Study On Preparation And Organics/water Separation Of MOFs Hybrid Membrane

Organic/inorganic hybrid membranes combine the advantage of both organic polymers and inorganic material and make up for their shortcomings. Organic/inorganic hybrid membranes have become one of the hotspots in the field of membranes in recent years. In organic/inorganic hybrid membranes, the compatibility and dispersion of inorganic particles in organic polymers are the major challenge. Metal organic frameworks(MOFs) are a new type of porous hybrid materials. They made up of organic ligands and inorganic metal ions, and have the characteristics of high specific surface area, high porosity, easy modification on the surface, selective adsorption and good compatibility with organic polymers. Using the MOFs in the field of organic/inorganic hybrid membranes can effectively improve the compatibility of organic polymers with inorganic particles, which enhance the separation performance and stability of membranes. Different types of MOFs as hybrid particles were chosen in this study, and then MOFs hybrid membrane were prepared successfully with a dipcoating method in organics/water separation. The results indicated that the MOFs hybrid membrane has potential application in industry.Firstly, MOFs hybrid membrane was prepared onto polysulfone(PS) supporting membrane in ethanol/water separetion using a dip-coating with sonication method. The morphology and structure were characterized by SEM, XRD, FTIR and AFM. Contact angle(CA) test was used to characterize the affinities of MIL-53 paticles and MIL-53/PDMS hybrid membrane with water and ethanol. In order to illustrate the effect of MIL-53 structure on pervaporation performance, comparative experiments were performed in this study. The effects of MIL-53 loading, feed concentration and operating temperature on membrane performances were explored finally. When the MIL-53 loading was 40 wt%, the feed solution was 5 wt% ethanol/water mixtures, the feed temperature was at 70 °C, the total permeate flux and separation factor were 5467 g/(m2h) and 11.1 respectively.In addition, In order to improve the resistance of Na A membrane to acid and separation performance, Na A membrane was dip-coated in UIO-66-NH2/PEI solution before heat treatment. And MOFs hybrid membrane was used for the separation of acetic acid/water. The morphology and structure were reavaled by SEM, EDX and XRD. Proved by FTIR characterization, UIO-66-NH2 reacted with PEI under high temperature, which resulted in improving the compatibility and dispersion of UIO-66-NH2 particles in PEI. In the end, the effects of PEI concentration, assembly layer number, UIO-66-NH2 loading and operating temperature on membrane performances were studied. When the PEI concentration was 1 wt%, assembly layer number was 2, UIO-66-NH2 loading was 30 wt%, the feed temperature was at 50 °C, the total permeate flux and separation factor were 167.5 g/(m2h) and 436.4 respectively.