Method using metal hydroxide nano fibers to prepare high-throughput PVDF porous film

A technology of nanofibers and hydroxides, applied in chemical instruments and methods, membrane technology, semipermeable membrane separation, etc., can solve problems affecting the flux of porous filtration membranes, achieve excellent chemical stability, increase porosity, and improve flux effect

Inactive Publication Date: 2017-08-04
JIANGSU BODA ENVIRONMENTAL PROTECTION
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although its nanomaterials include copper hydroxide and aluminum hydroxide, the nanomaterials are non-agglomerated nanomaterials dispersed ...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] a) adding copper hydroxide nanofibers to DMAc and stirring for 10 h to obtain a copper hydroxide nanofiber dispersion;

[0027] b) Adding PVDF and PVP K17 with a molecular weight of 300,000 to the dispersion in step a), stirring at 50°C for 3 hours, and then ultrasonically defoaming for 1 hour to obtain a casting solution;

[0028] Among them, the mass ratio of copper hydroxide nanofibers: PVDF: PVP K17: DMAc is 0.05:20:5:74.9.

[0029] c) Scrape the film casting solution prepared in step b) on a glass plate to make a PVDF flat film, after exposure to air for 10s, quickly put it into ethanol for 10min, and then soak it in deionized water for 48h;

[0030] d) The PVDF flat membrane in step c) was taken out and placed in a 5 wt.% acetic acid aqueous solution for 30 min to remove the copper hydroxide nanofibers, taken out, rinsed with deionized water, and dried to obtain a high-flux PVDF porous membrane.

[0031] The PVDF porous membrane has a flux of 408 L m at 25 °C and...

Embodiment 2

[0033] a) Add aluminum hydroxide nanofibers to NMP and stir for 10 h to obtain aluminum hydroxide nanofiber dispersion;

[0034] b) Adding PVDF and PEG 400 with a molecular weight of 570,000 to the dispersion in step a), stirring at 60°C for 4 hours, and then ultrasonically defoaming for 1.5 hours to obtain a casting solution;

[0035] Among them, the mass ratio of copper hydroxide nanofibers: PVDF: PVP K17: DMAc is 0.05:18:4:77.95.

[0036] c) Scrape the film casting solution prepared in step b) on a glass plate to make a PVDF flat film, after exposure to air for 10s, quickly put it into ethanol for 10min, and then soak it in deionized water for 48h;

[0037] d) The PVDF flat membrane in step c) was taken out and placed in a 5 wt% acetic acid aqueous solution for 30 min to remove the aluminum hydroxide nanofibers, taken out, rinsed with deionized water, and dried to obtain a high-flux PVDF porous membrane.

[0038] The PVDF porous membrane has a flux of 550 L m at 25 °C and ...

Embodiment 3

[0040] a) Adding copper hydroxide nanofibers to DMF, stirring for 10 hours, to obtain a copper hydroxide nanofiber dispersion;

[0041] b) Adding PVDF and PEG 800 with a molecular weight of 370,000 to the dispersion in step a), stirring at 50°C for 3 hours, and then ultrasonically defoaming for 1 hour to obtain a casting solution;

[0042] Among them, the mass ratio of copper hydroxide nanofibers: PVDF: PVP K17: DMAc is 0.05:15:5:79.95.

[0043] c) Scrape the film casting solution prepared in step b) on a glass plate to make a PVDF flat film, after exposure to air for 10s, quickly put it into ethanol for 10min, and then soak it in deionized water for 48h;

[0044] d) The PVDF flat membrane in step c) was taken out and placed in a 5 wt% acetic acid aqueous solution for 30 min to remove copper hydroxide nanofibers, taken out, rinsed with deionized water, and dried to obtain a high-flux PVDF porous membrane.

[0045] The PVDF porous membrane has a flux of 683 L m at 25 °C and 1 ...

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PUM

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Abstract

The invention relates to a method using metal hydroxide nano fibers to prepare a high-throughput polyvinylidene difluoride (PVDF) porous film. The method includes the steps of firstly, adding the metal hydroxide nano fibers into a solvent, and stirring to prepare metal hydroxide nano fiber dispersion liquid; secondly, adding PVDF and a pore-forming agent into the metal hydroxide nano fiber dispersion liquid, evenly stirring, and ultrasonically defoaming to obtain film casting liquid; thirdly, using an immersion precipitation phase inversion process to scrape the prepared film casting liquid to obtain a flat PVDF film; fourthly, placing the flat PVDF film into an acetic acid solution to remove the metal hydroxide nano fibers, washing with deionized water, and airing to obtain the high-throughput PVDF porous film. Compared with a traditional method for preparing a teflon film, the method has the advantages that the porosity of the prepared polyvinylidene difluoride film is increased evidently, and the throughput of the film is increased evidently.

Description

technical field [0001] The invention relates to a polyvinylidene fluoride membrane, more specifically a method for preparing a high-flux PVDF porous membrane based on metal hydroxide nanofibers. Background technique [0002] The application technology of separation membrane has the advantages of low energy consumption, high efficiency and simple equipment, and can be used in the fields of separation, purification and concentration. Among them, the separation membrane made of PVDF has been widely used in various fields due to its stable chemical properties and excellent mechanical strength. However, PVDF is a hydrophobic material, and flux tends to be weak in the case of comparable retention rates in water treatment processes. The commonly used methods to increase the flux of PVDF separation membranes are as follows: (1) chemical grafting method, including membrane material pretreatment, dehydrofluorination, washing, radicalization, grafting and other steps; (2) blending mod...

Claims

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Application Information

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IPC IPC(8): B01D71/34B01D67/00
CPCB01D71/34B01D67/0013
Inventor 姚雪萍常江吴倩
Owner JIANGSU BODA ENVIRONMENTAL PROTECTION
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