Self-cleaning flat plate type PVDF ultrafiltration membrane based on F-TiO2/Fe-g-C3N4 and preparation method of self-cleaning flat plate type PVDF ultrafiltration membrane

Abstract

The invention discloses a self-cleaning flat plate type PVDF ultrafiltration membrane based on F-TiO2 / Fe-g-C3N4 and a preparation method, and belongs to the technical field of membrane separation. 9.0%-19.0% (w / w) of polyvinylidene fluoride (PVDF), 5.0%-13.0% (w / w) of a pore-foaming agent, 0.1%-1.0% (w / w) of F-TiO2 / Fe-g-C3N4 and 67.0%-85.9% (w / w) of a solvent are added into a three-neck round-bottom flask according to a certain sequence, stirred and dissolved at 40-90 DEG C for 5-12 h to be completely dissolved, and left to be defoamed for 8-16 h to prepare a membrane casting solution; a membrane is scraped on a clean glass plate by adopting a phase inversion method to prepare the self-cleaning flat plate type PVDF mixed matrix ultrafiltration membrane. The pure water flux of the ultrafiltration membrane prepared by the method is greater than or equal to 330 L / m < 2 >. hr. 0.1 MPa, the bovine serum albumin rejection rate is greater than or equal to 90.00%, the degradation removal rateof humic acid reaches about 90% (under simulated visible light, the ultrafiltration membrane operates for 1 hour), and the ultrafiltration membrane has good anti-pollution performance and visible light catalytic performance. The product provided by the invention is especially suitable for micro-polluted source water treatment, chemical engineering, medicine, seawater desalination pretreatment, treatment and reuse of wastewater in the biological field and the like.

Description

technical field [0001] The invention belongs to the field of membrane technology, and relates to a polymer mixed matrix ultrafiltration membrane and a preparation method thereof, in particular to a F-TiO-based 2 / Fe-g-C 3 N 4 A self-cleaning flat-plate PVDF mixed matrix ultrafiltration membrane and a preparation method thereof. Background technique [0002] The scarcity of water resources and increasingly serious water pollution have become bottlenecks restricting social progress and economic development. The development of new water sources and the utilization of waste water resources have also become issues of global concern. Since most of the earth's water resources are seawater, and a large amount of sewage and wastewater are produced in the process of human production and life, sewage recycling and seawater desalination have quickly become one of the most promising solutions to meet water resource needs. In recent years, membrane technology has been widely used in wa...

AI Technical Summary

Problems solved by technology

In recent years, scholars at home and abroad have used the blending method or sol-gel method to prepare nano-inorganic material / polymer hybrid ultrafiltration membranes that respond to ultraviolet light, so that they have both photocatalytic and membrane separation functions. development and application prospects; for example, the Chinese patent ZL201410312781.8 uses the blending of nano-inorganic materials and membrane materials to prepare ultrafiltration membranes that respond to ultraviolet light, so that they can degrade organic pollutants under the action of ultraviolet photocatalysis; in view of The light energy of ultraviolet light accounts for less than 5% of the solar light energy, which seriously limits the practical application of ultraviolet photocatalyst modified membranes.

Therefore, by doping or coating visible light catalysts to prepare visible light catalytic ultrafiltration membranes, while improving the anti-pollution properties of ultrafiltration membranes, it also makes the ultrafiltration membranes have visible light catalytic activity and expands the application range of ultrafiltration membranes. A hotspot in the research of ultrafiltration membranes; the research team of the inventor Wang Liguo has developed related ultrafiltration membranes and preparation methods based on visible light-catalyzed nano-inorganic materials, but did not involve the preparation of mixed-matrix ultrafiltration membranes and preparation methods of visible-light-catalyzed nano-inorganic composite materials

[0004] Chinese patent CN104383821A uses graphene oxide to support magnetic particles with a core-shell structure @TiO 2 The modified separation membrane was prepared, and it was considered that the separation membrane showed good photocatalytic degradation performance and anti-protein pollution performance for the target pollutant bovine serum albumin, but the separation performance and visible light catalytic degradation performance of the prepared membrane were not clarified in the patent application advantages and disadvantages, and the preparation process of the separation membrane is complicated; at the same time, the magnetic particles @TiO 2 The preparation method is complicated and the cost is high

Chinese patent CN102989329A passed AgNO 3 、TiO 2 Blending modification to prepare ultrafiltration membranes, in fact, mainly uses AgNO 3 visible light catalytic activity, and the degradation rate is slow (in the patent, the degradation rate of methylene blue is characterized by light for 10 hours), and it is impossible to prepare a separation membrane for separation and visible light catalysis at the same time; 3 PO 4 / TiO 2 Complex (Ag 3 PO 4 Nanoparticle deposition onto TiO 2 Surface) and polyvinylidene fluoride materials are blended and modified, so that the modified film has visible light catalytic antibacterial and antifouling properties, mainly using the deposited on TiO 2 Ag on the surface 3 PO 4 Particles degrade the organic matter adsorbed during the application of the separation membrane to reduce membrane fouling, and have not been used to prepare a separation membrane with both separation and visible light catalytic properties; at the same time, neither of these two patents has made full use of silver salts and TiO through synergistic effects 2 The catalytic performance of silver salt or silver salt and TiO is only utilized by blending or deposition 2 Respective catalytic activity, visible light catalytic efficiency is low

[0006] The present invention through composite F-TiO 2 and Fe-g-C 3 N 4 To give full play to the synergistic effect of the two, further improve its visible light catalytic activity, and use F-TiO 2 and Fe-g-C 3 N 4 Improving the visible light catalytic properties of polymer ultrafiltration membranes and preparing flat mixed matrix ultrafiltration membranes with self-cleaning effect have not been reported in the literature at home and abroad