Preparation And Properties Of UiO-66-NH₂/Chitosan Composite Membrane

Metal-Organic Frames(MOFs)materials are generally porous crystalline materials with periodic networks self-assembled by one or more polyfunctional organic ligands with metal ions(or metal oxide ion clusters).MOFs materials with adjustable pore size and high specific surface area can generate high-density active centers,which made them becoming one of the ideal candidates for enzyme mimics.Some MOFs with inherent peroxidase activity can catalyze the H₂O₂ to·OH,with which the MOFs have good antibacterial.Therefore,these MOFs could have broad application in the field of antibacterial.In addition,the MOFs materials also have been used in catalysis for the contained coordination-unsaturated metal site and the catalytically active functional group.In this paper,UiO-66-NH₂ was synthesized by solvothermal method with Zr as the metal center,2-aminoterephthalic acid(H₂ATA)as the ligand and p-aminobenzoic(PABA)acid as the modulator.On one hand,the UiO-66-NH₂/CS composite membrane with the efficacy of hemostasis,analgesic,wound healing and antibacteria was synthesized by introducing the UiO-66-NH₂ into the chitosan(CS)membrane whose enzyme mimic activity and antibacterial activity were explored.On the other hand,the degradation performance of UiO-66-NH₂ in visible light was explored.The main contents of this paper are as follows:(1)Preparation of UiO-66-NH₂/CS composite membrane and its dual enzyme mimetic activityThe UiO-66-NH₂ materials with different particle sizes and different morphologies were synthesized by solvothermal method by introducing PABA as a modulator,which were successfully introduced into CS membrane to form UiO-66-NH₂/CS composite film.The cross-linking mechanism of UiO-66-NH₂/CS composite membrane was explored and the effect of PABA addition on the dual enzyme mimetic activity of UiO-66-NH₂ was studied by enzyme catalyzed experiments.(2)Study on antibacterial properties of UiO-66-NH₂/CS composite membraneThe antibacterial activity of the UiO-66-NH₂/CS composite membrane was investigated under the condition of adding trace H₂O₂,and it was unexpectedly found that the UiO-66-NH₂/CS composite membrane has UV-induced oxidase mimetic activity.The antibacterial mechanism of UiO-66-NH₂/CS composite membrane under the dual enzyme activity of UV-induced oxidase mimetic and H₂O₂-induced peroxidase mimetic was discussed by electron paramagnetic resonance(EPR),X-ray photoelectron spectroscopy(XPS)and TMB chromogenic experiments.The physical properties of the UiO-66-NH₂/CS composite membrane were characterized.It was proved that the UiO-66-NH₂/CS composite membrane was non-toxic,hydrophilic with a certain ability to absorb and retain water,which can be used as wound dressing.(3)Preparation of 3DOM-UiO-66-NH₂ and its photocatalytic performance for degradation of methylene blue3DOM-UiO-66-NH₂ was successfully synthesized by using PS as a template.And then,it was compared with UiO-66-NH₂ for different morphology prepared by solvothermal method.The materials were characterized by scanning electron microscope(SEM),Fourier Transform Infrared Spectrometer(FTIR)and X-ray diffraction(XRD),and the photocatalytic properties of different UiO-66-NH₂ were investigated by degradation of methylene blue.