Ml. Shi et Fc. Anson, EFFECTS OF HYDRATION ON THE RESISTANCES AND ELECTROCHEMICAL RESPONSESOF NAFION(R) COATINGS ON ELECTRODES, Journal of electroanalytical chemistry [1992], 415(1-2), 1996, pp. 41-46
Procedures are described for coating electrodes with films of Nafion(R
) that are saturated with Os(bpy)(3)(2+) and exist in one of two limit
ing states: fully hydrated or dehydrated. The anodic electrochemical r
esponses from Os(bpy)(3)(2+)-saturated, dehydrated coatings include un
usual spiked features that are the result of the initially high ionic
resistance of such coatings. Electro-oxidation of such coatings leads
to immediate decreases in resistance as one-third of the Os(bpy)(3)(2) counterions are ejected and large quantities of H2O molecules are in
corporated by the coatings. On the basis of quartz crystal microgravim
etric, a.c. impedance, and voltammetric measurements, a model is propo
sed for the internal structures of Nafion(R) coatings which accounts f
or their observed behavior.