A STUDY ON ION TRANSPORTS AND GROWTH OF CONDUCTING POLYPYRROLE WITH ELECTROCHEMICAL QUARTZ-CRYSTAL MICROBALANCE

Growth of polypyrrole and ion exchange processes in the polypyrrole we re investigated by an electrochemical quartz crystal microbalance for various electrolytes. The polymer was deposited potentiodynamically or potentiostatically on a gold film electrode. The mass change associat ed with insertion and expulsion of ions in the polymer matrix with suc cessive potential scans at the electrode and during the growth of the polymer were monitored in situ. The observation supports that insertio n of anions ink, polymer matrix in CH3CN occurs for anodic polarizatio n and expulsion of the same ion for cathodic polarizaiton. However, ch arge compensation occurs also by cations in aqueous electrolyte even w hen the polymer is composed of small dopant anions. Also, it is found that growth of polymer is much faster and induction period is much sho rter in H2O than in CH3CN.