| Membrane separation technology has been widely used in many fields due to it have no pollution,convenient operation,energy saving and high separation efficiency.Poly(vinylidene fluoride)(PVDF)is one of the commonly raw material in membrane preparation.It has excellence aging resistance,weather resistance,ultraviolet radiation resistance and good chemical stability,which will not be corroded by strong acid,strong alkali or strong oxidizing agents.However,PVDF membrane is highly susceptible to organic pollutant because of the strong hydrophobicity properties for the low surface energy,which plugs membrane pore and reduce the separation efficiency and the membrane life.These disadvantages limit the application of PVDF membrane in many fields.In this study,PVDF/PAA powders were prepared by semi-IPN with acrylic acid as monomer and PVDF powders.Then polymer and titania sol-gel were blended to prepare PVDF/PAA/TiO2 composite membrane.Using the self-polymerization of dopamine hydrochloride to polymerize on the surface of PVDF powder,and PVDF/PDA membrane was prepared by immersion precipitation phase inversion method,titanium dioxide inorganic nanoparticles were loaded on the surface and internal of membrane via liquid phase deposition method,PVDF/PDA/TiO2 composite membrane was prepared.In this paper,the characterization and testing of the composite membrane were systematically studied.Various techniques,such as FT-IR,FESEM,EDAX,XPS,UV-s and permeability measurements,were used to characterize the modified composite membranes.Results showed that PVDF membrane was successfully modified by PAA and PDA,and the hydrophilicity of PVDF membrane was improved.TiO2 nanoparticles distributed uniformly in the membrane,no obvious agglomeration phenomenon was found,and the composite membrane oobtained good self-cleaning performance.With the introduction of PDA,the TiO2 inorganic nanoparticles were heavily loaded on the surface of the membrane,which gave the composite membrane photosensitivity.The composite membrane showed excellent oil-water separation performance. |
