阅读说明：本技术 一种有机无机复合超滤膜及其制备方法 (organic-inorganic composite ultrafiltration membrane and preparation method thereof ) 是由 陈泉学 于 2019-08-28 设计创作，主要内容包括：本发明提出了一种有机无机复合超滤膜及其制备方法,所述有机无机复合超滤膜包括聚醚砜、聚乙烯醇、亲水改性剂、成膜添加剂、溶剂和改性纤维,通过将改性纤维投入到溶剂中,并与成膜添加剂混合搅拌得到第一混合物,将聚醚砜、聚乙烯醇、亲水改性剂和溶剂混合制成第二混合物,通过混合第一混合物和第二混合物,通过刮膜、真空脱气泡即可得到本发明的有机无机福和超滤膜,本发明不仅具有良好的抗污染能力,同时其还具有良好的机械性能,在高压力和含聚废水环境中仍然可以正常工作,具有良好的应用前景。(The invention provides an organic-inorganic composite ultrafiltration membrane and a preparation method thereof, wherein the organic-inorganic composite ultrafiltration membrane comprises polyether sulfone, polyvinyl alcohol, a hydrophilic modifier, a membrane forming additive, a solvent and modified fibers, the modified fibers are put into the solvent and mixed and stirred with the membrane forming additive to obtain a first mixture, the polyether sulfone, the polyvinyl alcohol, the hydrophilic modifier and the solvent are mixed to prepare a second mixture, and the organic-inorganic composite ultrafiltration membrane can be obtained by mixing the first mixture and the second mixture and performing membrane scraping and vacuum defoaming.)

1. The organic-inorganic composite ultrafiltration membrane is characterized by comprising the following components in parts by weight:

2. the organic-inorganic composite ultrafiltration membrane of claim 1, wherein the hydrophilic modifier is trifluoroethyl methacrylate.

3. the organic-inorganic composite ultrafiltration membrane of claim 1, wherein the film forming additive is one or more of ethylene glycol, glycerol, lithium chloride and lithium nitrate.

4. The organic-inorganic composite ultrafiltration membrane of claim 1, wherein the solvent is N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, or dimethylsulfoxide.

5. The organic-inorganic composite ultrafiltration membrane of claim 1, wherein the modified fibers are modified titanium dioxide fibers.

6. The organic-inorganic composite ultrafiltration membrane of claim 5, wherein the preparation method of the modified titanium dioxide fiber comprises the following steps: adding titanium dioxide fibers into a sodium dodecyl sulfate solution with the mass concentration of 1%, adjusting the pH value of the solution to 3-4, stirring for 2-3h at normal temperature, centrifugally collecting the titanium dioxide fibers, and drying to obtain the modified titanium dioxide fibers.

7. The organic-inorganic composite ultrafiltration membrane of claim 6, wherein the ratio of titanium dioxide fiber: the mass ratio of the sodium dodecyl sulfate solution is 1: (100-200).

8. The organic-inorganic composite ultrafiltration membrane of claim 1, wherein the weight average molecular weight of the polyvinyl alcohol is 200-.

9. The method for preparing the organic-inorganic composite ultrafiltration membrane according to claim 1, wherein the method comprises the following steps:

step one, adding modified fibers into a solvent, stirring and heating to 30-50 ℃, adding a film-forming additive, stirring until the system is gelatinous, and cooling to room temperature to obtain a first mixture;

Step two, mixing polyether sulfone, polyvinyl alcohol, a hydrophilic modifier and a solvent to prepare a membrane casting solution, heating to 30-50 ℃, and stirring for 2-3 hours to obtain a second mixture;

And step three, mixing the first mixture and the second mixture to obtain a membrane blending solution, pouring the membrane blending solution onto a dry and clean glass sheet, scraping a membrane with the thickness of 20-2000 mu m by using a membrane scraping rod, and removing bubbles in vacuum to obtain the organic-inorganic composite ultrafiltration membrane.

10. the method for preparing an organic-inorganic composite ultrafiltration membrane according to claim 9, wherein in the first step, the solvent: the mass ratio of the solvent in the second step is 20: (45-55).

Technical Field

The invention relates to the technical field of membranes, in particular to an organic-inorganic composite ultrafiltration membrane and a preparation method thereof.

Background

in the technical field of membranes, a traditional filtering membrane mostly adopts a hydrophobic material as a main body, and the hydrophobic material can cause irreversible deposition of macromolecules, colloids, electrolytes and the like in sewage on the surface or in the membrane in the long-term use process, so that the flux of the membrane is continuously reduced.

In order to reduce membrane pollution caused by the problem of hydrophobicity of materials as much as possible and improve the problem of membrane flux, hydrophilic modification is mostly carried out on hydrophobic membrane materials in the prior art, hydrophilic modifiers are mostly added in the modification method, however, hydrophilic modified membrane materials have the problems of poor stability and low mechanical strength, and the membrane is easy to deform under pressure so as to block membrane pores, so that the flux is difficult to increase even under the condition of increased pressure.

Disclosure of Invention

In view of the above, the invention provides an organic-inorganic composite ultrafiltration membrane with higher mechanical strength, good hydrophilicity and certain anti-pollution performance and a preparation method thereof.

The technical scheme of the invention is realized as follows: the invention provides an organic-inorganic composite ultrafiltration membrane, which comprises the following components in parts by weight:

on the basis of the above technical scheme, preferably, the hydrophilic modifier is trifluoroethyl methacrylate.

On the basis of the technical scheme, preferably, the film forming additive is one or more of glycol, glycerol, lithium chloride and lithium nitrate.

on the basis of the technical scheme, preferably, the solvent is N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone or dimethyl sulfoxide.

Still more preferably, the modified fiber is a modified titanium dioxide fiber.

in addition to the above technical means, it is preferable that the method for producing the modified titanium dioxide fiber comprises: adding titanium dioxide fibers into a sodium dodecyl sulfate solution with the mass concentration of 1%, adjusting the pH value of the solution to 3-4, stirring for 2-3h at normal temperature, centrifugally collecting the titanium dioxide fibers, and drying to obtain the modified titanium dioxide fibers.

on the basis of the above technical solution, preferably, the titanium dioxide fiber: the mass ratio of the sodium dodecyl sulfate solution is 1: (100-200).

Based on the above technical solution, preferably, the weight average molecular weight of the polyvinyl alcohol is 200-.

The invention also provides a preparation method of the organic-inorganic composite ultrafiltration membrane, which comprises the following steps:

Step one, adding modified fibers into a solvent, stirring and heating to 20-50 ℃, adding a film-forming additive, stirring until the system is gelatinous, and cooling to room temperature to obtain a first mixture;

Step two, mixing polyether sulfone, polyvinyl alcohol, a hydrophilic modifier and a solvent to prepare a membrane casting solution, heating to 30-50 ℃, and stirring for 2-3 hours to obtain a second mixture;

And step three, mixing the first mixture and the second mixture to obtain a membrane blending solution, pouring the membrane blending solution onto a dry and clean glass sheet, scraping a membrane with the thickness of 20-20000 microns by using a membrane scraping rod, and removing bubbles in vacuum to obtain the organic-inorganic composite ultrafiltration membrane.

on the basis of the above technical solution, preferably, the solvent in the step one: the mass ratio of the solvent in the second step is 20: (45-55).

Compared with the prior art, the organic-inorganic composite ultrafiltration membrane and the preparation method thereof have the following beneficial effects:

(1) the organic-inorganic composite ultrafiltration membrane is subjected to hydrophilic modification on the basis of a hydrophobic membrane material, so that the pollution resistance of the membrane material is effectively improved, and the problem of low mechanical strength of the conventional organic-inorganic composite membrane is solved;

(2) The invention also provides a preparation method of the organic-inorganic composite ultrafiltration membrane, which has simple steps, is easy to operate and has good application value.

Detailed Description

the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Preparing modified titanium dioxide fiber:

Adding 100g of titanium dioxide fiber into 10kg of sodium dodecyl sulfate solution with the mass concentration of 1%, uniformly stirring, dropwise adding hydrochloric acid, stirring until the pH value is 3, stirring for 2 hours at normal temperature, and drying after suction filtration to obtain the first modified titanium dioxide fiber.

adding 50g of titanium dioxide fiber into 10kg of 1% sodium alkyl sulfonate solution, uniformly stirring, dropwise adding hydrochloric acid, stirring until the pH value is 4, stirring for 3 hours at normal temperature, filtering, and drying to obtain second modified titanium dioxide fiber.