Preparation Of Crystal And Membrane Of IRMOF-3 And ZIF-7

Metal-Organic Frameworks (MOFs) as a new inorganic porous material, because of their excellent performance catch much attention in the international materials science, chemistry and physics, and quickly developed into one of the hot cross-disciplinary research. As an selective catalytic functional materials, MOFs shows a fascinating prospect in gas adsorption, optical materials and magnetic fields, also has become a new generation of excellent membrane material, in gas separation, such as H2/CH4, O2/N2, CO2/CH4 isolation and separation of chiral catalysis. Its preparation and made to membrane has great scientific values and potential industrial applications. At present, the study of the preparation of MOFs membrane has just started, many mechanisms and conditions are not perfect, makes it especiallyon the tubular carrier to be a research hot topic and difficulty.In this paper, we studied the influence of synthesis reaction conditions of IRMOF-3 crystal on the crystal morphology, structure and other physical chemical properties, used SEM, XRD to characterize the results. Studies have shown that:IRMOF-3 crystals which showed higher crystallinity were obtain under the following conditions:Zn2+:ABDC=2:1, synthesis temperature of 403 K. Through the study of heating, proved that IRMOF-3 crystals whose crystal particles were smaller and more uniform, were obtained under the microwave heating used only 30 min. Then we carried out the preparation of IRMOF-3 membrane onα-Al2O3 tubular carrier, the experimental results show that, used the microwave-assisted seed method get more continuous film at CZn2+= 0.05 mol/L, after repeated synthesis, can effectively improve the film quality, at 0.1 MPa psid hydrogen penetration rate of 4.39×10-7 mol/m2·s·Pa, the separation ratio of H2/CO2, H2/N2, H2/CH4 were 4.12,3.48,2.56, close to Knudsen diffusion value.In view of IRMOF-3 membrane performance was not perfect, based on experiment, we selected the ZIF-7 system whose aperture was about 3 A, carried out the preparation of crystal and membrane. We prepared out the crystal which matched carrier can used as the seed of secondary growth with dynamic crystallization method, under the following conditions: synthesis temperature of 393 K, reaction time of 120 min, and Zn2+:BIM= 1:2.8, CZn2+= 0.05 mol/L. Then use microwave-assisted seed method reduced the preparation time to 30 min, through repeated synthesis, improve the coating quality, the hydrogen penetration rate of 8.93×10-7 mol/m2·s·Pa, and the ideal separation ratio of H2/N2,H2/CO2,H2/CH4 achieved respectively to 4.04,4.86,2.05.