Preliminary List of Abstracts (Alphabetical Order)

1ST INTL. SYMP. ON SYNTHESIS AND PROPERTIES OF NANOMATERIALS FOR FUTURE ENERGY DEMANDS

In the past five years, nanoshell-based photothermal cancer therapy has been realized, and the transition from bench to bedside for this potentially revolutionary approach has begun [1]. Cancer is still amongst the major causes of death in the developed world [2]. The selective delivery of anticancer agents is important in order to suppress their systemic distribution and ensuing undesirable side-effects [3]. Conventional cancer chemotherapy is often ineffective and associated with serious side-effects. In order to overcome the problems associated with conventional chemotherapy, extensive research is being performed on the development of anticancer drug carriers which would be able to selectively deliver their drug-load to cancer cells. In the light of the present work, the gold has to functionalize with a copolymer which will provide antibiofouling characteristic to the nanoparticles and will allow for drug (e.g. Daunorubicin, doxorubicin etc) conjugation. These multifunctional drug nanocarriers will represent a significant step towards the development of safe and effective cancer treatment modalities. In the context of this work, multifunctional magnetic-core gold-shell nanoparticles will be developed and their comparative potential in comparison to another anti-cancer agent (non-antibiotic) will be studied. By a thermolytic process, syntheses of magnetic nanocrystals (the magnetic core) have been carried out and coating of the magnetic nanocrystals by a thin polymer layer is under process [4]. Along with the above methodology the Polymer based Nanocapsules are also being explored in the ensuing study.References[1] S. Lal, S. E. Clarke, N. J. Halas, Acc. Chem. Res., 2008, 41, 1842.[2] A. Jemal, R.Siegel, E.Ward, Y. Hao, J. Xu, M. J. Thun, 2009, 225-249.[3] R. Duncan 2006, 6, 688.[4] H. Wang, D.W. Brandl, F. Le, P. Nordlander, N. J. Halas, Nano Lett. 2006, 6, 827.

The increase in world energy consumption and limited availability of fossil fuels has made the renewable energy sources the most discussed issue these days. There are several renewable energy sources such as solar, wind, rain and geothermal energy etc. Among these, solar energy is identified as the best renewable energy source due to its longevity, cost effectiveness and clean properties. Harnessing of solar energy for significant technological applications is another cause of great concern as it requires materials that have a high ability of solar energy collection and conversion. Therefore, a wide variety of materials such as Si, CdSe, CdS, CuInSe2 etc have been used for fabrication of solar cells with high conversion efficiency. Although silicon with 22 % efficiency has been the traditional solar cell material of choice, its high cost and fragility reduces its residential applications. Cadmium based solar cells are also considered in commercial modules due to their high efficiency of up to 19%, but highly toxic nature of Cd limits its applications. In this presentation, Silver based ternary chalcopyrite (AIS) films will be explored for possible photovoltaic applications.

Alq3 films have been deposited onto glass substrate using thermal evaporation technique under different experimental conditions. AFM investigations of films revealed that films were homogeneous and crack free with RMS roughness of 4.34 nm. UV-Vis spectroscopy studies of the films show two absorption peaks at a wavelength of about 294nm and 390nm. An intense green colour emission peak is observed at wavelength of about 514nm. Attempts have been made to fabricate ITO/Alq3/Ag heterojunction. The capacitance of junction is shown to be strongly frequency dependent at low frequencies region and tends to attain a constant value at high frequency. The V-I characteristics show that the Alq3 has potential to be used for nonvolatile memory devices.

The corrosion process can occur in the operations of the metallic industry indoors, located in Mexicali, which is considered as an arid zone city in the northwest of Mexico. The reason why it happens is related to the extreme values of relative humidity (RH) and to the temperature, considered as a climatic factor with ranges higher than 90% of RH in some months of summer and winter, 45 C in summer and less than 10°C in winter. This climatic parameter, combined with the concentration levels of sulfates that exceed the air quality standards (AQS), generates aggressive environments in the indoors of the metallic industry of Mexicali. These factors originate the corrosion process if the SS is the process of thermal diffusivity of carbon in this type of material, reducing their corrosion resistance. Industrial operations at high temperatures, where are added chrome to the steel in order to increase the corrosion resistance, show good results with controlled environments in closed rooms. However, with uncontrolled environments, aggressive atmospheres in the indoors of the metallic industry are formed and the inter-granular corrosion (IC) occurs because of the chromium high affinity and the presence of carbon, hidden in some types of SS used in this kind of industry of this city. Since the carbon has good diffusivity, it creates a chrome drag to where the carbon is in the grain boundary, causing IC. In this case, and in other zones of the SS, low chromium levels and this process, associated with the increase and maintenance of the temperature between 450°C to 850°C, provoke the corrosion phenomena attack. For this reason, a characterization study, using the Scanning Electron Microscopy (SEM), was made to detect the minimum and maximum concentration levels of sulfurs that generate the electrochemical process in the SS manufactured in the company evaluated.

A detailed study of conduction mechanism of glassy Se70Te28M2 (M=Ag, Cd, Zn) systems has been carried out in terms of dielectric and a.c. Conductivity. Temperature and frequency dependent dielectric, loss tangent and a.c. Conductivity for the same systems were measured in the frequency spectrum, 1 KHz -1 MHz and temperature, 303-338K range. The a.c. Conductivity, i³ac is found to be proportional to (where, s < 1). The temperature dependence of both a.c. Conductivity and frequency exponent 's' is reasonably well interpreted by the correlated barrier hopping (CBH) model. We showed that the bi-polaron hopping is dominant over the potential barrier and estimated the density of defect states (DOS) at 50 KHz. We found a good agreement in fitting of data (single and bi-polaron conductivity) with experimental results. Surface and structural morphology of as-prepared semiconducting glasses were confirmed by XRD, SEM and TEM. Glass kinetics (glass transition and crystallization) was interpreted by differential scanning calorimetry (DSC).

This paper reports on the microwave assisted synthesis of ZnO nanophosphors. The as synthesized ZnO nanophosphor was annealed at 500°C for three hours in air. X-ray diffraction pattern confirmed that the powder was pure ZnO oriented along the (101) direction. The ZnO powder was analyzed by photoluminescence before and after annealing to identify the emission of defects in the visible range. There was no effect on the position of the band to band emission while the position of the defect level emission has shifted from 575 to 536 nm after annealing. The concentration of oxygen doubly ionized related defects have decreased after annealing and oxygen singly ionized related defects have increased. The formation of oxygen and zinc related defect was confirmed by X-ray photoelectron spectroscopy.

Tungsten carbide (WC) is known for its exceptional tribo-mechanical properties. It is extensively used in cutting and mining tools, surface coatings, defence, chemical and electronic industries. Apart from mechanical properties, it also possesses good catalytic properties. It is considered as an economical alternative to precious noble metal platinum (Pt) used in fuel cells. Nano tungsten carbide is prepared from pure tungsten precursors like WO, W(CO)6, W, WCl6 and WCl4. These pure precursors are obtained from tungsten ore(s) through lengthy and costly extraction processes. The direct production of nano tungsten carbide from scheelite (tungsten ore) can reduce the use of chemicals and cost of production. This paper investigates the effect of different carbon sources, activated charcoal (solid) and acetone (liquid) with or without magnesium on direct reduction/carburization of scheelite to nano tungsten carbide. The reactions were carried out in an autoclave at 800°C. The impurities were removed after synthesis by washing the reaction products with dilute HCl (1:1). The results indicate that even the use of only carbon (activated charcoal or acetone) can produce nano WC. However, reaction products also contained unreacted scheelite. On the other hand, the use of solid carbon with magnesium as a reducing agent produces single phase nano tungsten carbide. The powders were characterized by X- ray diffraction, SEM and TEM.

Oxide ion conductors are the important class of materials that can be used as an electrolyte in SOFC applications. The conductivity in these types of electrolytes is mainly due to motion of ions. So, the development of a suitable electrolyte that can operate at intermediate temperature range, Ba-doped lanthanum indate has been prepared by solid state reaction method. X-ray analysis and Reitveld refinement were used to confirm the desired phase formation. The Ac-impedance technique was used to verify the electrical conduction behavior of the synthesized system. The curved behavior of the oxygen ion conductivity was observed in the Arrhenius plot. Therefore, the activation energy in the low-temperature region is higher than that in the high temperature region. The defect-cation association is the reason for higher activation energy of ionic conduction in the present system.

Recently, dye-sensitized solar cells have proven to be one of the preferable technologies because of their ease of fabrication and cost effectiveness. But DSSC suffered from problem of low conversion efficiency in comparison to conventional solar cells. Conversion efficiency can be enhanced by increasing the absorption coefficient of photoabsorbing layer. Much effort has been done to synthesize the dyes of higher absorption coefficient. A complementary approach is to trap the light using surface plasmon resonance of metal nanoparticles. But bare metal nanoparticles being in direct contact with dye and electrolyte leads to the recombination of photogenerated carriers which further puts a limit on the efficiency enhancement of DSSC via plasmonic property of metal nanoparticles. Keeping these reports into consideration, we have focused our work on the preparation and characterization of surfactant capped silver nanoparticles by chemical reduction method to develop improved plasmonic DSSC. SPR band of silver nanoparticles has been confirmed by UV-Vis spectroscopy. FTIR confirms the capping of CTAB on silver nanoparticles occurs via their head group. Finally, these particles have been incorporated in DSSC to study the plasmonic effect of nanoparticles on performance of DSSC. The power conversion efficiency of DSSC and the plasmonic DSSC were found to be 4.3 % and 5.38%, showing an improvement of 25.11%

Liquid crystalline materials are ubiquitously applied to display devices in modern electro-optical technology. The dispersion of nanomaterials in liquid crystals (LCs) has created tremendous attention among various scientific communities due to the unique physical, mechanical and electrical properties of nanomaterials with liquid crystalline materials. These nanomaterials doped in liquid crystals have been studied for enhanced physical properties for display applications.In the present work, very small concentration of one dimensional CdS nanoparticles (0.0, 0.1 and 0.3 wt. /wt. %) was dispersed into ferroelectric liquid crystal material. The composites were prepared and studied between two indium tin oxide (ITO) coated glass substrates and separated by 4Aμm thickness mylar spacer. It was noticed that CdS nanoparticles have good coupling with FLC molecules because of the same structural behavior and a considerable impact on the spontaneous polarization and switching time has been investigated at the expense of increasing CdS nanoparticles concentration. The effect of bistability (memory effect) in doped samples has also been analyzed. A long lasting memory behaviour has been observed in doped samples even after the removal of bias voltage. Such kind of devices may be helpful in many display as well as non-display applications.

L-α-diheptanoylphosphatidycholine (DHPC) capped gold (Au) nanoparticles (NPs) were synthesized to explore their application for future energy. The purpose of choosing this phospholipid is simply based upon the fact that L-α-diheptanoylphosphatidycholine (DHPC)is micelle forming phospholipid due to its readily soluble nature in pure water. Reactions were performed by precisely controlling the temperature and monitoring simultaneously UV-Visible and fluorescence spectrophotometer measurements. UV-visible spectra of colloidal Au solutions were taken by UV spectrophotometer in the wavelength range of 200-900 nm to determine the absorbance due to Surface Plasmon Resonance (SPR) of nanometallic Au. The formation of Au NP was monitored in the visible absorption range of 540 nm. The hydrophobicity of DHPC was determined with the help of pyrene fluorescence measurements by using Hitachi fluorescence spectrophotometer. The pyrene emission spectra were recorded employing an excitation wavelength of 334 nm. Emission intensities I1 and I3 were measured at the wavelengths corresponding to the first and third vibronic bands located at 373 and 384 nm. Since DHPC is not a florescence active molecule, therefore pyrene has been used as a florescence probe in order to detect the DHPC gold NP interactions. I have used seed growth (S-G) method to synthesize lipid-capped Au NP. It seems that the citrate solubilized gold NP provides desired electrostatic interaction with positively charged ammonium group of phospho-choline zwitterionic head group of DHPC monomers that formed the micelles. Such an association is expected to reduce the interhead group repulsions existing in the stern-layer of micelle thus providing it a greater stability with enhanced hydrophobicity. The present results clearly explain a strong association between DHPC micelle and gold NP as evaluated by pyrene fluorescence measurement. Phospholipid-NP conjugate materials are foreseen as the basic components for bionanometallic devices with potential applications in sensors, gene sequencing, and biocatalysis.

The organic-inorganic hybrid materials produced from tetraethoxysilane, citric acid and ethylene glycol and immobilizing complex tris(4,7-diphenyl-1,10-phenanthroline) ruthenium(II) dichloride (Rudpp) are prepared and their morphology is studied by atomic force microscopy. The studied hybrid matrix is suitable for production of thermally stable, dense and uniform films with a good adhesion to glass. The matrix ensures uniform distribution of the immobilized dye. Films prepared by dip coating at a withdrawn speed of 0.4 mm s-1 from sonicated sol with molar ratio TEOS : CA : EG = 4 : 1 : 1 produced by acid catalyzed hydrolysis were studied by multifractal analysis. The structural complexity of the 3D surface roughness revealed that the 3D surface can be described using the multifractal geometry. The generalized dimension Dq and the singularity spectrum f(I±) provided quantitative values that characterize the local scale properties of the 3D surface geometry at nanometer scale. Detailed surface characterization of the surface topography was obtained using statistical parameters, according with ISO 25178-2: 2012.

Thin uniform films with good adhesion of the type MIIFe2O4 (M = Cu, Mg, Zn) with grains from 30-100 nm (M = Cu, Mg) to 0.15-2 I¼m (M = Zn) are prepared by spray-pyrolysis using ethylene glycol solutions of mixed-metal citric complexes. The thin ferrite films are investigated by atomic force microscopy and multifractal analysis.The generalized dimension Dq and the singularity spectrum f(±) provided quantitative values that describe the degree of heterogeneity in the 3D surface geometry at nanometer scale. Detailed surface characterization of the surface topography was obtained using statistical parameters, according with ISO 25178-2: 2012. These results demonstrate that multifractal analysis could be a useful tool for characterizing quantitatively the 3D surface geometry of thin ferrite films deposited by spray-pyrolysis.

Since the last decades, Lithium-ion batteries, the most common type of secondary rechargeable batteries, have gained wide attention in electrical energy storage and almost in all portable electronic devices. The demand for lithium-ion batteries as a major power source is rapidly increasing. However, their high price discourages the large-scale energy storage. Therefore, in order to use abundant source of sodium based compound, researchers are focusing on Na+ based rechargeable batteries. In the present study, glass samples have been synthesized with composition xNa2S + (100-x) P2S5 at different x. These glass samples have been further heat treated above their crystallization temperatures under Argon atmosphere to get glass-ceramics. These glass/glass-ceramic samples have been characterized by various techniques XRD, DTA/TG, FT-IR, Dilatometer, Raman spectroscopy and Impedance spectroscopy. The XRD patterns of all samples showed a broad halo indicating its amorphous nature. The synthesized glasses show different glass transitions and crystallization temperatures at different compositions. Synthesized glasses show that x = 45 and x = 55 mol % Na2S have minor structural changes as compared to other samples. At room temperature, synthesized glasses show a conductivity in the range of (10-8-10-5)S/cm-1, which is comparable to that of Li ion based solid electrolyte. Present glass/glass-ceramic samples might be used as an electrolyte in Na-ion batteries and can substitute lithium-ion batteries at room temperature.

Multi-walled carbon nanotubes-nickel sulphide (MWCNTs-NiS) composites have been synthesized as a low cost counter electrode material for dye-sensitized solar cells (DSSCs) by hybridizing the surface of MWCNTs with nanocrystalline NiS particles using hydrothermal method. MWCNTs are initially functionalized by refluxing the MWCNTs in nitric acid using chemical bath technique. The obtained composites have been characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), EDX, FTIR and Raman spectroscopic techniques. FESEM results show that NiS nanoparticles with size less than 15 nm are anchored on the outside of MWNTs. EDX study provides the information about the existence of Ni, S and C elements in the composite. XRD studies show the presence of prominent peaks of NiS and MWCNTs. FTIR spectra gives the evidence of the presence of Ni-S, C=O, C=C, -COOH, O-H related peaks. DSSCs have been made using these composite as a counter electrodes alongwith TiO2 photoanode and ruthenium based N719 dye. I-V studies of DSSCs have been performed under dark and illumination conditions. The solar parameters namely current density, open circuit voltage, fill factor and power conversion efficiency have been evaluated. The maximum power conversion efficiency is found to be 4.5%.

Recently Heliatek has reported the 12% certified efficiency of organic photovoltaic (OPVs). This rapid progress suggests that the commercialization of OPVs will be executed soon. In addition to the achievement of such high efficiency in OPVs, there is still a wide need of improvements e.g. The need of electron-acceptors materials other than fullerene, better understanding of charge-transport mechanism in organic materials, requirement of the material compatible with the flexible substrate, durability of the organic materials based devices etc. The aim of this paper is to review the recent developments in OPVs and the potentials of organic photovoltaic, which has caught the attention of many researchers working in the field of optoelectronics. In this article, the organic solar cell mechanism, the basic design, the recent developments and the efficient organic materials for OPVs are reviewed. The authors have reviewed the recent articles to understand the mechanisms of photocurrent generation and sketched out the search for alternative materials for these devices.

Organic nanostructures have attracted the attention of both scientific as well as academic community due to their structure related chemical and semiconducting properties. Whilenanostructures of inorganic materials and metal oxides have been the center of attraction for many years, organic nanostructures of I conjugated molecules have several advantages over the inorganic counterparts, such as unlimited choices of molecular structures for property optimization, high flexibility, low cost of materials fabrication, ease for large area processing and compatibility with flexible and lightweight plastic substrates, thus opening broader scope for molecular electronic devices. In this direction, 1D nanowires (NWs) of Cu (II) 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine molecule have been grown onto glass substrate by cost effective solution processing technique. The density of NWs is found to be dependent on the concentration of solution and exposure time. These nanowires have been characterized by XRD, SEM and UV-Visible absorption spectroscopy. The conductivity of nanowires has found to be more than that of spin coated film. The possible formation mechanism of these structures is I-I interaction between phthalocyanine molecules. Although phthalocyanine nanostructures have been grown by OMBE, OPVD, thermal evaporation techniques with limitation of higher cost of fabrication but these nanowires with long range order, low fabrication cost and improved conductivity indicate their potential for molecular device applications.

Semiconductor oxide materials are one of the focuses in material science, owing to their unusual geometry and promising physical properties. Recently there is a great interest in the synthesis of wide-band gap semiconductors, since they have many possible applications in optical and electronic devices. Among such materials, Chromium oxide (Cr2O3) is a wideband gap (Eg~3eV), p-type semiconductor and it is an important refractory material because of its high melting temperature (~2300°C) and high temperature oxidation resistance. It is widely been used in a variety of applications, such as catalytic reactions, optical coatings and sensors. In the present communication we present a systematic study on preparation and characterization of Cr2O3 thin films. Cr2O3 thin films were prepared in two steps. Cr films were first deposited by electron-beam evaporation and subsequently subjected to thermal oxidation at 700EšC/2 h under oxygen flow of 50 sccm. The structural and optical characterization of prepared films was performed using X-ray diffraction (XRD), Scanning electron microscopy (SEM) and UV-Visible spectrometry.

NiO Oxide/multi-walled carbon nanotubes (NiO/MWCNTs) nanocomposite was prepared via precipitation method. This composite has been characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) technique. The sensing and electrical properties of NiO/MWCNTs composite film dropped on fabricated gold interdigitated electrodes (IDEs) were analysed at room temperature conditions. The sensitivity and electrical properties of NiO/MWCNTs increased to a higher value after the deposition of platinum (Pt) nanoclusters. The repeatability and low recovery time in N2 atmosphere of this sensor (Pt/NiO/MWCNTs) are the main advantages for the detection of low concentrations (0.05-1%) of H2 gas at the room temperature conditions. In this paper, a simple mechanism, in which H2 molecules are firstly adsorbed via Pt metal and then diffused into NiO nanoparticles with nanotubes providing better pathway to the charge flow, was proposed for H2 sensors.

Pure and doped zinc oxide thin films have been fabricated on glass substrates from the solutions of zinc acetate in isopropyl alcohol by spray pyrolysis. For structural, morphological and optical studies, samples have been characterized by x-ray diffraction, field emission scanning electron microscopy, atomic force microscopy and uv-visible spectroscopy techniques. It was revealed that the core factors defining the parameters of zinc oxide thin films are the growth temperature, precursor solution and the concentration of the dopant. The growth temperatures of 350 oC, aluminium doping levels of 2 at. % and precursor concentration of 0.1 molar are desirable to attain zinc oxide thin films with structural, optical and morphological assets as essential for photovoltaic applications.

We studied the influence of mixing TiO2 (8-10nm) and zinc oxides ZnO (E,100 nm) nanoparticles in photoactive layer of poly (3-hexylthiophene) (P3HT):[6,6]-phenyl C61-butyric acid methyl ester (PCBM) solar cells. Different amounts of ZnO, TiO2 and PCBM were mixed for a constant amount of P3HT to form blend for deposition of active layer using xylene as solvent. The addition of metal oxides in photoactive layer enhanced the power conversion efficiency (PCE) of the ITO/PEDOT:PSS/P3HT:PCBM:ZnO:TiO2/ LiF/Al devices from 1.13 % to 2.22 %. The increase in PCE is attributed to decrease in series resistance (Rs) of the devices and increase in the open circuit voltage (Voc), short circuit current density (Jsc) and External Quantum Efficiency (EQE) of the devices, originating from the rearrangement of energy levels in the active layer. The mixing is also found to introduce a red shift in the absorption spectra of the devices and increased absorption in the visible region probably due to the modification of the band gap of the active layer, originated from the change in the ratios of active layer materials and/or the rearrangement of energy levels in the active layer. The metal oxide nanoparticles are found to agglomerate as their concentration increases in the active layer and completely agglomerate in the absence of PCBM.

This project studied the appropriated conditions for a synthesis of N-type CdS0.9Se0.1 semiconductor to be used as thermoelectric materials. Cd (CH3COO) 2.2H2O, Thiourea and SeO2 as precursors and ethylene glycol as a solvent. Two methods were applied to prepare CdS0.9Se0.1.The first method was a solution method which was applied to prepare selenium powder. NaBH4 was used as a reducing agent with 8 hours reduction time. And the other method was a reflux method, which was used to prepare CdS powder, with 8 hours reaction time and 250 degree Celsius reaction temperature. The product powders were mixed together by the atomic ratio of Cd: S: Se to 1: 0.9: 0.1. Then, it was annealed with different temperatures at 500, 700, and 900 degree Celsius under nitrogen atmosphere and vary annealing time for 5 and 10 hours. Finally, all of the powder products were characterized by X-ray diffraction technique (XRD) while CaRine3.1 program for XRD pattern simulation and 3D lattice simulation, Scanning electron microscopy (SEM) with the analysis of Energy dispersive spectroscopy (EDS) for surface composition and Transmission electron microscopy (TEM).From the XRD result of the product powders, powder annealed at 700 degree Celsius under nitrogen atmosphere for 10 hours along with the TEM result of indexing single crystal diffraction pattern can confirm that the powder product is CdS0.9Se0.1.

The search for alternative fuels has gained importance due to the increase in the price of petroleum and environmental concerns about air pollution caused by the combustion of fossil fuels. Biodiesel is an immediate alternative solution for reducing petroleum consumption in an environment friendly manner. Biodiesel shows a decrease in the emission of CO2, SOx, NOx, and unburned hydrocarbons during the combustion process when compared with fossils fuels. Transesterification is the most common method used for biodiesel production, in which, according to stoichiometry, 1 mol of triglyceride reacts with 3 mol of alcohol (primarily methanol) in the presence of a catalyst (acid, base, or enzymatic), producing a mixture of fatty acid alkyl esters (biodiesel) and glycerol. Heterogeneous catalyst requires the high temperature and pressure for the reaction while homogenous catalyst leads to the formation of biodiesel under ambient reaction condition but contaminated with catalyst.To overcome the difficulties with existing homogenous as well as heterogeneous catalysts, the present work demonstrates the preparation of Na+ metal ion impregnated calcium oxide as a solid nano catalyst for biodiesel production from waste cooking oil with high FFA and moisture contents.

Interpenetrating network (IPN) Gg-cl-poly(acrylic acid-aniline) hydrogels were synthesized by a two-steps aqueous polymerization method using gamma-radiation-initiation. The first step involves the grafting of acrylic acid (AA) onto gum ghatti using N, Na-methylene-bis-acrylamide (MBA) as a cross linker. The effects of grafting parameters on the degree of grafting and percentage swelling were investigated, respectively. The grafting parameters include monomer and cross linker concentration, gamma dose and the amount of solvent. The degree of grafting and percentage swelling were found to be greatly dependent on the reaction parameters. In the second step, aniline monomer was absorbed in the network of Gg-cl-poly(AA) and followed by a polymerization reaction between aniline monomer. The copolymers were characterized using UV/vis spectroscopy, X-ray diffraction and thermogravimetric analysis. The biodegradation of cross-linked hydrogels were carried out by using soil burial test for a period of 60 days. The degree of degradation was analysed by weight loss measurement, FTIR and SEM techniques. Our results showed that Gg-cl-poly(AA) degraded at a rate of ~6.1% after 6 days, whereas the degradation rate for Gg-cl-poly(AA-IPN-aniline) was ~10% in soil burial test. Application of hydrogels to improve the water retention properties of different soils was studied for agricultural purposes and found that the IPN hydrogel can improve the moisture retention capacity of soil for cultivation.

The substituted rare earth cobaltites (RCo1-xNixO3) oxide materials have been proven to be good thermoelectric and solid oxide fuel materials. We here report x-ray absorption near edge spectroscopy (XANES) at Co and Ni K-edges of RCo1-xNixO3 (R = La, Nd) along with L3 edges of La/Nd and understand the spectral features related to the electronic structure of these perovskites. The XANES spectra of Co, Ni and La/Nd K-edge confirm the homovalent +3 valence state in all the compositions and exclude the possibility of oxygen non stochiometic type defects and any valence change upon substitution. The existence of pre- edge peak in Co K- edge spectra reflects 1s-3d transition and provides information about the occupancy of 3d orbitals. The pre-edge spectral features which are assigned as eg and t2g, further show strong dependence on Ni concentration and revealed spin state transition of Co ions. These spin state transitions have been explained in terms of crystal field effect and have been found consistent with x-ray diffraction and magnetization studies.

« Back To Technical Program