Reinforcing fabrics as the mechanical support of ion exchange membranes

Abstract

Mechanical, physical and electrochemical characteristics are one of the important properties of ion exchange membranes. These parameters are required for a next operation and for an application in an electrodialysis (as tightness of a stack, energy consumption, capacity of electrodialysis). The goal of this article is comparison of the influence of the different reinforcing fabric on the properties of ion exchange membranes. Six types of ion exchange membranes with the nonwoven fabric, the monofilament knit, the multifilament knit, the monofilament woven fabric, the multifilament woven fabric, and for comparison non-reinforcing ion exchange membranes were chosen. The most important properties of a fabric in this application are thickness, free area related to the warp and the weft, mechanical strength, the material (shrinkage), type of fabric (plain or twill weave, a knit, monofilament, multifilament) and of course price. Electrochemical, physical and mechanical properties of ion exchange membranes were studied. Non-reinforcing ion exchange membranes have lower mechanical strength, but the best elongation. These ion exchange membranes report big relative dimension changes after swelling in demineralized water and the lowest value of the areal resistance. The most appropriate ion exchange membrane is with woven fabric from monofilaments after comparison with other ion exchange membranes in terms of the quality of the lamination and other electrochemical, physical and mechanical parameters.