Hink, Steffen Henkensmeier, Dirk Jang, Jong Hyun Kim, Hyoung-Juhn Han, Jonghee Nam, Suk-Woo 2024-01-20T07:01:23Z 2024-01-20T07:01:23Z 2021-09-05 2015-06 1022-1352 https://pubs.kist.re.kr/handle/201004/125371 A biaxial modification process to reduce the in-plane swelling of perfluorosulfonic acid polymers is demonstrated for Nafion 212 membranes. The process is based on the one-way shape memory effect of the polymer, which can be installed by drying under constrained conditions and observed by water swelling. The through-plane/in-plane swelling ratio at 30 degrees C for treated Nafion 212 increases from 1.4 to 5.8 (ex situ) and approximate to 25 (after humidity cycling in a fuel cell). Young modulus and tensile strength increase. X-ray diffraction analysis shows an increase of crystallinity. The influence on through- and in-plane proton conductivity is studied. Finally, fuel cell tests are presented. The results suggest that the process enhances the durability of fuel cell systems under changing humidity conditions. English John Wiley & Sons Ltd. Reduced In-Plane Swelling of Nafion by a Biaxial Modification Process Article 10.1002/macp.201500063 1 Macromolecular Chemistry and Physics, v.216, no.11, pp.1235 - 1243 Macromolecular Chemistry and Physics 216 11 1235 1243 N scie scopus 000355699600010 2-s2.0-84930380134 Polymer Science Polymer Science Article POLYMER ELECTROLYTE MEMBRANE STRETCHED RECAST NAFION(R) PEM FUEL-CELLS MECHANICAL-PROPERTIES TEMPERATURE CONDUCTIVITY MORPHOLOGY TRANSPORT HUMIDITY IONOMERS direction of swelling ionomers polymer electrolyte membrane fuel cell shape memory effect wide-angle x-ray scattering