Preparation And Antibacterial Properties Of Copper(?)Metal Organic Framework Composite Membranes

Antibacterial materials have attracted more and more attention in food packaging,water treatment,medical and other fields.The design and synthesis of antibacterial materials with low toxicity,low cost,stability,high efficiency and environmental friendliness are the current research hotspot.However,the widely used metal organic frameworks(MOFs)ligands are expensive,MOFs powders are not easy to process,and the single antibacterial mode is inefficient have yet to be studied.Citric acid is an ideal MOFs ligand which has the advantages of low cost,degradability and green environmental protection in production process.Poly(lactic acid)(PLA)has good thermal stability and can be processed by extrusion,drawing and spinning.Polydopamine(PDA)has good biocompatibility,easy modification,good adhesion,and excellent photothermal properties.For the above reasons,the copper metal organic framework with citric acid(Cu-MOF-1)was synthesized,and antibacterial membranes were prepared by compositing with poly(lactic acid).The ion release and photothermal combined antibacterial membrane materials were prepared by introducing polydopamine.The main research contents are as follows:(1)Synthesis and antibacterial properties of Cu-MOF-1.Cu-MOF-1 spheres with uniform morphology and size were prepared by microwave hydrothermal with copper nitrate as metal source and citric acid as ligand by adjusting reaction time,solvent and surfactant.The structure,morphology and thermal stability of Cu-MOF-1 were characterized.The minimum inhibitory concentration of Cu-MOF-1 spheres against Escherichia coli and Staphylococcus aureus was 200?250?g m L^-1,and the bacteriostatic rate could reach more than 96.9%.The possible antibacterial mechanism was proposed by detecting the release of Cu²⁺and the production of reactive oxygen species of Cu-MOF-1.(2)Preparation and antibacterial properties of Cu-MOF-1/poly(lactic acid)(Cu-MOF-1/PLA)composite membranes.Cu-MOF-1/PLA composite membranes with good thermal stability,mechanical properties and hydrophily were prepared by scraping method and electrospinning method,respectively.Antibacterial test results showed that Cu-MOF-1/PLA fibrous membrane had higher antibacterial activity,and its antibacterial rate against Escherichia coli and Staphylococcus aureus could reach more than 99.4%,and its antibacterial activity came from stable and lasting Cu²⁺release ability.(3)Preparation and antibacterial properties of polydopamine modified Cu-MOF-1/PLA fibrous membranes.The Cu-MOF-1/PLA fibrous membrane was modified by completely immersed in the modified solution and floating on the surface of modified solution with dopamine hydrochloride as the modified solution,respectively.The experimental results showed that the self-polymerization of dopamine could be improved by contacting air in the modified process.The tensile strength of the fibrous membrane could be greatly improved by the modification of dopamine,and the photothermal temperature up to 94.9?made it have excellent antibacterial properties.(4)Preparation and antibacterial properties of Cu-MOF-1/polydopamine/poly(lactic acid)(Cu-MOF-1/PDA/PLA)fibrous membrane.Cu-MOF-1/PDA/PLA fibrous membrane was prepared by electrospinning method using Cu-MOF-1 spheres,polydopamine nanospheres and poly(lactic acid)as raw materials.The research showed that the addition of polydopamine did not change the crystal structure of Cu-MOF-1.Under laser irradiation,the temperature of Cu-MOF-1/PDA/PLA fibrous membrane was up to 81.0?,and the antibacterial rate of Cu-MOF-1/PDA/PLA fibrous membrane against Escherichia coli and Staphylococcus aureus could increase from about 80%to 99.7%,and Cu²⁺release and photothermal combined antibacterial effect was achieved.