鋯與鋁金屬有機骨架之溶劑脫附誘導結構快速轉換

Abstract

本論文主要在研究金屬有機框架 Metal – Organic Frameworks, MOF 的合成，特別注重於其快速結晶與相轉變的部分。研究步驟上，利用雙溶劑置換（Two Solvents Exchange，TOSE）與加熱抽真空（Heat under Vacuum，HEVA）可以達成 MOF 在合成時的溶劑脫附誘導結構快速轉換。每個步驟所獲得的樣品均有進行粉末 X 光繞射的鑑定，以便觀察其快速結晶與相轉變；也進行 77K 氮氣吸脫附的孔洞性質測試，結果顯示孔洞性質數據與文獻相近；樣品也進行 SEM 的測量，觀察其表面形貌與顆粒大小。在快速結晶化的實驗樣品性質鑑定上，ZrNDC I（Naphthalenedicarboxylate acid = NDC）與 AlNDC 藉由 TOSE& HEVA 兩個步驟的處置，使樣品快速的從非晶相轉變為晶相；氣體吸脫附實驗結果顯示，AlNDC 的吸附量與比表面積與文獻數值相近，ZrNDC I 則需要其他實驗優化方式來達成與文獻數值相近之結果。在相轉變的研究中發現，ZRN-bcu結構可以在適當的步驟下轉為 ZrNDC II。 綜合而言，本論文研究透過 TOSE & HEVA 這兩種活化的方式克服了一些合成上的困難，可縮短反應時間，也更了解合成反應機制，且其獲得的孔洞性質結果也與水熱法的結果相近。額外的，研究中也成功的新發現 Zr-MOF 彼此之間有結構的相轉變。This thesis focuses on the synthesis of MOF, with special emphasis on its rapid crystallization and phase transition. In this thesis, the synthesis of MOF is investigated by using Two Solvents Exchange (TOSE) and Heat under Vacuum (HEVA) to induce rapid structural transformation by solvent desorption. The samples obtained from each step were subjected to powder X-ray spectroscopy in order to observe the rapid crystallization and phase transition; the 77K nitrogen adsorption and desorption were also tested, and the results showed that the pore property data were similar to the literature; the samples were also subjected to SEM measurements to observe the surface morphology and particle size.In the rapid crystallization experiments, ZrNDC I and AlNDC were rapidly transformed from amorphous phase to crystalline phase by the two steps of TOSE& HEVA. In the phase transition study, it was found that the ZRN-bcu structure could be converted to ZrNDC II with appropriate steps. In summary, the present study overcomes some synthetic difficulties by using both TOSE & HEVA activation methods, shortens the reaction time and provides a better understanding of the synthetic reaction mechanism, and the results obtained for the pore properties are similar to those obtained by hydrothermal methods. In addition, a new structural phase transition between Zr-MOF and each other has been successfully discovered in the study.