An anti-pollution self-cleaning poly(vinylidene fluoride) flat-sheet ultrafiltration membrane, a preparing method thereof and applications of the membrane

A technology of polyvinylidene fluoride and polyvinylidene fluoride powder is applied in the field of anti-pollution self-cleaning polyvinylidene fluoride ultrafiltration membrane and its preparation, which can solve the problems of unimproved structure and performance, and avoid agglomeration and difficult separation. , Improve the effect of anti-pollution self-cleaning performance and economical improvement

Active Publication Date: 2017-06-30
HUAIYIN TEACHERS COLLEGE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the blending modification, since the nanoparticles are wrapped in the polymer membrane material, its photocatalytic performance is seriously affected. The modification can expose the nanoparticles on the surface of the membrane

Method used

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  • An anti-pollution self-cleaning poly(vinylidene fluoride) flat-sheet ultrafiltration membrane, a preparing method thereof and applications of the membrane

Examples

Experimental program
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preparation example Construction

[0042] The preparation raw materials of the ultrafiltration membrane include the following components: polyvinylidene fluoride powder, amphiphilic copolymer, organic solvent, attapulgite-graphite-like phase carbon nitride composite material powder, additives, and coagulation bath.

[0043] The organic solvent here refers to a solvent capable of dissolving polyvinylidene fluoride powder, for example: N-methyl-2-pyrrolidone, tetrahydrofuran, dimethyl sulfoxide; amides such as dimethylacetamide and dimethylformamide; Ester solvents such as trimethyl phosphate or triethyl phosphate; Lactone solvents such as γ-butyrolactone; and their mixed solvents.

Embodiment 1

[0051] Example 1 Preparation of attapulgite-graphite-like phase carbon nitride composite material

[0052] Weigh 3.02g of silane coupling agent-modified attapulgite and disperse it in 1000mL of deionized water, ultrasonically disperse; then add 6.01g of melamine, stir, condense and reflux at 80°C for 2h; then freeze-dry for 48h, grind and add to the quartz boat , the quartz boat was placed in the tube furnace, and the temperature was programmed in the tube furnace under the air atmosphere. The temperature rise program was as follows: room temperature was raised to 500 °C for 0.5 h, kept at 500 °C for 2 h, then continued to be heated to 520 °C for 2 min, and kept After 2 hours, the temperature was naturally lowered, and it was fully ground to a powder form to obtain an attapulgite-graphite-like phase carbon nitride composite material (for the preparation method, refer to patent document CN106179447A).

Embodiment 2

[0054] Add 1%, 4%, and 7% (relative to the quality of polyvinylidene fluoride powder) of the attapulgite-graphite-like carbon nitride prepared in Example 1 into 48g of triethyl phosphate, and the ultrasonic dispersion is uniform Finally, add 12g of polyvinylidene fluoride powder and 3% poly(methyl methacrylate-vinyl alcohol) (relative to the mass of polyvinylidene fluoride powder) and stir and dissolve at 80°C for 24h, then add 3g of polyethylene difluoride Stir with alcohol 400 for 24 hours to obtain the casting solution, and stand at 80 ° C for 24 hours to obtain the casting solution; then use a scraper to apply the casting solution on the flat plate, and use the immersion precipitation phase inversion method to form a film, the coagulation bath is the mass fraction 0.05% attapulgite-graphite-like phase carbon nitride aqueous suspension, the water temperature is 25°C, and the anti-pollution self-cleaning attapulgite-graphite-like phase carbon nitride / polyvinylidene fluoride u...

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Abstract

An anti-pollution self-cleaning poly(vinylidene fluoride) flat-sheet ultrafiltration membrane and a preparing method thereof are disclosed. The method includes dispersing a certain amount of attapulgite-graphite-like phased carbon nitride composite material particles in triethyl phosphate that is adopted as a solvent; adding poly(vinylidene fluoride) and an amphiphilic copolymer into the obtained dispersion; violently and mechanically stirring the mixture until added materials are dissolved; then adding a pore-forming agent that is poly(ethylene glycol); fully stirring the mixture; finally allowing the mixture to stand and defoaming the mixture to obtain a film casting liquid; and performing immerged phase-inversion to obtain the flat-sheet ultrafiltration membrane by adopting an aqueous suspension of an attapulgite-graphite-like phased carbon nitride composite material as a coagulating bath. A three-dimensional network structure formed by a unique nanometer fiber structure of attapulgite and poly(vinylidene fluoride) is utilized to effectively improve the structure and strength of a pure poly(vinylidene fluoride) ultrafiltration membrane and to enhance a membrane densification property. More importantly, photocatalytic performance of graphite-like phased carbon nitride on the surface and in the main body of the ultrafiltration membrane is utilized to achieve anti-pollution and self-cleaning functions of the membrane and to increase the economical efficiency of a membrane separating process.

Description

technical field [0001] The invention relates to an anti-pollution self-cleaning polyvinylidene fluoride ultrafiltration membrane and a preparation method and application thereof, belonging to the technical field of membrane separation materials. Background technique [0002] In recent years, the preparation of ultrafiltration membranes with polyvinylidene fluoride (PVDF) as the main material has attracted much attention. PVDF materials have many advantages such as excellent mechanical properties, stable chemical properties, resistance to acid and alkali corrosion, simple preparation process, and low cost. However, PVDF has extremely low surface energy and strong hydrophobicity, resulting in low water flux after film formation. During use, the intercepted substances are easily adsorbed on the surface of the membrane and in the pores of the membrane, resulting in blockage of the membrane pores, making the membrane anti-pollution. Flux decays quickly, reducing membrane life, ...

Claims

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Application Information

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IPC IPC(8): B01D71/34B01D71/02B01D69/06B01D69/02B01D67/00C02F1/44
CPCB01D67/0079B01D69/02B01D69/06B01D71/02B01D71/34B01D2325/10C02F1/444
Inventor 周守勇薛爱莲赵宜江杨禹魏东阳李梅生张艳张莉莉邢卫红严梦李常华徐珊珊荀莎莎
Owner HUAIYIN TEACHERS COLLEGE
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