Ionic Membranes

Abstract

Ionic membranes made of both natural and synthetic polymers have been developed for over 50 years and currently comprise a wide range of applications. In comparison with traditional industrial separation processes, such as adsorption, extraction, and distillation, membrane technology has inherent advantages (e.g., less reagent and solvent consumption, no chemical additives, and recyclability), leading to reduced energy consumption while the performance of the separation processes increases. The performance of ion exchange membranes can be assessed based on the following aspects: flux and selectivity, cost of production, thermal and chemical stability, and mechanical strength. These properties are essentially related to the chemical and physical nature of polymers. In the last few decades, the design of materials that are able to combine high ionic conductivity and durability, good mechanical strength, reduced permeability, and low cost for high-volume production has become one the major challenges in the field of new polymer materials for electrodialysis applications. Therefore, the main objective of the present chapter is to give a brief summary of the different materials, properties and characterization of ionic membranes as well as of the synthesis of electrodialysis membranes.