ELECTROCHEMICAL PROPERTIES OF POLYPYRROLE SULPHATE FILMS/

The peculiarity of polypyrrole/sulphate (PPy/SO4) films redox behaviou r has been investigated by cyclic voltammetry and electron probe micro analysis. The changes in PPy/SO4 film ionic composition during the red ox process, especially the influence of electrolyte cations on its red ox properties, were studied in detail. It was established that in the solutions of double charged metal- or bulky tetraalkylammonium cations the redox activity of PPy/SO4 film is suppressed, its mechanism is sp eculated on the basis of the film's morphological peculiarity (compact structure), hydration radii and energy of moving ions, also the aggra vations to effective charge balanced intermediate states during redox cycling are taken into account. In the case of tetraalkylammonium ions instead of the charge compensation problem the hydrophilic nature of PPy/SO4 film, and on the other hand the hydrophobicity of cations, cau ses additional kinetical aggravations or even suppression of film elec troactivity. (C) 1997 Published by Elsevier Science Ltd.