Functional ionic material, preparation method thereof and application of functional ionic material as CO2 adsorbent

Abstract

The invention provides a functional ionic material. The functional ionic material is a copolymer comprising a polymerization fragment A as shown in a formula (1) or a formula (2) and a polymerization fragment B as shown in a formula (3). The invention also provides a preparation method and application of the functional ionic material. The invention further provides a CO2 adsorption method and a CO2 trapping method. The functional ionic material provided by the invention contains rich CO2 adsorption active sites and a micropore-ultramicropore structure, so that the functional ionic material has excellent CO2 adsorption capacity and adsorption selectivity, is suitable for adsorption, removal or capture of CO2 in various scenes, takes a copolymer as a matrix, is high in strength, is easy to desorb and regenerate, and has a good application prospect. Adsorption capacity after regeneration is basically not reduced, and the adsorbent can be recycled for multiple times.

Description

Technical Field

[0001] The present invention belongs to the field of gas separation, and specifically relates to a functional ionic material, a preparation method thereof and use thereof as a CO2 adsorbent, and also relates to a CO2 adsorption method and a CO2 capture method. Background Art

[0002] The sources of CO2 emissions can generally be divided into two categories: (1) Natural sources: including CO2 emissions from natural processes on Earth, such as volcanic eruptions, plant respiration, decomposition of organic matter, etc. The CO2 emitted from these natural processes can usually be balanced by the natural system and will not have a significant impact on the environment; (2) Anthropogenic sources: including CO2 generated by human activities, such as the burning of fossil fuels such as oil, natural gas, and coal, as well as CO2 generated in industrial production, transportation, construction, agriculture, etc. The CO2 emissions from these anthropogenic sources are very large, which has had a serious impact on the global climate and environment and is one of the main causes of current global climate change.

[0003] In order to deal with this problem, many countries and regions have begun to explore the use of CO2 capture, utilization and storage (CCUS) technology to reduce CO2 emissions while meeting energy needs. CO2 capture can be carried out through three methods: chemical adsorption, physical adsorption and membrane separation. Chemical adsorption is to contact CO2 with a chemical absorbent to absorb CO2 into the adsorbent; physical adsorption is to capture CO2 by adsorbing CO2 on a solid surface under high pressure; and membrane separation is to separate CO2 from the gas by passing through a semipermeable membrane. These methods can effectively capture CO2, and different methods are suitable for different application scenarios.

[0004] For the chemical adsorption of CO2, adsorbents play a very critical role. Among the numerous adsorbents, functionalized ionic liquid materials are an important branch. For example, Chinese patent CN1709553A records the application of amino acid ionic liquids in the absorption of acidic gases, wherein the anions or cations of the ionic liquids are amino acids, amino acid derivatives or similar amino acid structure ions, and such ionic liquids can be used for the absorption of acidic gases such as carbon dioxide and sulfur dioxide. In addition, such ionic liquids can also be loaded on other porous solids through an impregnation process. For another example, Chinese patent CN116392928A records a porous amino-functional loaded ionic liquid suitable for multi-scenario CO2 capture, wherein the ionic liquid comprises quaternary ammonium cations and amino acid anions, and is loaded on a porous carrier material including mordenite molecular sieves, mesoporous carbon, and non-ionic porous resins by physical impregnation, thereby obtaining a porous amino-functional loaded ionic liquid, which can be applied to a variety of scenes containing CO2 gas sources. For another example, Chinese patent CN 111841626B records a type of Merrifield resin material-supported polyether functionalized ionic liquid catalyst and a preparation method thereof, specifically, a polyether functionalized ionic liquid (such as imidazole ionic liquid, guanidine ionic liquid, DBU ionic liquid) is immobilized on the surface of a Merrifield resin material by a chemical bonding method. This new type of Merrifield resin material-supported polyether functionalized ionic liquid catalyst has the potential to be used in catalytic hydrogenation, hydroformylation and CO2 catalytic conversion reactions.

[0005] It can be seen that although adsorbents used for CO2 capture have developed rapidly, they still have defects such as insufficient variety, complicated preparation, and high cost that are not suitable for industrial utilization. Moreover, there is also a lot of room for improvement in the adsorption capacity of CO2. Summary of the invention

[0006] In order to make up for the deficiencies in the prior art, one object of the present invention is to provide a functional ionic material which has excellent CO2 adsorption capacity and adsorption selectivity, is easy to regenerate, and can be recycled multiple times, and is a CO2 adsorbent with great application potential.

[0007] Another object of the present invention is to provide a preparation method of the functional ionic material and its use.

[0008] Another object of the present invention is to provide a method for adsorbing CO2.

[0009] Another object of the present invention is to provide a method for capturing CO2.

[0010] The first aspect of the present invention provides a functional ionic material, which is a copolymer comprising a polymer segment A represented by formula (1) or formula (2) and a polymer segment B represented by formula (3),

[0011]

[0012] Here, R represents an amino acid residue excluding the carboxyl portion.

[0013] The functional ionic material provided by the present invention uses a copolymer as a matrix, which has high strength and is easy to desorb and regenerate after adsorbing CO2. The adsorption capacity after regeneration is basically unchanged, so it can be recycled many times. Amino acids are further grafted on the copolymer matrix in the form of chemical bonds to form an amino acid functional ionic liquid, in which the active groups have a strong chemical reaction with CO2 molecules, thereby becoming active sites for selective adsorption of CO2. Moreover, the generation of amino acid anions can also change the pore structure of the copolymer to form a large number of micropores-ultramicropore structures. Through the synergistic effect of the CO2 adsorption site and the pore structure, the adsorption capacity of the functional ionic material for CO2 can be significantly improved, thereby achieving efficient capture or deep removal of CO2. It is suitable for the adsorption and capture of CO2 at low concentrations, such as coal chemical process gas, coal-fired / gas-fired power plant flue gas, and even air.

[0014] In addition, the functional ionic material provided by the present invention also has very ideal CO2 selective adsorption, and has very low adsorption for N2, and is therefore particularly suitable for the removal or capture of CO2 at low concentrations containing a large amount of N2. Taking power plant flue gas and air as an example, the flue gas contains medium-low concentrations of CO2 (volume fraction not exceeding 15%), and the CO2 concentration in air is even lower (volume fraction is about 0.04%). Both contain a large amount of N2, so a higher CO2 / N2 selectivity is required when capturing CO2.

[0015] In the functional ionic material provided by the present invention, the volume of micropores (including ultramicropores) with a pore size <2 nm can be more than 50% (volume ratio) of the total pore volume. In some preferred embodiments, the volume of micropores with a pore size <2 nm can be more than 60% of the total pore volume, for example, more than 70%, more than 80% or more.

[0016] The functional ionic material provided by the present invention has a specific surface area of ​​20 to 800 m 2 In some preferred embodiments, the specific surface area may be 50 to 500 m 2 / g, for example, 150 to 300 m 2 / g.

[0017] In the functional ionic material provided by the present invention, the total pore volume can be 0.02 to 1 cm 3In some preferred embodiments, the total pore volume may be 0.05 to 0.5 cm 3 / g, for example, 0.2 to 0.5 cm 3 / g.

[0018] In the functional ionic material provided by the present invention, the weight average molecular weight of the copolymer may be 15000 to 25000. In some preferred embodiments, the weight average molecular weight of the copolymer may be 18000 to 20000. The weight average molecular weight of the copolymer may be measured by a common test method in the art, such as the GPC method.

[0019] In the functional ionic material provided by the present invention, the R may represent a residue of a common natural amino acid or non-natural amino acid in the art with the carboxyl moiety removed, including but not limited to one or more of glycine, alanine, valine, leucine, isoleucine, methionine, proline, tryptophan, serine, tyrosine, cysteine, phenylalanine, asparagine, glutamine, threonine, aspartic acid, glutamic acid, lysine, arginine, histidine, selenocysteine, and pyrrolysine. In some preferred embodiments, the R may represent a residue of glycine and / or alanine with the carboxyl moiety removed.

[0020] In the functional ionic material provided by the present invention, the molar ratio of the polymer segment A to the polymer segment B can be 3 to 10:1, for example, about 3:1, about 4:1, about 5:1, about 6:1, about 7:1, about 8:1, about 9:1, about 10:1 or any molar ratio interval. In some preferred embodiments, the molar ratio of the polymer segment A to the polymer segment B can be 5 to 6:1.

[0021] The second aspect of the present invention provides a method for preparing the functional ionic material according to any one of the above technical solutions, comprising the following steps:

[0022] S1: N-vinyl imidazole or N-vinyl pyrrolidone and divinyl benzene are copolymerized in an aqueous solution in the presence of an initiator and a dispersant to obtain a copolymer matrix; and

[0023] S2: The copolymer matrix and the amino acid undergo an acid-base reaction in an organic solvent to obtain the functional ionic material.

[0024] In some preferred embodiments, in step S1, the initiator may be one or more of benzoyl peroxide, cumene hydroperoxide, methyl ethyl ketone peroxide, and azobisisobutyronitrile, and more preferably may be benzoyl peroxide.

[0025] In some preferred embodiments, in step S1, the dispersant may be one or more of polyvinyl alcohol (preferably polyvinyl alcohol having a weight average molecular weight of 25,000 to 35,000), gelatin, starch, methyl cellulose, bentonite, and calcium carbonate, and more preferably may be polyvinyl alcohol.

[0026] In some preferred embodiments, in step S1, the reaction temperature of the copolymerization reaction may be 70-110° C., and the reaction time may be 20-40 h. In some more preferred embodiments, the reaction temperature of the copolymerization reaction may be 75-100° C., and the reaction time may be 20-30 h.

[0027] In some preferred embodiments, in the step S1, the copolymerization reaction can be first carried out at 70-80°C for 4-10 hours, then at 85-90°C for 8-15 hours, and finally at 95-110°C for 8-15 hours.

[0028] In some preferred embodiments, the step S1 may further include: after the copolymerization reaction is completed, separating the solid, washing and drying (for example, drying at 75-90° C. for 8-15 hours), and collecting spherical products with a particle size of 0.35-0.60 mm as the copolymer matrix.

[0029] In some preferred embodiments, in step S2, the organic solvent may be one or more of acetonitrile, acetone, ethyl acetate, dichloromethane, chloroform, ethanol, N,N-dimethylformamide, and N,N-dimethylacetamide, more preferably acetonitrile.

[0030] In some preferred embodiments, in step S2, the reaction temperature of the acid-base reaction may be 50-90°C, and the reaction time may be 1-6 hours. In some more preferred embodiments, the reaction temperature of the acid-base reaction may be 60-80°C, and the reaction time may be 1-3 hours.

[0031] In the preparation method provided by the present invention, the desired material can be obtained through a separation step, for example, the generated copolymer matrix can be separated, and the separation method can be a common method in the art, including but not limited to natural sedimentation, (normal pressure or vacuum) filtration, centrifugation, etc.

[0032] The third aspect of the present invention provides the use of the functional ionic material described in any one of the above technical solutions or the functional ionic material prepared by the preparation method described in any one of the above technical solutions as a CO2 adsorbent.

[0033] The fourth aspect of the present invention provides a method for adsorbing CO2, which uses the functional ionic material described in any one of the above technical solutions or the functional ionic material prepared by the preparation method described in any one of the above technical solutions as an adsorbent for adsorbing CO2.

[0034] In some preferred embodiments, the adsorption temperature may be 5 to 100° C., and the adsorption pressure may be 0.04 kPa to 1 MPa. In some more preferred embodiments, the adsorption temperature may be 20 to 50° C., and the adsorption pressure may be 0.04 to 1 kPa, for example, 0.05 to 0.1 kPa.

[0035] The fifth aspect of the present invention provides a method for capturing CO2, which uses the functional ionic material described in any one of the above technical solutions or the functional ionic material prepared by the preparation method described in any one of the above technical solutions as an adsorbent to adsorb CO2, and the adsorbent after adsorption then desorbs CO2, thereby capturing CO2.

[0036] In some preferred embodiments, the adsorption temperature may be 5 to 100° C., and the adsorption pressure may be 0.04 kPa to 1 MPa. In some more preferred embodiments, the adsorption temperature may be 20 to 50° C., and the adsorption pressure may be 0.04 to 1 kPa, for example, 0.05 to 0.1 kPa.

[0037] In some preferred embodiments, the desorption temperature may be 50 to 150°C, and the desorption pressure may be 10 -6 kPa~0.01MPa. In some more preferred embodiments, the desorption temperature may be 60~100℃, and the desorption pressure may be 10 -6 ~1Pa, for example, it can be 10 -6 ~10 -4 Pa.

[0038] In some preferred embodiments, the desorbed functional ionic material can be recycled for multiple times.

[0039] The technical solution provided by the present invention has the following advantages:

[0040] 1) The functional ionic material provided by the present invention contains abundant CO2 adsorption active sites and microporous-ultramicroporous structure, thus having excellent CO2 adsorption capacity and adsorption selectivity, and is suitable for the adsorption, removal or capture of CO2 in various scenarios, such as coal chemical process gas containing low concentration CO2 and a large amount of N2, coal-fired / gas-fired power plant flue gas and other gases, and even has good application prospects in the fields of air carbon capture, confined space carbon capture, etc.

[0041] 2) The functional ionic material provided by the present invention is based on a copolymer, has high strength, is easy to desorb and regenerate, and has substantially no decrease in adsorption capacity after regeneration, and can be recycled for multiple times, thereby significantly reducing costs and improving adsorption efficiency.

[0042] 3) The functional ionic material provided by the present invention has a simple preparation process, is easy to operate and control, does not require expensive raw materials, and can be prepared by adjusting the types and amounts of comonomers and amino acids to obtain a variety of functional ionic materials with different properties, thereby expanding the types and application fields of CO2 adsorption materials and having great industrial practical value. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments.

[0044] Unless otherwise specified, the raw materials or reagents used in the examples and comparative examples of the present invention are commercially available products.

[0045] The percentages used in the embodiments and comparative examples of the present invention are all mass percentages unless otherwise specified.

[0046] Example 1

[0047] (1) Preparation of copolymer matrix

[0048] Add 50 g of N-vinyl imidazole (0.53 mol), 13 g of divinyl benzene (0.1 mol) and 1.0 g of benzoyl peroxide (0.004 mol) into a 500 ml three-necked flask, start the stirrer and stir for 0.5 hours, add a mixed solution of 200 ml of deionized water and 4 g of polyvinyl alcohol (molecular weight is ~30000), stir for 2 hours, then gradually heat up to 75°C, react for 5 hours, then heat up to 90°C, react for 10 hours, and finally heat up to 100°C, react for 10 hours. After the reaction is completed, pour out the upper liquid, wash with 85°C hot water, then wash with cold water, then filter, put into an oven at 80°C to dry for 12 hours, sieve, collect composite microspheres A1 with a particle size in the range of 0.35 to 0.60 mm, and the weight average molecular weight is 18500.

[0049] (2) Preparation of functionalized ionic materials

[0050] Add 20 g of composite microspheres A1 (wherein the molar amount of imidazole is 0.16 mol) and 200 ml of acetonitrile into a 500 ml three-necked flask, start stirring, add 20 g of glycine (0.26 mol) into a constant pressure funnel, slowly drip into the three-necked flask at room temperature, heat to 70°C after the addition is complete, condense and reflux, react for 2 hours, filter after the reaction is complete, wash 3 times with deionized water to obtain functionalized ionic material microspheres A2.

[0051] The pore structure of microsphere A2 was characterized by physical adsorption instrument (Machine ASAP2460), and the specific surface area was 260m 2 / g, the total pore volume is 0.4cm 3 / g, micropores and ultramicropores with pore diameters <2nm account for 63% (volume ratio).

[0052] The structure of microsphere A2 was characterized by Fourier transform infrared spectroscopy (Nicolet 380) at 2993, 787, 648, 1589 and 1400-1500 cm -1 The infrared characteristic peaks of glycine such as CH, C=O, CC, and NH were detected, indicating that this functionalized ionic material has been successfully synthesized.

[0053] CO2 capacity evaluation experiment: 0.2g of microsphere A2 was ground and its CO2 adsorption isotherm was measured using a physical adsorption instrument. The test temperature was 40℃, the test pressure was 0.06kPa, and the CO2 adsorption capacity of the A2 material was 0.4mmol CO2 / g adsorbent (the test gas was pure CO2).

[0054] In addition, the adsorption capacity of the microspheres under pure CO2 and pure N2 was measured under the same test conditions, and the ideal selectivity of CO2 / N2 was calculated to be 11000.

[0055] Desorption experiment: A physical adsorption instrument was used to vacuum desorb the adsorbed A2 material (vacuum degree was 10 -5 Pa, desorption temperature is 80°C). After desorption, the adsorption capacity is measured again under the above experimental conditions and is 0.39 mmol CO2 / g adsorbent.

[0056] Example 2

[0057] (1) Preparation of copolymer matrix

[0058] Add 50 g of N-vinyl imidazole (0.53 mol), 13 g of divinyl benzene (0.1 mol) and 1.0 g of benzoyl peroxide (0.004 mol) into a 500 ml three-necked flask, start the stirrer and stir for 0.5 hours, add a mixed solution of 200 ml of deionized water and 4 g of polyvinyl alcohol (molecular weight is ~30000), stir for 2 hours, then gradually heat up to 75°C, react for 5 hours, then heat up to 90°C, react for 10 hours, and finally heat up to 100°C, react for 10 hours. After the reaction is completed, pour out the upper liquid, wash with 85°C hot water, then wash with cold water, then filter, put into an oven at 80°C to dry for 12 hours, sieve, collect composite microspheres C1 with a particle size in the range of 0.35 to 0.60 mm, and the weight average molecular weight is 19000.

[0059] (2) Preparation of functionalized ionic materials

[0060] In a 500 ml three-necked flask, add 20 g of composite microspheres C1 (wherein the molar amount of imidazole is 0.16 mol), add 200 ml of acetonitrile, start stirring, add 24 g of alanine (0.27 mol) in a constant pressure funnel, slowly add it to the three-necked flask at room temperature, after the addition is complete, heat to 70°C and condense reflux, react for 2 hours, filter after the reaction is complete, wash 3 times with deionized water to obtain functionalized ionic material microspheres C2.

[0061] The pore structure of microsphere C2 was characterized by physical adsorption instrument (Machine ASAP2460), and the specific surface area was 180m 2 / g, and the total pore volume is 0.29cm 3 / g, micropores and ultramicropores with a pore size of <2nm account for 71% (volume ratio).

[0062] The structure of microsphere C2 was characterized by Fourier transform infrared spectroscopy (Nicolet 380) at 2982, 772, 649, 1583 and 1400-1500 cm -1 The infrared characteristic peaks of alanine such as CH, C=O, CC, and NH were detected, indicating that this functionalized ionic material has been successfully synthesized.

[0063] CO2 capacity evaluation experiment: 0.2g of microsphere C2 was ground and its CO2 adsorption isotherm was measured by physical adsorption instrument. The test temperature was 40℃, the test pressure was 0.06kPa, and the CO2 adsorption capacity of C2 material was 0.44mmol CO2 / g adsorbent (the test gas was pure CO2).

[0064] In addition, the adsorption capacity of the microspheres under pure CO2 and pure N2 was measured under the same test conditions, and the ideal selectivity of CO2 / N2 was calculated to be 13500.

[0065] Desorption experiment: The adsorbed C2 material was vacuum desorbed using a physical adsorption instrument (vacuum degree of 10 -5 Pa, desorption temperature is 80°C). After desorption, the adsorption capacity is measured again under the above experimental conditions and is 0.42 mmol CO2 / g adsorbent.

[0066] Comparative Example 1

[0067] Composite microspheres a1 were prepared according to step (1) of Example 1.

[0068] The pore structure of microsphere a1 was characterized by physical adsorption instrument (Mic ASAP2460), and the specific surface area was 430m 2 / g, and the total pore volume is 0.71cm 3 / g, micropores and ultramicropores with pore diameters <2nm account for 13% (volume ratio).

[0069] CO2 capacity evaluation experiment: 0.2g of microsphere a1 was ground and its CO2 adsorption isotherm was measured using a physical adsorption instrument. The test temperature was 40℃, the test pressure was 0.06kPa, and the CO2 adsorption capacity of the a1 material was 0.04mmol CO2 / g adsorbent (the test gas was pure CO2).

[0070] In addition, the adsorption capacity of the microspheres under pure CO2 and pure N2 was measured under the same test conditions, and the ideal selectivity of CO2 / N2 was calculated to be 450.

[0071] Comparative Example 2

[0072] (1) Preparation of copolymer matrix

[0073] Add 25 g of N-vinyl imidazole (0.265 mol), 13 g of divinyl benzene (0.1 mol) and 1.0 g of benzoyl peroxide (0.004 mol) into a 500 ml three-necked flask, start the stirrer and stir for 0.5 hours, add a mixed solution of 200 ml of deionized water and 4 g of polyvinyl alcohol (molecular weight is ~30000), stir for 2 hours, then gradually heat up to 75°C, react for 5 hours, then heat up to 90°C, react for 10 hours, and finally heat up to 100°C, react for 10 hours. After the reaction is completed, pour out the upper liquid, wash with 85°C hot water, then wash with cold water, then filter, put into an oven at 80°C to dry for 12 hours, sieve, and collect the composite microspheres B1 with a particle size in the range of 0.35 to 0.60 mm.

[0074] (2) Preparation of functionalized ionic materials

[0075] Add 20 g of composite microspheres B1 and 200 ml of acetonitrile into a 500 ml three-necked flask, start stirring, add 10 g of glycine (0.13 mol) into a constant pressure funnel, and slowly drip into the three-necked flask at room temperature. After the addition is completed, heat to 70°C and condense reflux, react for 2 hours, filter after the reaction is completed, wash 3 times with deionized water to obtain functionalized ionic material microspheres B2.

[0076] The pore structure of microsphere B2 was characterized by physical adsorption instrument (Machine ASAP2460), and the specific surface area was 410m 2 / g, and the total pore volume is 0.69cm 3 / g, micropores and ultramicropores with pore diameters <2nm account for 23% (volume ratio).

[0077] CO2 capacity evaluation experiment: 0.2g of microsphere B2 was ground and its CO2 adsorption isotherm was measured using a physical adsorption instrument. The test temperature was 40℃, the test pressure was 0.06kPa, and the CO2 adsorption capacity of the B2 material was 0.12mmol CO2 / g adsorbent (the test gas was pure CO2).

[0078] In addition, the adsorption capacity of the microspheres under pure CO2 and pure N2 was measured under the same test conditions, and the ideal selectivity of CO2 / N2 was calculated to be 8200.

[0079] Comparative Example 3

[0080] Add 200 ml of acetonitrile and 50 g of N-vinyl imidazole (0.53 mol) into a 500 ml three-necked flask, start stirring, add 48 g of alanine (0.54 mol) into a constant pressure funnel, slowly add it into the three-necked flask at room temperature, heat it to 70°C and condense it under reflux, and react for 2 hours. After the reaction is completed, remove the acetonitrile by rotary evaporation, wash it with ethyl acetate several times, remove the ethyl acetate by rotary evaporation, and put it into a 70°C oven for 12 hours to obtain a solid product powder [Vim][Ala].

[0081] CO2 capacity evaluation experiment: Take 5 grams of [Vim][Ala] (0.026 mol) powder, put it into a filter column with a sand plate (Φ20C sand plate), and weigh it. Pass the dried CO2 / N2 mixed gas from the bottom. The volume concentration of CO2 is 0.06%, the gas flow rate is 100mL / min, the gas temperature is 40°C, and the pressure is 100kPa. The end point is when the weight of the sand plate filter column no longer increases. The CO2 absorption amount is measured to be 0.09mmol CO2 / g adsorbent.

[0082] Desorption experiment: [Vim][Ala] was desorbed by N2 purging at 100°C. After cooling, the cyclic adsorption capacity was measured again under the above experimental conditions and was 0.06 mmol CO2 / g adsorbent.

[0083] It can be seen from Comparative Example 1 that the preparation processes of microsphere a1 and microsphere A1 are exactly the same, but a1 does not react with amino acids, so no corresponding anions are generated and fixed in the pores of the polymer material to change the pore structure, and thus a large number of micropores-ultramicropore structures are not formed, so the CO2 adsorption capacity is low and the CO2 / N2 selectivity is also low.

[0084] It can be seen from Comparative Example 2 that due to the reduction in the number of imidazole groups in microsphere B1, the sites that can react with amino acids are correspondingly reduced, resulting in less pore occupancy by amino acid anions, and the volume share of micropores and ultramicropores is significantly reduced relative to Example 1. Therefore, the CO2 adsorption capacity and CO2 / N2 selectivity are significantly inferior to those of microsphere A2 in Example 1.

[0085] It can be seen from Comparative Example 3 that although the ionic liquid [Vim][Ala] that has not formed a copolymer has a certain CO2 adsorption capacity, it has a poor adsorption capacity due to the lack of rich microporous-ultramicroporous structure, and the powdered [Vim][Ala] is difficult to regenerate completely. After desorption, CO2 is adsorbed again, and the adsorption amount decreases significantly, indicating that it is difficult to recycle.

[0086] Unless otherwise defined, the terms used in the present invention have the meanings commonly understood by those skilled in the art.

[0087] The embodiments described in the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Those skilled in the art may make various other substitutions, changes and improvements within the scope of the present invention. Therefore, the present invention is not limited to the above embodiments, but is only limited by the claims.

Claims

1. A functional ionic material, which is a copolymer comprising a polymer segment A represented by formula (1) or formula (2) and a polymer segment B represented by formula (3), in, R represents the residue of an amino acid minus the carboxyl portion.

2. The functional ionic material according to claim 1, characterized in that: In the functional ionic material, the volume of micropores with a pore size of less than 2 nm accounts for more than 50% of the total pore volume, preferably more than 60%; and / or The specific surface area of ​​the functional ionic material is 20 to 800 m 2 / g; and / or The total pore volume of the functional ionic material is 0.02 to 1 cm 3 / g; and / or The weight average molecular weight of the copolymer is 15,000 to 25,000.

3. The functional ionic material according to claim 1 or 2, characterized in that: The R represents the residue of the following amino acids without the carboxyl portion: one or more of glycine, alanine, valine, leucine, isoleucine, methionine, proline, tryptophan, serine, tyrosine, cysteine, phenylalanine, asparagine, glutamine, threonine, aspartic acid, glutamic acid, lysine, arginine, histidine, selenocysteine, and pyrrolysine; and / or The molar ratio of the polymer segment A to the polymer segment B is 3 to 10:1, preferably 5 to 6:

1.

4. The method for preparing the functional ionic material according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: N-vinyl imidazole or N-vinyl pyrrolidone and divinyl benzene are copolymerized in an aqueous solution in the presence of an initiator and a dispersant to obtain a copolymer matrix; and S2: The copolymer matrix and the amino acid undergo an acid-base reaction in an organic solvent to obtain the functional ionic material.

5. The preparation method according to claim 4, characterized in that: In the step S1, the initiator is one or more of benzoyl peroxide, cumene hydroperoxide, methyl ethyl ketone peroxide, and azobisisobutyronitrile; and / or The dispersant is one or more of polyvinyl alcohol (preferably polyvinyl alcohol with a weight average molecular weight of 25,000 to 35,000), gelatin, starch, methyl cellulose, bentonite, and calcium carbonate; and / or The reaction temperature of the copolymerization reaction is 70-110°C and the reaction time is 20-40h; Preferably, the copolymerization reaction is first carried out at 70-80° C. for 4-10 h, then at 85-90° C. for 8-15 h, and finally at 95-110° C. for 8-15 h.

6. The preparation method according to claim 4 or 5, characterized in that: The step S1 further comprises: after the copolymerization reaction is completed, separating the solid, washing it with water and drying it, and collecting the spherical product with a particle size of 0.35 to 0.60 mm as the copolymer matrix.

7. The preparation method according to any one of claims 4 to 6, characterized in that: In step S2, the organic solvent is one or more of acetonitrile, acetone, ethyl acetate, dichloromethane, chloroform, ethanol, N,N-dimethylformamide, and N,N-dimethylacetamide; and / or The reaction temperature of the acid-base reaction is 50-90° C., and the reaction time is 1-6 hours.

8. Use of the functional ionic material according to any one of claims 1 to 3 or the functional ionic material prepared by the preparation method according to any one of claims 4 to 7 as a CO2 adsorbent.

9. A method for adsorbing CO2, characterized in that: Using the functional ionic material described in any one of claims 1 to 3 or the functional ionic material prepared by the preparation method described in any one of claims 4 to 7 as an adsorbent for adsorbing CO2; Preferably, the adsorption temperature is 5 to 100° C., and the adsorption pressure is 0.04 kPa to 1 MPa.

10. A method for capturing CO2, characterized in that: The functional ionic material according to any one of claims 1 to 3 or the functional ionic material prepared by the preparation method according to any one of claims 4 to 7 is used as an adsorbent to adsorb CO2, and the adsorbent after adsorption then desorbs CO2, thereby capturing CO2; Preferably, the adsorption temperature is 5 to 100°C, and the adsorption pressure is 0.04 kPa to 1 MPa; and / or Preferably, the desorption temperature is 50-150°C and the desorption pressure is 10 -6 Pa~0.01MPa.

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