Permselectivity of films prepared by electrochemical oxidation of phenol and amino-aromatic compounds

Abstract

A selective permeability of the polymers—being derived by electrochemical polymerization from phenol and amino-aromatic compounds—to the various oxidation-reduction species dissolved in the solution was investigated by means of hydrodynamic voltammetry at a rotating disk electrode. Selective permeability was varied with the kind of polymer films coated on the electrode and the kind of ions dissolved in the solution. The films prepared had high permeability to hydrogen ion because of their small size, but inhibited the diffusion of large, highly charged ions (e.g. Fe 2+, Eu 3+) to the electrode surface. It is demonstrated that platinum electrodes coated with these films can be used as a pH sensor, since they respond selectively to hydrogen ion even in a test solution containing some transition metal ions.