Solvent induced lattice rearrangement of defective aluminum metal organic framework

• Main Authors: Cheng-Cheng-Shih, 施政丞
• Other Authors: Chia-Her Lin
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/22j79h

碩士 === 中原大學 === 化學研究所 === 106 === In this study, using H2TzDB (4,4''-(1,2,4,5-tetrazine-3,6- diyl)dibenzoic acid) as an organic ligand and metal aluminum as the central metal synthesize a porous metal organic framework(MOFs). Highly defective Al(OH)x(solvent)y(TzDB)z-53, which was synthesized with DEF as a solvent, with imperfect crystallinity was transformed into the rigid and highly crystalline isomer AlTz-68 upon solvent desorption. Topological structure from sra (square) transform to Kgm (Kagome) phase. In order to study the structure conversion, discussions include replacement of the solvent and the removal of the solvent. First using ether or acetone as replacement exchanges original solution then perform different methods of phase transformation (solvent removal). Roughly divided into four ways(1) General dry (2) Vacuum dry (3) Solvothermal before Vacuum dry (4) Solvothermal before General dry. To study the structure change, with powder X-ray diffraction identification structure, Nitrogen adsorption/desorption instrument analysis pore size distribution, thermal gravimetric analyzer thermal stability, infrared spectrometer (IR) to explore the changes in the functional groups. From the above analysis, it was assumed that the structural transformation was caused by a defect. And the solvent played a role in inducing structural transformation. When solvent leaving caused the movement of the ligand and eventually caused the rearrangement of the defective MOF. Finally, it was found that after the purification have the best crystallinity, gas adsorption, and specific surface area. Resulting in a remarkable increase in nitrogen adsorption phase was converted to about 1050 cm3/g after conversion from about 300 cm3/g to kgm before conversion and the surface area from 1060 m2/g to 3198 m2/g.