Polymer, carbon dioxide absorption / release device, method for producing composite, and method for producing carbon dioxide absorption / release device

Abstract

The present invention can provide a novel anthraquinone polymer. Also provided is a carbon dioxide absorption / release device having good electron conductivity due to inclusion of the anthraquinone polymer in pores of a porous carbon-containing member.　A polymer is formed with at least one monomer selected from the group consisting of 2-ethynylanthraquinone represented by formula (1), 2,6-diethynylanthraquinone represented by formula (2), and 2,3,6,7-tetraethynylanthraquinone represented by formula (3), or is a polymerized product containing, as a constituent, at least one selected from the group consisting of 2-ethynylanthraquinone represented by formula (1), 2,6-diethynylanthraquinone represented by formula (2), and 2,3,6,7-tetraethynylanthraquinone represented by formula (3).

Description

Polymer, carbon dioxide absorption / release device, method for producing composite, and method for producing carbon dioxide absorption / release device

[0001] The present disclosure relates to a polymer, a carbon dioxide absorption / release device, a method for manufacturing a composite, and a method for manufacturing a carbon dioxide absorption / release device.

[0002] Carbon dioxide separation and capture has been attracting attention as a technology for reducing the greenhouse gas carbon dioxide (CO2). Carbon dioxide separation and capture technology is mainly used to separate and capture carbon dioxide contained in exhaust gases from factories and the atmosphere from other substances.

[0003] Carbon dioxide Capture and Utilization (CCU), which uses carbon dioxide to produce chemicals and fuels, and Carbon dioxide Capture and Storage (CCS), which stores carbon dioxide deep underground, require the separation of carbon dioxide from other gases. The technology for capturing, utilizing, and storing carbon dioxide is called CCUS, and carbon dioxide separation and capture is a technology required to promote CCUS.

[0004] As an example of such a carbon dioxide separation and recovery technology, Non-Patent Document 1 discloses a carbon dioxide absorption and release device having a configuration in which a composite in which molecules exhibiting redox activity, such as polyanthraquinone or polyvinylferrocene, are bound to carbon nanotubes is provided on the surface of a non-woven carbon mat collector.

[0005] Furthermore, Patent Document 1 discloses a carbon dioxide absorption / release device including an electrode having a porous composite including a conductive member and a porous body that is disposed on the conductive member, has pores of angstrom size or nanometer size, and contains molecular moieties that exhibit redox activity in response to electricity.

[0006] Japanese Patent Application Laid-Open No. 2023-033072

[0007] S. Voskian, TA Hatton, Energy Environ. Sci., 12, 3530 (2019)

[0008] The carbon dioxide absorption / release devices disclosed in Non-Patent Document 1 and Patent Document 1 have a porous composite film provided on the surface of an electrode. The porous composite is produced by physically fixing an anthraquinone derivative such as polyanthraquinone or anthraquinone to the surface of a conductive member such as carbon nanotubes using a binder or the like.

[0009] However, if the anthraquinone derivative is physically fixed to the surface of the conductive member, the electronic conductivity may be reduced.

[0010] In view of the above problems, the present embodiment aims to provide a novel anthraquinone polymer and a carbon dioxide absorption / release device having good electronic conductivity by providing the anthraquinone polymer in the pores of a porous carbon-containing member.

[0011] The above-mentioned problems can be solved by the following embodiments: Item 1. A polymer containing at least one monomer selected from the group consisting of 2-ethynylanthraquinone represented by the following formula (1), 2,6-diethynylanthraquinone represented by the following formula (2), and 2,3,6,7-tetraethynylanthraquinone represented by the following formula (3), or a polymer containing at least one monomer selected from the group consisting of 2-ethynylanthraquinone represented by the following formula (1), 2,6-diethynylanthraquinone represented by the following formula (2), and 2,3,6,7-tetraethynylanthraquinone represented by the following formula (3) as a constituent component. Item 2. A carbon dioxide absorption / release device comprising: a composite comprising a porous carbon-containing member and the polymer according to Item 1 provided in the pores of the porous carbon-containing member; and an electrode having the composite provided on a surface. Item 3. The carbon dioxide absorption / release device according to Item 2, wherein the porous carbon-containing member is one or more types selected from the group consisting of activated carbon, ordered mesoporous carbon, and graphene mesosponge. Item 4. The carbon dioxide absorption / release device according to Item 2 or 3, wherein the porous carbon-containing member is formed into one or more shapes selected from the group consisting of film, sheet, thin plate, stick, fiber, tube, and flake. Item 5. The carbon dioxide absorption / release device according to any one of Items 2 to 4, further comprising an electrolyte held in the composite. Item 6. Item 7. The carbon dioxide absorption and release device according to any one of Items 2 to 5, wherein the electrode is made of one or more materials selected from the group consisting of carbon, aluminum, copper, stainless steel, and nickel, and further includes a current collector formed in one or more shapes selected from the group consisting of a film, a sheet, a flake, a stick, a fiber, a tube, a plate, and a mesh, and the composite is provided on a surface of the current collector. Item 8. A method for producing a composite, comprising: a step of dissolving a monomer containing at least one selected from the group consisting of 2-ethynylanthraquinone represented by the following formula (1), 2,6-diethynylanthraquinone represented by the following formula (2), and 2,3,6,7-tetraethynylanthraquinone represented by the following formula (3) in an organic solvent; a step of mixing the organic solvent in which the monomer is dissolved with a porous carbon-containing member, and then removing the organic solvent; and a step of heating the residue after the removal of the organic solvent to carry out a polymerization reaction, thereby obtaining a composite in which a polymer is provided in the pores of the porous carbon-containing member. Item 8. A method for producing a carbon dioxide absorption / release device, comprising the step of applying the composite produced by the method described in Item 7 to the surface of an electrode and drying by heating to form a composite film on the surface of the electrode. Item 9. A composite having a polymer provided in the pores of a porous carbon-containing member, produced by a method comprising the following steps (1) to (4): (1) a step of dissolving at least one monomer selected from the group consisting of 2-ethynylanthraquinone, 2,6-diethynylanthraquinone, and 2,3,6,7-tetraethynylanthraquinone in an organic solvent; (2) a step of mixing the organic solvent in which the monomer is dissolved with the porous carbon-containing member; (3) a step of removing the organic solvent; and (4) a step of heating the residue after removing the organic solvent to carry out a polymerization reaction.

[0012] According to the present embodiment, a novel anthraquinone polymer can be provided. Furthermore, according to the present embodiment, by providing the anthraquinone polymer in the pores of a porous carbon-containing member, a carbon dioxide absorption / release device with good electronic conductivity can be provided.

[0013] FIG. 1 is a schematic diagram of a carbon dioxide absorption / release device according to the present embodiment. FIG. 2 is a graph showing CV measurement results according to Test Example 3. FIG. 3 is a graph showing CV measurement results according to Test Example 4. FIG. 4 is a graph showing CV measurement results according to Test Example 11. FIG. 5 is a graph showing CV measurement results according to Test Example 12. FIG. 6 is a graph showing CV measurement results according to Test Example 13. FIG. 7 is a graph showing CV measurement results according to Test Example 14. FIG. 8 is a graph showing CV measurement results according to Test Example 15. FIG. 9 is a graph showing CV measurement results according to Test Example 16. FIG. 10 is a graph showing CV measurement results according to Test Example 17. FIG. 11 is a graph showing CV measurement results according to Test Example 18. FIG. 12 is a graph showing CV measurement results according to Test Example 19. FIG. 13 is a graph showing CV measurement results according to Test Example 20.

[0014] Next, embodiments of the present disclosure will be described in detail with reference to the drawings. It should be understood that the present invention is not limited to the following embodiments, and that appropriate design changes, modifications, and the like may be made based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention.

[0015] (Polymer) The polymer according to this embodiment is a polymer containing at least one monomer selected from the group consisting of 2-ethynylanthraquinone represented by the following formula (1), 2,6-diethynylanthraquinone represented by the following formula (2), and 2,3,6,7-tetraethynylanthraquinone represented by the following formula (3). Alternatively, the polymer according to this embodiment is a polymer containing at least one monomer selected from the group consisting of 2-ethynylanthraquinone represented by the following formula (1), 2,6-diethynylanthraquinone represented by the following formula (2), and 2,3,6,7-tetraethynylanthraquinone represented by the following formula (3) as a constituent component.

[0016] Polymers containing at least one monomer selected from the group consisting of 2-ethynylanthraquinone represented by the above formula (1), 2,6-diethynylanthraquinone represented by the above formula (2), and 2,3,6,7-tetraethynylanthraquinone represented by the above formula (3) are formed by polymerization through reaction of ethynyl groups. Polymers of these monomers can take various structures depending on the position of the ethynyl group that reacts, how many ethynyl groups react, how many monomers form the minimum unit structure that constitutes the polymer, and the position of the anthraquinone skeleton when the ethynyl group reacts. Specific structural formulas for polymers composed of the above monomers are listed below.

[0017] The polymer represented by the following formula (4) is a polymer obtained by polymerizing the ethynyl group of 2-ethynylanthraquinone, which is a monomer represented by the above formula (1). In formula (4), the degree of polymerization n is 50,000 to 10,000.

[0018] The polymer represented by the following formula (5) is a polymer obtained by polymerizing each of the two ethynyl groups of 2,6-diethynylanthraquinone represented by the above formula (2) as a monomer. In formula (5), the degree of polymerization n is 5 to 10,000.

[0019] The polymer represented by the following formula (6) uses 2,6-diethynylanthraquinone represented by the above formula (2) as a monomer, and is formed by polymerizing the ethynyl groups at both ends of 2,6-diethynylanthraquinone with the ethynyl groups of other 2,6-diethynylanthraquinones. In formula (6), the degree of polymerization n is 50,000 to 10,000.

[0020] The polymer represented by the following formula (7) uses 2,6-diethynylanthraquinone represented by the above formula (2) as a monomer, and three ethynyl groups of the 2,6-diethynylanthraquinone form benzene rings through a cycloaddition reaction, thereby forming a polymer having a three-dimensional network structure.

[0021] When the polymer according to the present embodiment is a copolymer of two or three monomers selected from the group consisting of 2-ethynylanthraquinone represented by the above formula (1), 2,6-diethynylanthraquinone represented by the above formula (2), and 2,3,6,7-tetraethynylanthraquinone represented by the above formula (3), the order and ratio of the arrangement of these monomers are not particularly limited and may be random.

[0022] (Method for Producing Polymer) The polymer according to this embodiment is produced by heating 2-ethynylanthraquinone represented by the above formula (1), 2,6-diethynylanthraquinone represented by the above formula (2), and / or 2,3,6,7-tetraethynylanthraquinone represented by the above formula (3) at 100 to 300° C. to cause a polymerization reaction. Next, the resulting mixture is vacuum dried, thereby producing the polymer according to this embodiment.

[0023] (Configuration of Carbon Dioxide Absorption / Release Device) Fig. 1 shows a schematic diagram of a carbon dioxide absorption / release device 10 according to an embodiment of the present disclosure. The configuration shown in Fig. 1 is an example, and is not limited to this. In the carbon dioxide absorption / release device 10, a composite 11 is provided on the surface of an electrode 12. When the electrode 12 is in the form of a film as shown in Fig. 1, the composite 11 may be provided on both surfaces thereof, or on only one surface thereof. The composite 11 may be provided on a part of the surface of the electrode 12, or on the entire surface of the electrode 12.

[0024] <Composite> The composite of the carbon dioxide absorption / release device according to this embodiment includes a porous carbon-containing member and a polymer having, as a monomer, 2-ethynylanthraquinone represented by the above formula (1), 2,6-diethynylanthraquinone represented by the above formula (2), and / or 2,3,6,7-tetraethynylanthraquinone represented by the above formula (3), provided in the pores of the porous carbon-containing member.

[0025] <Porous Carbon-Containing Member> The porous carbon-containing member contained in the composite is preferably composed of a porous carbon material having good electrical conductivity, and one or more types selected from the group consisting of activated carbon, regular mesoporous carbon, and graphene meso-sponge can be used. The shape of the porous carbon-containing member is not particularly limited, and a shape suitable for the desired device configuration can be used. The porous carbon-containing member is preferably formed into one or more shapes selected from the group consisting of, for example, a film, a sheet, a flake, a stick, a fiber, a tube, and a flake. In an embodiment of the present invention, the porous carbon-containing member is produced from a powder, and the powder can be processed to form the desired shape.

[0026] When the porous carbon-containing member is a powder, it is preferable that the particle size is 1 μm or less. With this configuration, the surface area of ​​the porous carbon-containing member is large, which allows for better penetration of carbon dioxide and the electrolyte, thereby providing a better carbon dioxide absorption / release device. When the porous carbon-containing member is a powder, the lower limit of the particle size is not particularly limited, but in practice it can be set to 100 nm or more.

[0027] Activated carbon is a substance whose main component is carbon that has been subjected to chemical or physical treatment (activation / activation). The surface of activated carbon is highly porous, and the interior of its tiny holes (pores) is complexly developed. This structure allows activated carbon to adsorb many substances, mainly organic matter. The activated carbon contained in the composite can be processed into films, sheets, flakes, sticks, tubes, etc. for use.

[0028] Regular mesoporous carbon is a porous carbon with regular pores with diameters of 2 to 50 nm. The surface of regular mesoporous carbon is highly porous, and this structure allows it to adsorb many substances, primarily organic matter. In addition, regular mesoporous carbon has uniform pores and exhibits superior diffusion and molecular selectivity compared to activated carbon, which has non-uniform pore sizes, thereby further improving the functionality of carbon dioxide absorption / desorption devices. The regular mesoporous carbon contained in the composite can be processed into films, sheets, flakes, sticks, tubes, and other shapes for use.

[0029] Graphene meso sponge is a new carbon material developed by Tohoku University. It has a foam-like pore structure with pore diameters of 3 to 8 nm, and the pore walls are composed of a single layer of defect-free graphene sheets. Its precisely designed nanostructure achieves both excellent porosity and oxidation resistance (chemical durability) that far exceed those of conventional carbon materials. Furthermore, graphene meso sponge's flexibility allows it to be reversibly compressed and restored. This allows it to follow the movements of the active material, which undergoes drastic structural changes during charging and discharging, and it also has excellent mechanical durability.

[0030] <Polymers> Polymers containing 2-ethynylanthraquinone represented by the above formula (1), 2,6-diethynylanthraquinone represented by the above formula (2), and / or 2,3,6,7-tetraethynylanthraquinone represented by the above formula (3) as monomers are redox-active molecules, and as shown in formula (8) below, when anthraquinone (skeleton) is reduced (E1) in the presence of carbon dioxide, carbon dioxide reacts with one of the oxygen atoms to produce carbonate. When further reduced (E'1), carbon dioxide reacts with the other oxygen atom to produce carbonate here as well. The reverse reaction is also possible, and repeated elimination of carbon dioxide and oxidation returns the anthraquinone (skeleton) to its original state.

[0031]

[0032] A polymer containing 2-ethynylanthraquinone represented by the formula (1), 2,6-diethynylanthraquinone represented by the formula (2), and / or 2,3,6,7-tetraethynylanthraquinone represented by the formula (3) as a monomer is provided within the pores of the porous carbon-containing member. The polymer is preferably provided in a dispersed state on the inner walls of the pores of the porous carbon-containing member. This configuration allows for highly efficient electron transfer to the anthraquinone.

[0033] The polymer containing 2-ethynylanthraquinone represented by formula (1), 2,6-diethynylanthraquinone represented by formula (2), or 2,3,6,7-tetraethynylanthraquinone represented by formula (3) as a monomer preferably fills 50 to 500%, and more preferably 50 to 400%, of the surface area of ​​the porous carbon-containing member. This configuration allows for highly efficient electron transfer to the anthraquinone.

[0034] In the composite according to the embodiment of the present invention, the polymer containing at least one monomer selected from the group consisting of 2-ethynylanthraquinone represented by the above formula (1), 2,6-diethynylanthraquinone represented by the above formula (2), and 2,3,6,7-tetraethynylanthraquinone represented by the above formula (3) has a mass ratio of the polymer to the porous carbon-containing member having a micropore structure of preferably 0.7:1 to 3.2:1, more preferably 0.7:1 to 3.0:1, even more preferably 0.8:1 to 2.8:1, and most preferably 1.3:1 to 1.8:1.

[0035] The carbon dioxide absorption / release device according to this embodiment adsorbs and releases carbon dioxide to and from the anthraquinone (skeleton) by changing the potential applied to the device. That is, the carbon dioxide absorption / release device according to this embodiment performs gas adsorption / desorption using an electrochemical swing process in which a specific potential is maintained in the forward direction and a different potential is maintained in the reverse direction, repeatedly. In this process, affinity for the substance to be adsorbed (carbon dioxide) can be adjusted by using a redox-active molecule that can be oxidized at a predetermined potential and reduced at a different potential. The carbon dioxide absorption / release device according to this embodiment can absorb and release carbon dioxide at room temperature by using a complex that absorbs and releases carbon dioxide using a redox-active molecule having this configuration.

[0036] <Electrode> The electrode of the carbon dioxide absorption and release device according to this embodiment may include a current collector on whose surface the composite is provided. The current collector may be made of a known electrode material, and may be made of, for example, one or more materials selected from the group consisting of carbon, aluminum, copper, stainless steel, and nickel. The current collector may be formed into one or more shapes selected from the group consisting of a film, a sheet, a flake, a stick, a fiber, a tube, a plate, and a mesh. The current collector may be porous.

[0037] The current collector functions as a conductor for transmitting electric charge to the composite and causing an electrical response in the polymer whose monomer is 2-ethynylanthraquinone represented by the above formula (1), 2,6-diethynylanthraquinone represented by the above formula (2), and / or 2,3,6,7-tetraethynylanthraquinone represented by the above formula (3). By changing the potential of the current collector, the polymer contained in the composite can be oxidized / reduced, and carbon dioxide can be adsorbed and released by the polymer.

[0038] The electrode of the carbon dioxide absorption / release device according to this embodiment can further include another porous carbon-containing member in addition to the porous carbon-containing member contained in the composite. By further including another porous carbon-containing member, the electrical connection between the composites can be reinforced. Furthermore, when the electrode includes a current collector, the electrical connection between the composite and the current collector can be reinforced. As with the porous carbon-containing member contained in the composite described above, activated carbon, ordered mesoporous carbon, graphene mesosponge, and the like can be used as such another porous carbon-containing member.

[0039] The carbon dioxide absorption / release device according to this embodiment may further include an electrolyte held in the composite. The components of the electrolyte are not particularly limited, but may include ionically bonded salts or their solutions, solid electrolytes, or ion-conductive polymers. By including an electrolyte in the composite, the electrical conductivity is improved, and the carbon dioxide absorption and release capacity is enhanced.

[0040] The carbon dioxide absorption / release device according to this embodiment uses an electrode including the above-described composite as a working electrode, and by applying a potential to this working electrode, an electric charge is applied to the polymer of the composite, whose monomers are 2-ethynylanthraquinone represented by formula (1), 2,6-diethynylanthraquinone represented by formula (2), and / or 2,3,6,7-tetraethynylanthraquinone represented by formula (3). In other words, by controlling the potential of the electrode, the redox state of the composite is switched between an oxidized state and a reduced state. The polymer is capable of adsorbing carbon dioxide in a reduced state and releasing carbon dioxide in an oxidized state.

[0041] The carbon dioxide absorption / release device according to an embodiment of the present invention is a device that uses a composite that absorbs and releases carbon dioxide using a polymer whose monomer is the electrically responsive 2-ethynylanthraquinone represented by the above formula (1), 2,6-diethynylanthraquinone represented by the above formula (2), and / or 2,3,6,7-tetraethynylanthraquinone represented by the above formula (3), and is capable of absorbing and releasing carbon dioxide at room temperature. Therefore, the device can be used in equipment for capturing carbon dioxide contained in factory exhaust gases and the atmosphere. Furthermore, carbon dioxide separation and capture technology is a pressing social issue, and the potential for industrial use of this device is extremely high.

[0042] (Method for Producing a Composite) First, 2-ethynylanthraquinone represented by the above formula (1), 2,6-diethynylanthraquinone represented by the above formula (2), and / or 2,3,6,7-tetraethynylanthraquinone represented by the above formula (3) are mixed with an organic solvent such as chloroform, toluene, or acetone, and stirred at room temperature to dissolve the monomer in the organic solvent. Next, a powder of a porous carbon-containing material is added, followed by further addition of the organic solvent and stirring at room temperature. The amount of the monomer added is preferably 40 to 1000 mass% relative to the amount of porous carbon-containing material added. At this time, the monomer dissolved in the organic solvent penetrates into the pores of the porous carbon-containing material. Next, the organic solvent is evaporated and removed using an evaporator or the like while heating to 30 to 50°C. Next, a polymerization reaction is carried out by heating at 100 to 300°C for 10 to 720 minutes, followed by vacuum drying, thereby producing a composite in which the polymer is provided in the pores of the porous carbon-containing material. Here, the composite is obtained as a powder.

[0043] (Method of manufacturing a carbon dioxide absorption / release device) Next, a method of manufacturing a carbon dioxide absorption / release device according to this embodiment will be described. In the carbon dioxide absorption / release device according to this embodiment, first, powder of the composite according to this embodiment obtained as described above is applied to the surface of an electrode. Next, the composite is heated and dried to form a film of the composite on the surface of the electrode. Furthermore, the shape of the composite may be other than a film, and it may be processed into a desired shape such as a sheet, thin film, stick, fiber, tube, or flake, and then formed on the surface of the electrode. In this way, the carbon dioxide absorption / release device according to this embodiment can be manufactured.

[0044] (Method for separating and recovering carbon dioxide using a carbon dioxide absorption / release device) In the carbon dioxide absorption / release device according to this embodiment, carbon dioxide can be separated and recovered from a gas containing carbon dioxide by adsorbing carbon dioxide onto the composite, and the composite can be regenerated by desorbing carbon dioxide from the composite. Carbon dioxide can be adsorbed onto the composite by passing a current through the composite at the reduction potential of the composite, and contacting the composite with a gas containing carbon dioxide while maintaining the potential flowing through the composite at the reduction potential. Carbon dioxide can be desorbed from the composite and regenerated by switching the potential flowing through the composite that has adsorbed carbon dioxide to the oxidation potential of the composite. After carbon dioxide has been separated from the composite, the device can be set to the reduction potential again to perform the carbon dioxide adsorption process. In this way, by switching the potential of the current passed through the composite between the reduction potential and the oxidation potential, the device can be used repeatedly.

[0045] The present invention will be described in further detail below with reference to examples, but is not limited to these. <Test Example 1: Synthesis of 2,6-diethynylanthraquinone> A stir bar, 1.011 g (2.76 mmol) of 2,6-dibromoanthraquinone, 195 mg (0.278 mmol) of bis(triphenylphosphine)palladium(II) dichloride, and 159 mg (0.835 mmol) of copper(I) iodide were placed in a 300 mL beaker and purged with nitrogen. Next, 34.5 mL of degassed triethylamine was added, and 2.28 mL (16.6 mmol) of trimethylsilylacetylene was added while stirring. The mixture was heated to 50°C and stirred overnight. Next, the mixture was cooled to room temperature, and 30 mL of saturated aqueous ammonium chloride solution was added dropwise over 30 minutes, followed by extraction with dichloromethane. The organic layer was washed with 1 N hydrochloric acid and dried over magnesium sulfate. The dried organic layer was concentrated and purified using silica gel to obtain 678.8 mg (yield 60%) of 2,6-bis(trimethylsilyl)ethynylanthraquinone. The NMR spectrum data of the obtained 2,6-bis(trimethylsilyl)ethynylanthraquinone is shown below. 1H-NMR (CDCl3) δ: 0.29 (s, 18H), 7.83 (dd, 2H), 8.24 (dd, 2H), 8.37 (dd, 2H).

[0046] Next, a stir bar and 260 mg (0.649 mmol) of 2,6-bis(trimethylsilyl)ethynylanthraquinone were placed in a 100 mL recovery flask, and 13 mL of chloroform was added to dissolve the mixture. Next, 2.0 mL of a 1 mol / L tetrabutylammonium fluoride tetrahydrofuran solution was added dropwise, and the mixture was stirred under reflux for 6 hours. After cooling to room temperature, saturated brine was added, and the aqueous layer was extracted with chloroform. The organic layer was then dried over magnesium sulfate, and the solvent was removed. The solid obtained by removing the solvent was washed with methanol and dried under vacuum, yielding 130 mg of 2,6-diethynylanthraquinone (78% yield). The NMR spectral data for the resulting 2,6-diethynylanthraquinone are shown below. 1H-NMR (CDCl3) δ: 3.38 (s, 2H), 7.88 (dd, 2H), 8.28 (d, 2H), 8.41 (d, 2H).

[0047] Test Example 2: Synthesis of a Composite of Graphene Meso-Sponge and Polymer Based on 2,6-Diethynylanthraquinone as a Monomer> 26.0 mg of 2,6-diethynylanthraquinone represented by formula (2) above and 20 mL of chloroform were added to a 50 mL recovery flask, mixed, and stirred at room temperature for 3 minutes to dissolve the monomer in the organic solvent. Next, 30.4 mg of graphene meso-sponge powder with a micropore structure (pore diameter 3-8 nm) was added to the recovery flask, followed by 10 mL of chloroform and stirring at room temperature for 60 minutes. Next, the temperature of the reaction mixture in the recovery flask was raised to 30°C, and the chloroform was removed by evaporation in an evaporator. Next, the mixture was heated at 200°C for 1 hour to carry out a polymerization reaction, followed by vacuum drying to produce a composite in which a polymer based on 2,6-diethynylanthraquinone as a monomer was incorporated into the pores of the graphene meso-sponge. The mass of the resulting composite was 18.1 mg.

[0048] Test Example 3 CV Measurement of Carbon Dioxide Absorption / Release Device in the Presence of Ar 3.12 mg of a composite in which a polymer having 2,6-diethynylanthraquinone as a monomer was provided in the pores of the graphene meso-sponge produced in Test Example 2, 135 μL of 2-propanol, 22 μL of a 5% Nafion dispersion solution (solvent: 45.0 to 51.0 mass % 1-propanol, 42.0 to 48.0 mass % HO) manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd., and 1.02 mg of acetylene black were placed in a microtube and subjected to ultrasonic treatment until the mixture became ink-like. 10 μL of the mixture was then sampled and dropped onto the surface of a glassy carbon electrode, followed by drying at 70° C. for 24 hours, thereby producing a device sample. Next, a 1 M solution of 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (BMPTFSI) in dimethyl sulfoxide (DMSO) was prepared, and the electrodes of the device sample were immersed in the solution. Repeated voltages were applied to the electrodes of the device sample, and the current flowing was measured at a scan rate of 10 mV / s. The experiment was performed in the absence of CO2 by bubbling argon gas through the electrolyte beforehand. By repeatedly applying voltage to the electrodes of the device sample in this manner, the electrochemical behavior of the composite was evaluated by cyclic voltammetry (CV) measurements. A BioLogic SP50-e was used for the CV measurements. The CV measurement results are shown in Figure 2. As shown in Figure 2, the cyclic voltammogram is expressed as a current-voltage curve. The current is considered to be a response signal to the potential excitation signal. Since Test Example 3 was carried out in the presence of Ar, the anthraquinone (skeleton) of the complex was reduced in two stages, with reduction peaks observed in the region of E1 corresponding to the first reduction potential and in the region of E2 corresponding to the second reduction potential, which was located away from the region of E1. In addition, oxidation also occurred in two stages in the reverse reaction, with two oxidation peaks observed.

[0049] Test Example 4: CV Measurement of Carbon Dioxide Absorption / Desorption Device in the Presence of CO2> A sample electrode of the same device was prepared using the same procedure as in Test Example 3. Next, a dimethyl sulfoxide (DMSO) solution (1 M) of 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (BMPTFSI) was prepared, and the electrode of the device sample was immersed in the solution. A voltage was repeatedly applied to the electrode of the device sample, and the current flowing was measured by scanning at a scan rate of 10 mV / s. In the experiment, the electrolyte was bubbled with argon gas beforehand, followed by CV measurement. Further, CO2 gas was bubbled through the electrolyte, thereby performing CV measurement in the presence of carbon dioxide (CO2). In this way, by applying a voltage to the device sample, the electrochemical behavior of the composite was evaluated by cyclic voltammetry (CV) measurement. A BioLogic SP50-e was used for the CV measurement. The CV measurement results are shown in Figure 3. As shown in Figure 3, a cyclic voltammogram is expressed as a current-voltage curve. The current is considered to be a response signal to the potential excitation signal. Test Example 4 was performed in the presence of CO2, so the anthraquinone (skeleton) of the composite was reduced in one step, with the E1 and E2 regions overlapping each other, resulting in a single reduction peak. In the reverse reaction, oxidation also occurred in one step, with the E1 and E2 regions overlapping each other, resulting in a single oxidation peak. As shown in Figure 3, when the anthraquinone (skeleton) is reduced in the presence of carbon dioxide (E1), carbon dioxide reacts with one of the oxygen atoms to produce carbonate. When it is further reduced (E'1), carbon dioxide reacts with the other oxygen atom to produce carbonate. The reverse reaction is also possible, and it can be seen that the anthraquinone (skeleton) is restored to its original state by repeating the desorption and oxidation of carbon dioxide twice.

[0050] In the above-mentioned Test Examples 2 to 4, a composite of a polymer containing 2,6-diethynylanthraquinone represented by the above formula (2) as a monomer and graphene meso-sponge was produced, and CV measurement was performed on a carbon dioxide absorption / desorption device using the composite, which showed that a carbon dioxide absorption / desorption device with good electronic conductivity could be provided.

[0051] Test Example 5: Synthesis of a Composite of Graphene Meso Sponge and Polymer Based on 2,6-Diethynylanthraquinone as a Monomer> 45.5 mg of 2,6-diethynylanthraquinone represented by formula (2) above and 20 mL of chloroform were added to a 50 mL recovery flask, mixed, and stirred at room temperature for 3 minutes to dissolve the monomer in the organic solvent. Next, 30.4 mg of graphene meso sponge powder with a micropore structure (pore diameter 3-8 nm) was added to the recovery flask, followed by 10 mL of chloroform and stirring at room temperature for 60 minutes. Next, the temperature of the reaction mixture in the recovery flask was raised to 30°C, and the chloroform was removed by evaporation in an evaporator. Next, the mixture was heated at 250°C for 1 hour to carry out a polymerization reaction, followed by vacuum drying to produce a composite in which a polymer based on 2,6-diethynylanthraquinone as a monomer was incorporated into the pores of the graphene meso sponge. The mass of the resulting composite was 36.7 mg.

[0052] Test Example 6: Synthesis of a Composite of Graphene Meso Sponge and Polymer Based on 2,6-diethynylanthraquinone as a Monomer> 154.6 mg of 2,6-diethynylanthraquinone represented by formula (2) above and 40 mL of chloroform were added to a 200 mL recovery flask, mixed, and stirred at room temperature for 60 minutes to dissolve the monomer in the organic solvent. Next, 50.1 mg of graphene meso sponge powder with a micropore structure (pore diameter 3-8 nm) was added to the recovery flask, followed by 10 mL of chloroform and stirring at room temperature for 60 minutes. Next, the temperature of the reaction mixture in the recovery flask was raised to 30°C, and the chloroform was removed by evaporation using an evaporator. Next, the mixture was heated at 250°C for 1 hour to carry out a polymerization reaction, followed by vacuum drying to produce a composite in which a polymer based on 2,6-diethynylanthraquinone was incorporated into the pores of the graphene meso sponge. The mass of the resulting composite was 47.7 mg.

[0053] Test Example 7: Synthesis of 2-ethynylanthraquinone A stirrer bar, 2.668 g (9.3 mmol) of 2-bromoanthraquinone, 641 mg (0.91 mmol) of bis(triphenylphosphine)palladium(II) dichloride, and 534 mg (2.8 mmol) of copper(I) iodide were placed in a 300 mL recovery flask and purged with nitrogen. Next, 115 mL of triethylamine was added, and 2.718 g (27.7 mmol) of trimethylsilylacetylene was added while stirring. The mixture was heated to 50°C and stirred overnight. Next, the mixture was cooled to room temperature, and 300 mL of saturated aqueous ammonium chloride solution was added. The mixture was extracted with dichloromethane, and the organic layer was dried over magnesium sulfate. The dried organic layer was concentrated and purified using silica gel to obtain 2-(trimethylsilyl)ethynylanthraquinone. The resulting 2-(trimethylsilyl)ethynylanthraquinone was used in the next reaction without further purification. The NMR spectrum data of the obtained 2-(trimethylsilyl)ethynylanthraquinone is shown below: 1H-NMR (CDCl3) δ: 0.29 (s, 9H), 7.80-7.84 (m, 3H), 8.25 (d, 1H), 8.30-8.33 (m, 2H), 8.37 (d, 1H).

[0054] To a 500 mL recovery flask containing the aforementioned 2-(trimethylsilyl)ethynylanthraquinone and a stir bar, 40 mL of methanol and 80 mL of acetone were added. 481.5 mg (12 mmol) of sodium hydroxide was added and stirred at room temperature for 3.5 hours. After the reaction, the solvent was removed under reduced pressure, and 150 mL of saturated aqueous ammonium chloride solution was added. After extraction with chloroform, the organic layer was dried over magnesium sulfate and the solvent was removed. The resulting solid was purified by recrystallization to obtain 1.5801 g of 2-ethynylanthraquinone (73% yield, two steps). NMR spectral data for the resulting 2-ethynylanthraquinone are shown below. 1H-NMR (CDCl3) δ: 3.37 (s, 1H), 7.80-7.84 (m, 2H), 7.87 (dd, 1H), 8.28 (d, 1H), 8.31-8.33 (m, 2H), 8.41 (d, 1H)

[0055] Test Example 8: Synthesis of a Composite of Graphene Meso-Sponge and Polymer with 2-Ethynylanthraquinone as a Monomer> 50.0 mg of 2-ethynylanthraquinone represented by formula (1) above and 10 mL of chloroform were added to a 50 mL recovery flask, mixed, and stirred at room temperature for 3 minutes to dissolve the monomer in the organic solvent. Next, 61.0 mg of graphene meso-sponge powder with a micropore structure (pore diameter 3-8 nm) was added to the recovery flask, followed by 30 mL of chloroform and stirring at room temperature for 60 minutes. Next, the temperature of the reaction mixture in the recovery flask was raised to 30°C, and the chloroform was removed by evaporation using an evaporator. A 50.9 mg sample was then subjected to the following heat treatment. Next, the mixture was heated at 250°C for 1 hour to carry out a polymerization reaction, followed by vacuum drying to produce a composite in which a polymer with 2-ethynylanthraquinone as a monomer was incorporated into the pores of the graphene meso-sponge. The mass of the resulting complex was 40.5 mg.

[0056] Test Example 9: Synthesis of a Composite of Graphene Meso Sponge and Polymer with 2-Ethynylanthraquinone as a Monomer> 98.4 mg of 2-ethynylanthraquinone represented by formula (1) above and 10 mL of chloroform were added to a 200 mL recovery flask, mixed, and stirred at room temperature for 3 minutes to dissolve the monomer in the organic solvent. Next, 60.0 mg of graphene meso sponge powder with a pore structure (pore diameter 3-8 nm) was added to the recovery flask, followed by 50 mL of chloroform and stirring at room temperature for 60 minutes. Next, the temperature of the reaction mixture in the recovery flask was raised to 30°C, and the chloroform was removed by evaporation using an evaporator. Next, the mixture was heated at 250°C for 1 hour to carry out a polymerization reaction, followed by vacuum drying to produce a composite in which a polymer with 2-ethynylanthraquinone as a monomer was incorporated into the pores of the graphene meso sponge. The mass of the resulting composite was 36.7 mg.

[0057] Test Example 10: Synthesis of a composite of a polymer (copolymer of 2-ethynylanthraquinone and 2,6-diethynylanthraquinone) and graphene meso-sponge. 44.0 mg of 2-ethynylanthraquinone represented by formula (1) above, 50.0 mg of 2,6-diethynylanthraquinone represented by formula (2) above, and 10 mL of 1,2-dichloroethane were added to a 50 mL recovery flask, mixed, and stirred at room temperature for 3 minutes to dissolve the monomer in the organic solvent. Next, 60.4 mg of graphene meso-sponge powder with a micropore structure (pore diameter 3-8 nm) was added to the recovery flask, followed by an additional 10 mL of 1,2-dichloroethane and stirring at room temperature for 60 minutes. Next, the temperature of the reaction mixture in the recovery flask was raised to 30°C, while the 1,2-dichloroethane was evaporated and removed using an evaporator. Next, the mixture was heated at 250°C for 1 hour to carry out a polymerization reaction, followed by vacuum drying to produce a composite in which a polymer, a copolymer of 2-ethynylanthraquinone and 2,6-diethynylanthraquinone as monomers, was provided in the pores of the graphene meso-sponge. The mass of the resulting composite was 66.3 mg.

[0058] Test Example 11: CV measurement of carbon dioxide absorption / release device in the presence of Ar Using a composite in which a polymer having 2,6-diethynylanthraquinone as a monomer was provided in the pores of the graphene meso-sponge produced in Test Example 5, a sample electrode of the same device was produced in the same procedure as Test Example 3. Next, CV measurement was carried out in the presence of Ar (in the absence of CO) in the same procedure as Test Example 3. The CV measurement results are shown in FIG.

[0059] Test Example 12: CV Measurement of Carbon Dioxide Absorption / Desorption Device in the Presence of CO Using a composite in which a polymer containing 2,6-diethynylanthraquinone as a monomer was provided within the pores of the graphene meso-sponge prepared in Test Example 5, a sample electrode of the same device was prepared in the same manner as in Test Example 4. Next, CV measurement was performed in the presence of carbon dioxide (CO) using the same procedure as in Test Example 4. The CV measurement results are shown in FIG. 5. Test Example 11 used a composite in which a polymer containing 2,6-diethynylanthraquinone as a monomer was provided within the pores of the graphene meso-sponge prepared in Test Example 5 as described above, but this composite was heated to a higher temperature (250°C) than the heating temperature (200°C) used for the polymerization reaction when prepared in Test Example 2, and the result was that the decrease in current value over three cycles was suppressed compared to the sample electrode prepared in Test Example 2. This is thought to be because when heat treatment was performed at 250°C, a polymer with a higher degree of polymerization was formed compared to when heat treatment was performed at 200°C, and the elution of poly-(2,6-diethynylanthraquinone) that had undergone electrochemical reduction was suppressed.

[0060] Test Example 13: CV measurement of carbon dioxide absorption / release device in the presence of Ar Using a composite in which a polymer having 2-ethynylanthraquinone as a monomer was provided in the pores of the graphene meso-sponge produced in Test Example 8, a sample electrode of the same device was produced in the same procedure as Test Example 3. Next, CV measurement was carried out in the presence of Ar (in the absence of CO) in the same procedure as Test Example 3. The CV measurement results are shown in FIG.

[0061] Test Example 14: CV measurement of carbon dioxide absorption / release device in the presence of CO Using a composite in which a polymer having 2-ethynylanthraquinone as a monomer was provided in the pores of the graphene meso-sponge produced in Test Example 8, a sample electrode of the same device was produced in the same procedure as Test Example 4. Next, CV measurement was carried out in the presence of carbon dioxide (CO) in the same procedure as Test Example 4. The results of the CV measurement are shown in Figure 7. According to Test Examples 12 and 13, two redox peaks were confirmed after Ar bubbling, and CO ２After bubbling, it was confirmed that the peaks were concentrated into one, and the CO ２ As described above, by preparing a composite of a polymer containing 2-ethynylanthraquinone as a monomer represented by formula (1) and graphene meso-sponge and performing CV measurements on a carbon dioxide absorption / desorption device using this composite, it was possible to provide a carbon dioxide absorption / desorption device with good electronic conductivity.

[0062] Test Example 15: CV measurement of carbon dioxide absorption / release device in the presence of Ar Using a composite in which a polymer having 2-ethynylanthraquinone as a monomer was provided in the pores of the graphene meso-sponge produced in Test Example 9, a sample electrode of the same device was produced in the same procedure as Test Example 3. Next, CV measurement was carried out in the presence of Ar (in the absence of CO) in the same procedure as Test Example 3. The CV measurement results are shown in FIG.

[0063] Test Example 16: CV measurement of carbon dioxide absorption / release device in the presence of CO Using a composite in which a polymer having 2-ethynylanthraquinone as a monomer was provided within the pores of the graphene meso-sponge produced in Test Example 9, a sample electrode of the same device was produced in the same procedure as Test Example 4. Next, CV measurement was carried out in the presence of carbon dioxide (CO) in the same procedure as Test Example 4. The results of the CV measurement are shown in Figure 9. Test Examples 15 and 16 used approximately twice the amount of 2-ethynylanthraquinone compared to Test Examples 13 and 14, and it was found that the decrease in current value over three cycles was further suppressed.

[0064] Test Example 17: CV measurement of carbon dioxide absorption / release device in the presence of Ar> A composite in which a polymer that is a copolymer having 2-ethynylanthraquinone and 2,6-diethynylanthraquinone as monomers was provided in the pores of the graphene meso-sponge produced in Test Example 10 was used to produce a sample electrode of the same device in the same procedure as Test Example 3. Next, CV measurement was carried out in the presence of Ar (in the absence of CO) in the same procedure as Test Example 3. The CV measurement results are shown in FIG.

[0065] Test Example 18: CV measurement of carbon dioxide absorption / release device in the presence of CO Using a composite in which a polymer that is a copolymer whose monomers are 2-ethynylanthraquinone and 2,6-diethynylanthraquinone is provided within the pores of the graphene meso-sponge prepared in Test Example 10, a similar device sample was prepared in the same manner as in Test Example 4. Next, CV measurement was performed in the presence of carbon dioxide (CO) using the same manner as in Test Example 4. The results of the CV measurement are shown in FIG. 11. FIGS. 10 and 11 show that a carbon dioxide absorption / release device with good electronic conductivity could be provided by preparing a composite in which a polymer that is a copolymer whose monomers are 2-ethynylanthraquinone and 2,6-diethynylanthraquinone is provided within the pores of a graphene meso-sponge and performing CV measurement on the carbon dioxide absorption / release device using the composite.

[0066] Test Example 19: CV measurement of carbon dioxide absorption / release device in the presence of Ar A similar device sample was produced using a composite in which a polymer having 2,6-diethynylanthraquinone as a monomer was provided in the pores of the graphene meso-sponge produced in Test Example 6, in the same manner as in Test Example 3. Next, CV measurement was carried out in the presence of Ar (in the absence of CO) in the same manner as in Test Example 3. The CV measurement results are shown in FIG.

[0067] Test Example 20: CV measurement of carbon dioxide absorption / release device in the presence of CO Using a composite in which a polymer having 2,6-diethynylanthraquinone as a monomer was provided within the pores of the graphene meso-sponge produced in Test Example 6, a sample electrode of the same device was produced in the same manner as in Test Example 4. Next, CV measurement was carried out in the presence of carbon dioxide (CO) in the same manner as in Test Example 4. The results of the CV measurement are shown in FIG. 13. Test Examples 19 and 20 used approximately four times the amount of 2,6-diethynylanthraquinone compared to Test Examples 3 and 4, but a comparison of the two showed that Test Examples 3 and 4 were able to provide carbon dioxide absorption / release devices with better electronic conductivity.

[0068] Furthermore, a polymer containing 2,3,6,7-tetraethynylanthraquinone as a monomer, as represented by the above formula (3), can construct a multidimensional network with a polymer containing 2-ethynylanthraquinone as a monomer, as represented by the above formula (1), and a polymer containing 2,6-diethynylanthraquinone as a monomer, as represented by the above formula (2). Therefore, when a composite of a polymer containing 2,3,6,7-tetraethynylanthraquinone as a monomer, as represented by the above formula (3), and a graphene meso-sponge is prepared and a carbon dioxide absorption / desorption device using the composite is subjected to CV measurement, it can be said that it is clear that a carbon dioxide absorption / desorption device with better electronic conductivity can be provided compared to the results shown in the above-mentioned Test Examples 2 to 4, 5, 6, 8, 9, 10, and 11 to 20.

[0069] 10 Carbon dioxide absorption / release device 11 Composite 12 Electrode

Claims

1. A polymer having at least one monomer selected from the group consisting of 2-ethynylanthraquinone represented by the following formula (1), 2,6-diethynylanthraquinone represented by the following formula (2), and 2,3,6,7-tetraethynylanthraquinone represented by the following formula (3), or a polymer containing at least one monomer selected from the group consisting of 2-ethynylanthraquinone represented by the following formula (1), 2,6-diethynylanthraquinone represented by the following formula (2), and 2,3,6,7-tetraethynylanthraquinone represented by the following formula (3) as a constituent.

2. A carbon dioxide absorption / release device comprising: a composite comprising a porous carbon-containing member and the polymer according to claim 1 provided in the pores of the porous carbon-containing member; and an electrode having the composite provided on its surface.

3. The carbon dioxide absorption / release device according to claim 2, wherein the porous carbon-containing member is one or more selected from the group consisting of activated carbon, ordered mesoporous carbon, and graphene meso-sponge.

4. A carbon dioxide absorption / release device according to claim 2 or 3, wherein the porous carbon-containing member is formed into one or more shapes selected from the group consisting of a film, a sheet, a thin plate, a stick, a fiber, a tube, and a flake.

5. The carbon dioxide absorption / release device according to claim 2 or 3, further comprising an electrolyte held in the composite.

6. The carbon dioxide absorption / release device according to claim 2 or 3, wherein the electrode is made of one or more materials selected from the group consisting of carbon, aluminum, copper, stainless steel, and nickel, and further includes a current collector formed in one or more shapes selected from the group consisting of film, sheet, flake, stick, fiber, tube, plate, and mesh, and the composite is provided on the surface of the current collector.

7. A method for producing a composite, comprising: a step of dissolving in an organic solvent a monomer containing at least one selected from the group consisting of 2-ethynylanthraquinone represented by the following formula (1), 2,6-diethynylanthraquinone represented by the following formula (2), and 2,3,6,7-tetraethynylanthraquinone represented by the following formula (3); a step of mixing the organic solvent in which the monomer has been dissolved with a porous carbon-containing member, and then removing the organic solvent; and a step of heating the residue after the removal of the organic solvent to carry out a polymerization reaction, thereby obtaining a composite in which a polymer is provided in the pores of the porous carbon-containing member.

8. A method for producing a carbon dioxide absorption / release device, comprising the step of applying the composite produced by the method according to claim 7 to the surface of an electrode and drying it by heating to form a film of the composite on the surface of the electrode.

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