Preparation and Studies of Physical Properties of a Conducting Polymer

Abstract

newlinePolythiophene (PTh) has been synthesized at three different temperatures by newlineoxidation process. The samples were confirmed to be non-crystalline by XRD studies. SEM newlineimages showed an agglomeration of particles in the samples made at 278K and 305K newlineand tubes like structures were observed for sample made at 323K. The optical newlineabsorption (UV-Vis) studies indicated two bands for PTh samples synthesised at newline278K and 305K and three bands for the sample made at 323K . Temperature newlinedependence of DC conductivity has been measured and data analyzed using polaron newlinehopping models. newlineNanoparticles of Polythiophene-V2O5 (PTh-VO) composites were prepared by newlinemechanical mixing of Polythiophene and V2O5 in different weight percentages. XRD newlinepatterns of the these composites revealed peaks corresponding to V2O5 structure. SEM newlineimage of pure V2O5 showed nano size grains where as PTh-VO composites exhibited newlinenano size grains and some tubular structure. The temperature dependence of newlineconductivity has been determined and found to be semiconducting type. Conductivity newlinebehaviour with temperature has been analyzed in view of Mott s small polaron and newlinevariable range hopping models. Activation energies for DC conduction were newlinedetermined. Density of states at Fermi level were obtained by Mott s(VRH) model newlinefits. Dielectric properties were measured over wide range of frequency and newlinetemperature. Activation energy for ac conductivity was determined.