Preparation method of forward osmosis membrane based on 3D printing technology

Abstract

The invention discloses a preparation method of a forward osmosis membrane based on a 3D printing technology. The method comprises the following steps: (1) preparing a polyvinyl chloride supporting layer: mixing polyvinyl chloride, polyvinyl alcohol and N-methylpyrrolidone until the three substances are evenly stirred, standing the obtained mixture to defoam, uniformly forming a membrane by usinga membrane coating machine, and storing the membrane in deionized water for later use; and (2) preparing a polyvinyl chloride-polyamide composite membrane: preparing an n-hexane solution A containingtrimesoyl chloride and an aqueous solution B containing m-phenylenediamine, and sequentially depositing the solution B and the solution A on the polyvinyl chloride supporting layer by a 3D printer toobtain the composite membrane. The positive osmosis membrane prepared by the 3D printing technology has a controllable pore size and a controllable thickness; and the surface roughness of the membraneis reduced to about 2 nm from original about 80 nm (the surface roughness of membranes prepared through conventional interfacial polymerization methods), so the composite membrane is thin and smooth,thereby the water permeability and the salt rejection rate are greatly improved, good performances of the membrane are ensured, and the cost is reduced.

Description

Technical field [0001] The invention belongs to the field of membrane technology and water treatment technology, and specifically relates to a method for preparing a forward osmosis membrane based on 3D printing technology and its application in water treatment technology. Background technique [0002] Only 47.3% of the total precipitation in the country is converted into water resources, and most of the rest is consumed in evapotranspiration. In addition, my country's water resources have uneven distribution in time and space, rapid population growth, and water pollution, which have led to a shortage of water resources per capita in my country. [0003] Traditional water treatment technology is divided into thermal method and membrane method. Thermal method and membrane method based on distillation and adsorption have higher energy consumption. Membrane technology is divided into nanofiltration, ultrafiltration, reverse osmosis and forward osmosis. The technology has received wid...

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Problems solved by technology

[0004] The patent with the publication number CN107235745A discloses "a sewage treatment ceramic membrane prepared by 3D printing technology and its preparation method". This method uses a computer to design a three-dimensional file of the membrane with regular apertures. The membrane aperture and thickness are uniform and controllable, but The raw material carbon fiber used is expensive, cost-effective and less feasible

[0005] The patent with the publication number CN106747544A discloses "a ceramic membrane prepared by 3D printing technology and its preparation method". Although the membrane prepared by this method is resistant to high temperature and high pressure and is stable under long-term operating conditions, the same raw materials are expensive and cost-effective. Low

[0006] The patent with the publication number CN106582570A discloses "a filter membrane prepared by 3D printing technology and its preparation method". Low

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