DIELECTRIC-RELAXATION STUDIES OF ION MOTIONS IN ELECTROLYTE-CONTAINING PERFLUOROSULFONATE IONOMERS .1. NAOH AND NACL SYSTEMS

Nafion perfluorosulfonate membranes were equilibrated in concentrated aqueous NaOH and NaCl solutions, and the dielectric response of these electrolyte-imbibed materials was investigated with an impedance analyzer. The storage and loss components of the complex dielectric constants were determined over the frequency range 5 Hz to 13 MHz as a function of external solution concentration and temperature. The observed dielectric behavior, coupled with the knowledge of polymer microphase separation, strongly suggests a mechanism of the relaxation of an interfacial polarization that arises from the accumulation and dissipation of mobile ionic charge, between electric field reversals, at the boundaries of clusters along the direction of the external applied field.