Co2 separation composite membrane and method for producing same

Abstract

Provided is a CO2 separation composite membrane comprising a first separation layer and a second separation layer, wherein the first separation layer is a polysiloxane-containing layer and the second separation layer is a polyethylene glycol-containing layer or an imidazolium salt-type ionic liquid component-containing layer. The first separation layer and the second separation layer are chemically bonded. Also provided is a method for producing a CO2 separation composite membrane, the method comprising: a step for forming a first separation layer including a polysiloxane-containing layer; and a step for forming a second separation layer selected from the group consisting of a polyethylene glycol-containing layer and an imidazolium salt-type ionic liquid component-containing layer on the first separation layer. In the step for forming the second separation layer, a polyethylene glycol-containing layer or an imidazolium salt-type ionic liquid component-containing layer is chemically bonded to the polysiloxane-containing layer to form the second separation layer.

Description

CO2 separation composite membrane and method for manufacturing the same

[0001] The present invention is ２ The present invention relates to a separation composite membrane and a method for producing the same.

[0002] CO from the atmosphere ２ Direct Air Capture (DAC), a technology that directly captures CO, is expected to be a key solution to global warming. ２ Among the capture technologies, membrane separation has the advantage that it can be separated and captured with low energy and does not require special chemicals, so it can be used in a variety of places. However, conventional gas separation membranes have ２ Because of the low permeability and the large pressure difference required between the gas feed side and the permeate side, membrane-based DAC was thought to be impossible.

[0003] However, in recent years, CO2 gases have been detected using polydimethylsiloxane thin films, which have excellent gas permeability and mechanical properties. ２ Research into separation has been reported, and application to DACs is being considered (Non-Patent Document 1).

[0004] S. Fujikawa et al. , “Ultra-fast, Selective CO2 Permeation by Free-standing Siloxane Nanomembranes”, Chem. Lett. , 2019, 48, 1351-1354.

[0005] Non-Patent Document 1: CO of polydimethylsiloxane thin film ２ Although the permeability is excellent, CO ２ / N ２ The selectivity is about 11, and further CO ２ / N ２ An improvement in the selectivity is desired.

[0006] The present invention has been made in view of the above matters, and its object is to provide a CO ２ / N ２ CO that can improve selectivity ２ The present invention provides a separation composite membrane and a method for producing the same.

[0007] CO according to the first aspect of the present invention ２The separation composite membrane comprises a first separation layer and a second separation layer, the first separation layer being a polysiloxane-containing layer, the second separation layer being a polyethylene glycol-containing layer or an imidazolium salt-type ionic liquid component-containing layer, and the first separation layer and the second separation layer being chemically bonded to each other.

[0008] It is also preferable that the first separation layer is a polysiloxane-containing layer formed by polymerization of polymethylhydrosiloxane, polydimethylsiloxane having vinyl groups at both ends, and polyhedral oligosilsesquioxane having vinyl groups in side chains or cyclic oligosiloxane having vinyl groups in side chains, and that the second separation layer is a polyethylene glycol-containing layer.

[0009] It is also preferable that the first separation layer is a polysiloxane-containing layer formed by polymerization of polymethylvinylsiloxane, polydimethylsiloxane having Si-H groups at both ends, and polyhedral oligomeric silsesquioxane or polymethylhydrosiloxane having Si-H groups in side chains, and that the second separation layer is the imidazolium salt-type ionic liquid component-containing layer.

[0010] CO according to the second aspect of the present invention ２ A method for producing a separation composite membrane comprises the steps of: forming a first separation layer including a polysiloxane-containing layer; and forming a second separation layer selected from the group consisting of a polyethylene glycol-containing layer and an imidazolium salt-type ionic liquid component-containing layer on the first separation layer; wherein in the step of forming the second separation layer, the polyethylene glycol-containing layer or the imidazolium salt-type ionic liquid component-containing layer is chemically bonded to the polysiloxane-containing layer to form the second separation layer.

[0011] Preferably, in the step of forming the first separation layer, the polysiloxane-containing layer is formed by polymerizing polymethylhydrosiloxane, polydimethylsiloxane having vinyl groups at both ends, and polyhedral oligosilsesquioxane having vinyl groups on side chains or cyclic oligosiloxane having vinyl groups on side chains; and in the step of forming the second separation layer, a solution of polyethylene glycol having a polymerizable functional group is applied onto the polysiloxane-containing layer, and the polyethylene glycol-containing layer is covalently bonded to the polysiloxane-containing layer by a hydrosilylation reaction between the hydrosilyl groups of the polysiloxane-containing layer and the polymerizable functional groups of the polyethylene glycol.

[0012] Preferably, the step of forming the first separation layer comprises polymerizing polymethylvinylsiloxane, polydimethylsiloxane having Si—H groups at both terminals, and polyhedral oligosilsesquioxane or polymethylhydrosiloxane having Si—H groups in side chains to form the polysiloxane-containing layer; and the step of forming the second separation layer comprises applying a solution of polysiloxane having imidazolium groups and mercapto groups in side chains onto the polysiloxane-containing layer, and forming the imidazolium salt-type ionic liquid component-containing layer covalently bonded to the polysiloxane-containing layer through a thiol-ene reaction between the vinyl groups of the polysiloxane-containing layer and the mercapto groups of the polysiloxane having imidazolium groups and mercapto groups.

[0013] According to the present invention, CO ２ / N ２ CO that can improve selectivity ２ A separation composite membrane and a method for making the same are provided.

[0014] 1-1 is a cross-sectional view showing the structure of a PEG-PDMS-H (POSS) membrane specimen prepared in Experiment 1-1. 2-1 is a graph showing the FT-IR (ATR) spectrum of the PEG-PDMS-H (POSS) membrane surface in Experiment 1-1. 3-1 is a photograph showing an SEM image of the PEG-PDMS-H (POSS) membrane surface in Experiment 1-1. 4-1 is a photograph showing an SEM image of a composite membrane in which PEG is applied to a Sylgard membrane in Experiment 1-1. 5-1 is a photograph showing an SEM image of a cross section of a PEG-PDMS-H (POSS) membrane in Experiment 1-1. 6-1 is a cross-sectional view showing the configuration of a gas permeation test in Experiment 1-1. 7-1 is a graph showing the FT-IR (ATR) spectrum of the PEG-PDMS-H (POSS) membrane surface in Experiment 1-1. 8-1 is a photograph showing an SEM image of a composite membrane in which PEG is applied to a Sylgard membrane in Experiment 1-1. 9-1 is a photograph showing an SEM image of a cross section of a PEG-PDMS-H (POSS) membrane in Experiment 1-1. 10-1 is a cross-sectional view showing the configuration of a gas permeation test in Experiment 1-1. ２ / N ２ 1 is a graph showing the selectivity of CO2 for the Sylgard film, the PDMS-H (POSS) film, and the PEG-PDMS-H (POSS) film in Experiment 1-1. ２ 1 is a graph showing the gas permeability of the PEG-PDMS-H (POSS) membrane in Experiment 1-1. ２ / N ２ 1 is a graph showing the change in selectivity over time for the Sylgard membrane, the PDMS-H(CyOS) membrane, and the PEG-PDMS-H(CyOS) membrane in Experiment 1-2. ２ / N ２ 1 is a graph showing the selectivity of CO2 for the Sylgard membrane, the PDMS-H(CyOS) membrane, and the PEG-PDMS-H(CyOS) membrane in Experiment 1-2. ２ 1 is a graph showing gas permeability. ２ 1 is a cross-sectional view showing the structure of a PS-MeIm-NNf / PS-SH / PDMS-V (POSS) membrane specimen. ２ 1 is a graph showing the FT-IR (ATR) spectrum of the surface of the PS-MeIm-NNf / PS-SH / PDMS-V (POSS) film. ２ Photographs showing SEM images of the surface of the PS-MeIm-NNf / PS-SH / PDMS-V (POSS) film. ２ Photographs showing SEM images of composite membranes in which PS-MeIm-NNf was applied to a Sylgard membrane. ２1 is a graph showing an EDX pattern of the surface of the PS-MeIm-NNf / PS-SH / PDMS-V (POSS) film. ２ 1 is a photograph showing an SEM image of a cross section of a PS-MeIm-NNf / PS-SH / PDMS-V (POSS) membrane. 2 is a cross-sectional view showing the configuration of a gas permeation test in Experiment 2-1. 3 is a photograph showing an Sylgard membrane, a PDMS-V (POSS) membrane, and a PS-MeIm-NNf membrane in Experiment 2-1. ２ / PS-SH / PDMS-V (POSS) film CO ２ / N ２ 1 is a graph showing the selectivity ratio of the Sylgard film, the PDMS-V (POSS) film, and the PS-MeIm-NNf film in Experiment 2-1. ２ / PS-SH / PDMS-V (POSS) film CO ２ 10 is a graph showing gas permeability. ２ / PS-SH / PDMS-V (POSS) film CO ２ / N ２ Selectivity and CO ２ 1 is a graph showing the change in gas permeability over time for the Sylgard membrane, the PDMS-V (PMHS) membrane, and the PS-MeIm-NNf membrane in Experiment 2-2. ２ / PS-SH / PDMS-V (PMHS) film CO ２ / N ２ 1 is a graph showing the selectivity of the Sylgard membrane, the PDMS-V (PMHS) membrane, and the PS-MeIm-NNf membrane in Experiment 2-2. ２ / PS-SH / PDMS-V (PMHS) film CO ２ 1 is a graph showing gas permeability.

[0015] (CO ２ Separation composite membrane) CO ２ The separation composite membrane comprises a first separation layer and a second separation layer. The first separation layer is a polysiloxane-containing layer, and the second separation layer is a polyethylene glycol-containing layer or an imidazolium salt-type ionic liquid component-containing layer. The first separation layer and the second separation layer are chemically bonded to each other.

[0016] CO ２The composite separation membrane is used by being disposed so that the second separation layer faces the gas supply side. The polyethylene glycol and imidazolium salt type ionic liquid components contained in the second separation layer are CO ２ Since the polyethylene glycol-containing layer or the imidazolium salt type ionic liquid component-containing layer is a component that absorbs and adsorbs CO ２ The permeability coefficient of a gas is expressed as the product of the solubility coefficient and the diffusion coefficient. ２ The improvement of the solubility coefficient of CO ２ / N ２ In addition, since the first separation layer and the second separation layer are chemically bonded, CO ２ is smoothly diffused, and CO ２ By reducing the thickness of the second separation layer, which reduces the permeability of CO ２ The deterioration of gas permeability is also suppressed.

[0017] When the second separation layer is a polyethylene glycol-containing layer, the polysiloxane-containing layer contains a polysiloxane having a Si—H group, such as polymethylhydrosiloxane. On the other hand, the polyethylene glycol-containing layer contains polyethylene glycol containing a polymerizable functional group. The polysiloxane-containing layer and the polyethylene glycol-containing layer are covalently bonded together by a hydrosilylation reaction between the Si—H group and the polymerizable functional group.

[0018] When the second separation layer is an imidazolium salt-type ionic liquid component-containing layer, the polysiloxane-containing layer contains a polysiloxane having a vinyl group in its side chain. On the other hand, the imidazolium salt-type ionic liquid component-containing layer contains a polysiloxane having an imidazolium group and a mercapto group in its side chain. The polysiloxane-containing layer and the imidazolium salt-type ionic liquid component-containing layer are covalently bonded to each other through a thiol-ene reaction between the vinyl group and the mercapto group.

[0019] Furthermore, the polysiloxane-containing layer preferably contains a polyhedral oligosilsesquioxane. Since the mechanical strength is increased by the polyhedral oligosilsesquioxane, a CO2 filter having a polysiloxane-containing layer containing the polyhedral oligosilsesquioxane is ２ The separation composite membrane can also be used as a free-standing membrane.

[0020] Furthermore, the polysiloxane-containing layer may contain a cyclic oligosiloxane or a linear polysiloxane having a vinyl group and an Si—H group in the side chain, instead of a polyhedral oligosilsesquioxane having these side chain groups. ２ CO separation composite membrane ２ / N ２ Selectivity and CO ２ In consideration of both properties of transparency and transparency, it is preferable that the polyhedral oligosilsesquioxane is contained.

[0021] As shown in the examples below, CO ２ The separation composite membrane has the same CO ２ While showing the amount of CO ２ / N ２ The selectivity is about 30%. ２ It is expected that this will be applied to DACs that directly recover this.

[0022] (CO ２ (Method for producing a separation composite membrane) ２ First, a method for producing a CO 2 separation composite membrane in which the second separation layer is a polyethylene glycol-containing layer will be described. ２ The separation composite membrane can be produced, for example, as shown in Scheme 1 below.

[0023]

[0024] The first separation layer is obtained by polymerizing polymethylhydrosiloxane (hereinafter referred to as PMHS), vinyl-group-containing polyhedral oligosilsesquioxane (hereinafter referred to as V-POSS), and polydimethylsiloxane having vinyl groups at both ends (hereinafter referred to as PDMSVT). PMHS, V-POSS, and PDMSVT are mixed and dissolved in a solvent capable of dissolving them, such as chloroform, to prepare a precursor solution to which a Karstedt's catalyst is added. This precursor solution is applied to a support substrate or the like and polymerized to obtain a polysiloxane-containing layer having Si—H groups (hereinafter referred to as a PDMS-H(POSS) film).

[0025] PMHS, V-POSS, and PDMSVT can be purchased as common reagents or easily obtained by synthesis using known synthesis methods. The compounding ratio of PMHS, V-POSS, and PDMSVT is preferably a functional group (vinyl group, Si—H) ratio of 500 to 50:9:2, more preferably 400 to 200:9:2. The weight ratio is preferably 42 to 4:1:35, more preferably 34 to 17:1:35.

[0026] Monofunctional polyethylene glycol is reacted on this PDMS-H (POSS) film. Specifically, monofunctional polyethylene glycol is dissolved in a solvent such as 1,4-dioxane, and a solution to which Karstedt's catalyst has been added is applied to the PDMS-H (POSS) film and heated, whereby bonding occurs through a hydrosilylation reaction between the Si-H groups of the PDMS-H (POSS) film and the (meth)acrylic groups of the monofunctional polyethylene glycol. In this way, a CO film with a polyethylene glycol-containing layer bonded to the surface of the PDMS-H (POSS) film is formed. ２ Alternatively, instead of V-POSS, a polysiloxane-containing layer having Si—H groups can be prepared using a cyclic oligosiloxane having a vinyl group or a linear polysiloxane having a vinyl group, and a polyethylene glycol-containing layer can be formed on the polysiloxane-containing layer to produce a CO separation composite membrane. ２ Separation composite membranes can also be fabricated.

[0027] Examples of monofunctional polyethylene glycols include poly(ethylene glycol) methyl ether acrylate, poly(ethylene glycol) methyl ether methacrylate, etc. Heating may be carried out at a temperature and for a time that allows the hydrosilylation reaction to proceed sufficiently, for example, at 70°C for 1 hour.

[0028] In addition, the second separation layer is a layer containing an imidazolium salt type ionic liquid component. ２ The separation composite membrane can be produced, for example, as shown in Scheme 2 below.

[0029]

[0030] The first separation layer is obtained by polymerizing polymethylvinylsiloxane (hereinafter, PS-V), polyhedral oligomeric silsesquioxane having Si-H groups in its side chains (hereinafter, H-POSS), and polydimethylsiloxane having Si-H groups at both ends (hereinafter, PDMSHT). For example, PS-V, H-POSS, and PDMSHT are mixed and dissolved in a solvent capable of dissolving them, such as chloroform, and a precursor solution is prepared by adding a Karstedt's catalyst. This precursor solution is applied to a support substrate or the like and polymerized to obtain a polysiloxane-containing layer having vinyl groups (hereinafter, PDMS-V(POSS) film).

[0031] PS-V, H-POSS, and PDMSHT can be synthesized by known synthesis methods. The compounding ratio of PS-V, H-POSS, and PDMSHT is preferably a functional group (vinyl group, Si—H) ratio of 250 to 50:9:2, more preferably 150 to 100:9:2. The weight ratio is preferably 19 to 4:1:21, more preferably 11 to 8:1:21.

[0032] On this PDMS-V (POSS) film, a polysiloxane containing imidazolium groups and mercapto groups in the side chains is reacted. Such polysiloxane can be synthesized by polycondensation of imidazolium group-containing dimethoxymethylsilane or the like with 3-mercaptopropyldimethoxymethylsilane or the like. Polysiloxane containing imidazolium groups and mercapto groups in the side chains is dissolved in a solvent such as ethanol, and a photoinitiator is further added to prepare a solution. This solution is then applied to the PDMS-V (POSS) film. Then, by irradiating with light having a wavelength of about 400 nm, a thiol-ene reaction between the mercapto groups and the vinyl groups proceeds, and a CO 2 -containing layer containing an imidazolium salt-type ionic liquid component is covalently bonded to the surface of the PDMS-V (POSS) film. ２ Alternatively, instead of H-POSS, a cyclic oligomethylhydrosiloxane or a linear polymethylhydrosiloxane may be used to prepare a polysiloxane-containing layer having a vinyl group, and then a layer containing an imidazolium salt-type ionic liquid component may be formed to prepare a CO separation composite membrane. ２ Separation composite membranes can also be fabricated.

[0033] Experiment 1-1: CO with polyethylene glycol-containing layer ２ Preparation of separation composite membrane (PEG-PDMS-H(POSS) membrane) and evaluation of properties> According to the above scheme 1, a PEG-PDMS-H(POSS) membrane was prepared as follows, and its properties were evaluated.

[0034] (Preparation of PEG-PDMS-H (POSS) film) Glass substrate (28 mm × 48 mm = 1344 mm ２ A poly(sodium 4-styrenesulfonate) (hereinafter referred to as PSS) (Mw=about 70,000) aqueous solution (7.5 wt %, 1.0 mL) was spin-coated onto the glass substrate (1,000 rpm, 50 seconds), followed by heating (100°C, 1 hour), to form a PSS layer as a sacrificial layer on the glass substrate.

[0035] Polymethylhydrosiloxane (hereinafter referred to as PMHS) (average Mn = 1700-3200, 60.13 g / mol unit, 6.0 mmol, 0.3609 g), vinyl-containing polyhedral polysiloxane (hereinafter referred to as V-POSS) (79.12 g / mol unit, 0.27 mmol, 0.0214 g), and polydimethylsiloxane having vinyl groups at both ends (hereinafter referred to as PDMSVT) (average Mw = ∼25000, 0.030 mmol, 0.7500 g) were mixed in chloroform (12.5 mL), and a platinum catalyst (platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex) (19.0-21.5% as A precursor solution (PDMS-H solution) was prepared by adding PMHS, V-POSS, and PDMSVT (0.3 μmol, 0.015 wt %, 0.244 μL) to the mixture. The functional group ratio (vinyl group or Si—H group) of PMHS, V-POSS, and PDMSVT was 200:9:2 (weight ratio of 17:1:35).

[0036] The prepared PDMS-H solution (1.2 mL) was spin-coated onto the PSS layer (1000 rpm, 45 seconds) and left at room temperature (12 hours) to allow the hydrosilylation reaction to proceed, producing a polydimethylsiloxane-containing film (hereinafter referred to as a PDMS-H (POSS) film) on the PSS layer.

[0037] Poly(ethylene glycol) methyl ether acrylate (hereinafter referred to as PEG-Acrylate) (0.7721 g) was dissolved in dehydrated 1,4-dioxane (3.0 mL) (20 wt %), and platinum catalyst (0.13 μL) was added to prepare a solution. The PEG-Acrylate used was oily and had an average degree of polymerization of 8.

[0038] This solution (1.5 mL) was added dropwise to the PDMS-H(POSS) film so as to cover the entire film, and the film was heated at 70° C. for 1 hour. The film surface was then washed with ethanol to remove unreacted PEG-Acrylate, yielding a PEG-PDMS-H(POSS) film.

[0039] Then, an O-ring-shaped protective tape was attached, and the glass substrate was immersed in water to dissolve the PSS, thereby peeling off the PEG-PDMS-H (POSS) film from the glass substrate. The film was then protected with a porous polyacrylonitrile (PAN) film and aluminum tape, thereby producing a PEG-PDMS-H (POSS) film specimen with the structure shown in Figure 1.

[0040] For comparison, a Sylgard membrane was prepared with reference to Non-Patent Document 1, and a PEG-Sylgard membrane having a PEG layer on the Sylgard membrane was prepared in the same manner as above.

[0041] The formation of a uniform PEG layer on the PDMS-H film was confirmed by FT-IR (ATR) and SEM measurements at multiple points. Figure 2 shows the FT-IR spectra of the Sylgard film, PDMS-H (POSS) film, PEG-Sylgard film, and PEG-PDMS-H (POSS) film. Figure 3A shows an SEM image of the surface of the PEG-PDMS-H (POSS) film, and Figure 3B shows an SEM image of the surface of the PEG-Sylgard film for comparison.

[0042] The FT-IR spectrum of the PEG-Sylgard film in FIG. 2 shows an absorption peak (1720-1740 cm ) attributed to the ester bond of PEG-acrylate. －１ ) was not observed in the PEG-PDMS-H(POSS) film, but was observed in the PEG-PDMS-H(POSS) film. In addition, compared with the PDMS-H(POSS) film, the PEG-PDMS-H(POSS) film exhibited an absorption peak (2160-2165 cm) attributed to the hydrosilyl group. －１ ) clearly decreased, suggesting the progress of the hydrosilylation reaction.

[0043] Furthermore, while oil droplet-like aggregates were observed on the surface of the PEG-Sylgard film (a comparative sample) in the SEM image of Figure 3B, no aggregation of the PEG layer was observed in the SEM image of the PEG-PDMS-H(POSS) film in Figure 3A. This suggests that a uniform PEG layer exists on the PDMS-H(POSS) film.

[0044] (Evaluation of membrane thickness) The membrane thickness was measured from an SEM image of the cross section of the separation membrane, as shown in Fig. 4. Specifically, the central portion of the membrane for which gas permeation measurement was performed was cut with a slicer, and the cut surface was observed by SEM. The membrane thickness was measured at 10 or more points, and the average value of these measurements was taken as the membrane thickness.

[0045] (CO ２ / N ２ Selectivity and CO ２ Evaluation of Gas Permeation Amount) For gas permeation measurement, the prepared separation membrane was placed in a gas permeation test cell as shown in FIG. 5, and gas (N ２ or CO ２ ) was supplied to the membrane, and the flow rate of the gas that permeated the membrane was measured.

[0046] In Fig. 6, CO ２ / N ２ Selectivity, CO ２ The results of measuring the amount of CO permeation through the PEG-PDMS-H (POSS) membrane are shown below. ２ / N ２ The selectivity was 15 to 17 in the film thickness range of 0.5 to 1.0 μm, and the CO ２ / N ２ This was a higher value than the selectivity ratios of 11 to 12. ２ The presence of a soluble PEG layer on the surface of the PDMS-H film (POSS) prevents CO ２ / N ２ This is presumably due to the increased solubility coefficient ratio.

[0047] On the other hand, the CO ２ The permeation rate is slightly lower than that of the PDMS-H(POSS) membrane without PEG. ２ The permeation rate is higher than that of the Sylgard membrane used for comparison, which has been reported so far. Therefore, the PEG-PDMS-H (POSS) membrane, in which PEG is introduced into the PDMS-H (POSS) membrane, has the same CO permeation rate as the conventional PDMS membrane (Sylgard membrane). ２ It showed permeability.

[0048] (CO２ / N ２ Evaluation of time-dependent change in selectivity) CO2 of PEG-PDMS-H (POSS) membrane ２ / N ２ The change in selectivity over time was examined. The PEG-PDMS-H (POSS) membrane with a thickness of about 0.94 μm was subjected to gas permeation measurement in the same manner as above 1 day, 3 days, and 7 days after preparation. ２ / N ２ The selectivity ratio was measured.

[0049] The results are shown in Figure 8. Even after 7 days, ２ / N ２ The crosslinked structure of PDMS-H (POSS) is stabilized by the rigid and multifunctional POSS, which is thought to have suppressed aggregation of the PEG layer formed on the surface and kept it uniform, thereby maintaining separation performance.

[0050] Experiment 1-2: CO with polyethylene glycol-containing layer ２ Preparation of Separation Composite Membrane (PEG-PDMS-H(CyOS) Membrane) and Characterization> A polydimethylsiloxane-containing membrane (PDMS-H(CyOS) membrane) and a PEG-PDMS-H(CyOS) membrane in which PEG was introduced into this PDMS-H(CyOS) membrane were prepared in the same manner as in Experiment 1-1, except that V-POSS was replaced with a cyclic oligosiloxane containing a vinyl side chain group (CyOS).

[0051] The CO concentration of the prepared PEG-PDMS-H(CyOS) film was measured in the same manner as in Experiment 1-1. ２ / N ２ Selectivity and CO ２ The measurement results of the permeation amount are shown in Figures 9 and 10. ２ / N ２ The selectivity was 14-15, and the CO ２ / N ２ This was a higher value than the selectivity ratios of 11 to 12.

[0052] CO2 of PEG-PDMS-H(CyOS) films ２The CO permeation rate was similar to that of the PEG-PDMS-H (POSS) membrane and the conventional PDMS membrane (Sylgard membrane). ２ It showed permeability.

[0053] <Experiment 2-1: CO with imidazolium salt-type ionic liquid component-containing layer ２ Separation composite membrane (PS-MeIm-NNf ２ Preparation of PS-MeIm-NNf / PS-SH / PDMS-V (POSS) film and evaluation of its properties> According to the above scheme 2, PS-MeIm-NNf ２ A / PS-SH / PDMS-V (POSS) film was fabricated and its properties were evaluated.

[0054] (PS-MeIm-NNf ２ Preparation of / PS-SH / PDMS-V (POSS) film) A solution of poly(4-vinylphenol) (hereinafter referred to as PVP) (average Mn = 25000, 15 wt%, 0.2 mL) dissolved in ethanol was applied to a glass substrate (28 mm × 48 mm = 1344 mm). ２ The PVP layer was spin-coated (2000 rpm, 40 seconds) onto the sacrificial layer, followed by heating (100° C., 10 minutes) to form a PVP layer as a sacrificial layer.

[0055] Polysiloxane having vinyl groups in the side chains (hereinafter referred to as PS-V, 86.17 g / mol unit, 1.6 mmol, 0.1379 g), polyhedral oligomeric silsesquioxane having Si—H groups in the side chains (hereinafter referred to as H-POSS, Mw=1017.96, 127.25 g / mol unit, 0.144 mmol, 0.0183 g), and polydimethylsiloxane having Si—H groups at both ends (hereinafter referred to as PDMSHT, Mn=∼24.000, 16 μmol, 0.3840 g) were mixed in chloroform (8.73 mL), and a platinum catalyst (platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex) (19.0-21.5% as A precursor solution (PDMS-V solution) was prepared by adding PS-V, H-POSS, and PDMSHT (195.1 g / mol, 0.12 mmol, 9.76 μL). The functional group ratio (vinyl group or Si—H group) of PS-V, H-POSS, and PDMSHT was 100:9:2 (8:1:21 by weight).

[0056] The prepared PDMS-V solution (1.5 mL) was spin-coated (1000 rpm, 45 sec) onto the sacrificial layer and heated at 80°C for 12 hours to produce a polydimethylsiloxane film containing vinyl groups (hereinafter referred to as a PDMS-V (POSS) film).

[0057] Then, an O-ring-shaped protective tape was attached and the substrate was immersed in ethanol to dissolve the PVP sacrificial layer, thereby peeling off the PDMS-V (POSS) film from the glass substrate, and the film was protected with a porous polyacrylonitrile (PAN) film and aluminum tape.

[0058] Separately, imidazolium group-containing dimethoxymethylsilane (264.83 g / mol, 4.5 mmol, 1.1917 g), 3-mercaptopropyldimethoxymethylsilane (180.34 g / mol, 95%, 0.5 mmol, 0.0949 g), and ethanol (1.5033 g, 50 wt%) were mixed, and catalytic amounts of concentrated hydrochloric acid (36.46 g / mol, 36%, 1.0 mmol, 0.1013 g) and water (18.016 g / mol, 10.0 mmol, 0.1154 g) were added. The mixture was heated in a closed oil bath at 60°C for 20 hours, and then heated in an open system at 70°C until the solvent was completely evaporated. Finally, the mixture was heated in an oven at 100°C for 2 hours to obtain PS-MeIm-Cl / PS-SH. Subsequently, the counter ion was converted to Cl by ion exchange reaction. － From NNf ２ － By converting it to PS-MeIm-NNf ２ / PS-SH was synthesized.

[0059] PS-MeIm-NNf ２ An ethanol solution consisting of / PS-SH and a photoinitiator was dropped onto the surface of the PDMS-V (POSS) film, and the film was irradiated with visible light (wavelength: 380-420 nm) for 5 minutes to form PS-MeIm-NNf having the structure shown in Figure 11. ２ A / PS-SH / PDMS-V (POSS) membrane specimen was prepared.

[0060] The formation of a uniform imidazolium salt-type ionic liquid layer on the PDMS-V (POSS) film was confirmed by FT-IR (ATR), SEM, and energy dispersive X-ray spectroscopy (EDX) measurements at multiple points. ２ The FT-IR spectrum of the / PS-SH / PDMS-V (POSS) film surface is shown in FIG. 12, the SEM image is shown in FIG. 13, and the EDX pattern is shown in FIG.

[0061] PS-MeIm-NNf in FIG. ２ From the FT-IR spectrum of the / PS-SH / PDMS-V (POSS) film, the imidazolium salt-type ionic liquid component NNf ２ － The absorption peak (1350-1355 cm) attributed to the S=O bond in －１ ) was observed.

[0062] Also, PS-MeIm-NNf in FIG. ２ In the SEM image of the / PS-SH / PDMS-V (POSS) film surface, no aggregation of the imidazolium salt-type ionic liquid component was observed. ２ － A peak attributed to the ionic atom (S) contained in the compound was observed, suggesting that a uniform imidazolium salt type ionic liquid layer was present on the PDMS-V (POSS) film.

[0063] (Evaluation of membrane thickness) The membrane thickness was measured from an SEM image of the cross section of the separation membrane, as shown in Fig. 15. Specifically, the central portion of the membrane for which gas permeation measurement was performed was cut with a slicer, and the cut surface was observed by SEM. The membrane thickness was measured at 10 or more points, and the average value of these measurements was taken as the membrane thickness.

[0064] (CO ２ / N ２ Selectivity and CO ２ Evaluation of gas permeation amount) As shown in FIG. ２ The separation composite membrane was placed in a gas permeation test cell, and gas (N ２ or CO ２ ) was supplied to the membrane, and the flow rate of the gas that permeated the membrane was measured.

[0065] In FIG. ２ / N ２ Selectivity, CO ２ The measurement results of the permeation amount are shown below. ２ / PS-SH / PDMS-V (POSS) film CO ２ / N ２ The selectivity was about 14 in the film thickness range of 0.6-0.8 μm, and the CO ２ / N ２ This was a higher value than the selectivity ratio of 10 to 12. ２ The presence of a soluble imidazolium salt-type ionic liquid layer on the surface of the PDMS-V (POSS) film prevents CO2 from adsorbing to the film. ２ / N ２ This is presumably due to the increased solubility coefficient ratio.

[0066] PS-MeIm-NNf ２ / PS-SH / PDMS-V (POSS) film CO ２ The permeation rate is slightly lower than that of the PDMS-V membrane. However, the CO permeation rate of the PDMS-V (POSS) membrane is ２ Since the permeation rate is higher than that of the Sylgard membrane used for comparison, which has been reported so far, the PS-MeIm-NNf membrane, which has a PDMS-V (POSS) membrane and a layer containing an imidazolium salt-type ionic liquid component, is ２ The / PS-SH / PDMS-V (POSS) film exhibited CO 2 equivalent to that of the conventional PDMS film (Sylgard film). ２ It shows transparency.

[0067] (CO ２ / N ２ Selectivity and CO ２ Evaluation of change in gas permeability over time) PS-MeIm-NNf ２ / PS-SH / PDMS-V (POSS) film CO ２ / N ２ Selectivity and CO ２ The change in gas permeation rate over time was examined.

[0068] PS-MeIm-NNf with a film thickness of approximately 2.1 μm ２The gas permeation measurement for the / PS-SH / PDMS-V (POSS) membrane was performed in the same manner as above 0, 1, 3, 7, 14, and 21 days after preparation. ２ / N ２ Selectivity and CO ２ The gas permeation rate was measured.

[0069] The results are shown in Figure 19. ２ / N ２ Selectivity and CO ２ There was no significant change in any of the gas permeation amounts, and no deterioration in separation performance occurred over time.

[0070] Experiment 2-2: CO with imidazolium salt-type ionic liquid component-containing layer ２ Separation composite membrane (PS-MeIm-NNf ２ Preparation and Characterization of PS-SH / PDMS-V (PMHS) Films

[0071] A polydimethylsiloxane-containing film (PDMS-V(PMHS) film) was prepared in the same manner as in Experiment 2-1, except that H-POSS was replaced with polymethylhydrosiloxane (PMHS). A PS-MeIm-NNf film was also prepared by introducing an imidazolium salt-type ionic liquid component-containing layer into the PDMS-V(PMHS) film. ２ A / PS-SH / PDMS-V (PMHS) film was prepared.

[0072] The prepared PS-MeIm-NNf ２ The CO values ​​of the / PS-SH / PDMS-V (PMHS) membrane were measured in the same manner as in Experiment 2-1. ２ / N ２ Selectivity and CO ２ The measurement results of the permeation amount are shown in Figures 20 and 21, respectively. ２ / PS-SH / PDMS-V (PMHS) film CO ２ / N ２ The selectivity was 13 to 14, and the CO ２ / N ２ This was a higher value than the selectivity ratio of 10 to 12.

[0073] PS-MeIm-NNf２ / PS-SH / PDMS-V (PMHS) film CO ２ The permeation rate is slightly lower than that of the Sylgard membrane used for comparison. ２ Since the permeation rate is similar to that of the Sylgard membrane, the PS-MeIm-NNf membrane, which has a PDMS-V (PMHS) membrane and a layer containing an imidazolium salt-type ionic liquid component, ２ In the / PS-SH / PDMS-V (PMHS) film, the CO ２ It is lower than the permeability.

[0074] As described above, the PEG-PDMS-H (POSS) film and the PS-MeIm-NNf ２ In both the PS-SH and PDMS-V (POSS) membranes, CO ２ While showing gas permeation rate, the CO ２ / N ２ It was confirmed that the selectivity was improved.

[0075] The present invention allows various embodiments and modifications without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to explain the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of the invention equivalent thereto are considered to be within the scope of the present invention.

[0076] This application is based on Japanese Patent Application No. 2023-76917 filed on May 8, 2023. The entire specification, claims, and drawings of Japanese Patent Application No. 2023-76917 are incorporated herein by reference.

[0077] CO equivalent to conventional PDMS membrane (Sylgard membrane) ２ While showing the gas permeation amount, CO ２ / N ２ Improved selectivity of CO ２ It can provide a separation composite membrane, which can effectively remove CO2 that has diffused into the atmosphere. ２It is expected to be used in recovery technology.

Claims

1. A semiconductor device comprising a first separation layer and a second separation layer, the first separation layer and the second separation layer are chemically bonded to each other; the first separation layer is a polysiloxane-containing layer formed by polymerization of polymethylhydrosiloxane, polydimethylsiloxane having vinyl groups at both ends, and polyhedral oligosilsesquioxane having vinyl groups in side chains or cyclic oligosiloxane having vinyl groups in side chains; the second separating layer is a polyethylene glycol-containing layer; CO characterized by ２ Separation composite membrane.

2. A semiconductor device comprising a first separation layer and a second separation layer, the first separation layer and the second separation layer are chemically bonded to each other; the first separation layer is a polysiloxane-containing layer formed by polymerization of polymethylvinylsiloxane, polydimethylsiloxane having Si—H groups at both ends, and polyhedral oligosilsesquioxane or polymethylhydrosiloxane having Si—H groups in side chains; the second separation layer is an imidazolium salt type ionic liquid component-containing layer; CO characterized by ２ Separation composite membrane.

3. A method for manufacturing a semiconductor device, comprising: forming a first separation layer comprising a polysiloxane-containing layer; forming a second separation layer on the first separation layer, the second separation layer comprising a polyethylene glycol-containing layer; In the step of forming the first separation layer, polymethylhydrosiloxane, polydimethylsiloxane having vinyl groups at both ends, and polyhedral oligosilsesquioxane having vinyl groups in side chains or cyclic oligosiloxane having vinyl groups in side chains are polymerized to form the polysiloxane-containing layer; In the step of forming the second separation layer, a solution of polyethylene glycol containing a polymerizable functional group is applied onto the polysiloxane-containing layer, and the polyethylene glycol-containing layer is formed by a hydrosilylation reaction between the hydrosilyl group of the polysiloxane-containing layer and the polymerizable functional group of the polyethylene glycol, which is covalently bonded to the polysiloxane-containing layer. CO characterized by ２ Method for manufacturing a separation composite membrane.

4. A method for manufacturing a semiconductor device, comprising: forming a first separation layer comprising a polysiloxane-containing layer; forming a second separation layer containing an imidazolium salt type ionic liquid component on the first separation layer, In the step of forming the first separation layer, polymethylvinylsiloxane, polydimethylsiloxane having Si-H groups at both ends, and polyhedral oligosilsesquioxane or polymethylhydrosiloxane having Si-H groups in side chains are polymerized to form the polysiloxane-containing layer; In the step of forming the second separation layer, a solution of polysiloxane having an imidazolium group and a mercapto group in a side chain is applied onto the polysiloxane-containing layer, and the imidazolium salt-type ionic liquid component-containing layer is formed by a thiol-ene reaction between a vinyl group of the polysiloxane-containing layer and a mercapto group of the polysiloxane having the imidazolium group and the mercapto group, which is covalently bonded to the polysiloxane-containing layer. CO characterized by ２ Method for manufacturing a separation composite membrane.