CN-119701653-B - Super-osmosis separation membrane and preparation method and application thereof

Abstract

The invention discloses a super-osmotic separation membrane and a preparation method and application thereof. The super-permeable separation membrane is formed by combining a hydrophobic molecular shell layer and an ultra-fast transmission layer. The membrane can be used for enriching organic products such as low-concentration alcohol in water.

Inventors

• YANG WEISHEN
• LIU JIAYI
• BAN YUJIE

Assignees

• 中国科学院大连化学物理研究所

Dates

Publication Date

20260508

Application Date

20230926

Claims (6)

1. 1. The super-permeable separation membrane is characterized by comprising an affinity molecule surface layer and an ultra-fast transmission layer; the surface layer of the affinity molecule is crosslinked polysiloxane or ionic liquid; the thickness of the surface layer of the affinity molecule is 0-50 nm, and is not 0; The ultra-fast transmission layer is a continuous nano particle layer of a double ligand type metal-organic framework material with the particle size of 10-1000nm or a double ligand type metal-organic framework nano sheet stacking layer with the thickness of 1-100 nm; the preparation method of the double ligand type metal-organic framework material comprises the following steps: (1) Dissolving one of nitrate, acetate or halide salt of divalent metal zinc or cobalt in anhydrous methanol, and uniformly stirring to obtain a metal solution; (2) Dissolving 2-methylimidazole and 4, 5-dichloroimidazole in absolute methanol, and uniformly stirring to obtain a double-ligand solution; (3) And (3) mixing the metal solution obtained in the step (1) with the double-ligand solution obtained in the step (2), centrifuging a product obtained after reacting for 0.5-24 hours at 20-30 ℃, and washing with absolute methanol to obtain the double-ligand type metal-organic framework material, wherein the molar ratio of divalent metal zinc or cobalt ions to the sum of 2-methylimidazole and 4, 5-dichloroimidazole is 1:2.
2. 2. The method for preparing a super osmosis separation membrane according to claim 1, comprising the steps of: (1) Dispersing a double-ligand metal organic frame material in butanol to prepare a dispersion liquid, namely a solution A, dissolving silicon rubber in butanol to prepare a silicon rubber solution, namely a solution B, uniformly mixing the solution A and the solution B under ice water bath to obtain a mixed matrix film casting solution, wherein the mass ratio of the silicon rubber to the butanol to the double-ligand metal organic frame material is 1:2-10:0.1-0.8; (2) Coating the mixed matrix film casting solution on an alumina-based film to obtain a mixed matrix film; (3) And placing the mixed matrix film in an isooctane solution containing a silane coupling agent and a catalyst for interfacial crosslinking, wherein the temperature is 15-30 ℃ and the time is 0.5-72 h.
3. 3. The preparation method of the mixed matrix film casting solution is characterized in that in the step (1), the silicone rubber is hydroxy polymethylphenylsiloxane, and the preparation method of the mixed matrix film casting solution comprises the steps of adding 3-5 drops of solution B into solution A, uniformly dispersing by ultrasonic waves under ice water bath, adding all solution A into the rest solution B, stirring while adding, and uniformly dispersing by ultrasonic waves to obtain the mixed matrix film casting solution; In the step (2), the coating method is dip-coating method, spin coating method or knife coating method; In the step (3), the silane coupling agent is tetraethoxysilane, the catalyst is dibutyl tin dilaurate, and the mass ratio of the silane coupling agent, the catalyst and isooctane in the isooctane solution containing the silane coupling agent and the catalyst is 1:1-5:10-50.
4. 4. The method according to claim 3, wherein the dipping-pulling method is characterized in that the alumina-based film is dipped and pulled in the mixed matrix film casting solution at a dipping speed of 1-8 mm/s for a dipping time of 1-60 s and a pulling speed of 1-8 mm/s.
5. 5. Use of the ultra-permeable separation membrane of claim 1 for the enrichment of organic products of low concentration alcohols or aldehydes in water.
6. 6. The use according to claim 5, wherein the low concentration alcohol or aldehyde comprises methanol, ethanol or butanol and the aldehyde comprises furfural in a mass concentration of 0.01-10% in water.

Description

Super-osmosis separation membrane and preparation method and application thereof Technical Field The invention relates to a super-osmosis separation membrane, a preparation method and application thereof, and belongs to the field of material chemical separation. Background The excessive consumption of fossil energy causes problems such as environmental deterioration and energy exhaustion, and it is urgent to seek renewable and sustainable energy resources. The bio-based platform compound (such as polyalcohol and furans compound) prepared by the bio-refining technology can be used as raw materials to construct various biofuels and high-value chemicals, thereby leading to the economy of biomass chains. However, the isolation of bio-based platform compounds still faces significant challenges. The bio-based platform compound mainly derives from acid-catalyzed carbohydrate hydrolysis, is generated in a dilute aqueous solution, has a higher boiling point, relates to phase change of components to be separated in the traditional separation method (such as rectification, gas stripping and vapor phase adsorption technology), has a more complex process and higher energy consumption, and is more suitable for high-efficiency separation of the bio-based platform compound compared with a pervaporation membrane separation method which has lower energy consumption and higher efficiency. The pervaporation membrane is utilized to efficiently enrich organic products such as low-concentration alcohol in water, on one hand, membrane construction materials need to be further optimized, and on the other hand, a construction method of a membrane structure needs to be optimized. As for membrane materials, metal-organic framework materials (Metal-organic frameworks, MOFs) are a class of highly ordered porous organic-inorganic hybrid materials formed by coordination of Metal ions (clusters) with organic ligands. Zeolite imidazole ester frameworks (Zeolitic imidazolate frameworks, ZIFs) are widely used in the separation field as a subclass of MOF materials due to their particular thermal, chemical and microporous properties. In order to further modulate the framework structure and physicochemical properties of the ZIF material in order to further optimize its application potential in separation systems (Eum k.jacs,2015, 137:4191). In recent years, it has been reported that the permeability of propylene molecules in propylene/propane separation systems is improved by preparing dual ligand ZIF materials for growing polycrystalline films by introducing another ligand into the existing ZIF structure (Hillman f.acs appl. Mate. Interface,2019, 11:18377). The dual-ligand material synthesized by the mixed ligand provides a new design idea in the aspects of skeleton and physicochemical property regulation of the material, and is expected to provide a new opportunity in the application of the field of separation membrane construction. In the process of constructing the separation membrane, the construction of the membrane structure is another key to achieving better organophilic performance. Conventional pervaporation membrane materials for preferential permeation of organic substances mainly include inorganic molecular sieve membrane materials, organic polymer membrane materials, and organic-inorganic hybrid membrane materials. Although inorganic molecular sieve membranes have good thermal stability, chemical stability and mechanical strength, the preparation of complete, continuous, dense molecular sieve membranes is highly demanding in terms of process and substrate. The organic polymer material has the advantages of good flexibility and film forming performance, high selectivity, multiple varieties, simple preparation process, mature process and the like, but the stability and mechanical strength still need to be further improved. The organic-inorganic hybrid membrane is a Mixed Matrix Membrane (MMMs) obtained by adding inorganic particles into an organic matrix, can effectively combine the advantages of the organic-inorganic hybrid membrane and is one of the main development directions of the field of pervaporation membrane separation in the future. If interface defects are formed at the interface of the mixed matrix membrane, the separation performance cannot reach the expected target, so that the development of organic-inorganic hybrid membrane enriched organic matters is restrained. Disclosure of Invention The invention aims to provide a super-permeable separation membrane, a preparation method and application thereof, and the super-permeable separation membrane provided by the invention divides a separation membrane structure into an affinity molecular surface layer based on an organic polymer and an ultra-fast transmission layer based on a double-ligand metal organic framework material, and avoids the generation of interface defects through a construction idea of deconstruction-assembly, thereby optimizing the enrichment and separation