CN111804161B - Coated amino acid ionic liquid nanospheres/polymer hybrid membranes for CO separation - Google Patents

Abstract

The present invention aims to prepare high-performance CO ₂ separation membrane by introducing amino acid ionic liquid with high CO ₂ adsorption and absorption performance. Specifically, based on amino acid ionic liquid, AAILs@polymer (core-shell) composite nanospheres were prepared by interfacial polymerization of microemulsion system, and then composite nanospheres were combined with traditional CO ₂ separation membrane materials through phase inversion method and Polymer/(AAILs@polymer(core-shell)composite nanospheres) hybrid non-opposite membranes and composite membranes with high _- speed CO permeation and high separation channels were prepared by coating method.

Description

Coated amino acid ionic liquid nanospheres/polymer hybrid membranes for CO separation

technical field

The present invention relates to microemulsion polymerization and hybrid membrane preparation technology, in particular, firstly prepare polymer nano-microspheres coated with amino acid ionic liquid by microemulsion polymerization method, and then introduce nano-microspheres into polymer membrane to prepare polymer/( Amino acid ionic liquid@polymer (core-shell) composite nanospheres) hybrid membrane.

Background technique

In chemical, energy and environment related fields, separation and capture of CO ₂ is an important chemical process that is environmentally friendly and economical. Membrane separation technology has the advantages of low energy consumption, high efficiency, small footprint and convenient operation, and is one of the ideal technologies for _CO2 removal.

Amino Acid Ionic Liquids (AAILs) have excellent CO ₂ absorption and adsorption capacity, and many researchers have begun to apply AAILs to the field of CO ₂ separation and capture. At the same time, AAILs have also developed in the field of CO ₂ separation by membrane technology, but they can only be tested and operated under very low pressure, and the defect of not being able to withstand high pressure seriously hinders their subsequent development.

To solve this problem, this patent develops polymer composite nanospheres coated with AAILs (ie AAILs@polymer (core-shell) composite nanospheres): (1) The functionalized AAILs at the core of the microspheres can provide high-speed CO. _2. Infiltration and separation channels; (2) Microsphere coating can overcome the defect of easy loss of AAILs under higher pressure, and the polymer spherical shell can effectively avoid the problem of organic/inorganic hybrid interface; (3) Nano The size of the microspheres can be better added to the separation skin layer of the composite membrane, and it is easier to prepare the hybrid composite membrane.

SUMMARY OF THE INVENTION

The purpose of the present invention is to prepare a coated amino acid ionic liquid nano-microsphere/polymer hybrid membrane for _CO separation

To achieve the above object, the technical scheme adopted in the present invention is:

Based on amino acid ionic liquids, AAILs@polymer (core-shell) composite nanospheres were prepared by interfacial polymerization in a microemulsion system, and then combined with traditional _CO separation membrane materials to prepare polymers with high _- speed CO permeation and high separation channels composite/(AAILs@polymer (core-shell) composite nanospheres) hybrid film.

Specifically, the steps of the preparation method of the present invention are as follows:

1. To prepare compound/(AAILs@polymer (core-shell) composite nanospheres) hybrid membrane, the steps are as follows:

a Microemulsion system reaction solution preparation: First, the monomers and cross-linking agents required for the preparation of microspheres are dissolved in AAILs and an organic solvent, respectively, and then a certain amount of AAILs with monomers dissolved, organic solvents with cross-linking agents dissolved, and The emulsifier is mixed with the organic solvent-coated AAILs microemulsion system according to a certain ratio, ultrasonicated for 30min to make it completely a clear solution, left standing for 48h, the polymerization of the cross-linking agent and the monomer is completely reacted, and finally a polymer coated with AAILs is formed Nano-microspheres, white precipitates with nano-sized microspheres were suspended in the solution, rinsed with a large amount of organic solvent, filtered, and the obtained white composite microspheres were vacuum-dried at 60°C for 72h, and the finished product was stored in a desiccator at room temperature.

b Hybrid asymmetric membrane preparation: A certain amount of composite nano-microspheres, commercial polymers, organic solvents and pore-forming agents are prepared in a certain proportion of the homogeneous system solution, and left to stand for 24 hours for defoaming. The machine was scraped on the non-woven fabric, and the hybrid asymmetric membrane was prepared by the phase inversion method through the gel water bath. The solvent was completely replaced by placing it in water for 48 hours, and then it was taken out and dried at 100 °C for 24 hours for use.

c Hybrid composite membrane preparation: A certain amount of composite nano-microspheres, commercial polymers, organic solvents, and pore-forming agents are prepared with a certain proportion of coating solution, and left to stand for 24 hours for defoaming. Then take out the prepared polymer porous bottom film (the bottom film nitrogen flux is 50000GPU (1GPU=10 ^-6 cm ³ (STP)/(cm ² scmHg)), and use a small coating machine to coat the film. After the coating is completed, Put it in the air for half an hour, and then put it in an oven at 80°C for 5 hours for use.

d Preservation of film: Store at room temperature in a desiccator.

2. according to the described preparation method of claim 1, it is characterised in that the AAILs used in the step a are: 1-ethyl-3-methylimidazole glycinate, 1-butyl-3-methylimidazole glycinate, 1-Butyl-3-methylimidazole lysine, tetrabutylphosphine glycinate, tetrabutylphosphine serine, tetrabutylphosphine lysine, tetrabutylphosphine proline, tetramethyl Ammonium glycinate, tetramethylammonium lysinate.

3 according to the described preparation method of claim 1, it is characterized in that, the organic solvent used in step a: cyclohexane, n-hexane, n-heptane, chloroform, methylene chloride, tetrahydrofuran, water, methanol, ethanol, n-butyl Alcohol, isobutanol, N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-pyrrolidone, dimethylsulfoxide, perfluoro(N-methylmorpholine).

4. according to the described preparation method of claim 1, it is characterized in that, the additive used in step a is: polyethylene glycol 200, polyethylene glycol 400, polyethylene glycol 600, polyethylene glycol 800, 1, 4-Butyrolactone, water.

5. The preparation method according to claim 1, wherein the required monomers for preparing microspheres used in step a are: 5,5',6,6'-tetrahydroxy-3,3,3',3 '-Tetramethyl-1,1'-spiral bisindan, diphenolic propane, phenylenediamine (such as m-phenylenediamine, p-phenylenediamine) and its derivatives, diethylenetriamine, triethylenetetramine , polyethyleneimine, methyl m-phenylenediamine, ethylenediamine, hexamethylenediamine, octanediamine, branched polyamide polyamine, bis (2-aminopropyl) polypropylene glycol-block-polyethylene glycol - Block-polypropylene glycol.

6. according to the described preparation method of claim 1, it is characterised in that the required cross-linking agent for preparing microspheres used in step a is: trimesoyl chloride, terephthaloyl chloride, isophthaloyl chloride, o-phthaloyl chloride Diformyl chloride, 1,5-naphthalene disulfonyl chloride, 1,3,6-trisulfonyl chloride, 5-oxoformyl chloride-isopeptide acid chloride, 5-isocyanate-isopeptide acid chloride, 1,3,5-cyclohexane Tricarbonyl chloride, 3,3,5,5-biphenyltetracarbonyl chloride.

7. The preparation method according to claim 1, wherein the commercial polymers used in steps b and c are: polysulfone, polyethersulfone, polyetherimide, polyacrylonitrile, polyamide-polyamide Ethylene oxide copolymer (Pebax ^™ ), silicone rubber.

The present invention has the following advantages:

The AAILs with high _CO adsorption performance were coated by nano-microspheres and then incorporated into the polymer. The preparation of polymer/(AAILs@polymer(core-shell) composite nanospheres) hybrid membranes with high _- speed CO permeation and high separation channels has promising application prospects.

Example 1

First, the monomer 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spiral bis-indane and the cross-linking agent trimesoyl chloride were dissolved separately In 1-ethyl-3-methylimidazole glycinate aqueous solution and n-hexane, then add emulsifier isopropanol, mix according to (ionic liquid aqueous solution) 5: (n-hexane) 3: (isopropanol) 2 ratio The oil-in-water emulsion system was prepared, ultrasonicated for 30 minutes to make it a clear solution, and left to stand for 48 hours. After the polymerization was completely reacted, the polymer nanospheres coated with the amino acid ionic liquid were finally formed, and white precipitates of nanometer-sized microspheres appeared suspended in the solution. The white composite microspheres obtained were vacuum-dried at 60°C for 72h, and the finished product was stored in a desiccator at room temperature.

Hybrid asymmetric membrane preparation: 0.1wt.% of composite nano-microspheres, 39.9wt.% of polysulfone, 27wt.% of N-methyl-pyrrolidone, 15wt.% of additive 1-4 butyrolactone, additive of absolute ethanol The homogeneous system solution with a configuration ratio of 8wt.% was left for 24h to defoam for use, scraped on the non-woven fabric by a small film scraping machine, and prepared a hybrid asymmetrical hybrid by a phase inversion method through a gel water bath. The membrane was placed in water for 48 hours to complete the solvent replacement, and then taken out and dried in vacuum at 100 °C for 24 hours for use.

Preparation of pure polysulfone asymmetric membrane: 40wt.% of polysulfone, 27wt.% of N-methyl-pyrrolidone, 15wt.% of additive 1-4 butyrolactone, and 8wt.% of additive anhydrous ethanol were prepared in a proportion of homogeneous phase The system solution was left to stand for 24 hours for defoaming, and then scraped on the non-woven fabric by a small film scraping machine. The hybrid asymmetric membrane was prepared by the phase inversion method through the gel water bath. It was taken out and dried under vacuum at 100 °C for 24 h for use.

Storage of the film: Store at room temperature in a desiccator.

Gas separation performance of pure polysulfone asymmetric membrane: P _CO2 = 60GPU α _CO2/N2 = 29

Gas separation performance of hybrid polysulfone asymmetric membrane: P _CO2 = 109 GPU α _CO2/N2 = 35

Example 2

First, the monomer 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spiral bis-indane and the cross-linking agent trimesoyl chloride were dissolved separately In the tetrabutylphosphine proline salt aqueous solution and n-hexane, then add the emulsifier isopropanol, according to (ionic liquid aqueous solution) 5: (n-hexane) 3: (isopropanol) 2 ratios to mix and prepare oil-in-water The emulsion system was ultrasonicated for 30min to make it a clear solution, and it was left standing for 48h. After the polymerization was completely reacted, the polymer nanospheres coated with the amino acid ionic liquid were finally formed. The white precipitates of nanometer-sized microspheres were suspended in the solution. Rinse with methanol, filter, the obtained white composite microspheres are vacuum-dried at 60°C for 72h, and the finished product is stored in a desiccator at room temperature.

Hybrid asymmetric membrane preparation: 0.1wt.% of composite nano-microspheres, 39.9wt.% of polysulfone, 27wt.% of N-methyl-pyrrolidone, 15wt.% of additive 1-4 butyrolactone, additive of absolute ethanol The homogeneous system solution with a configuration ratio of 8wt.% was left for 24h to defoam for use, scraped on the non-woven fabric by a small film scraping machine, and prepared a hybrid asymmetrical hybrid by a phase inversion method through a gel water bath. The membrane was placed in water for 48 hours to complete the solvent replacement, and then taken out and dried in vacuum at 100 °C for 24 hours for use.

Storage of the film: Store at room temperature in a desiccator.

Gas separation performance of hybrid polysulfone asymmetric membrane: P _CO2 = 200GPU α _CO2/N2 = 60

Example 3

First, the monomer 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spiral bis-indane and the cross-linking agent trimesoyl chloride were dissolved separately In the tetrabutylphosphine proline salt aqueous solution and n-hexane, then add the emulsifier isopropanol, according to (ionic liquid aqueous solution) 5: (n-hexane) 3: (isopropanol) 2 ratios to mix and prepare oil-in-water The emulsion system was ultrasonicated for 30min to make it a clear solution, and it was left standing for 48h. After the polymerization was completely reacted, the polymer nanospheres coated with the amino acid ionic liquid were finally formed. The white precipitates of nanometer-sized microspheres were suspended in the solution. Rinse with methanol, filter, the obtained white composite microspheres are vacuum-dried at 60°C for 72h, and the finished product is stored in a desiccator at room temperature.

Preparation of hybrid composite membrane: 0.01 wt.% of composite nano-microspheres, 1 wt.% of polyamide-polyethylene oxide copolymer Pebax ^TM 1657, and 98.99 wt.% of mixed solvent (water:ethanol=7:3) were coated layer solution, and let stand for 24h to defoaming for use. Then take out the prepared polymer porous bottom film (the nitrogen flux of the bottom film is 50,000 GPU, and use a small coating machine to coat the film. After the coating is completed, place it in the air for half an hour, and then put it in an oven at 80 °C for 5 hours. use.

Storage of the film: Store at room temperature in a desiccator.

Gas separation performance of hybrid Pebax1657 composite membrane: P _CO2 = 309 GPU α _CO2/N2 = 80

Example 4

First, the monomer branched polyamide polyamine and the cross-linking agent trimesic acid chloride were dissolved in the tetrabutylphosphine proline salt aqueous solution and n-hexane, respectively, and then the emulsifier isopropanol was added, according to (ionic liquid aqueous solution) 5 : (n-hexane) 3: (isopropanol) 2 ratios were mixed to prepare an oil-in-water emulsion system, ultrasonicated for 30 min to make it completely a clear solution, left standing for 48 h, and the polymer that coats the amino acid ionic liquid was finally formed after the polymerization was completely reacted. Nano-microspheres, white precipitates with nano-sized microspheres were suspended in the solution, rinsed with a large amount of methanol, filtered, and the obtained white composite microspheres were vacuum-dried at 60 ℃ for 72h, and the finished product was stored in a desiccator at room temperature.

Preparation of hybrid composite membrane: 0.01 wt.% of composite nano-microspheres, 1 wt.% of polyamide-polyethylene oxide copolymer Pebax ^TM 1657, and 98.99 wt.% of mixed solvent (water:ethanol=7:3) were coated layer solution, and let stand for 24h to defoaming for use. Then take out the prepared polymer porous bottom film (the nitrogen flux of the bottom film is 50,000 GPU, and use a small coating machine to coat the film. After the coating is completed, place it in the air for half an hour, and then put it in an oven at 80 °C for 5 hours. use.

Storage of the film: Store at room temperature in a desiccator.

Gas separation performance of hybrid Pebax1657 composite membrane: P _CO2 =520GPU αCO2 _/N2 =82

In Example 1, compared with the pure polysulfone asymmetric membrane, the polysulfone hybrid asymmetric membrane with the addition of AAILs@polymer (core-shell) composite nanospheres has better _CO permeability and _CO permeability than the pure polysulfone asymmetric membrane. /N ₂ selectivity. It can be seen that the microspheres coated with amino acid ionic liquid have a very good role in promoting _CO2 transfer.

Comparing Example 1 with Example 2, it can be seen that tetrabutylphosphine proline salt can better improve CO ₂ osmotic transfer performance than 1-ethyl-3-methylimidazole glycinate, and it has a better effect on the performance of polysulfone membrane. The performance improvement is even more pronounced.

In Example 3, it can be seen that the amino acid ionic liquid-coated microspheres not only have a significant effect on glassy polysulfone, but also have a good effect on improving _CO2 transfer performance on rubbery polyamide-polyethylene oxide copolymers. effect.

Comparing Example 3 and Example 4, it can be seen that the microspheres formed by branched polyamide polyammonium as monomers are introduced into the membrane, and the effect on the composite membrane is much better than that of 5, 5', 6, 6'- Tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-helix double indane is a microsphere formed by a monomer.

In general, the CO ₂ permeation and separation performance of glassy polysulfone and rubbery polyamide-polyoxyethylene copolymer Pebax ^TM were greatly improved after the introduction of amino acid ionic liquid-coated nano-microspheres. The TEM photo of the ionic liquid-coated nano-microspheres prepared in Example 1 and the SEM photo of the hybrid film are shown in the accompanying drawings. Membrane cross-section structure.

Claims (7)

1. a method for preparing polymer/(AAILs@polymer (core-shell) composite nano-microspheres) hybrid membrane, the steps are as follows: a Microemulsion system reaction solution preparation: First, the monomers and cross-linking agents required for the preparation of microspheres are dissolved in AAILs and an organic solvent, respectively, and then a certain amount of AAILs with monomers dissolved, organic solvents with cross-linking agents dissolved, and The emulsifier is mixed with the organic solvent-coated AAILs microemulsion system according to a certain ratio, ultrasonicated for 30min to make it completely a clear solution, left standing for 48h, the polymerization of the cross-linking agent and the monomer is completely reacted, and finally a polymer coated with AAILs is formed Nano-microspheres, white precipitates with nano-sized microspheres were suspended in the solution, rinsed with a large amount of organic solvent, filtered, and the obtained white composite microspheres were vacuum-dried at 60 °C for 72 hours, and the finished product was stored in a desiccator at room temperature; b Hybrid asymmetric membrane preparation: A certain amount of composite nano-microspheres, commercial polymers, organic solvents and pore-forming agents are prepared in a certain proportion of the homogeneous system solution, and left to stand for 24 hours for defoaming. The machine is scraped on the non-woven fabric, and the hybrid asymmetric membrane is prepared by the phase inversion method through the gel water bath, placed in water for 48 hours to complete the solvent replacement, and then taken out and dried at 100 °C for 24 hours in vacuum for use; c Hybrid composite membrane preparation: mix a certain amount of composite nano-microspheres, commercial polymers, organic solvents and pore-forming agents with a certain proportion of coating solution, let stand for 24 hours for defoaming; then take out the prepared polymer Porous bottom film, the nitrogen flux of the bottom film is 50000GPU, 1GPU=10 ^-6 cm ³ (STP)/(cm ² scmHg), use a small coating machine to coat the film, after the coating is completed, place half of it in the air hours, and then put it in an oven at 80°C for 5 hours for use; d Preservation of film: Store at room temperature in a desiccator. 2. according to the method for preparing polymer/(AAILs@polymer (core-shell) composite nano-microspheres) hybrid membrane according to claim 1, it is characterized in that, the AAILs used in step a is: 1-ethyl -3-Methylimidazole glycinate, 1-butyl-3-methylimidazole glycinate, 1-butyl-3-methylimidazole lysine salt, tetrabutylphosphine glycinate, tetrabutylphosphine serine salt , tetrabutylphosphine lysine, tetrabutylphosphine proline, tetramethylammonium glycinate, tetramethylammonium lysine. 3. according to the method for preparing polymer/(AAILs@polymer (core-shell) composite nano-microspheres) hybrid membrane according to claim 1, it is characterized in that, the organic solvent used in step a: cyclohexane, n-hexane, n-heptane, chloroform, dichloromethane, tetrahydrofuran, water, methanol, ethanol, n-butanol, isobutanol, N,N-dimethylacetamide, N,N-dimethylformamide, N - Methyl-pyrrolidone, dimethyl sulfoxide, perfluoro(N-methylmorpholine). 4. according to the method for preparing polymer/(AAILs@polymer (core-shell) composite nano-microspheres) hybrid film according to claim 1, it is characterized in that, the emulsifier used in step a is: polyethylene glycol Alcohol 200, polyethylene glycol 400, polyethylene glycol 600, polyethylene glycol 800, 1,4-butyrolactone. 5. according to the method for preparing polymer/(AAILs@polymer (core-shell) composite nano-microspheres) hybrid membrane according to claim 1, it is characterized in that, in step a, the required monomer for preparing microspheres is : 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spiral bisindan, diphenol propane, phenylenediamine and its derivatives , Diethylenetriamine, triethylenetetramine, polyethyleneimine, methyl m-phenylenediamine, ethylenediamine, hexamethylenediamine, octanediamine, branched polyamide polyamine, bis (2-aminopropyl) Polypropylene glycol-block-polyethylene glycol-block-polypropylene glycol. 6. according to the method for preparing polymer/(AAILs@polymer (core-shell) composite nano-microspheres) hybrid membrane according to claim 1, it is characterized in that, the required cross-linking of the preparation microspheres used in step a Agents are: trimesoyl chloride, terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride, 1,5-naphthalene disulfonyl chloride, 1,3,6-trisulfonyl chloride, 5-oxycarbonyl chloride - isopeptide acid chloride, 5-isocyanate-isopeptide acid chloride, 1,3,5-cyclohexanetricarbonyl chloride, 3,3,5,5-biphenyltetracarbonyl chloride. 7. The method for preparing polymer/(AAILs@polymer (core-shell) composite nano-microspheres) hybrid membrane according to claim 1, wherein the commercial polymer used in steps b and c is : Polysulfone, polyethersulfone, polyetherimide, polyacrylonitrile, polyamide-polyethylene oxide copolymer, silicone rubber.

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