Krishnan, N. Nambi Henkensmeier, Dirk Jang, Jong Hyun Kim, Hyoung-Juhn Ha, Heung Yong Nam, Suk Woo 2024-01-20T13:02:55Z 2024-01-20T13:02:55Z 2021-09-01 2013-02 0360-3199 https://pubs.kist.re.kr/handle/201004/128417 A new alkyl chain modified sulfonated poly(ether sulfone) (mPES) was synthesized and formed into membranes. The MEAs were tested in the PEMFC and evaluated systematically in the DMFC by varying the methanol concentration from 0.5 to 5.0 M at 60 degrees C and 70 degrees C. The synthesized mPES copolymer has been characterized by nuclear magnetic resonance spectroscopy, fourier transform infrared spectroscopy, thermogravimetric analysis, and gel permeation chromatography. The proton conductivity of the resulting membrane is higher than the threshold value of 10(-2) S cm(-1) at room temperature for practical PEM fuel cells. The membrane is insoluble in boiling water, thermally stable until 250 degrees C and shows low methanol permeability. In the H-2/air PEMFC at 70 degrees C, a current density of 600 mA cm(-2) leads to a potential of 637 mV and 658 mV for 50 mu m thick mPES 60 and Nafion NRE 212, respectively. In the DMFC, mPES 60's methanol crossover current density is 4 times lower than that for Nafion NRE 212, leading to higher OCV values and peak power densities. Among all investigated conditions and materials, the highest peak power density of 120 mW cm(-2) was obtained with an mPES 60 based MEA at 70 degrees C and a methanol feed of 2 M. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. English Pergamon Press Ltd. Alkyl chain modified sulfonated poly(ether sulfone) for fuel cell applications Article 10.1016/j.ijhydene.2012.12.008 1 International Journal of Hydrogen Energy, v.38, no.6, pp.2889 - 2899 International Journal of Hydrogen Energy 38 6 2889 2899 N scie scopus 000315616400032 2-s2.0-84873167866 Chemistry, Physical Electrochemistry Energy & Fuels Chemistry Electrochemistry Energy & Fuels Article PROTON-EXCHANGE MEMBRANES POLYMER ELECTROLYTE ETHER KETONE) COMPOSITE MEMBRANES PERFORMANCE IONOMER POLYIMIDES Alkyl chain modification Poly(ether sulfone) Fuel cell membrane Proton exchange membrane fuel cell Direct methanol fuel cell