Organic Solvent-Resistant and Robust Kevlar Nanofiber-Based Cation-Exchange Membranes for Improved Electrodialysis Performance

Abstract

With the increasingly serious pollution of organic solvents, the development of durable resistance of organic solvents and robust ion-exchange membranes is of great significance for specific electrodialysis processes. In this work, a series of resistant organic solvent cation-exchange membranes (CEMs) have been prepared by using small and short Kevlar nanofibers modified with the poly­(4-styrene sulfonic acid-co-maleic acid) sodium salt and polyethyleneimine via amide condensation. The investigation demonstrates that the as-prepared Kevlar nanofiber-based CEM (PP-K-5.0 CEM) exhibits a high tensile strength of 142.23 MPa and good electrochemical performance. To evaluate the stability of the desalination performance of the prepared CEM in the organic solvent, the CEM was immersed in acetone and ethanol aqueous solutions at room temperature for 7 d. As for the evaluation of CEM performance, electrodialysis with treated CEM (PP-K-5.0 CEM) can achieve high desalination efficiencies (84.5% in 90% ethanol solution and 85.4% in 90% acetone solution) and concentration efficiencies (90.7% in 90% ethanol solution and 87.5% in 90% acetone solution), respectively. The results indicate that this work could provide a design route for preparing robust CEMs, which is potentially applied in desalination systems containing organic solvents.