A kind of preparation method of modified polyvinylidene fluoride film

A polyvinylidene fluoride membrane and modification technology, applied in the field of membrane separation, can solve the problems of low pressure resistance and membrane strength, poor comprehensive performance, poor membrane uniformity, etc., to improve pressure resistance and tightness. Strength issues, the effect of improving hydrophilicity and stain resistance, and good mechanical strength

Active Publication Date: 2021-11-26
GO HIGHER ENVIRONMENT GRP CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

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 purified water, the membrane is easy to adsorb organic pollutants, resulting in a decrease in membrane flux. , increase the operation, cleaning and maintenance cost of the membrane, and shorten its service life, so it is necessary to hydrophilize the PVDF membrane to improve the membrane performance
[0003] Adding a small amount of inorganic nanoparticles or PVA to the polymer matrix has become an important method to improve its material properties, but PVA is a polyhydric alcohol with alternate carbon atoms with hydroxyl groups, which has strong hydrophilicity and can be improved. Due to the high degree of water swelling of the membrane, the pressure resistance and strength of the membrane are very low, and the inorganic nanoparticles are easy to agglomerate due to their high polarity, large specific surface area and high surface energy. , resulting in poor uniformity of the modified membrane. Therefore, the modified membrane obtained by directly adding PVA or inorganic nanoparticles has limited improvement in hydrophilicity and poor overall performance, and its application range is limited.

Method used

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  • A kind of preparation method of modified polyvinylidene fluoride film
  • A kind of preparation method of modified polyvinylidene fluoride film
  • A kind of preparation method of modified polyvinylidene fluoride film

Examples

Experimental program
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Effect test

Embodiment 1

[0032] Add 1g of tetrabutyl titanate and 3g of glacial acetic acid to 10g of N-methylpyrrolidone solvent, stir evenly to obtain uniform and transparent TiO 2 Nanoparticle sol, spare;

[0033] Add 1g of PVA and 3g of lithium chloride to 70g of dimethylacetamide solvent, stir at 80°C for 4h until the system is evenly mixed, then add 2g of polyvinylpyrrolidone and 10g of PVDF, continue stirring at 80°C for 3h until the system is evenly mixed; Add the TiO 2 Nanoparticle sol, continue to stir at 80°C for 2 hours until the system is evenly mixed, and a uniform casting solution is obtained;

[0034] Stop the reaction, filter, stand for heat preservation and defoaming for 12 hours, cool until the temperature of the casting solution drops to 25°C, and evenly coat the cooled casting solution on the polyester non-woven fabric at a rate of 12m / min, and use a scraper The film was scraped evenly with a film knife to form a film, and the modified polyvinylidene fluoride film was obtained a...

Embodiment 2

[0036] Add 2g of tetrabutyl titanate and 4g of dodecylbenzenesulfonic acid to 10g of N-methylpyrrolidone solvent, and stir evenly to obtain uniform and transparent TiO 2 Nanoparticle sol, spare;

[0037] Add 2g of PVA and 2g of lithium chloride to 68g of dimethylacetamide solvent, stir at 85°C for 4h until the system is evenly mixed, then add 3g of polyethylene glycol and 9g of PVDF, continue stirring at 85°C for 3h until the system is evenly mixed; Add the TiO 2 Nanoparticle sol, continue to stir at 85°C for 2 hours until the system is evenly mixed, and a uniform casting solution is obtained;

[0038] Stop the reaction, filter, stand for heat preservation and defoaming for 12 hours, cool until the temperature of the casting solution drops to 25°C, apply the cooled casting solution evenly on the polyester non-woven fabric at a rate of 9m / min, and use a scraper The film was scraped evenly with a film knife to form a film, and the modified polyvinylidene fluoride film was obta...

Embodiment 3

[0040] Add 2.5g of tetrabutyl titanate and 6g of dodecylbenzenesulfonic acid to 10g of dimethylacetamide solvent, and stir evenly to obtain uniform and transparent TiO2 Nanoparticle sol, spare;

[0041] Add 1.5g of PVA and 2.5g of lithium chloride to 66.5g of dimethylacetamide solvent and stir at 85°C for 4h until the system is evenly mixed, then add 2g of polyvinylpyrrolidone and 9g of PVDF, and continue stirring at 85°C for 3h until the system is evenly mixed ; Then add the TiO 2 Nanoparticle sol, continue to stir at 85°C for 2 hours until the system is evenly mixed, and a uniform casting solution is obtained;

[0042] Stop the reaction, filter, stand for heat preservation and defoaming for 12 hours, cool until the temperature of the casting solution drops to 25°C, apply the cooled casting solution evenly on the polyester non-woven fabric at a rate of 9m / min, and use a scraper The film was scraped evenly with a film knife to form a film, and the modified polyvinylidene fluo...

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Abstract

The invention relates to the technical field of membrane separation, and discloses a method for preparing a modified polyvinylidene fluoride membrane. The method firstly prepares an inorganic nanoparticle sol, and then mixes it with PVDF and PVA to prepare a casting solution, and then obtains an improved polyvinylidene fluoride membrane. permanent polyvinylidene fluoride film. In the present invention, PVA is a polyhydric alcohol rich in hydroxyl, has strong hydrophilicity, and cooperates with inorganic nanoparticles to increase the pure water flux of the membrane. At the same time, the inorganic nanoparticle sol prepared by the sol-gel method has a small particle size, is easy to disperse in the casting solution, and is not easy to agglomerate, which helps to form a uniform casting solution and is conducive to improving the modified polymerization rate. Comprehensive properties of vinylidene fluoride membranes. In the present invention, PVA and inorganic nanoparticles are added to the casting liquid at the same time, so that the obtained PVDF membrane has the advantages of high flux, high hydrophilicity and pollution resistance, and also has good pressure resistance and mechanical strength, etc. Excellent performance, can be widely used in various wastewater treatment and other fields.

Description

technical field [0001] The invention relates to the technical field of membrane separation, in particular to a preparation method of a modified polyvinylidene fluoride membrane. Background technique [0002] Polyvinylidene fluoride (PVDF), a high molecular organic material, is a homopolymer of vinylidene fluoride or a copolymer of vinylidene fluoride and a small amount of other fluorine-containing vinyl monomers. It has excellent weather resistance and chemical stability, and is stable at room temperature. Corroded by strong oxidants such as acids and alkalis and halogens, and has the characteristics of high strength and wear resistance, it is often used as a membrane material in the field of chemical wastewater treatment. 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 purified water, the mem...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B01D71/34B01D67/00
Inventor 陈福泰郝福锦刘兴甜
Owner GO HIGHER ENVIRONMENT GRP CO LTD
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