INFLUENCE OF THE CATION SIZE ON THE CHARGE COMPENSATION PROCESS IN POLY(1-NAPHTHOL) COATED ELECTRODES - MULTIPLE INTERNAL-REFLECTION FTIR SPECTROSCOPY (MIRFTIRS) AND PROBE BEAM DEFLECTION (PBD) STUDY

The electrochemical oxidation-reduction process of poly(1-naphthol) (poly(NAP-1) film was studied by in situ FTIR spectroscopy and probe beam deflection techniques. On oxidation, the polymer film is positively charged and on reduction, it is in its neutral form. It is demonstrated that the charge compensation process depends on the electrolyte cation size. With bulky cations the role of the charge compensation is taken by the anion. With small cations a mixed contribution of anions and cations to the process is observed. Anion exchange is predominant al short periods (seconds) but cation exchange is also involved if one waits until equilibrium is established after several minutes.