International Journal of Hydrogen Energy, Vol.45, No.37, 18716-18730, 2020
New non-fluoridated hybrid proton exchange membranes based on commercial precursors
New hybrid proton conducting membranes based on sulfonated copolymers of styrene and allyl glycidyl ether using tetraethyl orthosilicate were syntheses. The composition and structure of the copolymers and membranes has been proven by elemental analysis, IR and NMR spectroscopy. Based on quantum chemical calculations a sulfonation mechanism of copolymers was proposed. The characteristics of membranes were evaluated by thermal analysis, dynamic mechanical analysis, electrochemical impedance spectroscopy, water uptake, swelling and ion exchange capacity tests. The hybrid membranes are characterized by high proton conductivity of 4.21 10(-2) S cm(-1) (70 degrees C, 75% RH), activation energy of proton transport (24.5 kJ mol(-1)), ion-exchange capacity (2.1 mmol g(-1)), and thermal stability up to 260 degrees C. The hybrid membranes showed water uptake of 6 and 51% at 30 degrees C and 100 degrees C, respectively. The suitability of the hybrid membranes toward fuel cell applications was tested through a single cell analysis. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Ion-conducting membranes;Ion-exchange capacity;Sol - gel synthesis;Tetraethyl orthosilicate;Copolymers of styrene with allyl;glycidyl ether