Preparation of click-driven cross-linked anion exchange membranes with low water uptake

摘要

Significant advancement in anion exchange membrane (AEM) fuel cell (AEMFC) technology is important in the field of renewable energy.AEMs with comb-shaped architectures have attracted considerable research interest because of some unique features,including high anion conductivity,low swelling,and high alkaline stability.Here,we report preparation,characterization,and performance evaluation of a novel comb-shaped cross-linked AEM synthesized by the thiol-ene click and Menshutkin reactions.The prepared ionomer decreases the trade-off between the water uptake and the conductivity.The thiol-ene click reaction was used to synthesize the 1,14-di(1H-imidazol-1-yl)-6,9-dioxa-3,12-dithiatetradecane (IDDT) cross-linker.IDDT was then introduced into the brominated poly(2,6-dimethyl-1,4-phenylene oxide) backbone by the Menshutkin reaction.The prepared ionomers show high thermomechanical stability,which is needed in AEMFC technology.The CLINK-15-100 membrane (ion exchange capacity 1.23 mmol/g) shows relatively good conductivities of 19.66 and 34.91 mS/cm at 30 and 60℃,respectively.Interestingly,the membrane shows water uptake of only 14.22％ at room temperature,which is considerably lower than many previously reported membranes.After 1 6 days of alkaline treatment in 1 M NaOH solution at 60 ℃,the CLINK-15-100 membrane retains 77％ of its initial conductivity,which is much better than the traditional quaternized poly(2,6-dimethyl-1,4-phenylene oxide) membrane.