Method for preparing ultrafiltration membrane

Abstract

The present invention discloses a method for preparing an ultrafiltration membrane. The method comprises the steps of: dissolving polyethersulfone in a solvent to form a casting film solution, wherein the solvent is dimethylformamide and / or dimethylacetamide, adding a P123 block copolymer to the casting film solution, sufficiently stirring to obtain a casting film solution containing dissolved block copolymer; by a flow casting method, spreading and coating the casting film solution containing dissolved block copolymer on a glass sheet to form a film; immerseing the film in a precipitation bath containing the P123 block copolymer, so as to deposit the film or to form a membrane; after drying in vacuum, soaking the membrane with an diethyl ether solution to remove the P123 block copolymer; and repeatedly washing and drying to obtain the ultrafiltration membrane. The preparation method combines the self-assembly trend of customized block copolymer in regular microphase separation structure and controlled separation by adding a non-solvent; and the method is simple, and can be transferred without problems to the existing industrial membrane preparation facilities.

Description

Technical field [0001] The invention relates to a method for preparing an ultrafiltration membrane. Background technique [0002] Ultrafiltration membranes and microporous membranes are used in pressure-driven filtration processes. Professionals in the field of membrane separation processes can easily distinguish between microporous membranes and ultrafiltration membranes, and usually distinguish them based on their applications and their structural status. Microporous membranes and ultrafiltration membranes are produced, sold and used as separate and distinct products. Although there are overlaps in names, they are different entities, and the same is true in the business world. [0003] Ultrafiltration membranes were originally used to concentrate or filter soluble macromolecules, such as proteins, DNA, starch, and natural or synthetic polymers. Its main purpose is to achieve ultrafiltration in the tangential flow filtration (TFF) mode. When the feed liquid crosses the surface ...

AI Technical Summary

Problems solved by technology

A wide variance in the pore size distribution has two disadvantages: on the one hand, such membranes cannot separate substance mixtures precisely, and on the other hand, such membranes tend to be prone to so-called fouling

But membranes with pores smaller than 1 μm in diameter cannot be prepared in this way

This preparation method is complicated and the price of the membrane is expensive

[0016] It is particularly difficult and expensive to prepare membranes on a large scale