Method for preparing high-flux polyvinylidene fluoride hollow fiber membrane

A polyvinylidene fluoride and fiber membrane technology, which is applied in chemical instruments and methods, membrane technology, and semipermeable membrane separation, can solve the problems of low pore size and pore density, poor strength, and low flux, and achieve increased Membrane flux, maintaining strength, and improving the effect of membrane flux

Active Publication Date: 2012-06-27
SUZHOU CNPT SOURCETECH ENVIRONMENTAL TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the typical linear polymer structure and strong hydrophobic properties of polyvinylidene fluoride, the polyvinylidene fluoride hollow fiber membrane has problems such as poor strength, easy deformation, no pressure resistance, and low flux in the actual application process.
In order to improve the application status of polyvinylidene fluoride hollow fiber membranes, the patent publication No. CN1128176A mixes polyvinylidene fluoride, solvent, polymer pore-forming agent, non-solvent, surfactant, etc., and through their interaction, prepares Hollow fiber membranes with stable structure and good flux have been produced, but the mechanical strength of the membrane prepared by this method is insufficient, and the flux is not high, which cannot meet the production needs
In the literature [Research on Nano-inorganic / Polyvinylidene Fluoride Composite Ultrafiltration Membrane], it is proposed to blend PVDF membrane materials with various inorganic nanoparticles, and use inorganic nanoparticles to compound and modify PVDF membrane materials. The inorganic-organic network lattice is formed through the interaction, and the ultrafiltration membrane with high pressure resistance is prepared. However, the ultrafiltration membrane with the addition of inorganic nanoparticles has a dense porosity structure, and the pore size and pore density are not high, which cannot meet the requirements of high flux. Membrane Industry Demand

Method used

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  • Method for preparing high-flux polyvinylidene fluoride hollow fiber membrane
  • Method for preparing high-flux polyvinylidene fluoride hollow fiber membrane
  • Method for preparing high-flux polyvinylidene fluoride hollow fiber membrane

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] The preparation steps are as follows:

[0026] 1) Preparation of film-forming liquid: 10-20% polyvinylidene fluoride, 2-8% gas porogen, 3-8% hydrophilic modifier, 0-10% additive, 65- 85% organic solvent is stirred and mixed at a temperature of 40-80 °C, and then left to stand for defoaming to obtain a film-forming liquid with a temperature of 40-80 °C;

[0027] 2) Preparation of hollow fiber membrane: use dry and wet spinning equipment under the set spinning speed (5-10m / min), mix the inner gel medium (water or water and one of acetic acid, hydrochloric acid, and glycerol according to The mixed solution with a mass ratio of 4-9:1) and the film-forming solution pass through the spinning nozzles on the dry and wet spinning equipment at the same time, and inject the outer gel medium (0.1 0.1 % of which is composed of hydrochloric acid or acetic acid and water). -1mol / L solution) to obtain the initial hollow fiber membrane by phase separation; the initial hollow fiber memb...

Embodiment 2

[0033] The preparation steps are the same as in Example 1, and the preparation conditions are as follows:

[0034]

[0035] The outer diameter of the obtained hollow fiber ultrafiltration membrane is about 1.48mm, the wall thickness is about 0.24mm, and the pure water flux at 0.1MPa reaches 463L / (m 2 h), the retention rate of BSA is basically maintained above 95%, and the tensile strength is about 3.70MPa.

Embodiment 3

[0037] The preparation steps are the same as in Example 1, and the preparation conditions are as follows:

[0038]

[0039]

[0040] The outer diameter of the obtained hollow fiber ultrafiltration membrane is about 1.61mm, the wall thickness is about 0.30mm, and the pure water flux under 0.1MPa reaches 580L / (m 2 h), the retention rate of BSA is basically kept above 90%, and the tensile strength is about 3.21MPa.

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Abstract

The invention discloses a method for preparing a high-flux polyvinylidene fluoride hollow fiber membrane. The method comprises the following steps of: mixing polyvinylidene fluoride, a gaseous pore-forming agent, a hydrophilic modifier, additives and organic solvents and making a membrane-making solution; allowing an internal gelling medium and the membrane-making solution to pass through spinning nozzles on dry/wet spinning equipment at the same time, injecting into an external gelling medium, and performing phase-splitting treatment to make a primary membrane; and performing special chemical treatment on the primary membrane with a chemical treatment liquid to obtain a high-flux polyvinylidene fluoride hollow fiber membrane. The invention is characterized in that the membrane is reinforced with the pores by chemical reactions between the internal gelling medium, external gelling medium and chemical treatment liquid and the gaseous pore-forming agent; and the polyvinylidene fluoride hollow fiber membrane has a high flux, a high strength, a high entrapment rate and good hydrophilicity.

Description

technical field [0001] The invention relates to a preparation method of a polyvinylidene fluoride hollow fiber membrane, in particular to a preparation method of a high-flux polyvinylidene fluoride hollow fiber membrane. Background technique [0002] Polyvinylidene fluoride fiber membrane is a kind of porous membrane that has appeared in recent years. It has the advantages of excellent chemical stability, high heat resistance and strong anti-pollution properties, so it is widely used in filtration and separation in various fields. However, due to the typical linear polymer structure and strong hydrophobic properties of polyvinylidene fluoride, the polyvinylidene fluoride hollow fiber membrane has problems such as poor strength, easy deformation, low pressure resistance and low flux in the actual application process. In order to improve the application of polyvinylidene fluoride hollow fiber membrane, the patent publication number is CN1128176A by mixing polyvinylidene fluori...

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 孙兵王磊柴续斌黄丹曦周刚容志勇黄游孟晓荣张东海苗瑞王旭东吕永涛余铭皋赵解杨
Owner SUZHOU CNPT SOURCETECH ENVIRONMENTAL TECH
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