Volume 4, Issue 4, April 2013

Advanced Materials World Congress (AMWC) 

Ashutosh Tiwari

Advanced Materials Letters, 2013, Volume 4, Issue 4, Pages 251-251
DOI: 10.5185/amlett.2013.4001

We are glad to announce Advanced Materials Word Congress (AMWC, http://www.amwc2013.org/) together with the International Association of Advanced Materials (www.iaamonline.org) and hosted by the Ä°zmir Institute of Technology in the beautiful coastal town ÇeÅŸme, Turkey at Altinyunus Hotel ÇeÅŸme during 16-19 September, 2013. The goal of congress is to provide a global platform for researchers and engineers coming from academia and industry to present their research results and activities in the field of materials science and engineering with a special attention on interdisciplinary research of advanced materials. The conference will provide opportunities for the delegates to exchange their face-to-face novel ideas and experiences with the international experts during plenary & invited talks, oral presentations and poster sessions. We will set up ten sessions with keynote forum, panel discussion and project negotiation. The full article of presentations will be published in the special issue of Advanced Materials Letters.

Transition Metal Ion-induced Anisotropic Architectures Using 4,4’-dicarboxy-2,2’-bipyridyl-silver Nanopetals

Narayanasamy Vilvamani; Sasanka Deka; Tarkeshwar Gupta

Advanced Materials Letters, 2013, Volume 4, Issue 4, Pages 252-260
DOI: 10.5185/amlett.2012.8405

Designing anisotropic nano- and micro-structures are imperative in many technology oriented fields. Here we have reported a self templating method, where flower like microstructure of silver particles were used as template to generate several anisotropic structures such as rectangular cum dumbbell, cubes, hexagonal whiskers, and rectangular bars etc. under controlled catalytic activity of Co 2+ , Ni 2+ , Cu 2+ , and Zn 2+ respectively. The initial flower like microstructure (template) of silver particles have been prepared from silver salt using disodium salt of 4,4’-dicarboxy-2,2’-bipyridyl(Na2dcbpy) as the reducing as well as capping agent. Then this architecture was used as the initial template to generate several anisotropic structures. The straightforward anisotropic microstructure preparation procedure does not require any other external template, which avoids the subsequent complicated workup. The nucleation processes and optical properties were studied using optical absorption spectroscopy. The anisotropic structure of the as-synthesized Ag particles and the formations of various shaped microstructures have been confirmed by Scanning Electron Microscopy (SEM). A possible mechanism has been proposed explaining the role of dcbpy in the growth of silver particles and the transition metal ion induced anisotropic structures.

Effects Of Multi Walled Carbon Nanotubes And Graphene On The Mechanical Properties Of Hybrid Polymer Composites

P.S. Shivakumar Gouda; ;Dayananda Jawali; Raghavendra Kulkarni; S.N. Kurbet; and Dayananda Jawali

Advanced Materials Letters, 2013, Volume 4, Issue 4, Pages 261-270
DOI: 10.5185/amlett.2012.9419

A small amount of Graphene and Multi walled carbon nanotubes (MWCNT) by direct mixing were employed to disperse these nanoparticles into a mono-component epoxy system and used as matrix for advanced composites with woven Glass and Carbon fiber reinforcements. These nanoparticles were added directly into the hosting system and dispersion was carried out by using mechanical stirring. In this study the hybrid polymer composite with Glass fiber, Carbon fiber and epoxy polymer in the ratio of 9:12.5:78.5, 13.5:18.75:67.75 and 18:25:57 percent of volume with addition of fillers, Graphene (0.2 wt%) and MWCNT (0.2wt%) have been developed. The mechanical characterization results confirm that the composite developed by using graphene nanoparticles represents a fundamental feature in enhancing the tensile elastic modulus and hardness behavior of the composite system, where as MWCNT has significant effect on the bending modulus and impact behavior. The optical microscopic study for the fractured samples reveals a significant increase in the fiber-matrix interface adhesion where as decrease in fiber breakage, fiber pullout and debonding.

Preparation, Characterization And Cr(VI) adsorption Behavior Study Of Poly(acrylic Acid) grafted Ficus Carica Bast Fiber

Shikha Sharma; Deepak Pathania;Pardeep Singh

Advanced Materials Letters, 2013, Volume 4, Issue 4, Pages 271-276
DOI: 10.5185/amlett.2012.8409

In the present study the chemical modification of Ficus carica bast fiber with acrylic acid using ceric ammonium nitrate and nitric acid was done in aqueous medium. The raw and modified fibers were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The raw and modified samples were evaluated for swelling behavior in water and chloroform. The chemical resistance was investigated against 0.1N HCl and 0.1N NaOH. The chemically modified Ficus carica fiber (CMBF) showed morphological transformations, thermal stability and chemical resistance. The adsorption potential of modified fiber was investigated for Cr(VI) removal from aqueous system.

Performance Evaluation Of Solar Cooker Using Some [N+4444] Based Ionic Liquids As Thermal Energy Storage Materials

Vasishta D. Bhatt;Kuldip Gohil

Advanced Materials Letters, 2013, Volume 4, Issue 4, Pages 277-282
DOI: 10.5185/amlett.2012.9420

Seven ionic liquids (ILs) based on tetrabutylammonium cation [N+4444] and inorganic anions were tested for their applications in a solar cooker. Thermophysical characteristics like melting point, density, heat of fusion, heat of solid - solid transitions, specific heat capacity and thermal conductivity were used to determine the efficiency of ILs used as phase change materials (PCMs) in solar thermal applications. A delay time of two hours was observed on an average in achieving the highest temperatures. A majority of the ILs extended the time required for achieving ambient temperature to a tune of around four hours. The ILs containing bromide, iodate and nitrate proved to be more efficient than the thiocyanate, bromate and hexafluorophosphate moieties.

Thermodynamic And Structural Behaviour Of liquid Al-Ga Alloys

R.P. Koirala; I.S. Jha;D. Adhikari; B.P. Singh

Advanced Materials Letters, 2013, Volume 4, Issue 4, Pages 283-287
DOI: 10.5185/amlett.2012.8412

Quasi-chemical approximation has been used to study the mixing behaviour of liquid aluminium-gallium binary alloys by computing thermodynamic functions, such as free energy of mixing, heat of mixing, entropy of mixing, activity and microscopic functions, such as concentration fluctuation in long wavelength limit (Scc(0)), Warren-Cowley short range order parameter ( ) and ratio of diffusion coefficients of the alloys at 1023 K. The theoretical analysis reveals that the ordering energy is found to be temperature dependent and Al-Ga alloy in molten state is slightly segregating.

Synthesis, Electrical And Dielectrical Properties Of Lithium Iron Oxide

P. Rosaiah; O. M. Hussain

Advanced Materials Letters, 2013, Volume 4, Issue 4, Pages 288-295
DOI: 10.5185/amlett.2012.8416

Lithium iron oxide (LiFeO2) cathode material was prepared by using hydrothermal synthesis. The XRD spectrum exhibited predominant (200) orientation peak at 2q= 43.63o corresponding to cubic rock-salt structure with Fm3m space group and the estimated lattice parameter of the sample is 4.176 Å. Electric and dielectric properties were studied over a frequency range of 1 Hz – 1 MHz and in the temperature range from 300 K to 573 K. The ionic conductivity of the sample was found to be 1.9 x 10-6 S/m at 373 K. The temperature dependent conductivity was conformed from the Arrhenius relation and the activation energy was found to be 0.39 eV. A mixed, ionic and electronic conduction was observed from the analysis. The electrical conductivity was found to be decreased with increasing temperature. The dielectric properties were analyzed in the framework of complex dielectric permittivity and complex electric modulus formalisms. The evolution of the complex permittivity as a function of frequency and temperature was investigated. Several important parameters such as activation energy, ionic hopping frequency, carrier concentration, ionic mobility and diffusion coefficient etc, were determined.

High Specific Capacitance Of Electrochemically synthesized Nano MnO2 – Gold Electrodes For supercapacitors

S. Ravi; V.S. Prabhin

Advanced Materials Letters, 2013, Volume 4, Issue 4, Pages 296-299
DOI: 10.5185/amlett.2012.8411

Transition metal ions like MnO2 are promising materials for electrodes in supercapacitors owing to their high capacitance for storing electrical charges and also eco-friendly with plenty of availability. We have decorated honey-bee like MnO2 nanostructure over gold coated silicon wafer by electrodeposition. The electrodeposited material was studied by scanning electron microscope (SEM), which reveals the honey-bee like structure. The thickness was found to be in the range of 30–80 nm using atomic force microscope (AFM). The specific capacitance of this electrode is found to be 1149 Fg -1 , which is very high and flexible for high power applications.

Electrical Properties Of Barium Titanate Dispersed Silver Sulphate

S. W. Anwane

Advanced Materials Letters, 2013, Volume 4, Issue 4, Pages 300-309
DOI: 10.5185/amlett.2012.8404

Composite materials which are heterogeneous mixtures of two or more solid phases offer value added properties for device applications. When ion conducting Ag2SO4 is dispersed with insulating BaTiO3, enhanced electrical properties are observed along with improved surface morphology. The electrical properties have been derived from the Complex Impedance Spectroscopic studies. Arrhenius Plot, Concentration and Temperature dependent conductivity and activation energy have also been studied. The ionic transference number of the composite system remains unchanged on dispersion thereby retaining its category as Solid Ionic Conductor (SIC). Moreover, 30 Wt% BaTiO3 dispersed in Ag2SO4 offers promisingly enhanced ionic conductivity and reduced activation energy of ion migration. This material has further scope for its utilization as a silver ion conductor in electrochemical applications like solid state batteries, gas sensors etc. The results obtained fit well in the established theories of composites.

Mossbauer, Magnetic, Dielectric And Dc conductivity Of Al3+ ions Substituted Mg-Mn-Ni nano Ferrite Synthesized By Citrate Precursor method

Satish Verma; Jagdish Chand;M. Singh

Advanced Materials Letters, 2013, Volume 4, Issue 4, Pages 310-316
DOI: 10.5185/amlett.2012.8410

Nanocrystalline Al3+ ions doped Mg0.2Mn0.5Ni0.3AlyFe2-yO4 compositions, where y=0.0, 0.05 and 0.10 have been synthesized by citrate precursor method. The X-ray diffraction (XRD) revealed that the ferrite has single phase cubic spinel structure. The calculated particle size from XRD data have been verified using transmission electron microscopy (TEM). TEM photographs show that the ferrite powders consist of nanometer-sized particle. It was observed that the particle size decreases as the non-magnetic Al content increases. A decrease in lattice parameter and saturation magnetization with increase in aluminium concentration was attributed to smaller ionic radius and weakening of exchange interaction. Dependence of Mössbauer parameters such as isomer shift, quadrupole splitting and hyperfine magnetic field on Al 3+ ions concentration have been discussed. Initial permeability ‘µi’, relative loss factor (RLF), saturation magnetization and remanent magnetization decreases with increasing substitution of Al 3+ ions. The dielectric constant and dielectric loss decreases with increase in non magnetic Al 3+ ions. The dielectric constant follows the Maxwell–Wagner interfacial polarization. The electrical conduction in these ferrites is explained on the basis of the hopping mechanism.

Microstructure And Photo-catalytic Dye Degradation Of Silver- Silica Nano Composites Synthesised By Sol-gel Method

Surender Duhan; B.S. Dehiya;Vijay Tomer

Advanced Materials Letters, 2013, Volume 4, Issue 4, Pages 317-322
DOI: 10.5185/amlett.2012.8414

Sol–gel chemistry has recently attracted a large attention with a view of preparation of silver-silica nano-composites for photo-catalytic applications. This method of synthesis allows glassy materials to be prepared at a much lower temperature than the traditional melt-glass techniques. Moreover, it enables higher doping concentrations and a more uniform distribution of silver in the glass host matrix to be achieved. This method produces large quantities of amorphous gels that are thermal treated in air at the temperature of 500°C for one hour. The silver-silica samples were investigated through X-ray diffraction (XRD for the determination of their microstructure, phase and compositions. It is found that the microstructure depends closely on the solution pH and the extent of silver-doping. MB dye degradation by undoped and Ag doped SiO2 was studied under UV and Visible light irradiation. The results are intriguing as the doping by Ag produces opposite effects on photocatalytic degradation rates under the two conditions.

Impulsive Excitation Of Mechanoluminescence In γ-ray Irradiated ZnAl2O4:Dy Phosphors synthesized By Solution Combustion Technique

K. K. Satapathy;F. Khan

Advanced Materials Letters, 2013, Volume 4, Issue 4, Pages 323-326
DOI: 10.5185/amlett.2012.8415

The mechanoluminescence (ML) of γ-irradiated Anchor ZnAl2O4: Dy phosphor has been studied. ZnAl2O4 samples having different concentrations of Dy were prepared by solution combustion technique by using hydrazine as a fuel. ML was excited impulsively by dropping a load onto the sample. Two distinct peaks have been observed in the ML intensity versus time curve. Maximum intensity is obtained for 0.1 mol% of Dy doped ZnAl2O4 phosphor. ML spectra of the phosphors show two distinct peaks around 482 nm and 585 nm which is characteristic emission of Dy 3+ . It is also observed that the ML intensity of the samples increases almost linearly with increasing mass of the sample and gamma ray doses given to the sample. Experimental results suggest that the ML excitation is related to the movement of dislocation with defect centres and it may be used for dosimeter applications.