Large-flux enhanced hollow fiber membrane and preparation method thereof

Abstract

The invention relates to a large-flux enhanced hollow fiber membrane. A separation membrane layer is prepared from, by weight, 22-30 parts of polyvinylidene fluoride, 10-20 parts of a hydrophilic agent, 50-60 parts of a polar solvent, 10-20 parts of a pore forming agent and 5-10 parts of an auxiliary agent; the hydrophilic agent contains triethanolamine. According to the large-flux enhanced hollowfiber membrane, by blending and modifying the hydrophilic agent, the auxiliary agent and the polyvinylidene fluoride in the polar solvent, the surface tension of the surface of the membrane and the inner walls of membrane pores is reduced, and the hydrophilicity of the polyvinylidene fluoride is improved; the triethanolamine in the hydrophilic agent can have hydrogen-bond interaction with polar bonds in the auxiliary agent, the hydrophilicity can be maintained for a long time accordingly, the antifouling property of the hollow fiber membrane is improved, and the high operating flux is kept for a long time; meanwhile, the excessive triethanolamine in a membrane casting solution can be adsorbed on the surface of a hollow fiber material under hydrogen-bond acting force, the adhesion strengthbetween the separation membrane layer and hollow fibers is enhanced, and therefore the hollow fibers are added as support to prevent the membrane material from filament breakage.

Description

technical field [0001] The invention relates to the technical field of ultrafiltration membranes, in particular to a large flux reinforced hollow fiber membrane and a preparation method thereof. Background technique [0002] Ultrafiltration is a membrane separation process that takes pressure difference as the driving force and uses the sieving mechanism to intercept macromolecular solutes and separate them from solvents or small molecular solutes according to the size of the substance. The effective pore size of the ultrafiltration membrane used is between 2 ~100nm. Utilizing the screening effect of the micropores on the surface of the ultrafiltration membrane, the separation and purification of substances with different molecular weights can be realized, and it has a good effect on the removal of particles, colloids, bacteria and various organic substances. In recent years, it has been widely used in water treatment, food, Electronics, machinery, chemical industry, petrol...

AI Technical Summary

Problems solved by technology

[0004] The hollow fiber membranes in the prior art have some defects: 1. The unsupported polyvinylidene fluoride hollow fiber membrane has a thick skin layer, which is prone to broken wires and low processing efficiency; 2. The inner lining enhances the bonding strength of the hollow fiber membrane separation layer Low, the shedding of the cortex affects the treatment effect and service life; 3. The polyvinylidene fluoride hollow fiber membrane has poor hydrophilicity, and it is easy to absorb pollutants during use, reducing the treatment efficiency and other defects

The bond strength and surface hydrophilicity of the separation layer are two important factors affecting the separation performance of the lining-reinforced hollow fiber membrane. It can be seen that the performance of the hollow fiber membrane in the prior art needs to be further improved