1. Cross-Linker Effect in ETFE-Based Radiation-Grafted Proton-Conducting Membranes.
- Author
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Gubler, Lorenz, Hicham Ben Youcef, Gürsel, Selmiye Alkan, Wokaun, Alexander, and Scherer, Günther G.
- Subjects
STYRENE ,FUEL cells ,ENERGY storage ,PROTONS ,ELECTRIC conductivity ,ELECTRIC batteries ,OHMIC contacts ,ELECTROCHEMISTRY ,DIRECT energy conversion - Abstract
Cross-linking of styrene grafted and sulfonated fuel cell membranes is essential to obtain well-performing and durable membranes. In this study, the properties and fuel cell performance of radiation grafted membranes based on poly(ethylene-alt-hexafluoropropylene) (ETFE) (25 μm) with different extent of cross-linking, using divinylbenzene (DVB) as a cornonorner to styrene, were investigated. The water uptake and proton conductivity decrease as a function of increasing the extent of cross- linking. Also, the membranes become more brittle. Fuel cell performance is limited by the high ohmic resistance of the membrane at high degrees of cross-linking, whereas at low degrees of cross-linking the membrane-electrode interface is of poor quality. Optimum performance is obtained at an extent of cross-linking corresponding to a styrene:DVB monomer ratio (v/v) of 95:5 in the grafting solution. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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