CN116808846A - Gas separation membrane and preparation method thereof - Google Patents
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- CN116808846A CN116808846A CN202310931424.9A CN202310931424A CN116808846A CN 116808846 A CN116808846 A CN 116808846A CN 202310931424 A CN202310931424 A CN 202310931424A CN 116808846 A CN116808846 A CN 116808846A
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- 239000012528 membrane Substances 0.000 title claims abstract description 141
- 238000000926 separation method Methods 0.000 title claims abstract description 109
- 238000002360 preparation method Methods 0.000 title abstract description 16
- 229920001721 polyimide Polymers 0.000 claims abstract description 34
- 239000004642 Polyimide Substances 0.000 claims abstract description 33
- 238000000034 method Methods 0.000 claims abstract description 32
- 239000004693 Polybenzimidazole Substances 0.000 claims abstract description 25
- 229920002480 polybenzimidazole Polymers 0.000 claims abstract description 25
- 238000001914 filtration Methods 0.000 claims abstract description 15
- 230000007704 transition Effects 0.000 claims abstract description 15
- 229920002379 silicone rubber Polymers 0.000 claims abstract description 13
- 239000004945 silicone rubber Substances 0.000 claims abstract description 10
- 239000002033 PVDF binder Substances 0.000 claims abstract description 3
- 229920002492 poly(sulfone) Polymers 0.000 claims abstract description 3
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims abstract description 3
- 239000007789 gas Substances 0.000 claims description 193
- 239000002131 composite material Substances 0.000 claims description 46
- 238000001035 drying Methods 0.000 claims description 31
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 28
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 claims description 28
- 239000000243 solution Substances 0.000 claims description 28
- 239000011259 mixed solution Substances 0.000 claims description 24
- 239000012510 hollow fiber Substances 0.000 claims description 20
- 238000000108 ultra-filtration Methods 0.000 claims description 18
- 229920000642 polymer Polymers 0.000 claims description 17
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 claims description 14
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 14
- 235000019253 formic acid Nutrition 0.000 claims description 14
- 238000005191 phase separation Methods 0.000 claims description 13
- -1 polysiloxane Polymers 0.000 claims description 12
- 238000001471 micro-filtration Methods 0.000 claims description 10
- ANSXAPJVJOKRDJ-UHFFFAOYSA-N furo[3,4-f][2]benzofuran-1,3,5,7-tetrone Chemical compound C1=C2C(=O)OC(=O)C2=CC2=C1C(=O)OC2=O ANSXAPJVJOKRDJ-UHFFFAOYSA-N 0.000 claims description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 4
- GTDPSWPPOUPBNX-UHFFFAOYSA-N ac1mqpva Chemical compound CC12C(=O)OC(=O)C1(C)C1(C)C2(C)C(=O)OC1=O GTDPSWPPOUPBNX-UHFFFAOYSA-N 0.000 claims description 4
- WKDNYTOXBCRNPV-UHFFFAOYSA-N bpda Chemical compound C1=C2C(=O)OC(=O)C2=CC(C=2C=C3C(=O)OC(C3=CC=2)=O)=C1 WKDNYTOXBCRNPV-UHFFFAOYSA-N 0.000 claims description 4
- 150000004985 diamines Chemical class 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 229920000491 Polyphenylsulfone Polymers 0.000 claims description 3
- 229920002635 polyurethane Polymers 0.000 claims description 3
- 239000004814 polyurethane Substances 0.000 claims description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 2
- 239000004743 Polypropylene Substances 0.000 claims description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 2
- 239000001569 carbon dioxide Substances 0.000 claims description 2
- 239000001257 hydrogen Substances 0.000 claims description 2
- 229910052739 hydrogen Inorganic materials 0.000 claims description 2
- 229910052757 nitrogen Inorganic materials 0.000 claims description 2
- 239000001301 oxygen Substances 0.000 claims description 2
- 229910052760 oxygen Inorganic materials 0.000 claims description 2
- 229920001155 polypropylene Polymers 0.000 claims description 2
- 229920001296 polysiloxane Polymers 0.000 claims description 2
- 239000011148 porous material Substances 0.000 claims 1
- 230000035699 permeability Effects 0.000 abstract description 48
- 238000003618 dip coating Methods 0.000 abstract description 28
- 239000010410 layer Substances 0.000 description 76
- 230000000052 comparative effect Effects 0.000 description 30
- 238000001179 sorption measurement Methods 0.000 description 24
- 238000012360 testing method Methods 0.000 description 23
- 239000000463 material Substances 0.000 description 17
- 125000000959 isobutyl group Chemical group [H]C([H])([H])C([H])(C([H])([H])[H])C([H])([H])* 0.000 description 11
- 229920005597 polymer membrane Polymers 0.000 description 11
- 239000004205 dimethyl polysiloxane Substances 0.000 description 7
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 description 7
- 229920001971 elastomer Polymers 0.000 description 6
- 238000004528 spin coating Methods 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 239000012621 metal-organic framework Substances 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- SFMSVSNKGFIDAB-UHFFFAOYSA-N aniline;1h-benzimidazole Chemical compound NC1=CC=CC=C1.C1=CC=C2NC=NC2=C1 SFMSVSNKGFIDAB-UHFFFAOYSA-N 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- WFRXSXUDWCVSPI-UHFFFAOYSA-N 3h-benzimidazol-5-amine Chemical compound NC1=CC=C2NC=NC2=C1 WFRXSXUDWCVSPI-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000001891 gel spinning Methods 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 229910003471 inorganic composite material Inorganic materials 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 125000000999 tert-butyl group Chemical group [H]C([H])([H])C(*)(C([H])([H])[H])C([H])([H])[H] 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 238000002166 wet spinning Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02C20/00—Capture or disposal of greenhouse gases
- Y02C20/40—Capture or disposal of greenhouse gases of CO2
Landscapes
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
The invention relates to the technical field of gas separation membranes, in particular to a gas separation membrane and a preparation method thereof. The gas separation membrane sequentially comprises a base membrane layer, a transition layer, a filtering cortex and a separation cortex; the base membrane layer comprises polysulfone or polyvinylidene fluoride, the transition layer comprises polyimide, the filtration skin layer comprises polybenzimidazole derivative, and the separation skin layer comprises silicone rubber; the preparation method comprises the steps of preparing a base film layer, then forming polyimide film on the base film layer, and then dip-coating polybenzimidazole derivative and silicone rubber in sequence to form a gas separation film in sequence. The gas separation membrane prepared by the method adopts the base membrane with high temperature resistance and good toughness as the supporting structure, polyimide is coated to improve the combination degree of the base membrane and the filtering cortex, and finally the separating cortex is arranged on the surface of the filtering cortex, so that the prepared gas separation membrane has higher mechanical strength and air permeability, the preparation process steps are simple and convenient, and the method is easy to popularize and use industrially.
Description
Technical Field
The invention relates to the technical field of gas separation membranes, in particular to a gas separation membrane and a preparation method thereof.
Background
The membrane separation of the gas is realized by utilizing the difference of permeation rates of components in the gas mixture in the membrane under the action of pressure difference at two sides of the membrane, wherein the components with fast permeation are enriched at the permeation side, and the components with slow permeation are enriched at the residual permeation side. The gas membrane separation technology has been receiving more and more attention because of the advantages of simple process, low energy consumption, high separation efficiency, no pollution to the environment, etc. Gas separation membranes can be classified into porous and non-porous (dense) membranes by type. The three main categories of polymer materials, inorganic materials and polymer-inorganic composite materials are distinguished according to the properties of the materials. The existing inorganic membrane has better gas separation performance, and the polymer membrane for gas separation has the advantages of low manufacturing cost, strong structure controllability, good film forming property and the like.
However, the inorganic membrane with better gas separation performance has been hindered from industrial application due to the disadvantages of high price and poor modeling, etc., while the better the permeability of the polymer gas separation membrane to gas is, the worse the strength is. In addition, simplification of the preparation process of the gas separation membrane is very important, and chinese patent No. CN110404423a discloses a high-performance polyimide hollow fiber membrane, and a preparation method and application thereof, wherein the polyimide hollow fiber membrane is prepared by using a dry-wet spinning method, in which the nascent fiber membrane is required to be annealed at a high temperature to be close to the glass transition temperature, the operation method is relatively complex, and the requirement on environmental equipment is high. The invention of China patent CN110270231A discloses a MOF derived gas separation membrane, a preparation method and application thereof, wherein toxic organic solvents such as NMP and the like are used for multiple times in the preparation process, a high-temperature environment is needed when MOFs materials are processed, and an ultrasonic stirring technology is utilized when the MOFs materials are mixed with polymer solutions, so that the production cost is high, the operation is complex, and the environmental pollution is high. Because the gas separation membrane is a selective membrane, the mechanical strength of the membrane can be ensured to bear a certain pressure difference, so that development of membrane materials with high mechanical strength and good gas permeability and simple and effective membrane preparation technology are urgently needed, and development of membrane gas separation technology is further promoted.
Disclosure of Invention
In order to solve the problems, the invention provides a gas separation membrane and a preparation method thereof based on the existing gas separation membrane.
In one aspect, the invention provides a gas separation membrane, comprising a base membrane layer, a transition layer, a filtering skin layer and a separation skin layer in sequence; wherein the base membrane layer comprises polysulfone or polyvinylidene fluoride, the transition layer comprises polyimide, the filtration skin layer comprises polybenzimidazole derivative, and the separation skin layer comprises silicone rubber.
Further, the thickness of the base film layer is 8 μm to 12 μm, the thickness of the transition layer is 1 μm to 3 μm, the thickness of the filter skin layer is 0.3 μm to 0.8 μm, and the thickness of the separation skin layer is 0.05 μm to 0.15 μm.
Further, the base membrane layer is a hollow microfiltration bottom membrane, a hollow ultrafiltration bottom membrane or a hollow fiber ultrafiltration membrane, and the membrane aperture of the base membrane layer is 30nm-500nm.
Further, the polyimide is prepared by reacting dianhydride and diamine.
Further, the dianhydride is selected from one of 6FDA, PMDA, BPDA, BTDA, wherein the structural formula of 6FDA is as follows:
the structural formula of the PMDA is as follows:
the structural formula of the BPDA is as follows:
the structural formula of the BTDA is as follows:
further, the diamine is selected from one or more of PABZ, TAB-p-AB, i-PABZ, TAB-m-AB, DP, DAB-p-AB and DAB-m-AB, wherein the structural formula of PABZ (5-amino-2-4 (aminobenzene) benzimidazole) is as follows:
TAB-p-AB (2-2' -bis-p-aminobenzene-2-6-aminobenzimidazole) has the structural formula:
the structural formula of the i-PABZ (5-amino-2-3 (aminobenzene) benzimidazole) is as follows:
TAB-m-AB (2-2' -bis-m-aminobenzene-2-6-aminobenzimidazole) has the structural formula:
DP (2, 2' -p-benzobis (5-aminobenzimidazole)) has the structural formula:
DAB-p-AB (2-2 '-bis-p-aminobenzene-5-5' -bisbenzimidazole) has the structural formula:
DAB-m-AB (2-2 '-bis-m-aminobenzene-5-5' -bisbenzimidazole) has the structural formula:
further, the polybenzimidazole derivative is a nitrogen-substituted isobutyl-modified polybenzimidazole derivative or a tert-butyl-modified polybenzimidazole derivative.
Further, the silicone rubber comprises one or more of polysiloxane, polyurethane, polyphenylsulfone and polypropylene.
Further, the gas is a mixed gas of hydrogen and carbon dioxide or a mixed gas of oxygen and nitrogen.
In another aspect, the present invention also provides a method for preparing a gas separation membrane, comprising the steps of:
(1) Preparing a base film layer by a phase separation method;
(2) Polyimide is dissolved in DMAc to obtain polyimide solution with the concentration of 2% -10%, and then a film is formed on the base film layer to obtain a composite film I;
(3) Dissolving a polybenzimidazole derivative in formic acid to prepare a polymer solution with the concentration of 1% -2.5%, then forming a film on the first composite film, drying, and then exposing to steam to obtain the second composite film;
(4) Completely dissolving silicone rubber in r-butyrolactone to prepare a mixed solution with the concentration of 1-5 mill, and then forming a film of the mixed solution on a composite film II to obtain the gas separation film.
Further, the film forming mode in the step (2) is coating, spin coating, dip coating or doctor blade.
Further, the film forming mode of the step (3) is dip coating, the drying treatment is microwave drying, the drying temperature is 75-90 ℃, the drying time is 8-12 min, and the time of exposure to steam is 5-10 s.
Further, the film forming mode of the step (4) is dip coating, and the dip coating temperature is 60-70 ℃.
Compared with the prior art, the invention has the beneficial effects that:
1. the gas separation membrane prepared by the invention firstly adopts the base membrane with high temperature resistance and good toughness as the supporting structure of the whole separation membrane, and lays a good foundation for high-pressure gas separation; secondly, the polyimide transition layer is coated on the base film, so that the base film can be protected, the combination degree of the base film and the filtering cortex can be improved, and the air permeability of the separation film is improved, so that the gas separation coefficient is improved; finally, a separation skin layer is arranged, silicone rubber is coated on the surface of the filtration skin layer, and defects generated in the film forming process of the polymer of the polybenzimidazole derivative of the filtration skin layer are reduced, so that the separation coefficient of the film is further improved, and finally, the prepared gas has higher mechanical strength and air permeability, good air permeability selectivity and excellent heat and chemical stability.
2. The gas separation membrane of the invention is prepared by a mode of re-coating the membrane, and the gas flux of the inner separation layer is not influenced by the coating with high flux on the outer layer; the preparation process has simple steps, simple operation and low cost, and is easy to be popularized and used in industry.
Detailed Description
The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to fall within the scope of the invention.
In the present invention, unless otherwise indicated, all materials used are commercially available.
In the present invention, unless otherwise indicated, unless otherwise specified, experimental methods for specifying specific conditions are generally conducted under conventional conditions or under conditions of use recommended by the manufacturer.
Example 1
The present example provides a gas separation membrane prepared as follows:
(1) Preparing a hollow fiber ultrafiltration membrane with the aperture of 200nm and the thickness of 10 mu m by adopting a conventional phase separation method, and taking the hollow fiber ultrafiltration membrane as a base membrane layer;
(2) Dissolving polyimide prepared by adopting 6FDA and PABZ in DMAc, preparing polyimide solution with the concentration of 2.5%, and forming a film on the base film layer obtained in the step (1) in a spin coating mode, wherein the film forming thickness is 2 mu m, so as to obtain a composite film I;
(3) Dissolving an isobutyl modified polybenzimidazole derivative in formic acid to prepare a polymer solution with the concentration of 2%, then forming a film on the first composite film obtained in the step (2) in a dip-coating mode, drying for 10min at 80 ℃ by adopting microwave drying, exposing to steam for 8s, and finally forming a film with the thickness of 0.5 mu m to obtain the second composite film;
(4) And (3) completely dissolving polydimethylsiloxane silicone rubber in r-butyrolactone to prepare a mixed solution with the concentration of 3 per mill, and then forming a film of the mixed solution on the composite film II obtained in the step (3) at 65 ℃ in a dip-coating mode, wherein the film forming thickness is 0.1 mu m, thus obtaining the gas separation film.
The gas separation membrane prepared in this example was subjected to H at 35℃and 0.50MPa, as described in Standard GB/T40260-2021 method for testing gas permeation Performance of Polymer Membrane Material 2 /CO 2 The gas permeability test, characterized by permeability coefficient P1, shows that when gas stably passes through, the volume of gas in standard condition of gas passing through unit area sample in unit time under constant temperature and unit pressure difference is calculated according to permeability coefficient H 2 /CO 2 Adsorption selectivity s1=p of two gases H2 /P CO2 The results are shown in Table 1; o was carried out at 35℃and 0.50MPa 2 /N 2 The gas permeation performance was measured, characterized by permeation coefficient P2, and gas adsorption selectivity S2 was calculated, and the results are shown in table 2.
Example 2
This example provides a gas separation membrane which differs slightly from example 1 in the preparation process and raw materials, and is prepared as follows:
(1) Preparing a hollow fiber ultrafiltration bottom membrane with the aperture of 30nm and the thickness of 9 mu m by adopting a conventional phase separation method, and taking the hollow fiber ultrafiltration bottom membrane as a base membrane layer;
(2) Dissolving polyimide prepared by PMDA and TAB-p-AB in DMAc to prepare polyimide solution with the concentration of 2%, and forming a film on the base film layer obtained in the step (1) in a scraper mode, wherein the film forming thickness is 1 mu m, so as to obtain a composite film I;
(3) Dissolving tert-butyl modified polybenzimidazole derivative in formic acid to prepare a polymer solution with the concentration of 1.8%, then forming a film on the first composite film obtained in the step (2) in a dip-coating mode, drying for 12min at 90 ℃ by adopting microwave drying, exposing to steam for 5s, and finally forming a film with the thickness of 0.4 mu m to obtain a second composite film;
(4) And (3) completely dissolving polydimethylsiloxane rubber in r-butyrolactone to prepare a mixed solution with the concentration of 5 per mill, and then forming a film of the mixed solution on the composite film II obtained in the step (3) at the temperature of 60 ℃ in a dip-coating mode, wherein the film forming thickness is 0.05 mu m, thus obtaining the gas separation film.
The gas separation membrane prepared in this example was subjected to H at 35℃and 0.50MPa, as described in Standard GB/T40260-2021 method for testing gas permeation Performance of Polymer Membrane Material 2 /CO 2 The gas permeability test, characterized by permeability coefficient P1, shows that when gas stably passes through, the volume of gas in standard condition of gas passing through unit area sample in unit time under constant temperature and unit pressure difference is calculated according to permeability coefficient H 2 /CO 2 Adsorption selectivity s1=p of two gases H2 /P CO2 The results are shown in Table 1; o was carried out at 35℃and 0.50MPa 2 /N 2 The gas permeation performance was measured, characterized by permeation coefficient P2, and gas adsorption selectivity S2 was calculated, and the results are shown in table 2.
Example 3
The present example provides a gas separation membrane prepared as follows:
(1) Preparing a hollow microfiltration bottom membrane with the aperture of 500nm and the thickness of 11 mu m by adopting a conventional phase separation method, and taking the hollow microfiltration bottom membrane as a base membrane layer;
(2) Dissolving polyimide prepared by adopting BTDA, i-PABZ and DP in DMAc, preparing polyimide solution with the concentration of 5%, and forming a film on the base film layer obtained in the step (1) in a coating mode, wherein the film forming thickness is 3 mu m, thus obtaining a composite film I;
(3) Dissolving an isobutyl modified polybenzimidazole derivative in formic acid to prepare a polymer solution with the concentration of 2%, then forming a film on the first composite film obtained in the step (2) in a dip-coating mode, drying for 10min at 80 ℃ by adopting microwave drying, exposing to steam for 9s, and finally forming a film with the thickness of 0.6 mu m to obtain the second composite film;
(4) And (3) completely dissolving polydimethylsiloxane rubber in r-butyrolactone to prepare a mixed solution with the concentration of 2 per mill, and then forming a film of the mixed solution on the composite film II obtained in the step (3) at the temperature of 70 ℃ in a dip-coating mode, wherein the film forming thickness is 0.08 mu m, thus obtaining the gas separation film.
The gas separation membrane prepared in this example was subjected to H at 35℃and 0.50MPa, as described in Standard GB/T40260-2021 method for testing gas permeation Performance of Polymer Membrane Material 2 /CO 2 The gas permeability test, characterized by permeability coefficient P1, shows that when gas stably passes through, the volume of gas in standard condition of gas passing through unit area sample in unit time under constant temperature and unit pressure difference is calculated according to permeability coefficient H 2 /CO 2 Adsorption selectivity s1=p of two gases H2 /P CO2 The results are shown in Table 1; o was carried out at 35℃and 0.50MPa 2 /N 2 The gas permeation performance was measured, characterized by permeation coefficient P2, and gas adsorption selectivity S2 was calculated, and the results are shown in table 2.
Example 4
The present example provides a gas separation membrane prepared as follows:
(1) Preparing a hollow microfiltration bottom membrane with the aperture of 250nm and the thickness of 10 mu m by adopting a conventional phase separation method, and taking the hollow microfiltration bottom membrane as a base membrane layer;
(2) Dissolving polyimide prepared by PMDA, TAB-m-AB and DAB-p-AB in DMAc to prepare polyimide solution with the concentration of 2%, and forming a film on the base film layer obtained in the step (1) in a coating mode, wherein the film forming thickness is 2 mu m, so as to obtain a composite film I;
(3) Dissolving an isobutyl modified polybenzimidazole derivative in formic acid to prepare a polymer solution with the concentration of 1%, then forming a film on the first composite film obtained in the step (2) in a dip-coating mode, drying for 8min at 75 ℃ by adopting microwave drying, exposing to steam for 5s, and finally forming a film with the thickness of 0.3 mu m to obtain the second composite film;
(4) And (3) completely dissolving polysiloxane silicon rubber in r-butyrolactone to prepare a mixed solution with the concentration of 1 per mill, and then forming a film of the mixed solution on the composite film II obtained in the step (3) at the temperature of 70 ℃ in a dip-coating mode, wherein the film forming thickness is 0.11 mu m, thus obtaining the gas separation film.
The gas separation membrane prepared in this example was subjected to H at 35℃and 0.50MPa, as described in Standard GB/T40260-2021 method for testing gas permeation Performance of Polymer Membrane Material 2 /CO 2 The gas permeability test, characterized by permeability coefficient P1, shows that when gas stably passes through, the volume of gas in standard condition of gas passing through unit area sample in unit time under constant temperature and unit pressure difference is calculated according to permeability coefficient H 2 /CO 2 Adsorption selectivity s1=p of two gases H2 /P CO2 The results are shown in Table 1; o was carried out at 35℃and 0.50MPa 2 /N 2 The gas permeation performance was measured, characterized by permeation coefficient P2, and gas adsorption selectivity S2 was calculated, and the results are shown in table 2.
Example 5
The present example provides a gas separation membrane prepared as follows:
(1) Preparing a hollow microfiltration bottom membrane with the aperture of 400nm and the thickness of 8 mu m by adopting a conventional phase separation method, and taking the hollow microfiltration bottom membrane as a base membrane layer;
(2) Dissolving polyimide prepared by adopting BPDA, DAB-m-AB, TAB-p-AB and i-PABZ in DMAc to prepare polyimide solution with the concentration of 8%, and forming a film on the base film layer obtained in the step (1) in a spin coating mode, wherein the film forming thickness is 2 mu m, so as to obtain a composite film I;
(3) Dissolving an isobutyl modified polybenzimidazole derivative in formic acid to prepare a polymer solution with the concentration of 1.5%, then forming a film on the first composite film obtained in the step (2) in a dip-coating mode, drying for 12min at 90 ℃ by adopting microwave drying, and exposing to steam for 9s, wherein the thickness of the film is 0.7 mu m, thus obtaining the second composite film;
(4) And (3) completely dissolving polyurethane silicon rubber in r-butyrolactone to prepare a mixed solution with the concentration of 5 per mill, and then forming a film of the mixed solution on the composite film II obtained in the step (3) at the temperature of 60 ℃ in a dip-coating mode, wherein the film forming thickness is 0.12 mu m, thus obtaining the gas separation film.
The gas separation membrane prepared in this example was subjected to H at 35℃and 0.50MPa, as described in Standard GB/T40260-2021 method for testing gas permeation Performance of Polymer Membrane Material 2 /CO 2 The gas permeability test, characterized by permeability coefficient P1, shows that when gas stably passes through, the volume of gas in standard condition of gas passing through unit area sample in unit time under constant temperature and unit pressure difference is calculated according to permeability coefficient H 2 /CO 2 Adsorption selectivity s1=p of two gases H2 /P CO2 The results are shown in Table 1; o was carried out at 35℃and 0.50MPa 2 /N 2 The gas permeation performance was measured, characterized by permeation coefficient P2, and gas adsorption selectivity S2 was calculated, and the results are shown in table 2.
Example 6
The present example provides a gas separation membrane prepared as follows:
(1) Preparing a hollow microfiltration bottom membrane with the aperture of 350nm and the thickness of 10 mu m by adopting a conventional phase separation method, and taking the hollow microfiltration bottom membrane as a base membrane layer;
(2) Dissolving polyimide prepared by BTDA and TAB-m-AB, DP, DAB-p-AB in DMAc, preparing polyimide solution with the concentration of 10%, and forming a film on the base film layer obtained in the step (1) in a dip-coating mode, wherein the film forming thickness is 3 mu m, so as to obtain a composite film I;
(3) Dissolving an isobutyl modified polybenzimidazole derivative in formic acid to prepare a polymer solution with the concentration of 2.5%, then forming a film on the first composite film obtained in the step (2) in a dip-coating mode, drying for 8min at 75 ℃ by adopting microwave drying, exposing to steam for 10s, and finally forming a film with the thickness of 0.8 mu m to obtain a second composite film;
(4) And (3) completely dissolving polyphenylsulfone silicon rubber in r-butyrolactone to prepare a mixed solution with the concentration of 3 per mill, and then forming a film of the mixed solution on the composite film II obtained in the step (3) at 65 ℃ in a dip-coating mode, wherein the film forming thickness is 0.15 mu m, thus obtaining the gas separation film.
The gas separation membrane prepared in this example is referred to "Standard GB/T40260-2021 PolymerMethod for testing gas permeability of membrane material, H is carried out at 35 ℃ and 0.50MPa 2 /CO 2 The gas permeability test, characterized by permeability coefficient P1, shows that when gas stably passes through, the volume of gas in standard condition of gas passing through unit area sample in unit time under constant temperature and unit pressure difference is calculated according to permeability coefficient H 2 /CO 2 Adsorption selectivity s1=p of two gases H2 /P CO2 The results are shown in Table 1; o was carried out at 35℃and 0.50MPa 2 /N 2 The gas permeation performance was measured, characterized by permeation coefficient P2, and gas adsorption selectivity S2 was calculated, and the results are shown in table 2.
Comparative example 1
This comparative example provides a gas separation membrane differing from example 1 mainly in that: the gas separation membrane prepared in this comparative example comprises a base membrane layer, a separation skin layer, a transition layer and a filtration skin layer in this order, and the preparation steps are as follows:
(1) Preparing a hollow fiber ultrafiltration membrane with the aperture of 200nm and the thickness of 10 mu m by adopting a conventional phase separation method, and taking the hollow fiber ultrafiltration membrane as a base membrane layer;
(2) Completely dissolving polydimethylsiloxane silicone rubber in r-butyrolactone to prepare a mixed solution with the concentration of 2 per mill, and then forming a film of the mixed solution on the base film layer obtained in the step (1) at 65 ℃ in a dip-coating mode, wherein the film forming thickness is 0.1 mu m, so as to obtain a composite film I;
(3) Dissolving polyimide prepared by adopting 6FDA and PABZ in DMAc, preparing polyimide solution with the concentration of 5%, and forming a film on the first composite film obtained in the step (2) in a spin coating mode, wherein the film forming thickness is 2 mu m, so as to obtain a second composite film;
(4) And (3) dissolving the isobutyl modified polybenzimidazole derivative in formic acid to prepare a polymer solution with the concentration of 2%, then forming a film on the composite film II obtained in the step (3) in a dip-coating mode, drying for 10min at 80 ℃ by adopting microwave drying, exposing to steam for 8s, and finally forming a film with the thickness of 0.5 mu m to obtain the gas separation film.
The gas separation membrane prepared in this comparative example is referred to the gas of the Polymer membrane material of Standard GB/T40260-2021Body permeation Performance test method, H was performed at 35℃and 0.50MPa 2 /CO 2 The gas permeability test, characterized by permeability coefficient P1, shows that when gas stably passes through, the volume of gas in standard condition of gas passing through unit area sample in unit time under constant temperature and unit pressure difference is calculated according to permeability coefficient H 2 /CO 2 Adsorption selectivity s1=p of two gases H2 /P CO2 The results are shown in Table 1; o was carried out at 35℃and 0.50MPa 2 /N 2 The gas permeation performance was measured, characterized by permeation coefficient P2, and gas adsorption selectivity S2 was calculated, and the results are shown in table 2.
Comparative example 2
This comparative example provides a gas separation membrane differing from example 1 mainly in that: the gas separation membrane prepared in this comparative example comprises a base membrane layer, a filtering skin layer, a separation skin layer and a transition layer in this order, and the preparation steps are as follows:
(1) Preparing a hollow fiber ultrafiltration membrane with the aperture of 200nm and the thickness of 10 mu m by adopting a conventional phase separation method, and taking the hollow fiber ultrafiltration membrane as a base membrane layer;
(2) Dissolving an isobutyl modified polybenzimidazole derivative in formic acid to prepare a polymer solution with the concentration of 2%, then forming a film on the base film layer obtained in the step (1) in a dip-coating mode, drying for 10min at 80 ℃ by adopting microwave drying, exposing to steam for 8s, and finally forming a film with the thickness of 0.5 mu m to obtain a composite film I;
(3) Completely dissolving polydimethylsiloxane rubber in r-butyrolactone to prepare a mixed solution with the concentration of 2 per mill, and then forming a film of the mixed solution on the first composite film obtained in the step (2) at 65 ℃ in a dip-coating mode, wherein the film forming thickness is 0.1 mu m, so as to obtain a second composite film;
(4) And (3) dissolving polyimide prepared by adopting 6FDA and PABZ in DMAc to prepare polyimide solution with the concentration of 5%, and forming a film on the second composite film obtained in the step (3) in a spin coating mode, wherein the film forming thickness is 2 mu m, thus obtaining the gas separation film.
The gas separation membrane prepared in this comparative example is referred to the gas permeability of the polymeric membrane material of Standard GB/T40260-2021Test methods H was performed at 35℃and 0.50MPa 2 /CO 2 The gas permeability test, characterized by permeability coefficient P1, shows that when gas stably passes through, the volume of gas in standard condition of gas passing through unit area sample in unit time under constant temperature and unit pressure difference is calculated according to permeability coefficient H 2 /CO 2 Adsorption selectivity s1=p of two gases H2 /P CO2 The results are shown in Table 1; o was carried out at 35℃and 0.50MPa 2 /N 2 The gas permeation performance was measured, characterized by permeation coefficient P2, and gas adsorption selectivity S2 was calculated, and the results are shown in table 2.
Comparative example 3
This comparative example provides a gas separation membrane differing from example 1 mainly in that: the gas separation membrane prepared in this comparative example, which does not contain a base membrane layer, was prepared as follows:
(1) Polyimide prepared by adopting 6FDA and PABZ is dissolved in DMAc to prepare polyimide solution with the concentration of 5%, and a layer of hollow fiber membrane with the film thickness of 2 mu m is obtained in the conventional wet spinning process;
(2) Dissolving an isobutyl modified polybenzimidazole derivative in formic acid to prepare a polymer solution with the concentration of 2%, then forming a film on the hollow fiber membrane obtained in the step (1) in a dip-coating mode, drying for 10min at 80 ℃ by adopting microwave drying, exposing to steam for 8s, and finally forming a film with the thickness of 0.5 mu m to obtain a composite membrane I;
(3) And (3) completely dissolving polydimethylsiloxane rubber in r-butyrolactone to prepare a mixed solution with the concentration of 2 per mill, and then forming a film of the mixed solution on the composite film I obtained in the step (2) at 65 ℃ in a dip-coating mode, wherein the film forming thickness is 0.1 mu m, thus obtaining the gas separation film.
The gas separation membrane prepared in this comparative example was subjected to H at 35℃and 0.50MPa, with reference to Standard GB/T40260-2021 method for testing gas permeation Performance of Polymer Membrane Material 2 /CO 2 Gas permeability test, characterized by permeability coefficient P1, shows that when gas passes through stably, gas passes through a unit area sample in unit time under constant temperature and unit pressure differenceThe volume of the gas under standard conditions and calculating H according to the permeability coefficient 2 /CO 2 Adsorption selectivity s1=p of two gases H2 /P CO2 The results are shown in Table 1; o was carried out at 35℃and 0.50MPa 2 /N 2 The gas permeation performance was measured, characterized by permeation coefficient P2, and gas adsorption selectivity S2 was calculated, and the results are shown in table 2.
Comparative example 4
This comparative example provides a gas separation membrane differing from example 1 mainly in that: the gas separation membrane prepared in this comparative example, which does not contain a transition layer, was prepared as follows:
(1) Preparing a hollow fiber ultrafiltration membrane with the aperture of 200nm and the thickness of 10 mu m by adopting a conventional phase separation method, and taking the hollow fiber ultrafiltration membrane as a base membrane layer;
(2) Dissolving an isobutyl modified polybenzimidazole derivative in formic acid to prepare a polymer solution with the concentration of 2%, then forming a film on the base film layer obtained in the step (1) in a dip-coating mode, drying for 10min at 80 ℃ by adopting microwave drying, exposing to steam for 8s, and finally forming a film with the thickness of 0.5 mu m to obtain a composite film I;
(3) And (3) completely dissolving polydimethylsiloxane rubber in r-butyrolactone to prepare a mixed solution with the concentration of 2 per mill, and then forming a film of the mixed solution on the composite film I obtained in the step (2) at 65 ℃ in a dip-coating mode, wherein the film forming thickness is 0.1 mu m, thus obtaining the gas separation film.
The gas separation membrane prepared in this comparative example was subjected to H at 35℃and 0.50MPa, with reference to Standard GB/T40260-2021 method for testing gas permeation Performance of Polymer Membrane Material 2 /CO 2 The gas permeability test, characterized by permeability coefficient P1, shows that when gas stably passes through, the volume of gas in standard condition of gas passing through unit area sample in unit time under constant temperature and unit pressure difference is calculated according to permeability coefficient H 2 /CO 2 Adsorption selectivity s1=p of two gases H2 /P CO2 The results are shown in Table 1; o was carried out at 35℃and 0.50MPa 2 /N 2 Gas permeability test, characterized by permeability coefficient P2, and calculate gas adsorption selectivity S2, junctionThe results are shown in Table 2.
Comparative example 5
This comparative example provides a gas separation membrane differing from example 1 mainly in that: the gas separation membrane prepared in this comparative example, which does not include a separation skin layer, was prepared as follows:
(1) Preparing a hollow fiber ultrafiltration membrane with the aperture of 200nm and the thickness of 10 mu m by adopting a conventional phase separation method, and taking the hollow fiber ultrafiltration membrane as a base membrane layer;
(2) Dissolving polyimide prepared by adopting 6FDA and PABZ in DMAc, preparing polyimide solution with the concentration of 5%, and forming a film on the base film layer obtained in the step (1) in a spin coating mode, wherein the film forming thickness is 2 mu m, so as to obtain a composite film I;
(3) And (3) dissolving the isobutyl modified polybenzimidazole derivative in formic acid to prepare a polymer solution with the concentration of 2%, then forming a film on the composite film I obtained in the step (2) in a dip-coating mode, drying for 10min at 80 ℃ by adopting microwave drying, exposing to steam for 8s, and finally forming a film with the thickness of 0.5 mu m to obtain the gas separation film.
The gas separation membrane prepared in this comparative example was subjected to H at 35℃and 0.50MPa, with reference to Standard GB/T40260-2021 method for testing gas permeation Performance of Polymer Membrane Material 2 /CO 2 The gas permeability test, characterized by permeability coefficient P1, shows that when gas stably passes through, the volume of gas in standard condition of gas passing through unit area sample in unit time under constant temperature and unit pressure difference is calculated according to permeability coefficient H 2 /CO 2 Adsorption selectivity s1=p of two gases H2 /P CO2 The results are shown in Table 1; o was carried out at 35℃and 0.50MPa 2 /N 2 The gas permeation performance was measured, characterized by permeation coefficient P2, and gas adsorption selectivity S2 was calculated, and the results are shown in table 2.
Comparative example 6
This comparative example provides a gas separation membrane differing from example 1 mainly in that: the gas separation membrane prepared in this comparative example, which does not include a transition layer and a separation skin layer, was prepared as follows:
(1) Preparing a hollow fiber ultrafiltration membrane with the aperture of 200nm and the thickness of 10 mu m by adopting a conventional phase separation method, and taking the hollow fiber ultrafiltration membrane as a base membrane layer;
(2) And (3) dissolving the isobutyl modified polybenzimidazole derivative in formic acid to prepare a polymer solution with the concentration of 2%, then forming a film on the base film layer obtained in the step (1) in a dip-coating mode, drying for 10min at 80 ℃ by adopting microwave drying, exposing to steam for 8s, and finally forming a film with the thickness of 0.5 mu m to obtain the gas separation film.
The gas separation membrane prepared in this comparative example was subjected to H at 35℃and 0.50MPa, with reference to Standard GB/T40260-2021 method for testing gas permeation Performance of Polymer Membrane Material 2 /CO 2 The gas permeability test, characterized by permeability coefficient P1, shows that when gas stably passes through, the volume of gas in standard condition of gas passing through unit area sample in unit time under constant temperature and unit pressure difference is calculated according to permeability coefficient H 2 /CO 2 Adsorption selectivity s1=p of two gases H2 /P CO2 The results are shown in Table 1; o was carried out at 35℃and 0.50MPa 2 /N 2 The gas permeation performance was measured, characterized by permeation coefficient P2, and gas adsorption selectivity S2 was calculated, and the results are shown in table 2.
TABLE 1H 2 /CO 2 Gas separation performance
TABLE 2O 2 /N 2 Gas separation performance
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As can be seen from the results of Table 1 and Table 2, the gas separation membrane prepared according to the present invention was obtained by arranging the respective layers in order and coordinating the interlayer structureWith the same action, higher gas permeability coefficient and H are obtained 2 /CO 2 ，O 2 /N 2 The separation coefficient, the gas separation effect is good and the separation efficiency is high. Comparative example 1 compared to example 1, the separation skin layer was disposed at the second position, the filter skin layer was disposed at the outermost, and the permeation coefficient of the gas was significantly reduced due to the lack of protection of the separation skin layer; compared with the embodiment 1, the comparative example 2 has the filtering cortex arranged at the second position, the connection effect of the transition layer between the inner layer and the base layer film is lacked, and the outer layer is covered with two layers of film bodies, so that the gas permeability is more seriously reduced; comparative example 3 was poor in the subsequent film forming property due to the lack of the base film layer as a skeleton, and poor in the gas permeation effect; comparative example 4 does not include a transition layer, which lacks the tie effect of a transition layer between the filter skin layer and the base layer film; comparative example 5 does not contain a separation skin layer, and fails to effectively compensate for defects generated when a filtration skin layer is formed into a film; comparative example 6 a filter skin layer was formed directly on the base film backbone, which filter skin layer lacks protection. Therefore, it can be seen that when the arrangement order of the membranes is changed or the structure is deleted, the mutual effects are changed due to the change of the integral structure, and the gas permeation performance and the gas selectivity are obviously reduced.
The invention has been further described with reference to specific embodiments, but it should be understood that the detailed description is not to be construed as limiting the spirit and scope of the invention, but rather as providing those skilled in the art with the benefit of this disclosure with the benefit of their various modifications to the described embodiments.
Claims (10)
1. The gas separation membrane is characterized by comprising a base membrane layer, a transition layer, a filtering skin layer and a separation skin layer in sequence;
the base membrane layer comprises polysulfone or polyvinylidene fluoride, the transition layer comprises polyimide, the filtration skin layer comprises a polybenzimidazole derivative, and the separation skin layer comprises silicone rubber.
2. The gas separation membrane according to claim 1, wherein the base membrane layer is a hollow microfiltration base membrane, a hollow ultrafiltration base membrane or a hollow fiber ultrafiltration membrane, and the membrane pore size of the base membrane layer is 30nm to 500nm.
3. The gas separation membrane of claim 1, wherein the polyimide is prepared by reacting a dianhydride and a diamine.
4. A gas separation membrane according to claim 3, wherein the dianhydride is selected from one of 6FDA, PMDA, BPDA, BTDA.
5. A gas separation membrane according to claim 3, wherein the diamine is selected from one or more of PABZ, TAB-p-AB, i-PABZ, TAB-m-AB, DP, DAB-p-AB, DAB-m-AB.
6. The gas separation membrane of claim 1, wherein the polybenzimidazole derivative is a nitrogen-substituted isobutyl-modified polybenzimidazole derivative or a tert-butyl-modified polybenzimidazole derivative.
7. The gas separation membrane of claim 1, wherein the silicone rubber comprises one or more of polysiloxane, polyurethane, polyphenylsulfone, polypropylene.
8. The gas separation membrane according to claim 1, wherein the gas is a mixed gas of hydrogen and carbon dioxide or a mixed gas of oxygen and nitrogen.
9. The method for producing a gas separation membrane according to any one of claims 1 to 8, comprising the steps of:
(1) Preparing a base film layer by a phase separation method;
(2) Polyimide is dissolved in DMAc to obtain polyimide solution with the concentration of 2% -10%, and then a film is formed on the base film layer to obtain a composite film I;
(3) Dissolving a polybenzimidazole derivative in formic acid to obtain a polymer solution with the concentration of 1% -2.5%, forming a film on the first composite film, drying and exposing to steam to obtain a second composite film;
(4) Completely dissolving silicon rubber in r-butyrolactone to obtain a mixed solution with the concentration of 1-5 mill, and then forming a film of the mixed solution on the composite film II to obtain the gas separation film.
10. The method for producing a gas separation membrane according to claim 9, wherein the drying temperature in the step (3) is 75 ℃ to 90 ℃.
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