Polyvinylidene fluoride hydrophilic modified membrane and preparation method thereof

Abstract

The invention discloses a polyvinylidene fluoride hydrophilic modified membrane and a preparation method of the polyvinylidene fluoride hydrophilic modified membrane. The polyvinylidene fluoride hydrophilic modified membrane is composed of 12-22% polyvinylidene fluoride hydrophilic, 0.5-15% hydrophilic polymer and 63-87.5% polarity good solvent. By means of the prepared polyvinylidene fluoride hydrophilic modified membrane, a pore-forming agent does not need to be added. Compared with the prior art, the polyvinylidene fluoride hydrophilic modified membrane and the preparation method of the polyvinylidene fluoride hydrophilic modified membrane have the advantages of being simple in operation method, big in water flux, relatively small in water contact angle, good in hydrophilicity, good in uniformity and the like. The prepared polyvinylidene fluoride hydrophilic modified membrane is suitable for being made into a composite type flat sheet membrane and used for a membrane bioreactor.

Description

technical field [0001] The invention belongs to the technical field of membrane science and membrane materials, and specifically relates to a polyvinylidene fluoride hydrophilic modified membrane and a preparation method thereof. Background technique [0002] Polyvinylidene fluoride (PVDF) has good chemical stability, heat resistance and mechanical properties, as well as anti-ultraviolet radiation and aging resistance, and is soluble in some strong polar solvents. It is easy to form a film by phase inversion method. It is a new type of membrane material with excellent comprehensive performance, which has aroused great interest in membrane separation technology in recent years (see Zhang Kan et al., Fine Chemical Industry, 2001, 18: 100; Tang Guangjun et al., Chemical Industry Progress, 2004, 23: 480). However, due to its strong hydrophobicity, PVDF will cause two problems in the separation of water phases: one is the high driving force of mass transfer through the membrane ...

AI Technical Summary

Problems solved by technology

However, due to its strong hydrophobicity, PVDF will cause two problems in the separation of water phases: one is the high driving force of mass transfer through the membrane and high energy consumption; the other is that it is very easy to adsorb organic matter and protein, causing membrane pollution and water flux decline.

Surface chemical modification, although hydrophilic modification has been achieved from the membrane surface, it is difficult to chemically modify the membrane surface due to the high C-F bond energy (see Shao Pinghai et al., Water Treatment Technology, 1995, 21: 26); plasma Modification, due to the movement of PVDF molecular chains, the introduced polar groups will transfer to the membrane body with time, and the modification effect is unstable (see Iwata et al., J. Membr. Sci. 1988, 38: 185; Wang et al. , E. T. J. Membr. Sci. 2002, 19: 5103; Rafik et al. Eur. Polym. J. 2000, 36: 1911); irradiation graft modification, high cost of disposable equipment, difficult to realize industrialization (see Zuo Danying et al. , Membrane Science and Technology, 2006, 26: 41); in comparison, the blending modification of PVDF membranes can avoid the above-mentioned unfavorable factors, and the blending modification is simple and easy to operate, has industrialization prospects, and is of great significance

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