Reinforced type polyvinylidene fluoride hollow fiber hydrophobic membrane and preparation method thereof

A polyvinylidene fluoride and hydrophobic membrane technology, applied in chemical instruments and methods, membrane technology, semi-permeable membrane separation, etc., can solve the problems of poor selectivity of inorganic membranes, low effective filling area of ​​membrane modules, and high cost of membrane preparation

Inactive Publication Date: 2011-07-06
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

However, inorganic membranes have disadvantages such as poor selectivity, low ef

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Example 1: 200 grams of hydrophobic nano-calcium carbonate particles were uniformly dispersed in 1500 grams of dimethylacetamide solvent under high-speed stirring conditions, and then 350 grams of polyvinylidene fluoride, 120 grams of lithium chloride, and 80 grams of acetone were added , stirred and dissolved evenly at a constant temperature of 60°C, and spun after defoaming; in the coagulation bath, the inner and outer coagulants are deionized water, and the primary film is soaked in deionized water for three days and then dried naturally to obtain organic-inorganic Hybrid hollow fiber hydrophobic membrane. The obtained hollow fiber hybrid membrane has an outer diameter of 1.2 mm, a wall thickness of 0.15 mm, an inner diameter of 0.9 mm, a membrane pore diameter of 0.36 μm, a porosity of 79%, and a contact angle of 96 degrees. During the direct contact membrane distillation desalination process of brine with 3.5% sodium chloride content, the permeation flux of the mem...

Embodiment 2

[0028]Example 2: 150 grams of hydrophobic nanoclay was uniformly dispersed in 1500 grams of dimethylacetamide solvent under high-speed stirring conditions, and then 260 grams of polyvinylidene fluoride, 150 grams of lithium chloride, and 100 grams of ethylene glycol were added , stirring and dissolving evenly under constant temperature conditions of 60°C, and spinning after defoaming; in the coagulation bath, the internal coagulant (i.e. core liquid) is a dimethylacetamide aqueous solution with a mass percentage of 20%, and the external coagulant is Deionized water, the nascent membrane was soaked in deionized water for three days and then dried naturally to obtain an organic-inorganic hybrid hollow fiber hydrophobic membrane. The obtained hollow fiber hybrid membrane has an outer diameter of 1.5 mm, a wall thickness of 0.1 mm, an inner diameter of 1.3 mm, a membrane pore diameter of 0.52 μm, a porosity of 85%, and a contact angle of 103 degrees. During the direct contact memb...

Embodiment 3

[0029] Embodiment 3: 150 grams of hydrophobic nano-silica particles are uniformly dispersed in 1500 grams of dimethylacetamide solvent under high-speed stirring conditions, and then 250 grams of vinylidene fluoride and hexafluoropropylene copolymer resin (yidene fluoride) are added. Ethylene repeating units account for 80% of the total number of copolymer repeating units), 200 grams of lithium chloride, stir and dissolve evenly under 60 ℃ of constant temperature conditions, and spin after degassing; in the coagulation bath, the internal coagulant (i.e. core liquid) is 20% by mass sodium chloride aqueous solution, the external coagulant is deionized water, the nascent membrane is soaked in deionized water for three days and then dried naturally to obtain the organic-inorganic hybrid hollow fiber hydrophobic membrane. The obtained hollow fiber hybrid membrane has an outer diameter of 1.3 mm, a wall thickness of 0.15 mm, an inner diameter of 1.0 mm, a membrane pore diameter of 0.4...

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Abstract

A reinforced type polyvinylidene fluoride hollow fiber hydrophobic membrane belongs to an organic-inorganic hybridization membrane. For a commonly-used organic polymeric membrane has lower mechanical strength and shorter service life. In the invention, the reinforced type polyvinylidene fluoride hollow fiber hydrophobic membrane is prepared by adding hydrophobic inorganic nano particles in casting membrane liquid through utilizing a phase conversion method. The reinforced type polyvinylidene fluoride hollow fiber hydrophobic membrane is prepared by the following compositions in the casting membrane liquid in percentage by weight: 10-35 percent of high-molecular polymer, 1-20 percent of inorganic nano particles, 0-25 percent of an addition agent and 60-85 percent of solvent. For the hollow fiber hydrophobic membrane, the outer diameter ranges from 0.5 to 2.5mm, the wall thickness ranges from 0.05 to 0.5mm, the porosity ranges from 50 to 90 percent, and the membrane aperture ranges from 0.01 to 1mum. The hollow fiber hydrophobic membrane is simple in membrane forming technique, convenient to operate, and easy to realize industrial production; and the prepared hollow fiber hydrophobic membrane is good in hydrophobicity, high in water flux, strong in chemical stability, excellent in mechanical performance and high in retention efficiency and has wide application prospect.

Description

technical field [0001] The invention relates to a method for preparing a hydrophobic hollow fiber membrane, in particular to a method for preparing a reinforced polyvinylidene fluoride hollow fiber hydrophobic membrane with an asymmetric structure by using an immersion gel phase inversion method. The hydrophobic membrane is suitable for a membrane distillation process, and can also be used as a microfiltration membrane or an ultrafiltration membrane in an industrial or medical microfiltration or ultrafiltration process. Background technique [0002] Membrane distillation is a membrane separation process that utilizes a hydrophobic microporous membrane and is driven by the difference in vapor pressure across the membrane. Because of the hydrophobic nature of the membrane, aqueous solutions on both sides of the membrane cannot pass through the membrane and enter the other side. However, since the vapor pressure between the aqueous solution on the high temperature side and the...

Claims

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Application Information

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IPC IPC(8): B01D71/34B01D69/08B01D67/00
Inventor 栾兆坤侯得印王军贾智萍孙项城
Owner RES CENT FOR ECO ENVIRONMENTAL SCI THE CHINESE ACAD OF SCI
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