Hydrophilic polyvinylidene fluoride hollow fiber composite membrane and preparation method

Abstract

The invention discloses a hydrophilic polyvinylidene fluoride hollow fiber composite membrane and a preparation method. The aperture of the membrane is 0.01 to 0.1 micron; the porosity of the membrane is 60 to 80 percent; a polyvinylidene fluoride (PVDF) film is coated on the outer surface of a hollow woven fiber pipe; the thickness of the coating is 0.1 to 0.4 millimeter; the outer diameter of the membrane is 1.5 to 2.5 millimeters; and the PVDF film comprises the following components in percentage by mass: 80 to 95 percent of polyvinylidene fluoride, and 5 to 20 percent of amphiphilic copolymer, namely polyoxyethylene / polyoxypropylene / polyoxyethylene (PEO-PPO-PEO). The preparation method sequentially comprises the following steps of: preparing film casting solution, coating the hollow woven fiber pipe, forming a coagulating bath, cleaning, drying and the like. The hollow fiber composite membrane prepared by the method is stable and long-lasting in structure; the hydrophily of the membrane can be obviously improved; and the production cost is reduced and mass production is easy to realize by the method.

Description

【Technical field】 [0001] The invention belongs to the technical field of separation membrane material structure and hydrophilization modification, and particularly relates to a method for preparing a hydrophilic polyvinylidene fluoride hollow fiber composite membrane, which is suitable for advanced sewage treatment and reuse and water supply advanced purification treatment. 【Background technique】 [0002] As a new type of separation technology, membrane separation technology has the advantages of low energy consumption, good separation performance, and no secondary pollution during the separation process. It has been widely used in chemical, pharmaceutical, energy, environmental engineering, water treatment and other fields. The selection of separation membrane materials with excellent performance is the core of membrane separation technology, and it is also the research focus of membrane separation technology development. At present, most of the widely used separation membr...

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Problems solved by technology

[0003] At present, the general polyvinylidene fluoride (PVDF) hollow fiber membrane mainly has the following problems in the use process: (1) PVDF has low surface energy and strong hydrophobicity, resulting in poor hydrophilicity and poor anti-pollution ability of the membrane; (2) ) The water flux and mechanical strength of the membrane cannot be improved at the same time; (3) The mechanical strength of the membrane is not high, resulting in the membrane being easily broken during use

[0007] The above methods of hydrophilic modification of PVDF membranes have solved the problems of PVDF membranes such as hydrophilicity, anti-pollution and water permeability to varying degrees, but have not solved the problem of poor mechanical strength of PVDF hollow fiber membranes.

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