Graphene-Enabled Nanocomposite Ion Exchange Membranes for Electromembrane Processes

Abstract

Ion exchange membranes have gained considerable attention due to their use in electromembrane processes such as membrane capacitive deionization, fuel cells, flow batteries, chlor-akali process, electrodialysis, etc. IEMs are membranes with charged species that reject or attract ionic species depending on their charges. IEMs are a critical component of electromembrane processes. As a result, multiple studies have been conducted to improve the properties of IEMs for electromembrane processes. One of such approaches involves the use of nanomaterials to prepare nanocomposite IEMs with improved ion exchange properties and performance. Here, we report the incorporation of graphene-based nanomaterials into an uncharged polymeric matrix to create nanocomposite IEMs for electromembrane processes. The graphene-based nanomaterials were modified to transform them into ion exchange carriers, and used as the source of ion exchange capabilities in the nanocomposite IEMs. A newly developed mold-casting technique was used to fabricate nanocomposite IEMs with high content of graphene-based nanomaterials – a strategy that we have not seen reported in literature for preparing IEMs so far. The fabricated nanocomposite IEMs demonstrated favorable physicochemical and electrochemical properties such as ion exchange capacity, permselectivity, water uptake, linear swelling ratio, and area resistance. Tests on an electrodialysis process showed promising results with encouraging salt removal performance, current efficiency for salt removal and energy consumption during salt removal. Overall, the fabricated graphene-enabled nanocomposite

Date of Award	May 2020
Original language	American English