Hydrophilic modification method of PVDF ultrafilter membrane by utilization of nano-TiO2 sol

A technology of ultrafiltration membrane and hydrophilization, which is applied in the field of membrane separation, can solve the problems of increasing hydrophilicity, unsatisfactory hydrophilicity, and limited application range, and achieves easy preparation, low cost, and simple membrane making process Effect

Inactive Publication Date: 2012-09-26
RES CENT FOR ECO ENVIRONMENTAL SCI THE CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

CN1724586A has introduced adding nanometer Al in molten state in casting film liquid 2 o 3 , adding a dispersant to increase the nano-Al 2 o 3 Dispersibilit

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] 2.4 grams of pore-forming agent polyvinylpyrrolidone (PVP) and 4 grams of anhydrous lithium chloride (LiCl) were dissolved in 94 grams of N-N dimethylacetamide solvent, and after it was completely dissolved, 20 grams of polyvinylpyrrolidone (PVP) was added under stirring conditions. Vinylidene fluoride (PVDF), and finally 5 grams of nano-TiO 2 The sol is added dropwise into the uniform casting solution. Stir evenly for 24 hours to make the nano-TiO 2 The sol is evenly dispersed in the casting solution, sealed and left for 2 days to defoam, then scrape the film on the non-woven fabric at a temperature of 25°C and a humidity of 45%, and slowly put it into deionized water after volatilization for 20 seconds Soaked for 24 hours, then cleaned with deionized water to obtain nano-TiO 2 Sol modified polyvinylidene fluoride ultrafiltration membrane.

Embodiment 2

[0030] 2.4 grams of pore-forming agent polyvinylpyrrolidone (PVP) and 4 grams of anhydrous lithium chloride (LiCl) were dissolved in 94 grams of N-N dimethylacetamide solvent, and after it was completely dissolved, 20 grams of polyvinylpyrrolidone (PVP) was added under stirring conditions. Vinylidene fluoride (PVDF), and finally 7 grams of nano-TiO 2 The sol is added dropwise into the uniform casting solution. Stir evenly for 24 hours to make the nano-TiO 2 The sol is evenly dispersed in the casting solution, sealed and left for 2 days to defoam, then scrape the film on the non-woven fabric at a temperature of 25°C and a humidity of 45%, and slowly put it into deionized water after volatilization for 20 seconds Soaked for 24 hours, then cleaned with deionized water to obtain nano-TiO 2 Sol modified polyvinylidene fluoride ultrafiltration membrane.

Embodiment 3

[0032]Dissolve 2.4 grams of pore-forming agent polyvinylpyrrolidone (PVP) and 4 grams of anhydrous lithium chloride (LiCl) into 94 grams of N-N dimethylacetamide solvent, and add 17.5 grams of polyvinylpyrrolidone (PVP) under stirring conditions after it is completely dissolved. Vinylidene fluoride (PVDF), and finally 5 grams of nano-TiO 2 The sol is added dropwise into the uniform casting solution. Stir evenly for 24 hours to make the nano-TiO 2 The sol is evenly dispersed in the casting solution, sealed and left for 2 days to defoam, then scrape the film on the non-woven fabric at a temperature of 25°C and a humidity of 45%, and slowly put it into deionized water after volatilization for 20 seconds Soaked for 24 hours, then cleaned with deionized water to obtain nano-TiO 2 Sol modified polyvinylidene fluoride ultrafiltration membrane.

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Abstract

The invention discloses a hydrophilic modification method of a PVDF ultrafilter membrane by the utilization of nano-TiO2 sol and belongs to the field of membrane separation technologies. According to the method, PVDF is used as the main high-molecular membrane preparation material. The hydrophilic TiO2 sol prepared in advance is added into a casting solution containing PVDF, an organic solvent and an additive, and the hydrophilic PVDF ultrafilter membrane is prepared by the utilization of a phase inversion method. By the adoption of the method, water contact angle of the prepared PVDF ultrafilter membrane can be reduced from about 85 degrees to about 60 degrees, and hydrophilicity of the PVDF membrane is obviously raised. Various substances concerned in the invention comprise, by weight, 10-25% of polyvinylidene fluoride (PVDF), 60-80% of a solvent for dissolving polyvinylidene fluoride, 1-10% of the TiO2 sol, and 0-10% of the additive, wherein the additive contains a mixture of anhydrous LiCl and PVP. Porosity of the prepared membrane is 50-80% and its membrane pore size is 0.01-0.2 micron. The method provided by the invention has a simple membrane forming technology, is convenient to operate, and is easy to realize industrial production. In addition, the prepared ultrafiler membrane has good hydrophilicity and high water flux, and has a wide application prospect.

Description

technical field [0001] The invention relates to a method of utilizing nano TiO 2 The invention relates to a method for modifying PVDF ultrafiltration membrane by hydrophilization of sol, which belongs to the technical field of membrane separation. Background technique [0002] Polyvinylidene fluoride (PVDF) is a semi-crystalline material with a glass transition temperature of -39°C, a crystallization melting point of about 170°C, and a thermal decomposition temperature above 316°C. It has excellent chemical stability, thermal stability, and easy film formation, etc. Advantages, it has been widely used in the preparation of membrane materials. However, due to the low surface energy and strong hydrophobicity of PVDF, the prepared membrane has poor hydrophilicity. In the application process of water phase separation systems such as biopharmaceuticals, food and beverage, and water purification, the membrane is easy to absorb organic solutes and be polluted. Therefore, PVDF Hyd...

Claims

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Application Information

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IPC IPC(8): B01D71/34B01D69/12B01D67/00
Inventor 栾兆坤赵长伟闫勇王涛贾智萍
Owner RES CENT FOR ECO ENVIRONMENTAL SCI THE CHINESE ACAD OF SCI
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