Preparation method of superhydrophilic and underwater-superoleophobic polyacrylonitrile-based oil-water separating membrane

A polyacrylonitrile-based oil, underwater super-oleophobic technology, applied in separation methods, immiscible liquid separation, liquid separation, etc., can solve the problems of complex modification, complicated experimental process, small material size, etc., and achieve permanent Stable hydrophilicity, uniform pore size distribution, and good mechanical properties

Active Publication Date: 2018-07-06
TIANJIN POLYTECHNIC UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method needs to be irradiated by ultraviolet light, and the experimental process is relatively complicated.
[0005] The existing membrane materials for oil-water separation are expensive, complicated to modify, and not convenient for large-scale production. The modification process requires the use of a large amount of organic solvents, which is likely to cause secondary pollution.
[0006] These materials are small in size and complex in structure, so preparation methods are often too cumbersome
The current challenge is how to develop relatively simple, controllable, and efficient preparation of various artificially designed multi-scale micro-nano materials. It is imminent to prepare oil-water separation materials with stable structure and performance by more environmentally friendly and simple processes.

Method used

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  • Preparation method of superhydrophilic and underwater-superoleophobic polyacrylonitrile-based oil-water separating membrane
  • Preparation method of superhydrophilic and underwater-superoleophobic polyacrylonitrile-based oil-water separating membrane
  • Preparation method of superhydrophilic and underwater-superoleophobic polyacrylonitrile-based oil-water separating membrane

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] Add acrylonitrile-based binary copolymer acrylonitrile-methyl acrylate (molar ratio 4:1), crystalline compound diluent caprolactam and acetamide (mass ratio of caprolactam and acetamide is 3:1) into the stirred tank, propylene The mass percentage of nitrile-methyl acrylate (molar ratio: 4 / 1) binary copolymer is 20wt%, raise the temperature to 150°C, fully stir for 2h, stop stirring, defoam at this temperature for 20min, and make cast film liquid; preheat the mold in an oven with a set temperature of 155°C for 6 minutes, pour the casting solution into a mold with a thickness of 200 μm in the middle, and then place it in the oven, keep it at 150°C for 10 minutes, and quickly take out the mold And place it at 20-30°C to cool naturally in the air, after the casting liquid crystallizes and solidifies; open the mold, extract the diluent in the nascent film in deionized water, and obtain the acrylonitrile-based copolymer flat microporous film. After drying the prepared polyacr...

Embodiment 2

[0046] Such as figure 1 As shown, the carboxyl-rich microporous membrane prepared in Example 1 is directly immersed in a polyethyleneimine solution with a mass fraction of 2wt.% and a molecular weight of 600 at 40°C for 2 hours to prepare a superhydrophilic membrane rich in a large number of amine groups on the surface. Underwater superoleophobic polyacrylonitrile-based microporous membrane. The molecular structure of polyethyleneimine is

[0047]

[0048] After testing, the amine-rich acrylonitrile-based copolymer flat microporous membrane obtained in this example has a pore size distribution of 0.18-0.27 μm, and the cross-section presents a symmetrical double-connected dendritic structure with a porosity of up to 77.5% and a fracture strength of 2.6Mpa, the elongation at break is 17%, the surface has a micro-nano structure, the roughness is 3-8μm, the water droplets in the air quickly infiltrate the microporous membrane, the air-water contact angle is 0°, and the underwa...

Embodiment 3

[0050] Such as figure 1 As shown, the carboxyl-terminated microporous membrane prepared in Example 1 is directly soaked in a solution of 10wt.% glycerol and 2wt.% hydrochloric acid (catalyst) at 40°C for 2 hours to prepare a surface rich in a large number of hydroxyl groups. Hydrophilic, underwater superoleophobic polyacrylonitrile-based microporous membrane. The molecular structure of glycerol is

[0051]

[0052] After testing, the hydroxyl-rich acrylonitrile-based copolymer flat-plate microporous membrane obtained in this example has a pore size distribution of 0.18-0.27 μm, a symmetrical double-connected dendritic structure in cross-section, a porosity of up to 78.0%, and a breaking strength of 2.8 Mpa, the elongation at break is 16%, the surface has a micro-nano structure, and the roughness is 3-7μm. In the air, water droplets quickly infiltrate the microporous membrane, the air water is 0°, and the underwater oil contact angle is 163°. Flat microporous membrane. Sh...

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Abstract

The invention provides a preparation method of a superhydrophilic and underwater-superoleophobic polyacrylonitrile-based oil-water separating membrane. The preparation method comprises the following steps of: adopting acrylonitrile monomer as a main-body raw material, and adopting an aqueous-phase precipitated polymerization method to synthesize a polyacrylonitrile-based copolymer; selecting a crystalline diluting agent, combining with a thermally-induced phase separation method to construct a polyacrylonitrile-based microporous membrane with a micro/nano structure and high flux on the surface, and preparing the superhydrophilic and underwater-superoleophobic microporous membrane by simple modification and grafting, wherein the use of an organic solvent is avoided in synthesis and modification of the process. The oil-water separating membrane prepared by the preparation method has the advantages of high porosity, good pressure resistance, permanent hydrophilia and excellent underwateroleophobic property; in addition, the adhesion to oil drops is very low, the pollution resistance is good, long-time and stable operation can be achieved, and high-efficiency separation from an oil-water mixture to oil-in-water type oil-water emulsion can be realized only by means of gravity or lower pressure.

Description

technical field [0001] The invention belongs to the technical field of oil-water separation membrane preparation, and in particular relates to a preparation method of a superhydrophilic and underwater superoleophobic polyacrylonitrile-based oil-water separation membrane. Background technique [0002] Oil-water separation has always been a problem that plagues the world. With the development of industry, marine oil pollution and industrial oil spill accidents occur frequently, how to efficiently separate oil from water has become an urgent problem to be solved. As an emerging smart material, superwetting materials provide a new idea for solving the problem of oil-water separation. Oil-water separation materials based on superwetting materials are mainly divided into two categories: 1) superhydrophobic / superoleophilic materials; 2) superhydrophilic / superoleophobic materials. With a micro-nano structured surface, combined with the chemical composition of the surface of the ma...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D67/00B01D69/02B01D69/06B01D69/08B01D71/42B01D17/022
CPCB01D17/02B01D17/085B01D67/0009B01D67/0011B01D69/02B01D69/06B01D69/08B01D71/42B01D2323/02B01D2325/36
Inventor 韩娜谭林立张龙飞张文昕王卫静高宏坤邵卫
Owner TIANJIN POLYTECHNIC UNIV
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