Devi L.V.,Anna University |
Selvalakshmi T.,The Standard Fireworks Rajaratnam College for Women |
Sellaiyan S.,University of Tsukuba |
Uedono A.,University of Tsukuba |
And 2 more authors.
Journal of Alloys and Compounds | Year: 2017
Pure and La doped CuO have been successfully prepared by solution combustion synthesis (SCS) and annealed at different temperature. The crystal structure, functional group and surface morphology are analyzed using powder X-ray diffraction, Fourier transform infrared spectra and scanning electron microscopic images. The defects type and defect related photoluminescence properties are analyzed from positron annihilation spectroscopy and photoluminescence spectra respectively. This paper also examines the effect of annealing temperature and dopant concentration on lattice defect. Incorporation of La ion in CuO reduces the crystallite size and induces more number of non-radiative transition centers in CuO. © 2017 Elsevier B.V.
Premalatha M.,Nmss Vellaichamy Nadar College |
Premalatha M.,Materials Research Center |
Mathavan T.,Nmss Vellaichamy Nadar College |
Selvasekarapandian S.,Materials Research Center |
And 5 more authors.
Journal of Non-Crystalline Solids | Year: 2016
Naturally available materials such as biopolymers and polysaccharides have gained much attention in the development of polymer electrolytes due to its biodegradability, film forming nature and non-toxicity. The proton conducting biopolymer membranes have been prepared by polysaccharides, tamarind seed polysaccharide (TSP) with different concentrations of ammonium thiocyanate (NH4SCN) as dopant. Distilled water has been used as a solvent and solution casting technique has been employed to prepare the biopolymer membranes. The prepared biopolymer membranes have been characterized by different techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), AC-impedance spectroscopy and transference number measurement (TNM). From XRD results, the crystalline or amorphous nature of the biopolymer membranes with increasing salt concentration (NH4SCN) has been studied. The complex formation between the biopolymer-TSP and NH4SCN has been investigated by FTIR analysis. The glass transition temperature of the prepared biopolymer membranes has been found using DSC technique. The highest conductivity is 2.85 × 10− 4 S cm− 1 for the composition of 1 g TSP: 0.4 g NH4SCN at ambient temperature, which has been obtained by AC-impedance spectroscopic studies. The conduction of ions within the biopolymer membrane has been confirmed by TNM. The primary proton battery has been constructed with the highest conducting membrane 1 g TSP: 0.4 g NH4SCN. Its open circuit voltage is 1.51 V. The discharge characteristics of the battery for a load 1 MΩ has been explained. The present investigation confirms that the NH4SCN doped TSP biopolymer membrane has got the essential properties required for the electrochemical device applications. © 2016
Sangari N.U.,The Standard Fireworks Rajaratnam College for Women |
Jothi B.,The Standard Fireworks Rajaratnam College for Women |
Devi S.C.,The Standard Fireworks Rajaratnam College for Women |
Rajamani S.,The Standard Fireworks Rajaratnam College for Women
Journal of Water Process Engineering | Year: 2016
Zinc oxide (ZnO) nano rods were synthesized by utrasonication assisted chemical precipitation method without any templates. The influence of pH on the growth of ZnO rods was examined by adjusting the pH of the reaction mixture at values 7, 9 and 13. The as-synthesized rods were characterized by XRD, FT-IR, UV-DRS, SEM and Room Temperature Photoluminescence Spectroscopy. The photocatalytic activity of the synthesized ZnO rods was studied by photocatalytic decolourization of Methyl Orange (MO) dye in presence of UV (365 nm) light irradiation in aqueous solution. The effects of operational parameters such as initial concentration of the MO dye, amount of photocatalyst and initial pH of the dye solution were analyzed. The photocatalytic decolourization of MO dye was confirmed from the decrease in intensity of UV-vis absorption peaks at 464 nm due to lowering concentration of MO dye. Photocatalytic decolourization of MO dye followed pseudo-first order kinetics. © 2016 Elsevier Ltd.
Deepa B.,The Standard Fireworks Rajaratnam College for Women |
Ganesan V.,Center for Research and Post Graduate studies in Botany
International Journal of ChemTech Research | Year: 2015
The present study is aimed to compare the bioreduction behaviour of flower broth of Catharanthus roseus (Family: Apocynaceae) and Peltophorum pterocarpum (Family: Caesalpiniaceae) in the synthesis of selenium nanoparticles. Stable selenium nanoparticles were formed by exposing the flower broths of aforesaid plants to the aqueous sodium selenate solution (reaction medium) within a week. The bio-synthesized selenium nanoparticles were characterized using a range of diverse techniques like UV-Visible (UV-Vis) Spectroscopy, Luminescence Spectroscopy (LS), Fourier Transform Infra-Red Spectroscopy (FT-IR), X-Ray Diffraction (XRD) analysis, Energy Dispersive X-ray Spectroscopy (EDAX), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM).UV-Visible spectroscopic analysis showed the Surface Plasmon Resonance (SPR) vibrations with a λmaxat335nm and 325nm for the reaction medium prepared with the flower broth of C.roseusand P.pterocarpum respectively. Major peaks in the emission and excitation spectrum of both the reaction medium were very close to the peaks of SPR vibrations confirmed the synthesis of selenium nanoparticles.FT-IR analysis substantiated the role of esters, secondary and tertiary amides derived from the flower of C.roseusin the synthesis and stabilization of selenium nanoparticles whereas, P.pterocarpum flower reduced the sodium selenate with the help of ketones and primary amides. XRD studies confirmed the formation of face-centered cubic (fcc) phase of selenium nanoparticles with an average size of 32.02nm and 40.2nmwith the flower broth of C.roseusand P.pterocarpum respectively.The EDX and Scanning Electron Microscopic studies confirmed the formation of elemental spherical selenium nanoparticles. Further, TEM analysis reported the formation ofhollow spherical selenium nanoparticles with an average size of 23.2±6.06nm and 30.44±2.89nm using the flower broth of C.roseusand P.pterocarpum respectively. Availability of flowers throughout the year and synthesis of smaller sized nanoparticles by the C.roseus proved it as a better novel biomaterial for the synthesis of selenium nanopartilces than the P.pterocarpum. This eco-friendly approach employed for the synthesis of selenium nanoparticles is simple, amenable for large scale production and biomedical applications. © 2015, Sphinx Knowledge House. All rights reserved.
Francis K.M.G.,Bharathiar University |
Francis K.M.G.,The Standard Fireworks Rajaratnam College for Women |
Francis K.M.G.,Materials Research Center |
Subramanian S.,Materials Research Center |
And 4 more authors.
Polymer - Plastics Technology and Engineering | Year: 2016
A new blend polymer electrolyte based on poly(vinyl alcohol) and polyacrylonitrile doped with lithium nitrate (LiNO3) has been prepared and characterized. The complexation of blend polymer (92.5 PVA:7.5 PAN) with LiNO3 has been studied using X-ray diffraction and Fourier transform infrared spectroscopy. Differential scanning calorimetry thermograms show a decrease in glass transition temperature with the addition of salt. The maximum ionic conductivity of the blend polymer electrolyte is 1.5 × 10−3 Scm−1 for 15 wt% LiNO3 doped–92.5 PVA:7.5 PAN electrolyte. The conductivity values obey Arrhenius equation. Ionic transference number measurement reveals that the conducting species are predominantly ions. © 2016, Copyright © Taylor & Francis Group, LLC.
Ramanathan M.,The Standard Fireworks Rajaratnam College for Women |
Muthuramalingam R.,Sethu Institute of Technology |
Lakshmanan R.,Sethu Institute of Technology
Journal of Membrane Biology | Year: 2015
In this paper, mathematical model pertaining to the decomposition of enzyme–substrate complex in an artificial membrane is discussed. Here the transport through liquid membrane phases is considered. The model involves the system of non-linear reaction diffusion equations. The non-linear terms in this model are related to Michaelis–Menten reaction scheme. Approximate analytical expressions for the concentrations of substrate and product have been derived by solving the system of non-linear reaction diffusion equations using new approach of homotopy perturbation method for all values of Michaelis–Menten constant, diffusion coefficient, and rate constant. Approximate flux expression for substrate and product for non-steady-state conditions are also reported. A comparison of the analytical approximation and numerical simulation is also presented. The results obtained in this work are valid for the entire solution domain. © 2015, Springer Science+Business Media New York.
PubMed | The Standard Fireworks Rajaratnam College for Women and Sethu Institute of Technology
Type: Journal Article | Journal: The Journal of membrane biology | Year: 2015
In this paper, mathematical model pertaining to the decomposition of enzyme-substrate complex in an artificial membrane is discussed. Here the transport through liquid membrane phases is considered. The model involves the system of non-linear reaction diffusion equations. The non-linear terms in this model are related to Michaelis-Menten reaction scheme. Approximate analytical expressions for the concentrations of substrate and product have been derived by solving the system of non-linear reaction diffusion equations using new approach of homotopy perturbation method for all values of Michaelis-Menten constant, diffusion coefficient, and rate constant. Approximate flux expression for substrate and product for non-steady-state conditions are also reported. A comparison of the analytical approximation and numerical simulation is also presented. The results obtained in this work are valid for the entire solution domain.