Preparation method of microporous membrane with hydrophilicity and hydrophobicity

Abstract

The invention relates to a preparation method of a microporous membrane with hydrophilicity and hydrophobicity. The preparation method comprises the following steps of: dissolving a membrane material into a solvent; adding an additive; defoaming hermetically to obtain a membrane coating liquid; coating the membrane coating liquid onto a polyester non-woven fabric; evaporating a solvent in the membrane coating liquid; compounding a hydrophobic control layer on one side of the polyester non-woven fabric; entering a steam region and performing phase transformation to gel into a membrane; and drying to obtain a product. Compared with the prior art, the preparation method has the advantages that: the microporous membrane with two different properties is obtained; the membrane hole shape of the microporous membrane is stable and uniform; during liquid filtering operation, the microporous membrane is convenient to use, so that the filtering efficiency and the filtering accuracy of the microporous membrane are increased; the entire microporous membrane has high porosity, and a control layer is very thin, so that filtering resistance is small, and the microporous membrane has very high filtering efficiencies on substances of over 0.2 mu during liquid filtering; and the microporous membrane is suitable for purifying processes such as degerming, fine particle removing and the like in industrial production.

Description

technical field [0001] The invention relates to a preparation method of a microporous membrane, in particular to a preparation method of a microporous membrane having both hydrophilicity and hydrophobicity. Background technique [0002] At present, it is often necessary to use two materials with different properties as filter media in the fine filtration process of materials in China. For example, in gas terminal filtration, domestic hydrophobic polytetrafluoroethylene biaxially stretched membrane is used as filter medium; in liquid terminal filtration, imported hydrophilic polyethersulfone phase conversion membrane is used as filter medium. Advantages of PTFE: superior material performance, high filtration accuracy, low resistance, and low price; Disadvantages: It is difficult to change the technology into a hydrophilic membrane; since there is no support layer, the pores of the stretched network are easy to change, especially during the filtration process , The mesh holes...

AI Technical Summary

Problems solved by technology

Advantages of PTFE: superior material performance, high filtration accuracy, low resistance, and low price; Disadvantages: It is difficult to change the technology into a hydrophilic membrane; since there is no support layer, the pores of the stretched network are easy to change, especially during the filtration process , the mesh hole is easy to expand and deform, which affects the filtration accuracy

Advantages of polyethersulfone membrane: superior material performance, high filtration accuracy, and stable membrane pore structure; disadvantages: high price, domestic continuous production cannot be achieved with current domestic technology