Synthesis and characterization of polypyrrole nanofibers with different dopants

Nanostructures of polypyrrole (PPy) were synthesized in the presence of different dopants including hydrochloric acid (HCl), ferric chloride (FeCl(3)), p-toluene sulfonic acid (p-TSA), camphor sulfonic acid (CSA), and polystyrene sulfonic acid (PSSA), using a simple interfacial oxidative polymerization method. The method is a reliable non-template approach with relatively simple instrumentation, ease of synthesis, and economic viability for synthesizing PPy nanostructures. Morphology of synthesized PPy structures was investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which indicate the formation of one-dimensional (1D) nanofibers with average diameter of 75-180 nm. Energy dispersive spectrum (EDS) of the PPy nanofibers indicates the attachment of the dopants to the PPy backbone; the fact is further confirmed by the Fourier transform infrared (FTIR) spectra of PPy nanostructures. Thermal stabilities of the nanostructures explored using thermal gravimetric analysis (TGA) follow the order PPy-p-TSA > CSA > HCl > FeCl(3) > PSSA. It is noticed that the electrical conductivity (EC) of PPy nanostructures depends upon the nature of dopant (PPy-p-TSA > CSA > HCl > FeCl(3) > PSSA), PPy-p-TSA nanofibers showing the highest EC of 6 x 10(-2) Scm(-1). Copyright (C) 2009 John Wiley & Sons, Ltd.