An electrochemical impedance and ac-electrogravimetry study of PNR films in aqueous salt media

Electrochemical impedance spectra and ac-eletrogravimetry of poly(neutral red) films are studied in different aqueous media. The dependence of these experimental data on the nature of alkaline cation and monovalent anion present in the solution and on the pH is analysed. During the electrochemical processes, it is observed that all three species - the salt cation, the salt anion and the hydronium ion - participate to balance the electrical charge within the film. It is also possible to conclude that the participation of anions takes place faster than hydronium ions participation. Besides, the relative participation of these species is related to the pH of the solution. (C) 2002 Elsevier Science B.V. All rights reserved.