| 摘要: | 金屬框架材料metal-organic frameworks (MOFs)屬於多孔晶體物質，是由金屬離子與有機配體所組成。因為金屬框架材料有獨特的特性，所以有各式各樣的應用於不同領域，像是吸附、藥物輸送、催化、薄膜等。由於特殊結構、有機官能基、高比表面積、卓越的孔隙體積，這種材料的主要應用在氫氣儲存與二氧化碳分離。在工業上，薄膜已經常被使用。包括利用金屬框架材料所做得創新薄膜，已經廣泛運用在氣體分離。目前在文獻中，MOF-5是最有代表性的金屬有機框架材料，已經成功地合成MOF-5薄膜於氧化鋁上，藉由溶劑熱法。
本研究利用溶劑熱法合成MOF-5晶體與MOF-5/氧化鋁複合薄膜，並探討不同反應條件。首次成功合成MOF-5晶體是藉由溶劑熱法於反應溫度130℃、反應時間為21小時的情況下。為了瞭解反應時間、反應溫度以及金屬與有機配體的比例影響於MOF-5合成，數多合成條件被探討。本研究合成MOF-5薄膜於不同反應溫度下之探討。MOF-5晶體與MOF-5/氧化鋁複合薄膜藉由X光繞射分析儀、掃描式電子顯微鏡、傅立葉轉換紅外線光譜儀做分析鑑定。由X光繞射分析儀所產生的圖譜可以發現到有另一MOF產生，稱為MOF-69c。推測在合成MOF-5晶體前，MOF-69c與中間產物會先被產生。本次的研究結果發現到，反應時間、反應溫度以及有機配體的比例對於MOF-5合成有重要的影響。在較低的反應時間或反應溫度下、不容易產生出MOF-5晶體產生，是因為反應能量不足，無法產生反應。而在金屬與配體比例為3:1、1:1的時，不容易得到產物。因為本身沒有強烈的化學反應且DMF做溶液交換時，未反應的反應物被移除了，因此不容易得到產物。未來會將合成出來的MOF-5薄膜藉由自製的滲透機台做測試。
;Metal-organic frameworks (MOFs) are porous crystalline materials consisting of metal ions linked together by organic bridging ligands. Because of their outstanding properties, MOFs are used in a variety of promising applications in the fields of adsorption, drug delivery, catalysis, membranes, etc. With its special structure, functional groups, high surface area, and exceptional pore volume, one of the main applications of such material is hydrogen storage and CO2 separation. In industry, membranes, including novel membranes utilizing MOFs, are often used extensively to perform gas separation. Currently in literature, MOF-5, which is the most representative MOF, has been successfully synthesized on membrane via secondary growth on substrates such as porous α-alumina.
In this work, MOF-5 crystals and related MOF-5/α-Al2O3 membranes were synthesized to systematically investigate the various reaction conditions. MOF-5 crystals were successfully formed at 130℃ and 21 hours via solvothermal synthesis. In order to understand the impact of reaction time, temperature and metal-to-ligand ratio on synthesizing MOF-5, several synthesis conditions were investigated. Then, synthesis of MOF-5 membranes with different temperature were also investigated. MOF-5 crystals and related MOF-5/α-Al2O3 membranes were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR）. The results of the XRD pattern showed the presence of another crystal called MOF-69c. This suggests that before pure MOF-5 can be formed, MOF-69c and intermediate phases were synthesized first. Successfully changing for the first time the synthesis temperature to 120℃, it was found that MOF-5 crystals were formed, but with the intermediate phases present. As a result of this study, the reaction time, temperature, and metal-to-ligand ratio have been found to have a vital influence on forming MOF-5. We have laid the foundation for finding the best synthesis parameters to synthesize MOF-5 on porous α-alumina. Future work will include gas permeation of various gases, both single and binary components on membrane samples using a homemade permeation setup. |
