Hink, Steffen Ngoc My Hanh Duong Henkensmeier, Dirk Kim, Jin Young Jang, Jong Hyun Kim, Hyoung-Juhn Han, Jonghee Nam, Suk-Woo 2024-01-20T06:34:37Z 2024-01-20T06:34:37Z 2021-09-04 2015-07 0167-2738 https://pubs.kist.re.kr/handle/201004/125300 Polysulfone-based membranes with pyridine (PY) side chains, crosslinked by imidazole (IM) groups, are synthesised, doped with phosphoric acid (PA) and characterised in the hydrogen/air fuel cell at 160 degrees C. It is shown that the bisphenol A (BPA) group of Udel P-3500 (Solvay) acts as a breaking point, and Radel R-5000 NT (Solvay)-based membranes, in which BPA is substituted for biphenyl, show superior stability. Undoped membranes show thermal stability of up to 330 degrees C (3% weight loss, 10 degrees C/min, nitrogen). PA-doped membranes: The weight gain during acid doping is limited by the high crosslink density, and independent of the doping temperature. By varying the ratio of pyridine to imidazole units from 2:1 to 9:1, the PA uptake can be controlled between 200 and 500 wt%, respectively. The Young modulus increases with the crosslinking density from 12 to 129 MPa. Proton conductivity of the PY/IM 2:1 membrane at 160 degrees C reaches 59 mS/cm. In the fuel cell, the PY/IM 2:1 membrane achieved a potential of ca. 500 mV at 0.2 A/cm(2). After 430 h (330 h at 02 A/cm(2), then 0.4 A/cm(2)), the cell failed, and postmortem analysis suggested severe chemical degradation. Washing the membrane with ammonia solution before doping increased the stability further. (C) 2015 Elsevier B.V. All rights reserved. English Elsevier BV Radel-based membranes with pyridine and imidazole side groups for high temperature polymer electrolyte fuel cells Article 10.1016/j.ssi.2015.03.026 1 Solid State Ionics, v.275, pp.80 - 85 Solid State Ionics 275 80 85 N scie scopus 000355372700018 2-s2.0-84934315945 Chemistry, Physical Physics, Condensed Matter Chemistry Physics Article DOPED POLYBENZIMIDAZOLE MEMBRANES AROMATIC POLYETHERS CROSS-LINKING DURABILITY HT PEMFC Radel Pyridine Crosslinked membrane Phosphoric acid doping