阅读说明：本技术 一种高mof填料含量气体分离膜的制备方法 (Preparation method of gas separation membrane with high MOF (Metal organic framework) filler content ) 是由 郑文姬 郭自兴 孙天奇 焉晓明 代岩 贺高红 于 2019-09-03 设计创作，主要内容包括：本发明公开一种高MOF填料含量气体分离膜的制备方法,属于膜分离技术领域。将MOF颗粒分散于溶剂中制备MOF“油墨”,再将“油墨”与聚合物溶液混合水浴超声使两者形成良好相容。溶剂挥发后得到的膜液倒在玻璃板上刮涂,除去溶剂,得到高MOF填料含量膜。最后将得到膜浸入适量聚合物溶液,溶剂彻底挥发得到具有高气体分离性能的高MOF填料气体分离膜。该膜可以避免传统混合基质膜中填料含量过高发生团聚从而导致分离性能下降的问题,其MOF填料含量最高可达70％,并且表现出对CO<Sub>2</Sub>/N<Sub>2</Sub>、CO<Sub>2</Sub>/CH<Sub>4</Sub>、H<Sub>2</Sub>/N<Sub>2</Sub>、H<Sub>2</Sub>/CO<Sub>2</Sub>等气体对的适中选择性,其气体渗透系数可达到上千barrer,有望满足实际工业应用要求。(The invention discloses a preparation method of a gas separation membrane with high MOF filler content, and belongs to the technical field of membrane separation. Dispersing MOF particles in a solvent to prepare MOF 'ink', mixing the 'ink' with a polymer solution, performing water bath ultrasound to enable the 'ink' and the polymer solution to form a good phaseAnd (4) carrying out the following steps. And pouring the film liquid obtained after the solvent is volatilized on a glass plate for blade coating, and removing the solvent to obtain the film with high MOF filler content. And finally, immersing the obtained membrane into a proper amount of polymer solution, and completely volatilizing the solvent to obtain the high MOF filler gas separation membrane with high gas separation performance. The film can avoid the problem that the separation performance is reduced due to the agglomeration caused by overhigh filler content in the traditional mixed matrix film, the MOF filler content can reach 70 percent at most, and the film shows that the film has CO content 2 /N 2 、CO 2 /CH 4 、H 2 /N 2 、H 2 /CO 2 Moderate selectivity of the gas pair is equal, the gas permeability coefficient can reach thousands of barrers, and the gas is expected to meet the requirements of practical industrial application.)

1. A preparation method of a gas separation membrane with high MOF filler content is characterized by comprising the following steps:

(1) adding activated MOF powder into a solvent A, and performing water bath ultrasound for 30min to completely disperse the MOF in the solvent A to prepare MOF ink, wherein the concentration of the MOF in the solvent A is 5-30 g/L; adding the polymer C into the solvent B, and stirring to dissolve the polymer C into a membrane solution, wherein the concentration of the membrane solution is 6-10 wt% based on the formation of a viscous membrane solution;

(2) adding the membrane liquid into the MOF 'printing ink' obtained in the step (1), and continuing to perform ultrasonic treatment for 60 min; fully volatilizing the solvent A in the mixed solution by adopting a stirring and volatilizing mode to obtain a viscous membrane casting solution; pouring the prepared casting film liquid on a glass plate, scraping a film with the thickness of 200-300 mu m, then putting the glass plate into a preheating oven at 60-80 ℃, and taking the film down after the solvent B volatilizes;

(3) placing the film obtained in the step (2) on a tetrafluoro plate

2. The preparation method according to claim 1, wherein the mass ratio of the polymer D to the film obtained in the step (2) is 1: 5-15.

3. A method according to claim 1 or 2, wherein the MOF is UiO-66, UiO-66-NH₂ZIF-8, MIL-101(Fe), MIL-101(Cr) or HKUST-1.

4. The method according to claim 3, wherein the solvent A is acetone, chloroform, dichloromethane or 1, 1-dichloroethane.

5. The method according to claim 4, wherein the solvent B is water, N-dimethylformamide, N-methylpyrrolidone or dimethylsulfoxide.

6. The method according to claim 5, wherein the polymer C is polyvinylidene fluoride, polyethylene glycol or polysulfone.

7. The method according to claim 6, wherein the polymer D is a polyether copolyamide 1657, a polyimide, a polyetherimide, a polysulfone, a polyethersulfone or a polydimethylsiloxane.

Technical Field

The invention belongs to the technical field of membrane separation, and particularly relates to a preparation method of a gas separation membrane with high MOF filler content.

Background

CO₂As a greenhouse gas, with N in different industrial processes₂，H₂，CH₄The separation of gases has great significance. The disadvantages of high energy consumption and complex operation in the conventional gas separation field have prompted the search for new alternative separation techniques. The membrane separation technology is a novel separation technology for gas capture, and compared with the traditional separation method, the membrane separation technology has the advantages of no phase change, no regeneration process of a mass separating agent, mild process conditions, low operation cost, small occupied area and the like, and is rapidly developed in recent years.

Membrane materials are a key part of membrane separation technology. Inorganic membranes generally have regular pore channels, have adjustable pore diameters and affinity and are separated mainly by size sieving and a surface diffusion mechanism, so that high separation performance is easy to realize. The separation performance of the polymer membrane is relatively limited by trade-off, but the polymer membrane has better mechanical flexibility and is the mainstream of the current industrial application. Therefore, the research on membrane materials that can simultaneously satisfy the separation requirements and the mechanical property requirements is the focus of the field.

Mixed matrix membranes (mixedmatrixmambanes) combine the high separation performance of inorganic membranes with the mechanical properties and cost advantages of polymer membranes and are a future development trend in the field of membrane separation. In the traditional mixed matrix membrane, polymer is used as a matrix, and researchers prefer inorganic filler to improve the membrane separation performance. However, the filler content of the membrane material thus prepared cannot be too high (generally less than 30%), and when the filler content exceeds the "threshold value", the separation selectivity of the membrane is greatly reduced and, moreover, the mechanical properties are unsatisfactory. Therefore, the preparation of the membrane material with high filler content and high gas separation performance has very important significance in actual industrial production.

Disclosure of Invention

Based on the problems of the prior art, the object of the present invention is to provide a universal method for the production of gas separation membranes with a high MOF filler content.

The technical scheme of the invention is as follows:

a preparation method of a gas separation membrane with high MOF filler content comprises the following steps:

(1) adding activated MOF powder into a solvent A, and performing water bath ultrasound for 30min to completely disperse the MOF in the solvent A to prepare MOF ink, wherein the concentration of the MOF in the solvent A is 5-30 g/L; adding the polymer C into the solvent B, and stirring to dissolve the polymer C into a membrane solution, wherein the concentration of the membrane solution is 6-10 wt% based on the formation of a viscous membrane solution;

the MOF is UiO-66 or UiO-66-NH₂ZIF-8, MIL-101(Fe), MIL-101(Cr) or HKUST-1.

The solvent A is acetone, chloroform, dichloromethane or 1, 1-dichloroethane.

The solvent B is water, N-dimethylformamide, N-methylpyrrolidone or dimethyl sulfoxide.

The polymer C is polyvinylidene fluoride (PVDF), polyethylene glycol (PEG) or Polysulfone (PS).

(2) Adding the membrane liquid into the MOF 'printing ink' obtained in the step (1), and continuing to perform ultrasonic treatment for 60 min; fully volatilizing the solvent A in the mixed solution by adopting a stirring and volatilizing mode to obtain a viscous membrane casting solution; pouring the prepared casting film liquid on a glass plate, scraping a film with the thickness of 200-300 mu m, then putting the glass plate into a preheating oven at 60-80 ℃, and taking the film down after the solvent B volatilizes;

(3) placing the film obtained in the step (2) on a tetrafluoro plate

Adding a pre-configured 3 wt% polymer D solution into the glass ring; and (3) putting the tetrafluoro plate into a preheating oven at 60-90 ℃ to remove the solvent of the polymer D, so as to obtain the gas separation membrane with high MOF content.

The polymer D is polyether copolyamide 1657(Pebax1657), polyimide, polyetherimide, polysulfone, polyethersulfone or polydimethylsiloxane.

The mass ratio of the polymer D to the film obtained in the step (2) is 1: 5-15.

The invention has the beneficial effects that: the gas separation membrane with high MOF filler content prepared by the invention has the MOF filler content of 50-70%. For the prepared ZIF-8-PVDF-Pebax1657 membrane, under the test conditions of 25 ℃ and 0.3MPa, CO₂The permeability coefficient can reach 1529.9Barrer, H₂The permeability coefficient can reach 1344.2Barrer, CO₂/N₂Selectivity is 51.93, H₂/N₂Selectivity 46.25, H₂/N₂The selectivity was 46.25.

Drawings

FIG. 1 is a cross-sectional electron micrograph of a 59.5% ZIF-8/PVDF/Pebax 1657 film.

FIG. 2 is a section electron micrograph of a 61.2% UiO-66/PEG/PDMS film.

FIG. 3 is a cross-sectional electron micrograph of a 69.4% UiO-66/PVDF/PEI membrane.

Detailed Description

The following further describes the specific embodiments of the present invention in combination with the technical solutions.