Eureka AIR delivers breakthrough ideas for toughest innovation challenges, trusted by R&D personnel around the world.

Method for preparing alloy flat-sheet membrane by using low-temperature thermal induced phase separation method

A phase separation method and flat membrane technology, which is applied in semipermeable membrane separation, chemical instruments and methods, membrane technology, etc., can solve the problems of poor membrane pressure resistance, fewer flat membranes, and excessively large pore diameters, etc., and achieve long-term use. Effects of lifetime, small membrane pore size, and high crystallinity

Inactive Publication Date: 2015-02-04
唐山海清源科技股份有限公司
View PDF3 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method is rarely used in the field of flat film preparation. This is because the thermally induced phase separation method involves high-temperature dissolution, and the temperature is generally above 180°C. Some materials even need to be dissolved at a temperature above 300°C. rapid phase separation
Therefore, the thermally induced phase separation method is used to prepare flat membranes. The scraping equipment requires heating and heat preservation above 180°C. The requirements for equipment are high, the process conditions are complex and difficult to control, so thermally induced phase separation is rarely used to prepare flat membranes.
At the same time, due to the high temperature of the casting solution, the thermally induced phase separation method also requires a special non-woven substrate to cooperate, which also increases the difficulty and cost of membrane production, and the prepared membrane has the problem of excessively large pore size. , so that its field of application is limited
[0003] In the Chinese patent CN100478389C, an alloy flat membrane is prepared by blending polyvinylidene fluoride and polysulfone, and the flat membrane is directly prepared on a glass plate by a non-solvent-induced phase separation method. The non-solvent-induced phase separation method causes poor pressure resistance of the membrane and usually The amount is also slightly low, and without the use of non-woven substrates, it is difficult to mass-produce and practically use
Chinese patent CN101138708A adopts thermally induced phase separation to prepare polyvinylidene fluoride flat film. Although a mixed diluent is used, the mixed diluent is a high-temperature solvent of oil, resulting in a scraping film temperature of 180-260 ° C. For equipment The requirements are high, continuous production is difficult and the cost of film production is high. This method does not effectively reduce the temperature of the casting solution

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for preparing alloy flat-sheet membrane by using low-temperature thermal induced phase separation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] Mix polyvinylidene fluoride resin with a weight average molecular weight of 250,000 and polysulfone with a weight average molecular weight of 50,000, add a normal temperature solvent N,N-dimethylformamide and a high temperature solvent dibutyl phthalate as solvents, and then add a molecular weight of 10,000 polyethylene glycol and 50,000 molecular weight polyvinylpyrrolidone as additives, including polyvinylidene fluoride 12wt%, polysulfone 3wt%, polyethylene glycol 8wt%, polyvinylpyrrolidone 5wt%, dibutyl phthalate 42 wt% of ester, 30 wt% of N,N-dimethylformamide. Raise the temperature of the feed liquid to 70°C and stir to dissolve it. After unloading, put it into the trough of the film scraping equipment. The trough, scraper, and roller keep the temperature at 75-80°C, the winding speed is 8m / min, and the gas path is 5 ~10cm, the material liquid is coated on the non-woven fabric by a scraper, and enters the pure water gel bath at 15°C to solidify into a film after pa...

Embodiment 2

[0040] Mix polyvinylidene fluoride resin with a weight average molecular weight of 350,000 and polysulfone with a weight average molecular weight of 60,000, use normal temperature solvent N,N-dimethylformamide and high temperature solvent dibutyl phthalate as solvents, and additives with a molecular weight of 2,000 polyethylene glycol and polyvinylpyrrolidone with a molecular weight of 100,000. Its content is polyvinylidene fluoride 8.4wt%, polysulfone 3.6wt%, polyethylene glycol 8wt%, polyvinylpyrrolidone 2wt%, dibutyl phthalate 62.4wt%, N,N-dimethylformaldehyde Amide 15.6 wt%. Raise the temperature of the feed liquid to 110°C and stir to dissolve it. After unloading, put it into the trough of the film scraping equipment. The trough, scraper, and roller keep the temperature at 115-120°C. ~10cm, the material liquid is coated on the non-woven fabric by a doctor blade, and then enters the pure water gel bath at 25°C to solidify into a film after passing through the air process....

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
molecular weightaaaaaaaaaa
molecular weightaaaaaaaaaa
molecular weightaaaaaaaaaa
Login to View More

Abstract

The invention discloses a method for preparing an alloy flat-sheet membrane by using a low-temperature thermal induced phase separation method. The method comprises the steps of blending polyvinylidene fluoride and polysulfone; mixing under stirring at a temperature of 60-150 DEG C, by using polyethylene glycol and polyvinyl pyrrolidone as additives and a normal temperature solvent of N,N-dimethyl formamide and a high temperature solvent of dibutyl phthalate as diluents; then desorbing to obtain a membrane-casting solution; and then scraping the membrane-casting solution on a non-woven fabric with a flat-sheet membrane scraper to obtain the alloy flat-sheet membrane.

Description

technical field [0001] The invention belongs to the technical field of membrane preparation, and in particular relates to a method for preparing an alloy flat membrane by using a low-temperature thermotropic phase. Background technique [0002] In the field of separation membranes, there are many types of membranes, such as hollow fiber membranes, capillary fiber membranes, tubular membranes, and flat membranes. Among them, the flat membrane is valued because of its anti-pollution, easy cleaning, long service life, and easy use in the separation field with harsh conditions. The flat film prepared by the common non-solvent-induced phase separation method has low crystallinity of the polymer after film formation, resulting in poor strength of the flat film, which is not resistant to cleaning and has a short service life. The preparation of porous membranes by thermally induced phase separation can effectively solve the shortcomings of non-solvent induced phase separation. At ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): B01D69/06B01D67/00
Inventor 丁怀宇汤培秦利利史继岩
Owner 唐山海清源科技股份有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Eureka Blog
Learn More
PatSnap group products