In-situ preparation of cross-linked hybrid anion exchange membrane of quaternized poly (styrene-b-isobutylene-b-styrene) covalently bonded with graphene

Introducing graphene into polymer matrix is an effective way to enhance performances of anion exchange membrane (AEM). However, utilizing the advantages of graphene by physical approach is limited due to the weak interface interaction between graphene and polymer matrix. Herein, we report an effective strategy to covalently bond graphene with polymer matrix to improve the interface interaction and further to improve the properties of AEM. A series of cross-linked quaternized graphene-based hybrid AEM were fabricated by covalently bonding poly (vinylbenzyl chloride) grafted graphene (GN-g-PVBC) copolymer with chloromethyl functionalized poly (styrene-b-isobutylene-bstyrene) (SIBS) through the cross -linker (N,N,N',N'-tetramethyl-1,6-hexanediamine) by in -situ synthetic approach. The interface interaction between graphene and QSIBS is greatly enhanced according to micromorphology characterization of the hybrid membrane. The cross -linked quaternized hybrid AEM containing 0.55 wt% of GN-g-PVBC exhibits obviously improved dynamical mechanical properties (storage modulus: 418 MPa), ion conductivity (1.81 x 10(2) S cm(-1)), methanol barrier property (5.19 x 10(-7) cm(2) s(-1)), selectivity (3.49 x 10(4) S s cm(-3)) at 60 degrees C and especially a comparably excellent chemical stability to that of Nafion 115 due to the enhanced interface interaction between graphene and the polymer matrix. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.