Formulation and Characterization of Novel Hierarchical Ion Exchange Membranes for Electrodialysis Application - EXCEED
Electro-membrane processes are critical for implementing an effective water circular economy. Among these, electrodialysis (ED) is considered a convenient choice for blackish water desalination, wastewater treatment (in view of resource recovery), trace contaminants removal and fractionation of specific metals (Li+, Mg+, …). Currently, the development of ED processes is hindered by the high cost of the system, which largely comes from ion exchange membranes. Such membranes are used in the system to separate charged species through the application of an electric field. Ionic conductivity and selectivity, chemical and thermal stability are membrane properties determinant for the process effectiveness. The EXCEED project will focus on developing an ion exchange coating for a porous substrate, to fabricate a hierarchical ion exchange membrane and integrate it in an ED system. The use of a porous substrate as a baking for the ion exchange layer will bring two main advantages: (1) it will allow thinner layers of ion exchange material, compared with a typical self-supported membrane, increasing the membrane conductivity and thus the energy efficiency of the ED system; (2) the less demanding mechanical properties for the ion exchange layer will enable the use of low cost precursors for its formulation, leading to a competitive cost material. EXCEED will investigate chemistries and fabrication processes for innovative ion exchange membranes. The membrane prototypes will be extensively characterized both from a physiochemical and electrochemical point of view, to understand the correlation between the polymer structure and electrochemical properties. The most promising materials will be tested in laboratory scale ED experiments, to validate them for the targeted application. EXCEED will not only push the boarders of ion exchange membranes chemistry and fabrication, but also boost the use of sustainable membrane processes where now their capital cost is limiting.