In-situ crosslinking of anion exchange membrane bearing unsaturated moieties for electrodialysis

This study reports the preparation of the in-situ crosslinked anion exchange membrane that does not require the use of crosslinkers or catalysts. A polyelectrolyte bearing flexible unsaturated side chains was synthesized via the Menshutkin reaction with poly(2,6-dimethyl-1,4-phenylene oxide) and N,N-Dimethylvinylbenzylamine.The crosslinked derivatives were then prepared by the thermal crosslinking of the unsaturated side chains during the membrane formation process. This approach incorporates crosslinks, bearing quaternary ammonium cations, between the polymer chains in order to mitigate against excessive water swelling, and to enable the high ion contents to provide favorable low resistance of ion transport. Additionally, the resultant dense crosslinked network has the additional advantage of improving anion selective permeability of membrane. When being applied in ED application, the crosslinked membranes exhibit much higher desalination efficiency than commercial Neosepta AMX membrane, suggesting its potential application in ED. (C) 2015 Elsevier B.V. All rights reserved.