Synthesis, characterization and ac conductivity studies of polypyrrole-vanadium pentaoxide composites

Abstract

Organic polymer materials are being widely studied as potential components of optical switching, LEDs, optical storage, lithography, solid state sensors and other photonic devices. In the present work, synthesis of polypyrrole (PPy) is carried out by chemical oxidation method by using ammonium persulphate as an oxidant, and vanadium pent oxide (V2O5) is used as it is received. PPy-V2O5 composites were synthesized by using various weight percentages (10, 20, 30, 40 and 50) of V2O5 in PPy by in situ polymerization. The composites are characterized by using various techniques such as XRD, IR and SEM spectroscopy. SEM micrographs indicate that V2O5 is homogeneously distributed in the PPy. IR spectroscopy reveals that the characteristic stretching frequencies are shifted towards lower frequency side, as compared to pure PPy. XRD micrographs indicate that PPy-V2O5 have many aggregated pores which have been reduced due to homogeneous distribution of V2O5 in PPy. The ac conductivity is studied in the frequencies 102 to 107 Hz. It is observed from the ac conductivity studies that the ac conductivity is found to be constant up to 106 Hz and there after it increases steeply which is a characteristic feature of disordered materials. © 2007 Elsevier B.V. All rights reserved.