Perfluorosulfonic Acid Polymer Membranes: Microstructure and Basic Functional Properties

The progress of modern technologies and the requirements imposed on the production ecology demand the development of new ion-exchange membrane polymer materials with a set of desired properties. These materials are used in liquid and gas separation and purification systems, chemical and electrochemical syntheses, and alternative energetics. Membrane materials based on perfluorosulfonic acid polymers (PFSA) possess a set of characteristics necessary for their practical application: high ionic conductivity and selectivity and good chemical stability, strength, and elasticity. This review addresses the microstructure of PFSA membranes and its change induced by water and solvent uptake and discusses the features of ion and gas transport, mechanical properties, and the dependence of a number of parameters on polymer chain length and ionic form.