QCM ANALYSIS ON ELECTROPOLYMERIZATION OF ELECTROACTIVE POLYANILINE FILM FROM NONAQUEOUS MEDIA

Quartz crystal microbalance (QCM) technique has been employed to characterize an electrochemical formation of electroactive polyaniline film from non-aqueous media which had no acids. The QCM analysis together with cyclic voltammetry has proved that the initial charges up to some ten mC cm-2 were just consumed for the coupling of monomer radicals to form dimers, which accompanies proton release. The protons thus produced during this stage seems to play an important role in subsequent growth rate of an electroactive films. The mechanism will be plausibly explained by the initial oxidation of both aniline monomers and anilinium ions, which may show rather slow equilibrium, to give varieties of coupling among them in non-aqueous solvent. The chemical coupling and the surface morphology of the resulting polyaniline films were confirmed by IR spectroscopy and SEM microscopy.