Pervaporation Performance Of Surface Modificated Cu₃（BTC）₂ Filled PDMS/PEI Membranes

Metal organic frameworks (MOFs) are rapidly developed in the last 20 years, which has great potential application value in the gas adsorption and separation due to the large specific surface area and porosity. Cu3(BTC)2 is a kind of typical MOF materials with high adsorption affinity of CO2, often prepared to membrane adsorpting and separating of CO2. In this thesis, we synthesize Cu3(BTC)2 crystals with different size and modified it by different modifier.Then we added Cu3(BTC)2 into PDMS/PEI membrane and test separation factors against the composite membrane with unmodified Cu3(BTC)2, the main the work is as follows:1. We synthesised Cu3(BTC)2 by solvothermal and modified it by hexamethyldisiloxane. Then we texted the best reaction time of modification and the best modifier concentration through the experiment. With the reaction time lapsing, hydrophobic angle of Cu3(BTC)2 is growing. When modification time is less than 16h, SEM and XRD showed that the crystal is intact, and when the time is over 16h, the modified crystal is broken. As the molar solubility of reaction solution increased, extreme value of hydrophobic angle come when the molar solubility is 4%. We text the composite membrane with modified Cu3(BTC)2, finding that the best modification method improving the separation factor of 5.5%, in the condition of 16h modification and 4% molar solubility;2. The Cu3(BTC)2 was successfully modified by there different silane coupling agent. Using different group of siloxane, we text the effect of different groups on the modified. Mixed the siloxane with each other, we investigate the effects of multicomponent modifiers modificating Cu3(BTC)2 crystal. We find that the best modifiers is (3-Aminopropyl)triethoxysilane which raised 21% times as unmodified crystal, and the best mixed modifiers is (3-Aminopropyl)triethoxysilane mixed hexamethyldisiloxane which raised 20% times as unmodified crystal.3. The Cu3(BTC)2 was successfully synthesized in room temperature by coordination modulation method which is nanoscale crystal. Then modified it by best modifications, the results suggest that separation factor raised 35% and 41% times as unmodified crystal of 500nm crystal, and that separation factor raised 37% and 41% times as unmodified crystal of 50nm crystal.