Synthesis of Microwires of Polypyrrole via Chemical Polymerization using Track Etch Membrane as Template

Abstract

Low dimensional structures of conducting polymers, particularly polypyrrole, have attracted a great attention of researchers and engineers in recent years because of their diverse potential application on account of their unique properties of large aspect ratio, good electrical conductivity, environmental stability and biocompatibility. The present work describes synthesis of polypyrolle microwires by template assisted chemical polymerization at room temperature using FeCl3 as an oxidant. In this technique, the track etch membrane used as a template was fitted between two chambers in a chemical cell in such a way that the template acts as a separating wall between the chambers. One chamber was filled with an aqueous monomer pyrrole solution and other was filled with oxidant reagent of ferric chloride. Chemical polymerization takes place within the pores of the template as the monomer and the oxidant reagent diffuse towards each other, react to yield the conductive polymer which grows as microstructure in the shape of pores of host template. Synthesized samples have been characterized by Scanning Electron Microscopy (SEM), which reveals that the morphology of the microwires matches with the morphology of pores as mould in host template. Diameter, orientation and direction of growth of microwires were almost uniform because of the confined growth of microwires in the ordered and symmetric pores of TEM template. Conductivity of polypyrrole microwires was estimated equal 20.152 S/m form current-voltage characteristics measured using a two-probe-method.