Ion Conduction in Solid Polyelectrolyte Complex Ma

Authors: Cornelia Cramer Monika Schönhoff

Publish Date: 2013

Volume: , Issue: , Pages: 97-138

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Abstract

This chapter describes the progress made in understanding the mechanisms of ion conduction in polyelectrolyte complexes PEC Understanding of ion dynamics is based on frequencydependent conductivity data obtained by impedance spectroscopy as a function of temperature hydration and composition In most of the work strong polyelectrolytes such as polyalkali 4styrene sulfonate AlkaliPSS and polydiallyldimethyl ammoniumchloride PDADMAC are employed forming complexes of type xAlkaliPSS · 1 − x PDADMAC The dc conductivity is always determined by the alkali ions which exhibit a sizedependent mobility This holds even in PEC with an excess of PDADMAC The ion dynamics and transport mechanisms are different in PDADMACrich and in NaPSSrich PEC We review the treatment of the frequencydependent shape of conductivity spectra by scaling concepts and by models involving forward–backward hopping motions of small ions as well as localized motions of charges Thus many quantitative concepts established in other disordered ion conductors can be transferred to PEC In addition to the wellknown time–temperature superposition principle TTSP the novel concept of time–humidity superposition THSP was established for PEC and describes the dependence of ion dynamics on water content

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