Preparation method of polyvinylidene fluoride (PVDF) composite mesoporous membrane

Abstract

The invention belongs to the technical field of preparation of composite membranes, and relates to a preparation method of a polyvinylidene fluoride (PVDF) mesoporous membrane, and the method includes the following steps: dissolving polyvinylidene fluoride powder in an organic solvent, adding a pore forming agent, stirring evenly to prepare a polyvinylidene fluoride membrane casting solution; adding SBA-15 to obtain a mixed solution, heating and stirring the mixed solution to prepare a polyvinylidene fluoride-silica membrane casting solution; sealing, standing for defoaming; using an automatic coating machine to coat a glass substrate with the PVDF-SBA-15 membrane casting solution, and immersing the glass substrate in a solidification liquid to obtain a polyvinylidene fluoride-silica composite membrane. The preparation method is simple in operation, the membrane is prepared at low temperature, the polymer degradation can be reduced, the strength of the membrane is ensured, the prepared PVDF-SBA-15 can effectively improve the hydrophilic ability and water flux of the membrane, and the membrane has good application prospects in the field of water pollutant removal.

Description

technical field [0001] The invention belongs to the technical field of composite membrane preparation, and relates to a method for preparing a polyvinylidene fluoride mesoporous membrane. Background technique [0002] Polyvinylidene fluoride (PVDF) is a widely used polymer separation membrane material. Compared with polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), etc., it has good chemical stability and mechanical strength. High, acid and alkali resistance and other characteristics. Polyvinylidene fluoride (PVDF) film is easy to prepare and low in cost. It can still maintain good strength under certain temperature and pressure, and has good resistance to ultraviolet rays and weather aging. Its film can be placed outdoors for one to twenty years It will not be brittle or cracked. In addition, it is not corroded by acids, alkalis, strong oxidants and halogens at room temperature, and organic solvents such as aliphatic hydrocarbons, alcohols, and aldehydes ha...

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Problems solved by technology

Patent CN 102240510 A "A Preparation Method for Superhydrophilic Polyvinylidene Fluoride Membrane" adopts the method of blending and phase inversion to form a membrane to introduce active groups into the membrane material, and then immerse the membrane material in a solution containing aminosilane Reactive modification to form an organic-inorganic hybrid membrane surface with certain hydrophilic components and nanostructures. Although this method is simple in process and stable in superhydrophilic performance, the modification efficiency is not high and is limited to the modification of the membrane surface.

Chinese Patent CN 101319081 A "A Hydrophilic PVDF Material and Its Preparation Method" blends different ratios of raw materials in a molten state, and selects kaolin as the inorganic material. The polyvinylidene fluoride (PVDF) film prepared by this method It can reduce the water contact angle to about 70 degrees and greatly improve the hydrophilicity. However, the pore size of kaolin is not uniform and cannot be adjusted, so it has certain limitations in the application of pollutant treatment.

Chinese patent CN 1724586 A "Nano-alumina modified polyvinylidene fluoride film and its preparation method and application" obtains the casting film liquid through the method of organic and inorganic blending, and adopts the immersion gel phase inversion method (L-S phase inversion method) to prepare Film formation, this method can enhance the hydrophilicity of the film, improve the strength of the film and prolong its life, but this method has high requirements for inorganic particles, and aluminum oxide is an alkaline substance. In the prior art, a large amount of use will do more harm than good

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