Method for synthesizing nano silicon dioxide modified PVDF (polyvinylidene fluoride) hydrophobic microporous membrane in situ

Abstract

The invention discloses a method for synthesizing a nano silicon dioxide modified PVDF (polyvinylidene fluoride) hydrophobic microporous membrane in situ. The method comprises: preparing a PVDF solution, preparing a solution containing nano silicon dioxide, preparing a casting solution, casting, forming a membrane, drying and the like. According to the invention, the excellent characteristics of the PVDF hydrophobic microporous membrane are maintained, at the same time, the microstructure of the PVDF hydrophobic microporous membrane is improved, the membrane pore size, the membrane porosity and the membrane hydrophobicity are increased, the agglomeration of nanoparticles in the casting solution is overcome, the dispersibility of the nano silicon dioxide in the casting solution is improved,the hydrophobicity, membrane flux, chemical stability and membrane strength of the PVDF hydrophobic microporous membrane are enhanced, and the problem of reduction of the membrane flux caused by poordispersibility, prone agglomeration and easy blockage of membrane pores of the nanoparticles in the casting solution when inorganic nanoparticles are modified in the preparation of the PVDF hydrophobic microporous membrane is solved, so that the membrane is endowed with the characteristics of large water flux, high membrane flux, high hydrophobicity, high mechanical strength, and stable chemicalproperties.

Description

technical field [0001] The invention belongs to the field of membrane material preparation science and technology, and specifically relates to a method for in-situ synthesis of nano silicon dioxide modified PVDF hydrophobic microporous membrane. Background technique [0002] As a new type of separation technology, membrane technology is not only widely used in separation fields such as wastewater treatment and heavy metal removal, but also is increasingly used in engineering fields such as seawater desalination. Membrane separation technology has the advantages of high separation efficiency, less secondary pollution, simple separation process, and high economic benefits. This is consistent with my country's current development goal of building a resource-saving society, so it has attracted more and more attention from relevant researchers. [0003] So far, the membrane separation technologies that have been put into industrial application mainly include microfiltration, ult...

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Problems solved by technology

[0007] The object of the present invention is: the present invention provides a kind of method of in-situ synthesis nano-silica modified PVDF hydrophobic microporous membrane, obtains a kind of in-situ synthesis nano-silica modification and prepares PVDF hydrophobic microporous membrane, in PVDF On the basis of the original excellent characteristics of the hydrophobic microporous membrane, the microstructure of the PVDF hydrophobic microporous membrane is improved, the membrane pore size and porosity are increased, the hydrophobicity of the PVDF hydrophobic microporous membrane is increased, and the aggregation of nanoparticles in the casting solution is overcome. phenomenon, which greatly improves the dispersion of nano-silica in the casting solution, improves the hydrophobicity, pure water flux, membrane flux and strength of the PVDF hydrophobic microporous membrane, and solves the problem of inorganic nanoparticles in the modification When preparing the PVDF hydrophobic microporous membrane, the nanoparticles are prone to agglomeration, poor dispersion in the casting solution, and easy to block the membrane pores to reduce the membrane flux. The obtained PVDF hydrophobic microporous membrane has a large water flux, a membrane Features of high flux, strong hydrophobicity, high mechanical strength and stable chemical properties

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