Surface Modification of Polytetrafluoroethylene to Fabricate Reinforced Composite Membranes for Fuel Cells
발표자
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초록
내용
We focus on the development of a reinforced composite membrane that can enhance ionic conductivity by increasing the impregnability of the Nafion ionomer through surface modification of the support polymer which has good physical properties. In this study, the surface of expanded polytetrafluoroethylene (e-PTFE, 5 µm) is modified by plasma and silane treatment. The optimum conditions are observed at 10 W and 100 kHz of Ar plasma for 1 min and 0.5 vol% silane treatment at room temperature for 1 min. After surface modification, the surface of e-PTFE becomes hydrophilic with a contact angle of 65~70o. Therefore, the impregnability of the N-Methyl-2-Pyrrolidone (NMP) solvent-based Nafion inomer is increased. The PTFE/Nafion composite membranes have a tensile strength of 16 N·mm-1 and an elongation at break of 221 %, despite a thickness of less than 29 µm. It also shows an ion conductivity of 0.147 S·cm-1 achieving approximately 80% of commercial Nafion membranes.