A Comparative Study of Potentiodynamic and Potentiostatic Modes in the Deposition of Polyaniline

The electrodeposition of polyaniline films was performed under potentiodynamic and potentiostatic conditions. Cyclic voltammetry shows that the redox electrochemical behavior changed from quasi‐reversible to totally irreversible with increasing aniline concentration. In terms of the kinetics of the nucleation and growth processes in the potentiostatic deposition mode, progressive nucleation with two‐dimensional growth is predominant, followed by one‐dimensional growth leading to the formation of a fibrous structure. The overall polymer growth rates and the morphology of polymer surfaces are very different depending on the deposition method. The morphology associated with the kinetics is correlated with those experimentally determined by scanning electron microscopy and atomic force microscopy. Conductivity of the potentiostatically grown film is lower than the one potentiodynamically grown. The observed decrease in conductivity appears to be linked to a decrease in the charge carrier mobility due to the agglomerated structures that are formed during secondary growth.