Synthesis And Properties Of Core-shell Magnetic MOFS Composites

This paper mainly concentrated on the synthesis of core-shell magnetic MOFs composites materials and their catalytic applications,and we further applied MOF for MR imaging-guided chemotherapy in vivo.Metal-Organic Frameworks(MOFs)are reticular lattice structural crystal structures which are self-assembled by coordination bond between organic ligands and metal ions.It has a wide range of application in analytical separation,biosensing,catalysis and drug delivery and bioimaging due to the high surface area,wide pore size and preparation easiness etc.Magnetic MOFs in all of applications are identified as materials with potential application value as it not only has the advantages of MOFs materials also the advantages of magnetic properties of magnetic materials.Highly dispersed magnetic catalyst can be recovered by external magnetic field,and magnetic MOFs based on Fe3O4-DA has T2-weightcd MR imaging performance.Therefore,magnetic MOFs are a kind of magnetic porous multi-functional material with promising growth prospects.In this paper,magnetic core-shell materials(Fe3O4-DA@ZIF-67@ZIF-8)based on magnetic sphere dopamine(Fe3O4-DA)was prepared by a simple temperature-controlled ultrasonic method.Furthermore,the magnetic hollow core-shell composite Fe3O4-DA@Co/Zn-ZIF-H was prepared by solvothermal method.P-nitrophenol(4-NP)completely degraded to p-aminophenol(4-?P)at room temperature witnin 13 min which is corresponing to first-order kinetic mode,where the K is 0.1852 min-1.It shows that Fe3O4-DA@Co/Zn-ZIF-H has goood application applied in organic pollutant degradation.Due to its has high surface area and large porosity,the Fe3O4-DA@Co/Zn-ZIF-H can also be used as an excellent drug delivery carrier combining T2 magnetic resonance imaging with Fe3O4-DA and coexisting Co ions,the composite is used for MR imaging-guided chemotherapy in vivo.It have been found that the composite of Fe3O4-DA@Zn/Co-ZIF-H have more effects on doxorubicin(DOX),and loading capacity up to 71.72%.The slow-release drugs were 13.4%and 42.9%at pH 7.4 and 5.0,respectively,which showed good loading capacity and pH sensitive controllable release.In vivo experiments on tumor-bearing mice showed obvious curative effect.The core-shell composite Fe3O4-DA@ZIF-8 was prepared by heating and refluxing method.Then the magnetic core-shell composite with mesoporous titania shell Fe3O4-DA@ZIF-8@TiO2 was prepared by through a cooperative assembly-directed process at room temperature for 10 min.The mesoporous TiO2 shell was coated with hexadecylamine under alkaline conditions while etching the organic ligands of ZIF-8.The magnetic hollow core-shell Fe3O4-DA@ZIF-8@TiO2 composite was applied to the degradation of rhodamine B(30 mg·L-1),and Fe3O4-DA@ZIF-8@TiO2 completely degradate the rhodamine B within 30 min at room temperature,therefore,it has a huge potential applications in the analysis and detection of environmental organic pollutants...