Polyvinylidene fluoride hollow fiber membrane and preparation method thereof

A polyvinylidene fluoride and fiber membrane technology, applied in chemical instruments and methods, membrane technology, semi-permeable membrane separation, etc., can solve the problems of large permeable flux and high retention performance of ultra/microfiltration membranes, and achieve good retention effect , Filtration flux is large, the effect of increasing the effective filtration surface area

Active Publication Date: 2022-02-18
BEIJING SCINO MEMBRANCE TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Based on the above-mentioned problems, the present invention provides a polyvinylidene fluoride hollow fiber membrane and its preparation method to solve the problem that the ultra / microfiltration membrane prepared by the existing conventional means cannot meet the requirements of high water permeability and high retention performance at the same time problem

Method used

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  • Polyvinylidene fluoride hollow fiber membrane and preparation method thereof
  • Polyvinylidene fluoride hollow fiber membrane and preparation method thereof
  • Polyvinylidene fluoride hollow fiber membrane and preparation method thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0070] The specific implementation steps are as follows:

[0071](1) Prepare the casting solution: mix the diluent with PVDF, wherein the mass concentration of PVDF is 24wt%, the diluent is a mixture of benzophenone and myristyl alcohol, the mass concentration ratio is 80:20, and the temperature is raised to 220°C, Static defoaming and mixing uniformly to obtain casting solution;

[0072] (2) Extrusion of hollow fiber membrane: the casting liquid is further sheared and mixed at high temperature through a twin-screw extruder, and finally merged with the inner core liquid at the spinneret, and extruded through the spinneret together to form A hollow fiber-shaped homogeneous high-temperature casting film solution with a high-temperature core liquid in the inner cavity, and the inner core liquid is glycerol;

[0073] (3) Cooling and solidification to form a film: the hollow fiber-shaped homogeneous high-temperature solution is directly immersed in a water bath at 45° C. to cool, ...

Embodiment 2

[0085] The specific implementation steps are as follows:

[0086] (1) Preparation of casting solution: diluent and PVDF, wherein the mass concentration of PVDF is 22wt%, the diluent is a mixture of benzophenone and myristyl alcohol, the mass concentration ratio is 80:20, the temperature is raised to 220 ° C, and the Place defoaming and mix uniformly to obtain casting solution;

[0087] (2) Extrusion of hollow fiber membrane: the casting liquid is further sheared and mixed at high temperature through a twin-screw extruder, and finally merged with the inner core liquid at the spinneret, and extruded through the spinneret together to form A hollow fiber-shaped homogeneous high-temperature casting film solution with a high-temperature core liquid in the inner cavity, and the inner core liquid is glycerol;

[0088] (3) Cooling and solidification to form a film: the hollow fiber-shaped homogeneous high-temperature solution is directly immersed in a water bath at 45° C. to cool, sta...

Embodiment 3

[0093] The specific implementation steps are as follows:

[0094] (1) Prepare the casting solution: mix the diluent with PVDF, wherein the mass concentration of PVDF is 26wt%, the diluent is a mixture of benzophenone and myristyl alcohol, the mass concentration ratio is 80:20, and the temperature is raised to 220°C, Static defoaming and mixing uniformly to obtain casting solution;

[0095] (2) Extrusion of hollow fiber membrane: the casting liquid is further sheared and mixed at high temperature through a twin-screw extruder, and finally merged with the inner core liquid at the spinneret, and extruded through the spinneret together to form A hollow fiber-shaped homogeneous high-temperature casting film solution with a high-temperature core liquid in the inner cavity, and the inner core liquid is glycerol;

[0096] (3) Cooling and solidification to form a film: the hollow fiber-shaped homogeneous high-temperature solution is directly immersed in a water bath at 40° C. to cool,...

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Abstract

The invention provides a polyvinylidene fluoride hollow fiber membrane and a preparation method thereof. The hollow fiber membrane is a porous structure prepared by taking polyvinylidene fluoride (PVDF) as a raw material under the action of a diluent. The outer surface layer of the porous structure is of a pit structure, and the pit structure comprises a plurality of pits; the diameter of each pit is 0.1 [mu]m-1 [mu]m, a large number of small holes formed by piling PVDF spherocrystals are uniformly distributed in the pits, and the aperture of the small holes is 0.02 [mu]m-0. 04 [mu]m; a spongy macroporous structure with non-uniform pore diameter is arranged below the outer surface layer, the pore diameter of the spongy macroporous structure is gradually changed from the outer surface layer to the inside, and a change value is gradually increased from 1 micron to 10 microns. According to the PVDF hollow fiber membrane with the hourglass-like pore structure, provided by the invention, the effective filtering surface area of the hollow fiber membrane is obviously increased, so the hollow fiber membrane is large in filtering flux and has a good interception effect; namely, the unification of large flux and high interception of the PVDF hollow fiber membrane is realized.

Description

technical field [0001] The invention relates to the technical field of polymer membrane materials, in particular to a polyvinylidene fluoride hollow fiber membrane and a preparation method thereof. Background technique [0002] Large permeable flux and high retention performance have always been the goals pursued by excellent ultra / microfiltration membranes. Most of the ultrafiltration membrane products currently on the market are prepared by the Non-Solvent induced Phase Separation (NIPS) method. The membrane prepared by NIPS has a stepped asymmetric pore structure in the mainstream, and the separation layer that acts as a separation is on the outer surface of the membrane, with a pore diameter of about 0.03 μm, which is much smaller than the micropore diameter of the support layer; therefore, the surface While the dense skin improves the retention capacity of the membrane, it also limits its water permeability, making it difficult to effectively increase the water permeab...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D71/34B01D69/08B01D67/00
CPCB01D71/34B01D69/08B01D67/0016
Inventor 田野金宇涛张岩岗赵婧何柳东吴红梅
Owner BEIJING SCINO MEMBRANCE TECH
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