Effect of Pb2+ and Cu2+ as a codopant on the structure, morphology and conductivity of nanostructured polyaniline

Polyaniline (PANI) has been successively synthesized in aqueous diethylene glycol solution medium by chemical oxidative polymerization of aniline using ammonium peroxidisulfate [(NH4)(2)S2O8] as an oxidant in an aqueous solution of 0.5M acetic acid (CH3COOH) as a dopant. Polyaniline-lead (PANI-Pb) and polyaniline-copper (PANI-Cu) nanocomposites have been chemically prepared for the first time by oxidative polymerization of aniline in aqueous diethylene glycol/acetic acidic medium. The synthesized PANI and nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR). Conductivity measurements of the polymer and nanocomposites were performed using the four-probe technique. Morphology changes of the composites were investigated by scanning electron microscopy (SEM). PANI nanotubes were formed without added codopant, but when Pb(CH3COO)(2) or Cu(CH3COO)(2) was added as a codopant, the morphology of PANI obviously changed. The PANI-Cu and PANI-Pb nanocomposites exhibit higher conductivity than the PANI homopolymer, but the conductivity of the composites slightly decreased on increasing the metal concentrations.