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研究生: 黃奕雲
Yi-Yun Huang
論文名稱: 電場誘導聚乙烯醇改質雙馬來醯亞胺複合薄膜於鹼性直接乙醇燃料電池之應用
指導教授: 諸柏仁
口試委員:
學位類別: 碩士
Master
系所名稱: 理學院 - 化學學系
Department of Chemistry
論文出版年: 2018
畢業學年度: 106
語文別: 中文
論文頁數: 137
中文關鍵詞: 燃料電池
相關次數: 點閱:10下載:0
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  • 鹼性燃料電池因其可使用非白金觸媒,有望降低價格,為近年來再生能源研究發展的一大趨勢;然薄膜研究上仍欠缺足夠條件使其商業化,其中最需克服的為同時擁有良好的離子導電度以及較低的燃料竄透。
    本研究係利用分歧狀雙馬來醯亞胺聚合物(mBMI)和聚乙烯醇(PVA)之間形成semi-IPN(半互穿網絡)結構所製備的薄膜以降低乙醇的竄透率。同時,由於PVA及mBMI本身帶有親水官能基且相鄰醯亞胺基之間有利於氫氧根離子的傳遞,使此薄膜在鹼性溶液(KOH)下的離子導電度能隨添加mBMI的含量增加而有所提升,達到良好的離子導電度;另外,隨著添加mBMI含量增加,半互穿網絡交聯程度上升亦能使薄膜膨潤程度下降。
    此外,本研究另一重點為以外加電場極化的狀態下製備成膜,可以將薄膜內部電負度較大的原子(如:O、N等)暴露以增加親水官能基,同時形成有序的親水離子傳導通道使非結晶區更為緻密。相較於無電場極化下的複合薄膜,在外加電場極化下的mBMI/PVA複合薄膜顯示出更優異的OH- 離子導電率(1.20*10 -2 S / cm 至3.82*10 -2 S / cm)、更低的乙醇竄透性(3.61*10 -7 cm 2 / s至7.77*10 -8 cm2 / s), 以及極高的選擇率 (將近4*105);此外,電場極化產生更緻密膜材結構,亦提高了薄膜的化學穩定性以及機械強度。
    本研究顯示以外加電場的方式製備成膜可以提升離子導電度、降低燃料竄透以提升薄膜的選擇率,並同時提升薄膜的機械強度以及化學穩定性等物性,在最後ADEFC單電池測試中,薄膜亦相較於文獻中PVA薄膜有更卓越的表現,其電流密度達225 mA/cm2、功率密度達48 mA/cm2,顯示此類型薄膜可有效應用於鹼性燃料電池中。


    A new category of hydroxide ion exchange membrane bearing ordered interpenetrating network (semi-IPN) structure established by electric field poling during membrane formation, lead to balanced property where high ion conductivity and low alcohol (methanol and ethanol) permeability co-existed. Success of this membrane preparation scheme is illustrated with the semi-IPN membrane formed by dendritic modified bismaleimide (mBMI) and polyvinyl alcohol (PVA) hydrogel casted together under applied electric field (E-field> 2000V/cm, Ac=1-20Hz,). Detailed morphology and water diffusion studies shows electric field poling establishes higher ordered amorphous domains that induces preferentially oriented conducting path that raised ion conductivity. On the other hand, semi-IPN network effectively reduces methanol and ethanol permeation and improves membrane toughness. When PVA:mBMI equals 2 to 3 weight ratio, the membrane delivered impressive room temperature OH ion conductivity of 38.2 mS/cm and a substantially reduced ethanol permeation of 7.7x10-8 cm2/s; giving exceedingly high ethanol selectivity ratio (>105) with electric field poling preparation. Ordering in the semi-IPN structure by electric field poling also causses densification of the amorphous domain that leads to improved chemical stability (99wt% mass retention in 6M KOH for nearly a month) and mechanical toughness (Tensile strength increased from 3.5 MPa to 7.0 MPa, and elongation at break raised from 60% to 92%). The study concludes the application of an external electric field initiated reorganization of membrane morphology where high performance fuel cell membrane bearing high ion conductivity; low fuel permeation; high membrane strength; and high chemical stability can be established, simultaneously.

    中文摘要 ii Abstract iv 目錄 vi 圖目錄 xi 表目錄 xvi 第一章 緒論 1 1-1 前言 1 1-2 燃料電池簡介及原理 3 第二章 文獻回顧 8 2-1 鹼性燃料電池介紹 8 2-1-1 鹼性燃料電池的優缺點 8 2-1-2 鹼性直接乙醇燃料電池 9 2-2 鹼性燃料電池離子交換膜種類與介紹 11 2-2-1 離子交換膜傳遞機制 12 2-2-2 陰離子交換膜 17 2-2-3 鹼摻雜高分子薄膜 20 2-2-4 有機/無機複合高分子薄膜 23 2-3 聚乙烯醇(PVA)/改質雙馬來醯亞胺(mBMI)薄膜 25 2-4 電場誘導高分子與奈米無機物的性質與探討 32 2-4-1 電場裝置的設計與應用原理 32 2-4-2 外加電場誘導奈米無機物與高分子之性質探討 34 2-4-3 外加電場於離子交換膜上的應用 37 2-5 研究動機 44 第三章 實驗方法與原理 47 3-1 實驗儀器及技術原理 47 3-1-1 掃描式電子顯微鏡(Scanning Electron Microscopy, SEM) 47 3-1-2 示差掃描熱卡計(Differential Scanning Calorimeter, DSC) 48 3-1-3 熱重分析儀(Thermal Gravimetric Analysis, TGA) 48 3-1-4 小角度X光散射(Small angle X-ray scattering, SAXS) 49 3-1-5 X光散射光譜儀(X-Ray Diffraction, XRD) 50 3-1-6 薄膜吸水量(Water Uptake)及膨潤率(Swelling) 51 3-1-7 離子交換容量(Ion Exchange Capacity, IEC) 51 3-1-8 複合薄膜機械強度測試 52 3-1-9 化學穩定性測試(Chemical stability) 54 3-1-10 乙醇竄透率 54 3-1-11 離子導電度測量 55 3-1-12 ADEFC單電池效能測試 57 3-2 物質合成及薄膜製備 59 3-2-1 高分岐鏈鍵結雙馬來醯亞胺合成步驟 59 3-2-2 交聯型固態高分子電解質薄之製備 60 3-2-3 外加電場裝置設計 60 3-3 實驗藥品 62 3-4 樣品命名規則 63 第四章 結果與討論 64 4-1 添加不同分岐長度的雙馬來醯亞胺高分子(mBMI)複合薄膜性質探討 ……………………………………………………………………..66 4-1-1 NMR聚合程度分析 66 4-1-2 不同分歧長度mBMI之SAXS小角度散射為結構 68 4-1-3 不同分歧長度mBMI之DSC薄膜保水性質分析 70 4-1-4 不同分歧長度mBMI複合薄膜之吸水性、膨潤率與離子導電度之比較 71 4-1-5 不同分歧長度mBMI複合薄膜離子導電度與乙醇竄透比較 73 4-1-7 不同分歧長度mBMI複合薄膜之選擇性(Selectivity) 75 4-2 取較佳分歧長度的雙馬來醯亞胺高分子(mBMI),以添加不同含量對複合薄膜的性質探討 76 4-2-1 相同分歧長度mBMI複合薄膜之DSC薄膜保水性質分析 76 4-2-2 相同分歧長度mBMI複合薄膜之吸水性、膨潤率與離子導電度之比較 77 4-2-3 相同分歧長度mBMI複合薄膜之熱穩定性分析 79 4-2-4 相同分歧長度mBMI複合薄膜之機械效能測試 81 4-2-5 相同分歧長度mBMI複合薄膜離子導電度與乙醇竄透比較 82 4-2-6 相同分歧長度mBMI複合薄膜之選擇性(Selectivity) 84 4-3 外加電場誘導高分子複合薄膜探討及性質分析 85 4-3-1 SEM薄膜微結構影像 86 4-3-2 DSC薄膜保水性質分析 87 4-3-3 SAXS小角度散射微結構 89 4-3-4 XRD薄膜結晶度分析 91 4-3-5 複合薄膜之熱穩定性測試 93 4-3-6 IEC離子交換容量 94 4-3-7 吸水性、膨潤率及離子導電度比較 95 4-3-8 複合薄膜機械效能測試 97 4-3-9 化學穩定性測試 98 4-3-10 變溫及變濕離子導電度測試 100 4-3-11 離子導電度與乙醇燃料竄透率比較 102 4-3-12 複合薄膜選擇性(Selectivity) 103 4-3-13 ADEFC單電池效能測試 104 第五章 結論與未來展望 106 5-1 結論 106 5-2 未來展望與研究建議 108 參考文獻 110

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