Polyvinylidene difluoride hollow fiber micro-filtration membrane with permanent hydrophilicity, and preparation method thereof

A polyvinylidene fluoride and microfiltration membrane technology, which is applied in the preparation of the polyvinylidene fluoride hollow fiber microfiltration membrane and the field of polyvinylidene fluoride hollow fiber microfiltration membrane, can solve the problem of difficult adsorption on the membrane surface and membrane pores. Blockage, difficult to control the length of the graft segment, etc., to achieve good hydrophilic effect

Active Publication Date: 2012-06-13
BEIJING ORIGIN WATER FILM TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The advantage of surface grafting is good hydrophilic effect and long-lasting hydrophilicity. The disadvantage is that the hydrophilicity of the membrane surface is only improved, and the hydrophilicity of the inner wall of the membrane hole is not improved. The length of the grafted segment is difficult to control. The hydration process is complex
[0005] Surface modification can also be carried out by adsorbing a hydrophilic coating on the membrane surface. For example, someone soaks the membrane in polyvinyl alcohol solution and aldehyde compound aqueous solution (Chinese patent CN1792419A, Chinese patent CN101485960A). The polyvinyl alcohol and aldehyde compounds are highly hydrophilic substances, which are easy to dissociate in aqueous solution and difficult to adsorb on the surface of the membrane. As a result, the two types of compounds preferentially form crosslinks in the membrane pores to form gels, resulting in Pores clogged, pure water flux drops

Method used

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  • Polyvinylidene difluoride hollow fiber micro-filtration membrane with permanent hydrophilicity, and preparation method thereof
  • Polyvinylidene difluoride hollow fiber micro-filtration membrane with permanent hydrophilicity, and preparation method thereof
  • Polyvinylidene difluoride hollow fiber micro-filtration membrane with permanent hydrophilicity, and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0087] Example 1: Preparation of polyvinylidene fluoride hollow fiber microfiltration membrane of the present invention

[0088] The preparation steps are as follows:

[0089] A. Preparation of spinning solution

[0090] Dissolve 17 parts by weight of polyvinylidene fluoride, 3 parts by weight of ethylene-vinyl acetate copolymer, 4 parts by weight of polypyrrolidone, 5 parts by weight of polyethylene glycol, 6 parts by weight of polyvinyl alcohol, and 1 part by weight of lithium chloride in 40 parts by weight of In parts of dimethylacetamide and 24 parts by weight of dimethylformamide solvent, a spinning solution is obtained after filtering with a 100-mesh filter screen of aperture;

[0091] B. Preparation of core liquid and coagulation bath

[0092] Dissolving dimethylacetamide in water to obtain a core liquid with a concentration of 70% by weight;

[0093] Dimethylacetamide was dissolved in water to obtain a coagulation bath with a concentration of 20% by weight;

[0094...

Embodiment 2

[0102] Example 2: Preparation of polyvinylidene fluoride hollow fiber microfiltration membrane of the present invention

[0103] The preparation steps are as follows:

[0104] A. Preparation of spinning solution

[0105] Dissolve 16.5 parts by weight of polyvinylidene fluoride, 2 parts by weight of ethylene-vinyl acetate copolymer, 5 parts by weight of polypyrrolidone, 5 parts by weight of polyethylene glycol, 6 parts by weight of polyvinyl alcohol, and 1 part by weight of lithium chloride in 40 parts by weight In parts of dimethylacetamide and 24.5 parts by weight of dimethylformamide, a spinning solution is obtained after filtering with a 100-mesh filter screen of aperture;

[0106] B. Preparation of core liquid and coagulation bath

[0107] Dissolve dimethylacetamide in water to obtain a core liquid with a concentration of 40% by weight;

[0108] Dimethylacetamide was dissolved in water to obtain a coagulation bath with a concentration of 20% by weight;

[0109] C. Dry-...

Embodiment 3

[0117] Example 3: Preparation of polyvinylidene fluoride hollow fiber microfiltration membrane of the present invention

[0118] The preparation steps are as follows:

[0119] A. Preparation of spinning solution

[0120] Dissolve 16.5 parts by weight of polyvinylidene fluoride, 3.5 parts by weight of ethylene-vinyl acetate copolymer, 5 parts by weight of polypyrrolidone, 4 parts by weight of polyethylene glycol, 6 parts by weight of polyvinyl alcohol, and 1.5 parts by weight of lithium chloride in 40 parts by weight In parts of dimethylacetamide and 24 parts by weight of nitrogen methyl pyrrolidone, a spinning solution is obtained after filtering with a 100-mesh filter screen with an aperture;

[0121] B. Preparation of core liquid and coagulation bath

[0122] Dissolve dimethylacetamide in water to obtain a core liquid with a concentration of 40% by weight;

[0123] Dimethylacetamide was dissolved in water to obtain a coagulation bath with a concentration of 20% by weight;...

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Abstract

The invention relates to a polyvinylidene difluoride hollow fiber micro-filtration membrane and a preparation method thereof. The preparation method comprises steps of spinning liquid preparing, core liquid and coagulation bath preparing, dry-wet spinning, alcoholysis, cleaning, and the like. Compared to existing technologies, the polyvinylidene difluoride hollow fiber micro-filtration membrane provided by the invention has permanent hydrophilicity. With the micro-filtration membrane, a long-term stable pure water flux is maintained, and the pure water flux is high.

Description

【Technical field】 [0001] The invention relates to the technical field of hollow fiber membranes. More specifically, the present invention relates to a polyvinylidene fluoride hollow fiber microfiltration membrane with permanent hydrophilicity, and also relates to a preparation method of the polyvinylidene fluoride hollow fiber microfiltration membrane. 【Background technique】 [0002] Due to the large electronegativity of the fluorine atom on the molecular chain, the small atomic radius, the short C-F bond, and the bond energy as high as 500KJ / mol, polyvinylidene fluoride has a certain degree of crystallinity. Therefore, polyvinylidene fluoride has excellent thermal stability and oxidation resistance. It has become the most widely used polymer film material at present. Polyvinylidene fluoride has good film-forming properties, and can form ultrafiltration membranes with smaller pore sizes and microfiltration membranes with larger pore sizes. Polyvinylidene fluoride can be ma...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D71/34B01D67/00B01D69/08B01D69/02
Inventor 陈亦力林勇文剑平吴强
Owner BEIJING ORIGIN WATER FILM TECH
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