A study on the initial growth of polypyrrole on a gold electrode by electrochemical quartz crystal microbalance

Growth of polypyrrole on a gold electrode was investigated by electrochemical quartz crystal microbalance(EQCM) when the polymer was synthesized by applying a constant potential(potentiostatic) or a sweeping the electrode potential(potentiodynamic) between a cathodic limit and an anodic limit. It has been shown that polypyrrole films grow nonlinearly in aqueous solution at the initial stage and finally reach a steady state growth region. The effect of cations on the electrochemical polymerization is more distinct in the potentiodynamic case than in the potentiostatic case. We believe that charge interaction between the cations and cation radical of pyrrole monomer plays an important role at the initial stage of polymerization.