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Hollow fiber membrane and preparation method thereof

A fiber membrane and hollow technology, which is applied in the field of nanofiltration membranes, can solve the problems of long-term backwashing of oxidative cleaning agents and insufficient interface bonding performance, and achieve good acid resistance, good bonding, and improved strength.

Inactive Publication Date: 2020-01-24
梧州中科鼎新工业技术研究院(有限合伙)
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Since the pore size and porosity of the inner layer of the finger-like pore structure are large, and the thickness of the outer layer of the nanoporous structure can be reduced to 0.1-1 μm, the membrane flux is relatively large, but there is a clear interface between the inner layer and the outer layer Delamination, resulting in insufficient interface bonding performance, unable to resist long-term backwashing of oxidative cleaning agents

Method used

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  • Hollow fiber membrane and preparation method thereof
  • Hollow fiber membrane and preparation method thereof

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preparation example Construction

[0045] Correspondingly, the present invention also provides a method for preparing a hollow fiber membrane, comprising the following steps:

[0046] (1) Put 15-22wt% polyvinylidene fluoride, 65-75wt% dimethylacetamide and 10-13wt% polyvinylpyrrolidone into a container, stir evenly, let it stand for defoaming, and form the inner casting film ; Put 20-25wt% of polyvinylidene fluoride, 70-80wt% of dimethylacetamide and 2-5wt% of polyvinylpyrrolidone into the container, stir evenly, let stand for defoaming, and form the outer layer release solution.

[0047] Preferably, the inner layer casting solution is stirred evenly at 50-60°C, and left standing for 10-12 hours for defoaming; the outer layer casting solution is stirred evenly at 60-70°C, and left standing for 10-12 hours for defoaming.

[0048] (2) Inject the core liquid, the outer layer casting liquid and the inner layer casting liquid into the core liquid channel, the outer layer casting liquid channel and the inner layer ca...

Embodiment 1

[0060] (1) Put 15wt% polyvinylidene fluoride, 75wt% dimethylacetamide and 10wt% polyvinylpyrrolidone into a container, stir evenly at 50°C, let it stand for defoaming for 12 hours, and form an inner layer casting solution; Put 20wt% polyvinylidene fluoride, 77wt% dimethylacetamide and 3wt% polyvinylpyrrolidone into a container, stir evenly at 60°C, let stand for defoaming for 11 hours, and form the outer layer release solution; the inner layer cast The molecular weight of polyvinylpyrrolidone in the membrane solution is 8000, and the molecular weight of polyvinylpyrrolidone in the outer casting solution is 30000;

[0061] (2) Inject the core liquid, the outer layer casting liquid and the inner layer casting liquid into the core liquid channel, the outer layer casting liquid channel and the inner layer casting liquid channel of the three-way spinneret respectively, and spray them out through the spinneret Form a tubular liquid film, and the tubular liquid film enters the coagul...

Embodiment 2

[0066] (1) Put 17wt% polyvinylidene fluoride, 74wt% dimethylacetamide and 9wt% polyvinylpyrrolidone into a container, stir evenly at 55°C, let stand for defoaming for 11 hours, and form an inner layer casting solution; Put 20wt% polyvinylidene fluoride, 78wt% dimethylacetamide and 2wt% polyvinylpyrrolidone into a container, stir evenly at 63°C, let stand for defoaming for 10 hours, and form the outer layer release solution; the inner layer cast The molecular weight of polyvinylpyrrolidone in the membrane solution is 10000, and the molecular weight of polyvinylpyrrolidone in the outer casting solution is 33000;

[0067] (2) Inject the core liquid, the outer layer casting liquid and the inner layer casting liquid into the core liquid channel, the outer layer casting liquid channel and the inner layer casting liquid channel of the three-way spinneret respectively, and spray them out through the spinneret Form a tubular liquid film, and the tubular liquid film enters the coagulati...

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Abstract

The invention discloses a hollow fiber membrane and a preparation method thereof. The nanofiltration membrane (hollow fiber membrane) comprises an inner layer and an outer layer, wherein an inner layer membrane casting liquid consists of 15-22wt% of polyvinylidene fluoride, 70-80wt% of dimethylacetamide and 5-10wt% of polyethylene pyrrolidone; and an outer layer membrane casting liquid consists of20-25wt% of polyvinylidene fluoride, 70-80wt% of dimethylacetamide and 2-5wt% of polyethylene pyrrolidone. The inner layer and outer layer of the invention have the same material. The inner layer andthe outer layer are made of identical materials; in the spinning process, the outer layer membrane casting liquid and the inner layer membrane casting liquid have a mutual fusion phenomenon, and theouter layer membrane casting liquid and the inner layer membrane casting liquid are mutually mixed, so that the boundary between the outer layer and the inner layer can be reduced, interfaces are wellbonded, and long-term backwash can be endured.

Description

technical field [0001] The invention relates to the technical field of nanofiltration membranes, in particular to a hollow fiber membrane and a preparation method thereof. Background technique [0002] With the development of industry, the waste and pollution of water resources have seriously affected people's normal life, especially industrial acid-base wastewater has the most serious environmental pollution, and nearly one million cubic meters of waste acid solution is discharged in my country every year. During the process of factories, chemical fiber factories, metal surface treatment and smelting (such as iron and steel industry, titanium dioxide industry, wet steelmaking industry, titanium steel industry, rare earth industry, gold mining and non-ferrous metal smelting industry, etc.), a large amount of acidic wastewater will be discharged , not only will acidify the water body or soil, cause harm to the ecological environment, but also waste a lot of available resources,...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D69/08B01D67/00B01D69/12B01D71/06
CPCB01D67/0011B01D67/0013B01D69/08B01D69/082B01D69/12B01D71/06B01D2323/12B01D2325/24
Inventor 白仁碧唐勋宏王泽瑞李胜华
Owner 梧州中科鼎新工业技术研究院(有限合伙)