Effect of monomer concentration and substrate resistance on redox behaviour of polyaniline films

Abstract

The effect of monomer concentration and substrate resistance on the redox properties of polyaniline is investigated using cyclic voltammetry, The mechanism of polymerization is found to be affected drastically by the concentration of monomer while the influence of substrate resistance seems to become a predominant factor only at higher concentration. Both these parameters in combination are found to be responsible for the flattening of cyclic voltammograms due to a significant contribution of the uncompensated ohmic resistance. The extent of reversibility is observed to be a strong function of scan rate and the optimum oxidation-reduction transformation occur at a scan rate of 100 mV s^-at moderate monomer concentrations. Additionally, from the optical spectra it is observed that 0.2 M monomer concentration is seen to be appropriate for obtaining selectively the conducting phase of the polymer.