Preparation method and product of hydrophobic PVDF (Polyvinylidene Fluoride) microporous membrane with beta crystalline phase structure

A microporous membrane and hydrophobic technology, applied in the preparation and product field of hydrophobic PVDF microporous membrane with β crystal phase structure, can solve the problems of low membrane flux, high cost, small average pore size, etc., and achieve good application prospects , Low preparation cost, strong hydrophobic effect

Inactive Publication Date: 2012-10-31
ZHEJIANG GONGSHANG UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] By constructing new hydrophobic micro-nanostructures on the surface of the membrane, people can greatly improve the hydrophobic performance of the membrane, but the modified membrane also has some shortcomings.
Kong Ying et al. prepared polyvinylidene fluoride microporous membranes with inorganic salt lithium chloride as an additive (Kong Ying, Wu Yonglie, Yang Jinrong, et al.; Preparation and morphology of hydrophobic polyvinylidene fluoride microporous membranes for membrane distillation Research on the structure; Membrane Science and Technology; 10(3)(1990)84-89), the prepared membrane has both finger-like and sponge-like pore structures, and the hydrophobicity of the membrane is obviously improved. The existing problem is due to the The average pore size is small resulting in l

Method used

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  • Preparation method and product of hydrophobic PVDF (Polyvinylidene Fluoride) microporous membrane with beta crystalline phase structure
  • Preparation method and product of hydrophobic PVDF (Polyvinylidene Fluoride) microporous membrane with beta crystalline phase structure
  • Preparation method and product of hydrophobic PVDF (Polyvinylidene Fluoride) microporous membrane with beta crystalline phase structure

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] 1. Dissolve 1-butyl-3-methylimidazolium chloride ionic liquid and polyvinylidene fluoride in N-methylpyrrolidone (NMP), then stir at 60°C for 24 hours to prepare a uniform film-forming solution ; In this step, the ratio of raw materials input by mass percentage is: 2% for chlorinated-1-butyl-3-methylimidazolium ionic liquid, 15% for polyvinylidene fluoride, and 83% for N-methylpyrrolidone .

[0042] 2. Degas the film-making solution at 40°C for 18 hours, then use a scraper to scrape a 150 μm nascent flat liquid film on the flat carrier, and stay in the air at a temperature of 20°C and a relative humidity of 40% for 30 seconds ; Immerse the nascent liquid film on the flat carrier in deionized water at 20° C. to solidify to form a film, and the curing time to form a film is 20 seconds.

[0043] 3. Continue soaking in deionized water for 3 days after the membrane is cured, so that the ionic liquid can be completely removed from the membrane.

[0044] The properties of th...

Embodiment 2

[0046] 1. Dissolve 1-hexyl-3-methylimidazolium chloride ionic liquid and polyvinylidene fluoride in N,N-dimethylformamide (DMF), then stir at 65°C for 12 hours to prepare a homogeneous Membrane-making solution; in this step, the ratio of raw materials input by mass percentage is: 2% for chlorinated-1-hexyl-3-methylimidazolium ionic liquid, 15% for polyvinylidene fluoride, 15% for N, N-dimethyl The base formamide is 83%.

[0047] 2. Static defoaming of the film-making solution at 50°C for 20 hours, and then use a scraper to scrape a 200 μm nascent flat liquid film on the flat carrier, and stay in the air at a temperature of 25°C and a relative humidity of 50% for 40 seconds ; The nascent liquid film on the flat carrier is immersed in deionized water at 25° C. to solidify into a film, and the solidification time is 30 seconds.

[0048] 3. Continue soaking in deionized water for 3 days after the membrane is cured, so that the ionic liquid can be completely removed from the membr...

Embodiment 3

[0051] 1. Dissolve 1-octyl-3-methylimidazolium chloride ionic liquid and polyvinylidene fluoride in N,N-dimethylacetamide (DMAc), then stir at 70°C for 12 hours to prepare a homogeneous film-making solution; in this step, the raw material ratio calculated by mass percentage is: chlorinated-1-octyl-3-methylimidazolium ionic liquid is 2%, polyvinylidene fluoride is 15%, N, N- Dimethylacetamide is 83%.

[0052] 2. Degas the film-making solution at 60°C for 24 hours, then use a scraper to scrape a 250 μm nascent flat liquid film on the flat carrier, and stay in the air at a temperature of 30°C and a relative humidity of 60% for 50 seconds ; The nascent liquid film on the flat carrier is immersed in deionized water at 30° C. to solidify into a film, and the solidification time is 30 seconds.

[0053] 3. Continue soaking in deionized water for 3 days after the membrane is cured, so that the ionic liquid can be completely removed from the membrane.

[0054] The properties of the po...

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Abstract

The invention discloses a preparation method of a hydrophobic PVDF (Polyvinylidene Fluoride) microporous membrane with a beta crystalline phase structure. The preparation method comprises the following steps of: dissolving ionic liquid and polyvinylidene fluoride into an organic solvent I and stirring for at least 8 hours to prepare uniform membrane formation solution; defoaming the membrane formation solution, scraping a primary flat plate liquid membrane of 150-250 mum on a flat plate carrier, remaining in air for 30-50 seconds and soaking the primary flat plate liquid membrane into a solidification bath to cure and form a membrane; and soaking the membrane formed by curing and membrane formation in de-ionized water to prepare the hydrophobic PVDF microporous membrane with the beta crystalline phase structure. The invention also discloses the hydrophobic PVDF microporous membrane with the beta crystalline phase structure prepared by the method. The preparation method of the hydrophobic PVDF microporous membrane with the beta crystalline phase structure has the advantages of simple process and low preparation cost; and the prepared PVDF microporous membrane has strong hydrophobicity and has excellent application value in the aspects of membrane distillation, oil/water separation and the like.

Description

technical field [0001] The invention belongs to the field of membrane technology, in particular to a preparation method and product of a hydrophobic PVDF microporous membrane with a β crystal phase structure Background technique [0002] Membrane technology is a high-efficiency fluid separation technology. Compared with traditional separation technologies (such as distillation, etc.), it has the characteristics of high efficiency, low energy consumption, easy operation, and no pollution to the environment. increasingly important role in the economy. In the membrane separation technology, the membrane material plays a key role. At present, people's research on polymer membrane materials is mainly the hydrophilization and hydrophobic modification of the membrane. In recent years, with the application of membrane materials in petrochemical industry, membrane distillation, seawater desalination and oil / water separation systems, the hydrophobic modification of membranes is attra...

Claims

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Application Information

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IPC IPC(8): B01D71/34B01D69/02B01D67/00
Inventor 杜春慧吴春金吴礼光
Owner ZHEJIANG GONGSHANG UNIVERSITY
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