本研究以PTFE為基材,浸漬於不同濃度的幾丁聚醣(chitosan)溶液製作成PTFE/chitosan複合膜,熱分析使用儀器有TGA、DSC,並且利用SEM來觀察複合膜表面情形,再利用恆電位儀、頻率應答分析儀來測出複合膜材的電阻抗,由實驗室自行設計模組測試膜材氣體滲透率,以單電池測試系統測試複合膜製成之MEA燃料電池效能,最後利用GC測試膜材的甲醇滲透率。由SEM發現膜材表面平整,而複合膜經TGA測試出初始裂解溫度為233℃,由DSC發現複合膜兼具幾丁聚醣與PTFE的性質,使用之幾丁聚醣溶液有1 wt%和1.5 wt%兩種不同濃度。研究結果顯示濃度1.5 wt%製成之複合膜較濃度1 wt%所製成的複合膜有較高的導電度。複合膜氣體滲透率較Nafion 117高,在室溫下甲醇滲透率情形較Nafion 117低,由P-FS1-CsH1.5複合膜所製成的MEA在70℃操作之單電池效能較Nafion 117低。
In this study, we prepared PTFE/chitosan composite membranes by impregnating porous PTFE membrane in chitosan solutions. The thermal properties, ionic resistance, gas permeability, methanol permeability, and morphology of composite membranes were investigated and reported in this thesis. Two solutions of different chitosan concentrations were used to preapare composite membranes,i.e. 1 wt% and 1.5 wt%. The results show that the composite membrane prepared from 1.5 wt% chitosan solutions has a higher conductivity than that prepared from 1 wt% chitosan solution. The gas permeability of the composite membranes is higher than that of Nafion 117, but the methanol permeability at room temperature is low than that Nafion 117. The performance of H2/O2 single fuel cell prepared from composite membrane is lower than that from Nafion 117.