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论文类型：期刊论文

发表时间：2020-01-22

发表刊物：ACS APPLIED MATERIALS & INTERFACES

收录刊物：PubMed、EI、SCIE

卷号：12

期号：3

页面范围：3510-3521

ISSN号：1944-8244

关键字：ether-containing cross-links; anion-exchange membrane; DABCO; conductivity; stability

摘要：Anion-exchange membranes (AEM) with high ion content usually suffer from excessive water absorption and dilution effects that impair conductivity and mechanical properties. We herein report a novel ether containing a cross-linking strategy without adopting high ion-exchange capacity (IEC). The ether-containing cross-links and the quaternized structure are created simultaneously by introducing an ether-containing flexible hydrophilic spacer between two 1,4-diazabicyclo[2,2,2,2]octane or DABCO molecules; the resultant bi-DABCO structure was further employed to react with chloromethylated polysulfone. The long spacer with the ether moiety may benefit the hydroxide ion transport, and the cross-links will control the swelling and water absorption of the AEM. The two ether groups in the long spacer of the cross-links will also shield the DABCO cation from OH- attack due to an electron-donating effect. The prepared membranes exhibited an improved conductivity of 31 mS/cm (at 25 degrees C) at a comparatively low IEC (1.08 mmol/g) with a rational water absorption and low swelling ratio (95.0 and 27.1%, respectively); they also displayed an enhanced alkaline stability in 1 M NaOH aqueous solution at 80 degrees C for 150 h. The density functional theory study and physical characterization after the alkaline treatment further confirm the better chemical stability of the cross-linked membrane over its counterpart. Our work presents an effective strategy to balance AEM conductivity and robustness.