| Summary: | 碩士 === 元智大學 === 化學工程學系 === 91 === Nafion ion exchange membrane is widely used as membrane of polymer electrolyte membrane fuel cell (PEMFC). In this thesis, we prepare Nafion solutions by replacing solvents of Nafion solutions with methanol/H2O, ethanol/H2O, propanol/H2O, and DMF (N,N-dimethyl formamide) solvents.The Nafion/alcohol/ H2O solutions were evaporated at room temperature to prepare Nafion membranes, which were brittle and had poor mechanical properties. However, these membranes crystallized after annealing at 120℃. The Nafion/DMF solutions were evaporated at 120℃ to prepare membranes. DSC and WAXD data revealed that the degree of crystallinity of Nafion membrane increased with increasing annealing time, which leaded to decreases in the degree of swelling of membrane in water and the ionic conductivity as annealing time increased. SAXS data showed that the long spacing of crystalline domain increased and the long spacing of ionic cluster decreased with increasing annealing time. The long spacing of ionic cluster increased after the membrane were swelled with water.
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