Polyimide microporous film and preparation method thereof, and application of polyimide microporous film in oil-water separation

Abstract

The invention relates to a polyimide microporous film and a preparation method thereof, and application of the polyimide microporous film in oil-water separation. The preparation method comprises thefollowing steps: (1) providing a polyamide acid solution; (2) adding a hydrophobic modifier into the polyamide acid solution; (3) molding a mixed solution obtained in the step (2) into a film material, and solidifying the obtained film material by adopting a coagulating bath to obtain a polyamide acid microporous film; (4) carrying out solvent replacement on the polyamide acid microporous film byadopting a low-surface-tension solvent; and (5) imidizing the polyamide acid microporous film treated in the step (4) to obtain the polyimide microporous film. The polyimide microporous film providedby the invention has good mechanical flexibility and structural designability, shows high separation efficiency on different types of oil-water mixtures, and has the advantages of low cost, high flux,high precision and high applicability; and the preparation method is simple in preparation process, easy to realize, rich in raw material sources and low in cost.

Description

technical field [0001] The invention relates to the technical field of functional materials, in particular to a polyimide microporous film, a preparation method thereof and an application in oil-water separation. Background technique [0002] With the rapid development of modern industry, the effective control of marine oil spills has attracted more and more attention, and has become a health and environmental issue that is concerned all over the world. Due to the high viscosity of crude oil, the fluidity of the oil-water mixture in the ocean at room temperature is relatively poor when the oil spills. How to efficiently remove the oil-water mixture formed by the oil spill in the ocean is a worldwide problem. Traditional methods such as incineration, blotting felts, oil skimmers, and dispersants either show low absorption efficiencies or present severe operational limitations. [0003] Among all oil-water separation methods, super-wetting oil-water separation membranes are c...

AI Technical Summary

Problems solved by technology

However, the existing membrane separation materials have obvious disadvantages: (1) the separation rate is low due to the limitation of the membrane area, and the separation purity of the emulsion is not high enough; (2) the pore structure is single, the designability is poor, and the separation or transmission of oil and water in the membrane The design of the characteristics is not high, and the separation efficiency is low; (3) the mechanical properties and temperature resistance of the existing gravity separation membrane are poor. For the separation of high-viscosity oil and water in the marine environment, auxiliary thermal energy technology (self-heating or auxiliary heating) cannot be used. High-efficiency and high-purity separation by means of power or power (injection by a high-power circulating pump)

Although the membrane materials prepared by the above technical solutions all have the ability to separate oil and water, the complex preparation process of the above materials, the difficulty of large-scale preparation, and the inability to separate oil-water emulsions or heavy oil emulsions limit their wide application.

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