Method for preparing hollow fiber nanofiltration membrane by using thermally induced phase separation/interface cross linking synchronization method

A thermally induced phase separation and interfacial cross-linking technology, which can be used in semi-permeable membrane separation, hollow filament manufacturing, fiber chemical characteristics, etc. It can solve the problems of unsuitable hollow fiber nanofiltration membrane, poor uniformity, and many defects. , to achieve the effect of simple and easy performance, high requirements to avoid stickiness, and easy control of thickness and uniformity

Inactive Publication Date: 2014-07-02
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the above process still has some shortcomings: ①The process is cumbersome; ②The adhesion between the support layer and the composite layer is poor, and there are many defects; ③The thickness of the composite layer is difficult to control and the uniformity is not good; ④It is not suitable for hollow fiber nanofiltration Difficult preparation of membranes, especially internal pressure membranes
Therefore, the promotion and application of nanofiltration technology are greatly limited.

Method used

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  • Method for preparing hollow fiber nanofiltration membrane by using thermally induced phase separation/interface cross linking synchronization method
  • Method for preparing hollow fiber nanofiltration membrane by using thermally induced phase separation/interface cross linking synchronization method
  • Method for preparing hollow fiber nanofiltration membrane by using thermally induced phase separation/interface cross linking synchronization method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Select polyacrylonitrile, dimethyl sulfone and p-dichlorobenzyl with a mass ratio of 10:90:1, add them into the stirring tank and mix evenly, heat to 160°C, stir well until the mixed system becomes a homogeneous solution, then let it stand for defoaming , to obtain the casting liquid; select glycerol as the core liquid; extrude the casting liquid and the core liquid through the outer hole of the ring spinning head at a speed of 3 m / min at 160 ° C and a pressure of 0.2 MPa, and then immerse the In an air bath at 30°C, a hollow primary membrane was obtained. The hollow nascent membrane was soaked in polyethyleneimine aqueous solution with a polyethyleneimine concentration of 5 g / L at 40° C. for 8 hours, and taken out to obtain a polyacrylonitrile hollow fiber nanofiltration membrane.

[0026] After the above-mentioned hollow fiber nanofiltration membrane is made into a membrane module, a nanofiltration membrane performance evaluation instrument is used to measure the volu...

Embodiment 2

[0036] Select polyacrylonitrile, propylene carbonate and p-dichlorobenzyl with a mass ratio of 20:80:1, add them into the stirring tank and mix evenly, heat to 160°C, stir well until the mixed system becomes a homogeneous solution, then let stand for defoaming, Obtain the casting liquid; select glycerol as the core liquid; the casting liquid and the core liquid are extruded through the outer hole of the ring spinning head at 160 ℃ and 0.2 MPa pressure at a speed of 3 m / min, and then immersed in 30 In an air bath at ℃, a hollow nascent membrane was obtained. Soak the hollow nascent membrane in a polydimethylaminoethyl methacrylate ethanol solution with a polydimethylaminoethyl methacrylate concentration of 5g / L at 40°C for 8 hours, take it out, and obtain a polyacrylonitrile hollow fiber nanofiltration membrane .

[0037] After the above-mentioned hollow fiber nanofiltration membrane is made into a membrane module, test the water flux and the rejection rate of magnesium sulfat...

Embodiment 3

[0039] Select polyvinylidene fluoride, cyclohexanone and p-dichlorobenzyl with a mass ratio of 30:70:3, add them into the stirring tank and mix evenly, heat to 140°C, stir well until the mixed system becomes a homogeneous solution, then let it stand for defoaming , to obtain the casting solution; select polyethylene glycol with a number average molecular weight of 200 as the core solution; pass the casting solution and the core solution through the ring spinning head at a speed of 5 m / min at 140° C. and a pressure of 0.2 MPa The outer hole was extruded and then immersed in an air bath at 20°C to obtain a hollow nascent membrane. Soak the hollow nascent membrane in a polyethyleneimine ethanol solution with a polyethyleneimine concentration of 15 g / L at 60°C for 12 hours, and take it out to obtain a polyvinylidene fluoride hollow fiber nanofiltration membrane.

[0040] After the above-mentioned hollow fiber nanofiltration membrane is made into a membrane module, test the water f...

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Abstract

The invention discloses a method for preparing a hollow fiber nanofiltration membrane by using a thermally induced phase separation / interface cross linking synchronization method; the preparation method comprises the following steps: 1) mixing polymer, a diluting agent and a cross linking agent to form a homogeneous phase membrane casting solution; 2) extruding the membrane casting solution and core solution, or the membrane casting solution and nitrogen by a ring-shaped spinning head, then conducting the thermally induced phase separation in a cooling bath so as to obtain a hollow primary membrane; 3) soaking the hollow primary membrane in extracting solution containing cross linking pre-polymer, conducting the interface cross linking at the same time with removing diluting agent, thereby obtaining a hollow fiber nanofiltration membrane. According to the method provided by the invention, the preparations of holing and separation layer is finished, and the difficulty point of high require of bonding property between a separation layer and a supporting layer of a combining method in the prior art can be avoided, and meanwhile the thickness and the evenness of the separation layer are easy to control; the simple new method for preparing the hollow fiber nanofiltration membrane with excellent property by using the thermally induced phase separation / interface cross linking synchronization method is provided; and the prepared nanofiltration membrane is little in defect, high in stability and high in controllability.

Description

technical field [0001] The invention relates to the technical field of preparation of separation membranes, in particular to a method for preparing hollow fiber nanofiltration membranes by a thermally induced phase separation / interface crosslinking synchronous method. Background technique [0002] Nanofiltration membrane is a new type of separation membrane developed in the late 1980s. It has the characteristics of low operating pressure requirements, high throughput, high rejection rate for inorganic salts and organic substances with a molecular weight between 200 and 1000, and has incomparable advantages in the separation and concentration of organic and inorganic mixtures. , has been widely used in drinking water purification, industrial water softening, waste water treatment, concentration and purification of ingredients in the pharmaceutical and food industries and other fields. [0003] Composite method is currently the most used and most effective method for preparin...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B01D71/68B01D69/08B01D67/00D01D5/24
Inventor 徐志康吴青芸梁洪卿胡梦欣
Owner ZHEJIANG UNIV
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