification systems.

CHAPTER-V
RESULT AND DISCUSSION
Pure PANI, Pure POT and PANI-POT-CrO3 nanocomposites are synthesized by emulsion polymerization with sulphuric acid as dopant in nitrogen gas atmosphere method in which potassium dichromate acts as oxidant and sulphuric acid (H2SO4) acts as dopant. PANI-POT-CrO3 nanocomposites samples prepared with different weight percentage as PANI-POT-CrO3 (25%), PANI-POT-CrO3 (50%), and PANI-POT-CrO3 (75%). These samples are characterized by Fourier transform infrared spectroscopy (FTIR),UV-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM),Energy dispersive X-ray spectroscopy (EDAX) and antibacterial activity studies, from the above characterization technique the properties such as functional group, optical nature, crystalline structure, surface morphology and antibacterial effect are analysed.

5.1 Fourier Transform Infrared analysis
FTIR analysis is to confirm the chromium trioxide nanocomposites formation and to identify the functional groups present in the sample. The system of functional group on PANI-POT-CrO3 nanocomposites powders are recorded using KBr pellets. Fig 5.1 shows the spectrum of prepared samples in the range of 400-4000 cm-1. The structural information on all the electrode substance was identified by FTIR spectra.

The spectrum of PANI-POT-CrO3 (25%) nanocomposites are acquires the main characteristic peaks at 3146 cm-1, 2341 cm-1, 1594 cm-1,1496 cm-1,1398 cm-1 and 1123 cm-1.The very strong and broad peak in the range 3146 cm-1 corresponding to O-H stretching vibration. The strong peak in the range of 2341cm-1 at N-H stretching. The presence of sharp peak at 1594 cm-1 and 1496 cm-1 are attributed to N=H and C=C stretching mode of vibration for the quionoid and benzenoid ring. The peaks at 1398 cm-1 and 1123 cm-1 are assigned to S=O and C-O stretching mode of vibration.

The spectrum of PANI-POT-CrO3 (50%) nanocomposites are acquires the main characteristic peaks at 3146 cm-1,2350 cm-1,1604 cm-1, 1506 cm-1, 1407 cm-1 and 1132cm-1. The very strong and broad peak in the range 3146cm-1 correspond O-H stretching vibration. The strong peak in the range of 2350 cm-1 at N-H stretching. The presence of sharp peaks at 1604 cm-1 and 1506 cm-1 are attributed to (N=H) and (C=C) stretching mode of vibration for the quoined and benzenoid ring. The peaks at 1407 cm-1 and 1132 cm-1 are assigned to S=O and C-O stretching mode of vibration.

The spectrum of PANI-POT-CrO3(75%) nanocomposites are acquires the main characteristic peaks at 1156 cm-1,1150 cm-1, 1594 cm-1, 1506 cm-1, 1348 cm-1,and 1132 cm-1. The very strong and broad peak in the range 1156 cm-1 corresponds to stretching vibration. The strong peak in the range of 1150 cm-1at N-H stretching. The presence sharp peaks at 1594 cm-1and 1506 cm-1are attributed to (N=H) and (C=C) stretching mode of vibration for the quionoid and benzenoid ring. The peaks at1398 cm-1and 1132 cm-1 are assigned to S=O and C-O stretching mode of vibrations.

(b)

(c)
Fig.5.1.FTIR peaks and their assignments of (a) PANI-POT-CrO3 (25%), (b)
PANI-POT-CrO3 (50%), (c) PANI-POT- CrO3 (75%) nanocomposites.

Table.5.1 FTIR peaks and their assignments of PANI-POT-CrO3 (25%), PANI-POT-CrO3 (50%), PANI-POT- CrO3 (75%) nanocomposites.

Characteristic
Vibration Wave number (cm-1)
PANI-POT-CrO3
(25%) PANI-POT-CrO3 (50%) PANI-POT-CrO3
(75%)
O-H Stretching 3146.85 3146.53 1156.43
N-H Stretching 2341.23 2350.81 1150.81
N=H (Quionoid) 1594.63 1604.21 1594.63
C=C (Benzenoid) 1496.13 1506.10 1506.10
S=O Stretching 1398.01 1407.98 1398.01
C-O Stretching 1123.21 1132.80 1132.80
5.2 UV-Visible analysis
The electrochemical property and optical nature of the prepared PANI-POT-CrO3 nanocomposites were analysed using UV-Visible spectroscopy technique. UV spectroscopy gives qualitative information about the prepared samples. Fig (5.2) gives the UV- absorption spectra of (a) PANI-POT-CrO3 25% (b) PANI-POT- CrO3 50% (c) PANI-POT-CrO3 75% nanocomposites respectively. All the powders are dissolved in DMSO solution for the analysis.

In UV analysis the bandgap energy of the copolymer with CrO3 nanocomposites and corresponding electron transition are measured. The values are tabulated in table(5.2). It is seen from the Fig (5.2) the prepared samples have two characteristic absorption peaks around 241-247 nm and the absorption peaks in the range of 241-247 nm is assigned to the ?- ?* transition of the benzene rings. The absorption peaks in the range of 946-1015 nm is assigned to n- ?* transition in the polymer matrix. The optical bandgaps of the prepared copolymer with CrO3 nanocomposites are listed in the table (5.2). The bandgap energy of 5.16 ev, 1.31ev, in PANI-POT-CrO3 (25%) and 5.03 ev, 1.32 ev in PANI-POT-CrO3 (50%) and finaly 5.16 eV, 1.22 eV in PANI-POT-CrO3 (75%) respectively. The values imply that there was a strong interaction between the prepared copolymer with CrO3 nanocomposites. From the above values it was confirmed that the comparison of the prepared PANI-POT-CrO3 nanocomposites shows a slightly increases in the band gap energy.

(b)

(c)
Fig.5.2.UV peaks and their electron transition of (a) PANI-POT-CrO3 25%, (b)
PANI-POT-CrO3 50%, (c) PANI-POT-CrO3 75% nanocomposites
S.NO Sample name Wavelength (nm) Electron Transition Bandgap (eV)
1
2
3 PANI-POT-CrO3 (25%)
PANI-POT-CrO3 (50%)
PANI-POT-CrO3 (75%) 241 nm
946 nm
247 nm
943 nm
241 nm
1051 nm ? – ?*
n – ?*
? – ?*
n – ?*
? – ?*
n – ?* 5.155
1.313
5.029
1.317
5.155
1.224
Table.5.2 UV peaks and their electron transition of (a) PANI-POT-CrO3 25%, (b) PANI-POT-CrO3 50%, (c) PANI-POT-CrO3 75% nanocomposites.

5.3 X- Ray Diffraction analysis
The crystalline nature of nanocomposites are determined from XRD analysis. The XRD pattern of PANI-POT-CrO3 nanocomposites at the different weight percentage of (25%,50% and 75%) as shown in Fig(5.3).

The XRD pattern of PANI-POT-CrO3 (25%) Fig (5.3.a) show a broad peak at 2?= 19.90? at the (d=4.45805) average crystal size in the range of 2.35. The XRD spectra of PANI-POT-CrO3 (50%) Fig (5.3.b) show a broad peak at the range 2?=20.63? due to the ( d=4.3014) average crystal size in the range of 3.89. Finally due to the XRD pattern of PANI-POT-CrO3 (75%) Fig (5.3.c) at the characteristic peak is broader ranging from 2?=17.55 at the (d=5.0493) the average crystal size from the range 3.15 with the different weight percentage of the average crystal size is increases with decreases the nanocomposites of the crystalline nature.

Fig.5.3.1 XRD data of PANI-POT-CrO325% nanocomposite

Fig.5.3.2 XRD data of PANI-POT-CrO350% nanocomposite

Fig.5.3.3 XRD data of PANI-POT-CrO375% nanocomposite

Table.5.3.1 XRD data of PANI-POT-CrO325% nanocomposite
PANI-POT-CrO3 25%
S.No 2?(deg) FWHM(deg) d spacing(Å) Intensity Crystal size(nm) Average crystal size Dislocation density×1015 Strain ×10-3
1 19.90 4.5000 4.4580 125 1.79 2.35 0.0311 4.9724
2 17.60 4.2000 5.0351 90 1.91 0.0273 5.2594
3 29.17 2.6500 3.0584 57 3.09 0.0104 1.9686
4 23.50 2.4000 3.7826 44 3.38 0.8751 2.2365
5 34.68 0.5250 2.5840 6 1.58 0.0398 0.4539
Table.5.3.2 XRD data of PANI-POT-CrO350% nanocomposite
PANI-POT-CrO3 50%
S.No 2?(deg) FWHM(deg) d spacing(Å) Intensity Crystal size(nm) Average crystal size Dislocation density×1015 Strain ×10-3
1 20.63 3.8150 4.3014 51 2.11 3.89
0.2233 4.0686
2 38.50 1.4000 2.3364 8 6.01 0.2767 7.7510
3 29.27 2.3500 3.0482 21 3.49 0.8197 1.7488
4 23.40 2.2000 3.7685 14 3.68 0.7356 2.0545
5 33.80 1.4000 2.6497 196 4.15 0.5804 1.2757
PANI-POT-CrO3 75%
S.No 2?(deg) FWHM(deg) d spacing(Å) Intensity Crystal size(nm) Average crystal size Dislocation density×1015 Strain ×10-3
1 17.55 4.1000 5.0493 49 1.96 3.15 0.0260 5.1340
2 20.88 1.7750 4.2424 43 4.54 0.4831 1.8748
3 75.22 0.9429 1.2620 32 0.10 0.8449 2.3523
4 32.84 0.9200 2.7250 26 9 0.1234 6.0547
5 44.26 0.6250 2.0447 21 0.13 5.3114 2.9572
Table.5.3.3 XRD data of PANI-POT-CrO375% nanocomposite
5.4 Scanning Electron Microscopy analysis
The morphology of nanocomposites are studied using Scanning Electron Microscopy. The SEM image of PANI-POT-CrO3 nancomposites at different weight percentage (25%, 50%, and 75%) are shown in the Fig.(5.4) refers to the SEM image of copolymer of aniline and O-toluidine with chromium trioxide nanocomposites with different weight percentage (25%, 50%, and 75%).

The SEM image of Fig (5.4.a) shows that the PANI-POT-CrO3 (25%) nanocomposites are large agglorametes and form spherical shape of the surface is smoother and its crystallinity is better with high porous nature. The Fig (5.4.b) shows that the SEM image of PANI-POT-CrO3 (50%) nanocomposites are aggregation to formed the surface is irregular shape of the crystallites. The Fig (5.4.c) shows that the SEM images of PANI-POT-CrO3 (75%) nanocomposites are large quantity of regular nanoparticle and spherical in shape morphology.

( a) (b)

(c)
Fig.5.4 SEM images of (a)PANI-POT-CrO3 (25%), (b)PANI-POT-CrO3 (50%) (c) PANI-POT- CrO3 (75%) nanocompoistes
5.5 Energy Dispersive X-ray Spectroscopy analysis
Energy dispersive X-ray spectroscopy is used to identify the chemical composition of prepared sample. The EDAX of PANI-POT-CrO3nanocomposites at different weight percentage ( 25%, 50% and 75%) are shown in Fig (5.5) respectively. The characteristic peaks in Fig (5.5) shows the formation of elements C, O and S confirm the formation of PANI-POT. The presence of elements Cr which conforms that the formation of Chromium trioxide nanocomposites. The EDAX spectrum gave the peaks for C,O,S, and Cr and their weight percentage are tabulated in table (5.5). The chemical composition of the samples are follows C (69.29), O (25.67), S (2.62) and Cr (2.41) in PANI-POT-CrO3 (25%), C (63.71), O( 28.29), S( 2.04) and Cr( 5.96) in PANI-POT-CrO3 (50%) and C (57.99), O(37.88), S(0.28) and Cr (3.85) in PANI-POT-CrO3 (75%) in comparion with chemical composition of PANI-POT. The chemical composition of copolymer with chromium trioxide nanocomposite at different weight percentage has decreased.

(a) (b)

(c)
Fig.5.5 EDAX spectrum of (a) PANI-POT-CrO3 (25%), (b) PANI-POT-CrO3 (50%), (c) PANI-POT-CrO3 (75 %) nanocomposites.
Table.5.5 EDAX spectrum of (a) PANI-POT-CrO3 (25%), (b) PANI-POT-CrO3 (50%), (c) PANI-POT-CrO3 (75 %) nanocomposites
Sample name Weight% of
Carbon(C) Weight% of Oxygen(O) Weight% of Sulphur(S) Weight % of Chromium (Cr)
PANI-POT-CrO3 25% 69.29 25.67 2.62 2.41

PANI-POT- CrO350% 63.71 28.29 2.04 5.96
PANI-POT- CrO375% 57.99 37.88 0.28 3.85
5.6 Antibacterial Activity analysis
The antibacterial activity of prepared copolymer with chromium trioxide nanocomposites against two gram positive bacteria such as Staphylococcus aurous and Bacillus subtilis and against two gram negative bacteria like Escherichia coli and Salmonella paratyphi were observed using ager diffusion method as shown Fig.(5.6) and measuring the diameter of the growth inhibition zone in mm. In this method pertridishes containing the bacterial inoculums on nutrient ager was used for the study. The values are measured in the table (5.6). The zone of inhabition of PANI-POT-CrO3 (25%) against inhabition for gram positive bacteria,S.Aureus and B.Subtilis are 13mm and 12mm. The zone of inhabition for gram negative bacteria E.Coli and S.Typhi are 10mm and 12mm. the zone of inhabition of PANI-POT-CrO3(50%) against inhabition for gram positive bacteria, S.Aureus and B.Subtilis are 09mm and 12mm. The zone of inhabition for gram negative bacteria E.Coli and S.Typhi are 09mm and 16mm. The zone of inhabition of PANI-POT-CrO3 (75%) against inhabition for gram positive bacteria, S.Aureus and B.Subtilis are 10mm and 11mm. The zone of inhabition for gram negative bacteria E.Coli and S.Typhi are 10mm and 10mm respectively. From the above values are observed that the copolymer with CrO3 nanocomposites are show lower zone of inhabition and the zone of inhabition for the gram negative gram positive bacteria for the better resistivity towards.

(a) (b)

(c) (d)
Fig.5.6. Anitibacterial activity of the prepared PANI-POT-CrO3 (25%), PANI-POT-CrO3 (50%), PANI-POT-CrO3 (75%), (a) Staphylococcus aurous, (b) Baciliussubtilis, (c) EscherichiaColi, (d) Salmonella Paratyphi
Table.5.6. Anitibacterial activity of the prepared PANI-POT-CrO3 (25%), PANI-POT-CrO3(50%), PANI-POT-CrO3(75%), (a)Staphylococcus aurous, (b) Baciliussubtilis, (c) EscherichiaColi, (d) Salmonella paratyphi
Sample Name Zone of inhibition
Standard Ciprofloxacin
(10µg/disc) Gram positive bacteria Gram negative bacteria
Staphylococcus acreus Bacilius subtilis Escherichia
coli Salmonellaparatyphi
PANI-POT-CrO3 (25%)
PANI-POT-CrO3 (50%)
PANI-POT-CrO3 (75%) 37
24
36
38
13
09
10
12
12
11 10
09
10 12
16
10
CONCLUSION
Polyaniline, Poly (O-toluidine) and CrO3 nanocomposite with the different weight percentage of the powder were successfully prepared by emulsion polymerization method in the presence of dopant sulphuric acid and oxidant potassium dichromate and metal oxide chromium trioxide and are named as PANI-POT-CrO3 25%, PANI-POT-CrO3 50%, and PANI-POT-CrO3 75%. The process was carried out at 60?C with nitrogen gas atmosphere. From the characterization of prepared samples the following conclusions were arrived.

FTIR analysis confirms the presence of the functional groups and also gives the characteristic stretching and bending of the prepared samples. It also confirms the interaction between PANI, POT and CrO3.

UV spectra of the samples PANI-POT-CrO3 (25%,50% and 75%) nano composites are assigned to ?-?* and n-?* transitions in the polymer matrix. From UV the band gap energy is calculated. With the addition of chromium to the copolymer matrix there is a slight increase in the band gap energy.

The XRD patterns of (PANI-POT-CrO3) nanocomposites with the different weight percentages of (25%,50%, and 75%) due to the diffraction peak at broader. The average crystal size is comparing the three types of nanocomposites increases with decreases the value. From the XRD analysis for crystal size, dislocation density and strain were also calculated.

The SEM images of PANI-POT-CrO3 (25%) nanocomposite with large agglorametes and from spherical shape.PANI-POT-CrO3 (50%) nano composites are aggregation to formed the irregular shape. Finally with the PANI-POT-CrO3(75%) nanocomposites are large quantity of regular nanoparticle and spherical shape morphology.

EDAX spectrum of (PANI-POT-CrO3) nanocomposites with the different weight percentage gave the peaks for C,O, S and Cr. The presence of elements C,O and S confirms the formation of PANI-POT. The presence of elements Cr which conforms that the formation of chromium trioxide nanocomposites. The PANI-POT-CrO3 in comparison with chemical composition of copolymer (PANI-POT) has decreased.

The antibacterial activity of PANI-POT-CrO3 nanocomposites with the different weight percentage of two gram positive bacteria such as staphylococcus aureus and bacillus subtilis and against two gram negative bacteria like Escherichia coli and salmonella paratyphi were observed using agar well diffusion method. It is clear from the above result that PANI-POT-CrO3 exhibit lower zone of inhibition compared to copolymer. Conducting PANI-POT-CrO3 nanocomposite useful for the antibacterial agent improved for human health and living environment.