Govindammal Aditanar College for Women

Tamil Nadu, India

Govindammal Aditanar College for Women

Tamil Nadu, India

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Praveena G.L.,Govindammal Aditanar College for Women
International Journal of ChemTech Research | Year: 2015

A new semiorganic nonlinear optical single crystal of Imidazole Potassium Chloride (IPC) has been grown successfully by slow evaporation method. Colourless, transparent IPC crystal of dimension 5 x 5 x 2 mm3 has been grown within a period of 21 days. The grown crystal was subjected to single crystal X-ray diffraction (XRD) analysis to determine the lattice parameters. The powder X-ray diffraction pattern of the grown crystal has been indexed. The presence of functional groups in the grown crystal was confirmed by fourier transform infrared spectroscopy (FTIR) analysis. The optical transmission property of the grown crystal was analysed using UV-Vis- NIR spectral analysis. The mechanical strength of the crystal was found out using Vickers microhardness test. The second harmonic generation (SHG) has been tested using Kurtz powder technique. © 2015, Sphinx Knowledge House. All rights reserved.


Vasantha Kumari V.,Govindammal Aditanar College for women | Thilagavathi R.,Govindammal Aditanar College for women
International Journal of ChemTech Research | Year: 2015

The growth and characterization of semiorganic L-Proline Potassium Sulphate (LPPS) crystal is reported. Single crystals of L- proline potassium sulphate were successfully grown for the first time by solution method with slow evaporation technique at room temperature. Single crystal X-ray diffractometer was utilized to measure the unit cell parameters and to confirm the crystal structure. The planes observed in the powder xray diffraction pattern of the grown LPPS crystal have been indexed. The modes of vibration of different molecular groups present in the sample were identified by FTIR spectral analysis and EDAX test was also carried out for confirmation. The optical transmittance window and the lower cut-off wavelength of LPPS have been identified by UV-Vis-NIR studies. Thermal stability of the LPPS was determined by TG/DTA studies. The Vickers microhardness test was also carried out to test the mechanical stability and the hardness parameters were determined. The second harmonic efficiency of the sample was also tested and compared with the standard KDP crystal. © 2015, Sphinx Knowledge House. All rights reserved.


Selvi N.T.,Govindammal Aditanar College for Women
Journal of the Serbian Chemical Society | Year: 2015

The influence of cetyltrimethylammonium bromide, CTAB, on the oxidative decarboxylation of phenylsulfinylacetic acid, PSAA, and several meta- and para-substituted PSAAs by Cr(VI) was investigated in 95 % H2O-5 % CH3CN medium. The rate profile displayed a peculiar trend with an initial rate increase at low CTAB followed by sharp rate inhibition at higher CTAB concentrations. The initial rate acceleration could be explained by strong binding of SO4 2- on the positively charged micellar surface. The specific partitioning of PSAA in the micellar phase by hydrophobic interaction and the oxidizing species HCrO3 + in aqueous phase by electrostatic repulsion accounted for the rate retardation at higher CTAB concentrations. The Hammett plot with different substituted PSAAs showed excellent correlation affording negative ? value, which supports the proposed mechanism involving the intermediate formation of sulfonium cation. The obtained ? value in CTAB medium was found to be slightly lower than that in aqueous medium. Quantitative analysis of the rate data for the inhibition shown by CTAB was performed using the Menger-Portnoy and the Piszkiewicz pseudo-phase models. The binding constant for PSAA with micelles was evaluated from the Piszkiewicz cooperative model.


Selvi N.T.,Govindammal Aditanar College for Women | Devi S.S.,Kamaraj College
Journal of the Korean Chemical Society | Year: 2014

The oxidative decarboxylation of phenylsulfinylacetic acid (PSAA) by Cr(VI) in 20% acetonitrile - 80% water (v/v) medium follows overall second order kinetics, first order each with respect to [PSAA] and [Cr(VI)] at constant [H+] and ionic strength. The reaction is acid catalysed, the order with respect to [H+] is unity and the active oxidizing species is found to be HCrO3 +. The reaction mechanism involves the rate determining nucleophilic attack of sulfur atom of PSAA on chromium of HCrO3 + forming a sulfonium ion intermediate. The intermediate then undergoes a,β-cleavage leading to the liberation of CO2. The product of the reaction is found to be methyl phenyl sulfone. The operation of substituent effect shows that PSAA containing electron-releasing groups in the meta- and para-positions accelerate the reaction rate while electron withdrawing groups retard the rate. An excellent correlation is found to exist between log k2 and Hammett s constants with a negative value of reaction constant. The p value decreases with increase in temperature evidencing the high reactivity and low selectivity in the case of substituted PSAAs.


Gandhimathi R.,Govindammal Aditanar College for Women | Krishnan C.M.,Sri Kgs Arts College
Optik | Year: 2015

A new semi-organic non-linear optical crystal of Manganese Sulpho Tartrate (MST) has been grown successfully by slow evaporation technique. The grown crystals were transparent and pink in color. The solubility study has been carried out in the temperature range 30-50 °C in de-ionized water. The lattice parameters of the grown crystals were determined by single crystal X-ray diffraction technique and the crystalline nature of the grown crystal was confirmed by powder XRD analysis. The presence of the functional groups in the crystal lattice was confirmed by Fourier Transform Infra Red spectral analysis. The UV-vis-NIR spectrum of MST shows good transmittance in the visible region which enables it to be suitable for optical applications. The nonlinear optical property of the grown crystal was confirmed by Kurtz-Perry powder technique and a study of its second harmonic generation (SHG) efficiency in comparison with potassium dihydrogen phosphate (KDP) has been made. The mechanical strength of the crystal was found by Vickers hardness test. © 2015 Elsevier GmbH. All rights reserved.


Selvi N.T.,Govindammal Aditanar College for Women
Bulletin of the Chemical Society of Ethiopia | Year: 2016

The kinetics and mechanism of picolinic acid promoted reaction of phenylsulfinylacetic acid (PSAA) with Cr(VI) was carried out in aqueous acetonitrile medium under pseudo first order conditions. The reaction follows Michaelis-Menten type of kinetics with respect to PSAA. The catalytic activity by picolinic acid can be interpreted on the basis of the formation of a highly active oxidizing species, Cr(VI)-PA complex. The mechanism involves the formation of a termolecular complex, Cr(VI)-PA-PSAA by the nucleophilic attack of the sulfur atom of PSAA on chromium of Cr(VI)-PA complex in an equilibrium step followed by ligand coupling in a slow step. Electron releasing substituents in the phenyl ring of PSAA accelerate while electron withdrawing groups retard the reaction rate. The overall rate constants for the para- and meta-substituted PSAAs are found to correlate excellently with Hammett ó constants with a very low reaction constant, ρ. © 2016 Chemical Society of Ethiopia.


Praveena G.L.,Govindammal Aditanar College for Women
Optik | Year: 2016

The single crystals of d-alanine alaninium bromide (DAAB), a semiorganic nonlinear optical material has been grown successfully from aqueous solution by slow evaporation solution growth technique. Single-crystal X-ray diffraction analysis shows that the grown crystal belongs to the monoclinic system. The crystalline nature and its various planes of reflections were observed by powder XRD analysis. Thermal studies reveal that the crystal is stable up to 100 °C. The functional groups of the grown crystal were determined by FTIR spectral analysis. The existence of second harmonic generation signals was observed using Nd:YAG laser with fundamental wavelength of 1064 nm possessing SHG efficiency of 1.7 times of KDP. The optical transmittance window and the lower cutoff wavelength of the DAAB have been identified by UV-vis-NIR studies. The mechanical property of the grown crystal studied using Vickers microhardness measurement reveals that the crystal is a soft material. The encouraging results show that the DAAB crystals have great potential applications in optical devices. © 2016 Elsevier GmbH. All rights reserved.


Jansi Rani M.,Govindammal Aditanar College for Women | Murugan M.,Sri Kgs Arts College | Subramanian E.,Manonmaniam Sundaranar University
Indian Journal of Chemical Technology | Year: 2016

Prosopis spicigera L.wood (PSLW), a plant material used as fuel by the rural mass in India is carbonized and used as an adsorbent for the removal of Methylene Blue and Erythrosine B dyes from aqueous solution by batch and column methods. The adsorbent is characterized by BET method (Nitrogen adsorption at 77. K) for pore and textural properties, scanning electron microscopy for surface morphology, potentiometric titration for pHZPC, FTIR for surface functional group and Boehm estimation of surface functional groups. The adsorption of Methylene Blue and Erythrosine B dyes on PSLW carbon has been carried out at different pH, adsorbate concentrations and contact time, adsorbent dosage and temperature conditions to determine the optimum condition for adsorption. Batch adsorption experiments show that maximum adsorption of Methylene Blue and Erythrosine B dyes is found at pH 2.0 and 3.0 respectively. Pseudo second order kinetics (Lagergren), surface mass transfer and pore diffusion models were used to evaluate the kinetic parameters and adsorption mechanism. To describe the equilibrium isotherm process, the data are analyzed using Langmuir model. Thermodynamic parameters indicate the adsorption interaction is found to be spontaneous and exothermic in nature. Column data fits to the Thomas Model. © 2016, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved.


Muthulakshmi S.,Govindammal Aditanar College for Women | Chithralekha P.,Indian Institute of Technology Madras | Balaji M.,Manonmaniam Sundaranar University | Sanjeev G.,Mangalore University | Padiyan D.P.,Manonmaniam Sundaranar University
Indian Journal of Pure and Applied Physics | Year: 2013

The oblenlion of biopolymer papain irradiated with 8 MeV energy of electron beam to different doses from 1 kGy to 10 kGy and the effect of the radiation on the electrical behaviour of the biopolymer have been investigated in the temperature range 29°-135°C. The etc impedance plots indicate a single relaxation process in biopolymer papain in different temperatures. An increase in bulk electrical conductivity was noted for biopolymer papain with temperature after irradiation which is related to the hopping of charge carriers between the sites. The electrical conductivity of fresh and irradiated papain follows the universal power law and from which it is observed that the ac conductivity is frequency dependent and it obeys the electron tunneling model of conduction mechanism. The SEM images reveal the larger particle size with non-uniform structure upon irradiation of papain.


Muthulakshmi S.,Govindammal Aditanar College for Women | Iyyapushpam S.,Manonmaniam Sundaranar University | Pathinettam Padiyan D.,Manonmaniam Sundaranar University
Bulletin of Materials Science | Year: 2014

The influence of temperature on the electrical behaviour of protein biopolymer papain and carbohydrate biopolymers like gum acacia, gum tragacanth and guar gum has been investigated using AC impedance technique. The observed semi-circles represent the material's bulk electrical property that indicate the single relaxation process in the biopolymers. An increase in bulk electrical conductivity in the biopolymers with temperature is due to the hopping of charge carriers between the trapped sites. The depression parameter reveals the electrical equivalent circuit for the biopolymers. The AC electrical conductivity in the biopolymers follows the universal power law. From this, it is observed that the AC conductivity is frequency dependent and the biopolymer papain obeys large polaron tunnelling model, gum acacia and gum guar obey ion or electron tunnelling model, and gum tragacanth obeys the correlated barrier hopping model of conduction mechanisms. © Indian Academy of Sciences.

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