Manifestation of electrolyte ion size effect on electrochemical behavior of poly(ferrocenylsilane) films

Abstract The influences of supporting electrolyte ion size on the cyclic voltammetric (CV) behavior of high‐molecular‐weight poly(ferrocenylsilane) films in organic solvents were investigated. Three supporting electrolytes with various ion sizes were tested. Electrolyte anions, as counter ions, take part in charge neutrality in the films, so that the size of anion affects the CV behavior of the films remarkably. The large anions are difficult to penetrate into the films, the resistances of the large ions migrating in films are more, the rates of the electroactive species diffusing in the films are slow, and the CV behavior of the polymer films exhibit irreversible features. The electrolyte cations do not take part in charge neutrality in the films, so that the size of cation does not actually affect the CV behavior of the films. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 515–523, 2006