Title of Paper:Tri-quaternized poly (ether sulfone) anion exchange membranes with improved hydroxide conductivity

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Date of Publication:2016-09-15

Journal:JOURNAL OF MEMBRANE SCIENCE

Included Journals:SCIE、EI、Scopus

Volume:514

Page Number:613-621

ISSN No.:0376-7388

Key Words:Anion exchange membrane; Fuel cells; Poly (ether sulfone); Micro-phase separation; Hydroxide conductivity

Abstract:A novel anion exchange membrane with tri-quaternized side chain has been developed in the present work. Di-cationic quaternary ammonium salt, 1-(4'-{1"-azonia-4"-azabicyclo [2.2.2] octyl} butyl) azonia-4-azabicyclo [2.2.2] octane (AABAA), is synthesized and used as tri-quaternization reagent. The tri-quaternized side chains enhance ionic interactions, which induce good micro-phase separation and excellent swelling resistance. Better aggregation of ionic clusters is observed in transmission electron microscopy (TEM) image in the tri-quaternized poly (ether sulfone) membrane (tri-QPESOH) compared to that in the mono-quaternized membrane (mono-QPESOH). Tri-QPESOH membranes achieve a well-balanced performance between high hydroxide conductivity and dimensional stability. Especially, the tri-QPESOH membrane with IEC 2.31 mmol g(-1) exhibits high hydroxide conductivity of 45.9 mS cm(-1) at 25 degrees C and 130.9 mS cm(-1) at 80 degrees C, and low swelling ratio of 21.5% even at 80 degrees C. Tri-QPESOH membranes also show improved thermal, mechanical and chemical stabilities. These observations suggest that the tri-cationic side chains provide a promising solution to the electrochemical-mechanical balance of anion exchange membranes. (C) 2016 Elsevier B.V. All rights reserved.