Study On The Construction And Performance Of Pickering Emulsion Catalyst System Based On MOFs

Metal-organic Frameworks?MOFs?,due to their unique properties,in addition to high specific surface area and porosity,uniform size,adjustable channel,structure and function,simple preparation,etc.,can also introduce special functional sites to achieve Functional modification of the surface.MOF is highly efficient as a catalyst,but is generally limited by the separation procedure from the reaction system.Surface-modified stimuli-responsive polymer brush Pickering emulsions have become an attractive catalytic system due to their good catalytic properties,recyclability and easy separation,and sustainable cycling.The surface modification stimulates the NMOF-loaded metal nanoparticles with stimuli-responsive polymer brush,can be used as an emulsifier or a catalyst to realize the enrichment of both functions.Not only efficiently promote the separation of the two-phase organic reaction and the product separation,but also can be recycled.In this thesis,two kinds of surface modified stimuli-responsive polymer brushes NMOF were prepared by post-modification of Ui O-66-NH₂,which was applied to the Pickering interface catalytic system.I.The PNIPAM-SH polymer obtained by the RAFT polymerization method was grafted to the surface-modified double-bonded Ui O-66-NH2 by click reaction,and then loaded with Pd NPs to obtain Pd@Ui O-66-S-PNIPAM,Which is used as an emulsifier into a Pickering emulsion.The emulsion not only has high stability,but also has good temperature responsiveness.The emulsification and demulsification cycles are achieved by adjusting the temperature.And the system promotes the dechlorination reaction at room temperature while achieving the purpose of product separation and multiple cycles of the catalyst.II.By conventional free radical polymerization method,PDEAEMA polymer was grafted on Ui O-66-Met and loaded with Pd NPs to obtain Pd@PDEAEMA-g-Ui O-66 NPs,which was used as emulsifier to prepare Pickering emulsion.The emulsion not only has high stability,but also has good p H responsiveness.By adjusting the p H of the system,multiple cycles ofemulsification and demulsification can be achieved.And the system can efficiently promote the one-pot Knoevenagel condensation-hydrogenation reduction cascade biphasic reaction at room temperature while achieving the purpose of product separation and multiple cycles of catalyst utilization.Studies have shown that by modifying the metal organic frameworks?MOFs?,stimuli-responsive polymers can be introduced into nanomaterials?MOFs?to achieve the enrichment of functions.As an emulsifier and catalyst,applying to Pickering emulsion interface catalysis,the diversification of NMOFs is realized.It provides some guiding design methods for the interface-catalyst system of other types of organic reactions based on MOF-based Pickering emulsion,and has a good application prospect...