Separation of ionic and solvent transport during charge compensation processes in electroactive polymers by a.c. electrogravimetry

Simultaneous measurement of the faradaic impedance and electrogravimetric t ransfer function during the redox reactions of a polymer in HClO4 allows an ions, cations and solvent contributions to the charge compensation processe s to be separated and their insertion/expulsion rate to be evaluated. A mod el of the transport processes in the polymer and the charge transfer kineti cs of the ions and solvent at the polymer/solution interface is proposed. For the polymers and experimental conditions investigated, it was shown tha t the anions are generally inserted and the solvent generally expelled. Con cerning the cations or species related to cations. e.g. hydronium ions, the y can be either inserted or expelled. (C) 1999 Elsevier Science Ltd. All ri ghts reserved.