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S. Rajendran - One of the best experts on this subject based on the ideXlab platform.

  • Solid Polymer Blend Electrolyte Based on Poly(ethylene oxide) and Poly(vinyl pyrrolidone) for Lithium Secondary Batteries
    Brazilian Journal of Physics, 2015
    Co-Authors: K. Kesavan, Chithra M. Mathew, S. Rajendran, C. Subbu, M. Ulaganathan
    Abstract:

    Solid polymer electrolytes have attracted considerable attention due to their wide variety of electrochemical device applications. In the present study, the fixed concentration of the salt lithium perchlorate (LiClO_4) and various concentrations of poly(ethylene oxide)/poly(vinyl pyrrolidone) (PEO/PVP)-based electrolytes were prepared by Solvent Casting Technique. The structural analysis of the present system shows that the amorphous character of the samples is responsible for the process of ion transport. Fourier transform infrared spectroscopy (FTIR) has been used to characterize the structure of polymer and confirm the complexation between the polymers and salt. The maximum ionic conductivity value is found to be 0.2307 × 10^−5 S cm^−1 for PEO (90 wt%)/PVP (10 wt%)/LiClO_4 (8 wt%) (A1) complex at 303 K (30 °C).

  • Analysis of plasticizer influence in Poly(vinyl acetate)/Poly(vinylidene fluoride) polymer blend electrolyte
    Ionics, 2014
    Co-Authors: Chithra M. Mathew, K. Kesavan, S. Rajendran
    Abstract:

    Gel polymer electrolyte based on poly(vinyl acetate) and poly(vinylidene fluoride) was prepared by Solvent Casting Technique, in which the addition of plasticizers improves the conductivity of polymer membranes. The blend polymer electrolyte containing propylene carbonate (PC) exhibits the highest conductivity of 0.922 × 10−2 S cm−1 at room temperature because of the higher dielectric constant as compared to other plasticizers used in the present study. Material characterizations were done with the help of SEM and FT-IR Techniques. The activation energy values were computed from ‘log σ−1/T’ Arrhenius plots.

  • Transport and optical studies of PEO/PVP/LiClO 4 based polymer blend electrolytes
    2014
    Co-Authors: K. Kesavan, Chithra M. Mathew, C. Subbu, S. Rajendran
    Abstract:

    Fixed ratio of poly (ethylene oxide)/poly (vinyl pyrrolidone) (PEO /PVP) and various concentrations of lithium perchlorate (LiClO 4) were prepared by Solvent Casting Technique. The m aximum ionic conductivity value was found to be 0.2307◊10 -5 Scm -1 for 8 wt% of LiClO 4 based system at ambient temperature. Three dimensional topographic image of the sample having a maximum ionic conductivity show small micropores which are responsible for the high ionic conductivi ty. The change in viscosity of the prepared samples were line with the ionic conductivity.

  • Role of Different Plasticizers in Li-Ion Conducting Poly(Acrylonitrile)-Poly(Methyl Methacrylate) Hybrid Polymer Electrolyte
    International Journal of Polymeric Materials, 2013
    Co-Authors: X. Helan Flora, Mani Ulaganathan, S. Rajendran
    Abstract:

    In this work, polymer electrolytes composed of PAN/PMMA/LiClO4 with different plasticizers are prepared using Solvent Casting Technique. Ionic conductivity of the electrolytes is evaluated with the help of ac impedance study at various temperatures. Structural and the complexation of the prepared electrolytes are studied by XRD and FTIR analysis, respectively. Thermogravimetric/differential thermal analysis (TG/DTA) is used to find the thermal stability of the polymer electrolytes. PAN/PMMA/EC/LiClO4-based plasticized polymer electrolyte is found to possess optimal properties in terms of conductivity and thermal stability. Porous nature of the polymer gel electrolytes is also confirmed by SEM analysis.

  • Investigations on PVC/PMMA Blends with Various Iithium Salts
    2013
    Co-Authors: M. Ramesh Prabhu, K. Sudalaimuthu, S. Rajendran
    Abstract:

    Hybrid, solid polymer electrolyte films consisting of poly(vinyl chloride)/poly(methyl methacrylate)-based polymer blend electrolytes comprising propylene carbonate as a plasticizer and a lithium salt LiX (X = BF4-, ClO4-, CF3SO3-) are prepared by a Solvent Casting Technique. X-ray diffraction, Fourier transform infrared spectroscopy and Differential scanning calorimeter analysis have been made to investigate the structural, complexation and variation in film morphology of the polymer electrolyte. The temperature dependence of ionic conductivity of the polymer films is explained on the basis of a free volume model. The electrolytes that contain LiBF4 exhibit maximum conductivity.

Rengapillai Subadevi - One of the best experts on this subject based on the ideXlab platform.

  • Development and characterizations of PVdF-PEMA gel polymer electrolytes
    Ionics, 2012
    Co-Authors: Rengapillai Subadevi, Marimuthu Sivakumar, S. Rajendran
    Abstract:

    A new class of gel polymer electrolytes comprising the blend of poly(ethyl methacrylate) (PEMA) and poly(vinylidene fluoride), the mixture of ethylene carbonate and propylene carbonate as a plasticizer, and lithium perchlorate (LiClO_4) as a salt was prepared using Solvent Casting Technique. The formation of polymer–salt complexes has been confirmed by XRD analysis. Morphological and thermal studies have been performed using SEM and DMA analyses. A comparative look between PEMA and poly(methyl methacrylate) (PMMA) electrolytes has showed that PEMA electrolytes exhibited better electrochemical performances than PMMA electrolytes, despites its lower conductivity.

  • Studies on the Effect of Anions of Various Lithium Salts in PEMA Gel Polymer Electrolytes
    Journal of Applied Polymer Science, 2010
    Co-Authors: Rengapillai Subadevi, Marimuthu Sivakumar, S. Rajendran
    Abstract:

    Polyvinylidene fluoride (PVdF)-polyethyl methacrylate (PEMA) based electrolytes comprising a binary mixture of Solvents (EC and PC) (ethylene carbonate and pro- pylene carbonate) and lithium salts LiX (X ¼ ClO4 ,B F 4, CF3SO3) have been prepared using Solvent Casting Technique. The prepared electrolytes were subjected to ionic conductivity, XRD, SEM, and FTIR analysis to understand the salt contribu- tion. Comparison of conductivity studies of the electrolytes with the three salts has also been made. These electrolytes exhibited good electrochemical properties, because they have

  • Compositional effect of PVdF-PEMA blend gel polymer electrolytes for lithium polymer batteries
    European Polymer Journal, 2007
    Co-Authors: Marimuthu Sivakumar, Rengapillai Subadevi, S. Rajendran
    Abstract:

    Abstract Owing to their improved mechanical properties and good polymer miscibility, the blend gel polymer electrolytes of poly (vinylidene fluoride) (PVdF)-poly(ethyl methacrylate) (PEMA) have been prepared using Solvent Casting Technique and characterized for their electrochemical performances. The electrolyte shows a maximum ionic conductivity of 1.5 × 10−4 S cm−1 at 301 K for the 90:10 blend ratio of PVdF:PEMA system with good transport property. The ionic conductivity is enhanced, in accompany with improved microstructural homogeneity, at low PEMA contents, while the decreased conductivity at high contents has been attributed to increasing crystalline PEMA domains. With the optimum PVdF:PEMA ratio, the complex system was found to facile reasonable ionic transference number and exhibit superior interfacial stability with Li electrode.

  • Electrochemical studies on [(1 − x)PVA–xPMMA] solid polymer blend electrolytes complexed with LiBF4
    Materials Chemistry and Physics, 2005
    Co-Authors: Marimuthu Sivakumar, Rengapillai Subadevi, S. Rajendran, Jai Young Lee
    Abstract:

    PVA–PMMA-based electrolyte films containing fixed LiBF4 salt are prepared using Solvent Casting Technique. The complexation has been confirmed from XRD and FTIR spectral studies. The ac impedance studies are performed to evaluate the ionic conductivity of the polymer electrolyte membranes in the range 302–373 K and the temperature dependence seems to obey the VTF relation. The influence of blend compositions on the ionic conductivity has been discussed. The maximum ionic conductivity value for PVA (60 wt.%)–PMMA (40 wt.%)–LiBF4 (10 wt.%) system is found to be 2.801 × 10 −5 Sc m −1 at 302 K. Thermal analysis and CV studies have been performed and reported here.

  • Characterization of PVA–PVdF based solid polymer blend electrolytes
    Physica B-condensed Matter, 2003
    Co-Authors: S. Rajendran, Rengapillai Subadevi, Marimuthu Sivakumar, M. Nirmala
    Abstract:

    Abstract In order to optimize the blend composition of PVA–PVdF–LiClO 4 polymer electrolytes, flexible films are prepared using Solvent Casting Technique. The complex formation has been ascertained by XRD and FTIR analyses. The AC conductivity studies are carried out to evaluate the ambient temperature conductivity of the polymer electrolytes. The maximum conductivity value 3.0364×10 −5  S/cm has been observed for PVA (67.5)–PVdF (22.5)–LiClO 4 (10 wt%) system. Thermal stability of the film exhibiting maximum conductivity is studied and the results are discussed.

Mehran Mehrabanian - One of the best experts on this subject based on the ideXlab platform.

  • ha nylon 6 6 porous scaffolds fabricated by salt leaching Solvent Casting Technique effect of nano sized filler content on scaffold properties
    International Journal of Nanomedicine, 2011
    Co-Authors: Mehran Mehrabanian, Mojtaba Nasresfahani
    Abstract:

    Nanohydroxyapatite (n-HA)/nylon 6,6 composite scaffolds were produced by means of the salt-leaching/Solvent Casting Technique. NaCl with a distinct range size was used with the aim of optimizing the pore network. Composite powders with different n-HA contents (40%, 60%) for scaffold fabrication were synthesized and tested. The composite scaffolds thus obtained were characterized for their microstructure, mechanical stability and strength, and bioactivity. The microstructure of the composite scaffolds possessed a well-developed interconnected porosity with approximate optimal pore size ranging from 200 to 500 μm, ideal for bone regeneration and vascularization. The mechanical properties of the composite scaffolds were evaluated by compressive strength and modulus tests, and the results confirmed their similarity to cortical bone. To characterize bioactivity, the composite scaffolds were immersed in simulated body fluid for different lengths of time and results monitored by scanning electron microscopy and energy dispersive X-ray microanalysis to determine formation of an apatite layer on the scaffold surface.

  • HA/nylon 6,6 porous scaffolds fabricated by salt-leaching/Solvent Casting Technique: effect of nano-sized filler content on scaffold properties
    International Journal of Nanomedicine, 2011
    Co-Authors: Mehran Mehrabanian, Mojtaba Nasr-esfahani
    Abstract:

    Nanohydroxyapatite (n-HA)/nylon 6,6 composite scaffolds were produced by means of the salt-leaching/Solvent Casting Technique. NaCl with a distinct range size was used with the aim of optimizing the pore network. Composite powders with different n-HA contents (40%, 60%) for scaffold fabrication were synthesized and tested. The composite scaffolds thus obtained were characterized for their microstructure, mechanical stability and strength, and bioactivity. The microstructure of the composite scaffolds possessed a well-developed interconnected porosity with approximate optimal pore size ranging from 200 to 500 μm, ideal for bone regeneration and vascularization. The mechanical properties of the composite scaffolds were evaluated by compressive strength and modulus tests, and the results confirmed their similarity to cortical bone. To characterize bioactivity, the composite scaffolds were immersed in simulated body fluid for different lengths of time and results monitored by scanning electron microscopy and energy dispersive X-ray microanalysis to determine formation of an apatite layer on the scaffold surface.

Marimuthu Sivakumar - One of the best experts on this subject based on the ideXlab platform.

  • Development and characterizations of PVdF-PEMA gel polymer electrolytes
    Ionics, 2012
    Co-Authors: Rengapillai Subadevi, Marimuthu Sivakumar, S. Rajendran
    Abstract:

    A new class of gel polymer electrolytes comprising the blend of poly(ethyl methacrylate) (PEMA) and poly(vinylidene fluoride), the mixture of ethylene carbonate and propylene carbonate as a plasticizer, and lithium perchlorate (LiClO_4) as a salt was prepared using Solvent Casting Technique. The formation of polymer–salt complexes has been confirmed by XRD analysis. Morphological and thermal studies have been performed using SEM and DMA analyses. A comparative look between PEMA and poly(methyl methacrylate) (PMMA) electrolytes has showed that PEMA electrolytes exhibited better electrochemical performances than PMMA electrolytes, despites its lower conductivity.

  • Studies on the Effect of Anions of Various Lithium Salts in PEMA Gel Polymer Electrolytes
    Journal of Applied Polymer Science, 2010
    Co-Authors: Rengapillai Subadevi, Marimuthu Sivakumar, S. Rajendran
    Abstract:

    Polyvinylidene fluoride (PVdF)-polyethyl methacrylate (PEMA) based electrolytes comprising a binary mixture of Solvents (EC and PC) (ethylene carbonate and pro- pylene carbonate) and lithium salts LiX (X ¼ ClO4 ,B F 4, CF3SO3) have been prepared using Solvent Casting Technique. The prepared electrolytes were subjected to ionic conductivity, XRD, SEM, and FTIR analysis to understand the salt contribu- tion. Comparison of conductivity studies of the electrolytes with the three salts has also been made. These electrolytes exhibited good electrochemical properties, because they have

  • Compositional effect of PVdF-PEMA blend gel polymer electrolytes for lithium polymer batteries
    European Polymer Journal, 2007
    Co-Authors: Marimuthu Sivakumar, Rengapillai Subadevi, S. Rajendran
    Abstract:

    Abstract Owing to their improved mechanical properties and good polymer miscibility, the blend gel polymer electrolytes of poly (vinylidene fluoride) (PVdF)-poly(ethyl methacrylate) (PEMA) have been prepared using Solvent Casting Technique and characterized for their electrochemical performances. The electrolyte shows a maximum ionic conductivity of 1.5 × 10−4 S cm−1 at 301 K for the 90:10 blend ratio of PVdF:PEMA system with good transport property. The ionic conductivity is enhanced, in accompany with improved microstructural homogeneity, at low PEMA contents, while the decreased conductivity at high contents has been attributed to increasing crystalline PEMA domains. With the optimum PVdF:PEMA ratio, the complex system was found to facile reasonable ionic transference number and exhibit superior interfacial stability with Li electrode.

  • Electrochemical studies on [(1 − x)PVA–xPMMA] solid polymer blend electrolytes complexed with LiBF4
    Materials Chemistry and Physics, 2005
    Co-Authors: Marimuthu Sivakumar, Rengapillai Subadevi, S. Rajendran, Jai Young Lee
    Abstract:

    PVA–PMMA-based electrolyte films containing fixed LiBF4 salt are prepared using Solvent Casting Technique. The complexation has been confirmed from XRD and FTIR spectral studies. The ac impedance studies are performed to evaluate the ionic conductivity of the polymer electrolyte membranes in the range 302–373 K and the temperature dependence seems to obey the VTF relation. The influence of blend compositions on the ionic conductivity has been discussed. The maximum ionic conductivity value for PVA (60 wt.%)–PMMA (40 wt.%)–LiBF4 (10 wt.%) system is found to be 2.801 × 10 −5 Sc m −1 at 302 K. Thermal analysis and CV studies have been performed and reported here.

  • Characterization of PVA–PVdF based solid polymer blend electrolytes
    Physica B-condensed Matter, 2003
    Co-Authors: S. Rajendran, Rengapillai Subadevi, Marimuthu Sivakumar, M. Nirmala
    Abstract:

    Abstract In order to optimize the blend composition of PVA–PVdF–LiClO 4 polymer electrolytes, flexible films are prepared using Solvent Casting Technique. The complex formation has been ascertained by XRD and FTIR analyses. The AC conductivity studies are carried out to evaluate the ambient temperature conductivity of the polymer electrolytes. The maximum conductivity value 3.0364×10 −5  S/cm has been observed for PVA (67.5)–PVdF (22.5)–LiClO 4 (10 wt%) system. Thermal stability of the film exhibiting maximum conductivity is studied and the results are discussed.

Mojtaba Nasr-esfahani - One of the best experts on this subject based on the ideXlab platform.

  • HA/nylon 6,6 porous scaffolds fabricated by salt-leaching/Solvent Casting Technique: effect of nano-sized filler content on scaffold properties
    International Journal of Nanomedicine, 2011
    Co-Authors: Mehran Mehrabanian, Mojtaba Nasr-esfahani
    Abstract:

    Nanohydroxyapatite (n-HA)/nylon 6,6 composite scaffolds were produced by means of the salt-leaching/Solvent Casting Technique. NaCl with a distinct range size was used with the aim of optimizing the pore network. Composite powders with different n-HA contents (40%, 60%) for scaffold fabrication were synthesized and tested. The composite scaffolds thus obtained were characterized for their microstructure, mechanical stability and strength, and bioactivity. The microstructure of the composite scaffolds possessed a well-developed interconnected porosity with approximate optimal pore size ranging from 200 to 500 μm, ideal for bone regeneration and vascularization. The mechanical properties of the composite scaffolds were evaluated by compressive strength and modulus tests, and the results confirmed their similarity to cortical bone. To characterize bioactivity, the composite scaffolds were immersed in simulated body fluid for different lengths of time and results monitored by scanning electron microscopy and energy dispersive X-ray microanalysis to determine formation of an apatite layer on the scaffold surface.