The influence of supporting electrolytes upon the "heterogeneous" electron‐transfer rate of the redox couple ( and MV +̣ are the dication and monocation of viologen sites, respectively, in polymer coatings) as poly(methylviologen) (PMV), poly(methylviologen)‐Nafion complex (PMV‐Nafion), and poly(methylviologen)‐poly(p‐styrenesulfonate) complex (PMV‐PSS), which were attached to basal‐plane pyrolytic graphite electrodes, as well as upon the "homogeneous" charge‐transport rate within these polymer films was examined by the normal pulse voltammetry. The values of standard rate constant and cathodic transfer coefficient (α) of the heterogeneous electron‐transfer process changed with the supporting electrolytes used. The values of the apparent diffusion coefficient for the homogeneous charge transport also changed with the supporting electrolytes. The relationship between the size of the counterion and was found not to be simple. The , , and α tended to decrease, though not monotonously, with an increase in or , irrespective of the kind of supporting electrolyte, where , , and are the concentration of the electroactive viologen site as PMV and the concentrations of the sulfonyl group as Nafion and PSS, respectively. For a given supporting electrolyte and under the conditions of the same ratio of and , the , , and α obtained with the PMV‐Nafion system were different from those obtained with the PMV‐PSS system. Furthermore, a linear correlation between and was observed. On the basis of the results obtained, the influence of the supporting electrolytes and the polymer morphology upon the heterogeneous electron transfer and the homogeneous charge transport is discussed.
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Ohsaka et al. (1985) studied this question.