- 學位論文
蒙脫土奈米複合材料之製備及其在燃料電池與銅箔基板上之應用
Preparation of Montmorillonite Nanocomposites and the Application on Fuel Cell and Printed Circuit Board
摘要
摘要 本研究主要將蒙脫土以化學改質的方法加工處理，製備出具脫層結構奈米材料與難燃有機黏土，且將其分散至高分子基材製備複合材料，藉由其特性提升高分子材料之性質。分為兩部份做討論： Part. 1 脫層化蒙脫土-二氧化矽奈米材料之製備及其在燃料電池上之應用 本部份研究用陽離子反應與溶膠-凝膠法，在不同比例下製備出脫層化蒙脫土-二氧化矽奈米材料S1C2、S1C1 及S2C1，並與Nafion 全氟磺酸化高分子混掺，製成Nafion 質子交換複合膜N/S1C2、N/S1C1 及N/S2C1，探討此複合膜之各項性能及其在燃料電池之應用。由於不同比例與孔洞比表面積分析，所製備之脫層化蒙脫土-二氧化矽奈米材料，結構比例、比表面積及孔洞特性有相當之差異。這些奈米材料之質子傳遞能力、含水率及甲醇滲透之效應對複合膜之影響探討結果顯示，在複合膜之含水率方面，添加脫層化蒙脫土-二氧化矽奈米材料之填充物含水率均有明顯提升，最高含水率可高達48.4 wt.%。導電度方面，因含 水率之提升，複合膜之導電度亦有效提升。甲醇滲透率均有明顯降低，最低滲透率可達4.11×10-7 cm2 s-1，比Nafion 膜降低85.6%。此外，本研究所製備之複合膜應用在質子交換膜燃料電池(PEMFC)之性能測試顯示，操作氣體為H2(g)/O2(g)，在TH2/Tcell/TO2 = 50/50/50°C 最佳化條件下，電壓為0.4V 時，最佳之複合膜組裝PEMFC 之功率密度為744mW/cm2，電流密度 1860 mA/cm2，比Nafion 重鑄膜(RN)製備之PEMFC 高 出58.6%；而在TH2/Tcell/TO2 = 50/80/50°C 條件下，電壓為0.4V 時，電流密度達1500 mA/cm2，相當於功率密度610 mW/cm2，其輸出功率比RN 製備之PEMFC 約高出1.9 倍之多。 Part. 2 高耐燃性酚醛環氧樹脂/無機層材基板材料之開發 本部份研究主要先成功放大試量產官能化碳球， 並將其作為改質劑之一， 加入天然黏土做為分散載體及補強材， 利用(1)黏土的結晶水與氫氧基受熱脫水， 可降低熱的傳導， (2)片狀結構阻隔外來的氧氣， 及(3)奈米碳球豐富的雙鍵在燃燒時產生自由基可以捕捉高分子熱裂解產生的自由基等特性， 使改值之黏土具備参重難燃的效果，應用在酚醛環氧樹酯之基板材料，提升其耐燃性。首先，將奈米碳球與天然黏土及其他的有機分子進行改質後， 利用廣角X-ray 繞射儀(WXRD)、熱重分析儀(TGA)及紅外線光譜儀(FT-IR)了解改質後與改質前黏土的層間距變化， 以及改質劑進入黏土層間所佔的比例。接著， 將改質後之黏土與酚醛環氧樹脂反應製成奈米複合材料，再藉由廣角X-ray 繞射儀(WXRD)、穿透式電子顯微鏡(TEM)及掃描式電子顯微鏡(SEM-EDS)了解黏土於酚醛環氧樹脂的分散性，並利用熱重分析儀(TGA)、示差掃描熱卡儀(DSC)測量奈米複合材料的熱裂解溫度 (Td)及複材的玻璃轉移溫度 (Tg)。最後， 利用極限氧指數儀(LOI)、圓錐量熱儀(Cone calorimeter)測試複材的耐燃性，LOI 從22.5 提升至31， 以及最大熱釋放量下降至358 kw/m2，比純的降低40.2%，總體的熱釋放速率下降至64.90 MJ/m2，降低29.5%。並將配方實際應用在銅箔基板的製程，以及探討其各項基板性質及UL94 之難燃性。結果發現，PI/BEN/OCNC-CL120 1 wt.%之複材其製成之銅箔基板，其降低吸水率4.3%與提高銅箔剝離強度 44.4%，以及通過漂錫等測試，並且基板通過UL94 V-1 等級之耐燃測試。
並列摘要
Abstract Part. 1 Synthesis of Exfoliated Montmorillonite – Silica Nanomaterial for Fuel Cells In this study, the exfoliated montmorillonire – silica nanomaterials, S1C2, S1C1 and S2C1, were prepared with different content by the cation exchange reaction and the sol-gel process. They were then separately used as a filler to produce the corresponding composite membranes, N/S1C2, N/S1C1 and N/S2C1, by blending with Nafion. The performances of the proton exchange membrane fuel cells fabricated with the as-prepared composite membranes were studied and compared to that with the recast Nafion membrane (RN). The as-prepared silica ‒ clay nanomaterials were characterized by WXRD, FTIR, SEM, TEM, BET and 29Si- solid state NMR measurements. The properties of the composite membranes were investigated by their proton conductivity, water uptake and methanol permeability. The results showed that compared with the recast Nafion membrane, the highest water uptake of the composite membrane was significantly enhanced to 48.4 wt.%. It was also found that compared to that of RN, the proton conductivity and methanol permeability of all the composite membranes were increased and reduced, respectively. In addition, the performances of the PEMFC with the as-prepared silica ‒ clay nanomaterial/Nafion composite membranes were also tested on a home-made system with H2/O2 gases. The best performance of the PEMFCs with the composite membranes was 58.6% and 1.9 times higher than that with RN membrane under TH2/Tcell/TO2 = 50/50/50°C condition and TH2/Tcell/TO2 = 50/80/50°C condition, respectively. Part. 2 Preparation of Novolac Epxoy/Montmorillonite Nanocomposite with Flame Resistant In this study, the preparation of the modified organic carbon nanocapsules, OCNC, has been scaled up and used to modify the MMT clay, CL120, together with 2-phenylimidazole and benzalkonium chloride to obtain a fire retardant clay, PI/BEN/OCNC-CL120. The fire retardant efficiency of PI/BEN/OCNC-CL120 was enhanced via the combination of heat barrier and free radical capture. The as-prepared clay were characterized by wide-angle X-ray diffraction (WAXD), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The clay PI/BEN/OCNC-CL120, was then dispersed in a novolac cured epoxy resin to form the composite bulk materials. The composites were then characterized by wide-angle X-ray diffraction (WXRD), transmission electron microscopy (TEM) and scanning electron microscopy ‒ energy dispersive spectroscopy (SEM-EDS). The results showed that the modified clay was well-dispersed in the epoxy matrix with a combination of intercalation and exfoilation platelet structures. The results of the rmo-gravimetric analysis (TGA) and Differential scanning calorimeter (DSC) measurements indicated the increased thermal property and the glss transition temperature. In addition, the result of limiting oxygen index (LOI) and cone calorimeter test showed the enhanced flammability of these nanocomposites. Finally, the composition of the modified clay nanocomposite was selected to make printed circuit boards (PCBs) and the PCBs were investigated their physical properties and flammability. It was found that the nanocomposite with 1 wt.% of PI/BEN/OCNC-CL120 had slightly lower water absorption and significantly higher peeling strength as well as met the standard of the UL94-V1 test. Therefore, the as-prepared PI/BEN/OCNC-CL120 can be a potencial fire retardant additive for PCB.