Organic solvent resistant Kevlar nanofiber-based cation exchange membranes for electrodialysis applications

Abstract

The development of organic solvent resistant ion exchange membranes (IEMs) with high ion conductivity is of significance for broader electrodialysis (ED) applications. In this work, a series of organic solvent resistant cation exchange membranes (CEMs) has been fabricated by splitting Kevlar fabrics into small and short nanofibers, followed by modifying with 4-amino-benzenesulfonic acid monosodium salt (ABS) and poly(4-styrenesulfonic acid-co-maleic acid) sodium salt (PSSMA) eater via amide condensation. By tuning the content of ABS, the as-prepared poly-p-phenylene terephthalamide sulfonated polymer (PAP) CEMs (PAP-CEMs) show high ion exchange capacities (up to 2.23 mmol⋅g−1), good electrochemical performance and desired capacity of cation/anion separation in ED. To evaluate the organic solvent resistance of as-prepared CEMs, PAP-CEMs were immersed in ethanol and acetone aqueous solutions for 48 h at room temperature, respectively. The investigation demonstrates that ED with the treated CEM (the optimized PAP-0.50 CEM) still exhibits high desalination efficiencies (81.2%, in 60% (Vethanol/Vwater) ethanol solution; 82.3%, in 60% (Vacetone/Vwater) acetone solution) and concentration efficiencies (57.4%, in 60% ethanol solution; 50.9%, in 60% acetone solution). As a result, it is believed that the study here highlights a design of simple route for the preparation of CEMs, which can be potentially applied in ED for organic solvent solution systems.