Articles written in Bulletin of Materials Science
Volume 28 Issue 3 June 2005 pp 233-238 Thin Films
Using photo acoustic technique, the thermal properties of CdS thin films grown by spray pyrolysis are measured. Thermal diffusivity and conductivity in these films decrease at least two orders compared with bulk. These results are compared with our study on nano CdS and the other available literature. The comparison is good. The dependence of thermal diffusivity on the thickness of the layer or the size of the particles on the glass substrate are analysed from the present measurement and discussed. The dependence of thermal diffusivity on the thickness of the layer on the glass substrate is discussed.
Volume 36 Issue 2 April 2013 pp 333-339
Lithium ion conducting polymer blend electrolyte films based on poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) with different Mwt% of lithium nitrate (LiNO3) salt, using a solution cast technique, have been prepared. The polymer blend electrolyte has been characterized by XRD, FTIR, DSC and impedance analyses. The XRD study reveals the amorphous nature of the polymer electrolyte. The FTIR study confirms the complex formation between the polymer and salt. The shifts in 𝑇g values of 70 PVA–30 PVP blend and 70 PVA–30 PVP with different Mwt% of LiNO3 electrolytes shown by DSC thermograms indicate an interaction between the polymer and the salt. The dependence of 𝑇g and conductivity upon salt concentration has been discussed. The ion conductivity of the prepared polymer electrolyte has been found by a.c. impedance spectroscopic analysis. The PVA–PVP blend system with a composition of 70 wt% PVA: 30 wt% PVP exhibits the highest conductivity of 1.58 × 10-6 Scm-1 at room temperature. Polymer samples of 70 wt% PVA–30 wt% PVP blend with different molecular weight percentage of lithium nitrate with DMSO as solvent have been prepared and studied. High conductivity of 6.828 × 10-4 Scm-1 has been observed for the composition of 70 PVA:30 PVP:25 Mwt% of LiNO3 with low activation energy 0.2673 eV. The conductivity is found to increase with increase in temperature. The temperature dependent conductivity of the polymer electrolyte follows the Arrhenius relationship which shows hopping of ions in the polymer matrix. The relaxation parameters (𝜔) and (𝜏) of the complexes have been calculated by using loss tangent spectra. The mechanical properties of polymer blend electrolyte such as tensile strength, elongation and degree of swelling have been measured and the results are presented.
Volume 38 Issue 1 February 2015 pp 183-190
The lithium ion conducting copolymer electrolytes based on poly(vinylidene chloride-co-acrylonitrileco- methyl methacrylate) P(VdCl-co-AN-co-MMA)-lithium per chlorate (LiClO4) (P(VdCl-co-AN-co-MMA): LiClO4) and poly(vinylidene chloride-co-acrylonitrile-co-methyl methacrylate)P(VdCl-co-AN-co-MMA)-lithium per chlorate (LiClO4)-ethylene carbonate (EC) (P(VdCl-co-AN-co-MMA):LiClO4:EC) of different compositions were prepared by solution-casting technique. Structural and surface morphological characterizations were studied by X-ray diffraction analysis and scanning electron microscopy measurements, respectively. Thermal and conductivity behaviour of copolymer–salt and copolymer–salt–plasticizer complexes were studied by employing differential scanning calorimetry and AC impedance measurements, respectively. The highest bulk conductivity was found to be 1.94 × 10-4 S cm-1 at 303 K for the plasticized sample. The dielectric behaviour and relaxation parameters of the samples have been presented and discussed.
Volume 42 | Issue 5
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