Self-microporous polymer/amino modified MOF mixed matrix membrane and preparation method and application thereof
阅读说明：本技术 一种自具微孔聚合物/氨基修饰mof混合基质膜及其制备方法和应用 (Self-microporous polymer/amino modified MOF mixed matrix membrane and preparation method and application thereof ) 是由 张国亮 李洋 于 2019-08-29 设计创作，主要内容包括：本发明公开了一种自具微孔聚合物/氨基修饰MOF混合基质膜及其制备方法和应用,所述的制备方法为：将金属有机骨架MIL-101(Cr)进行胺化处理得到胺化后的金属有机骨架MIL-101(Cr)；将自具微孔聚合物溶于有机溶剂A中得到自具微孔聚合物浓度为0.01～0.2g/mL的溶液A,将胺化后的金属有机骨架MIL-101(Cr)溶于有机溶剂B中得到胺化后的金属有机骨架MIL-101(Cr)浓度为0.005～0.1g/mL的溶液B,将所述的溶液A和溶液B混合搅拌均匀,室温下缓慢相转化蒸发得混合基质膜。本发明所述的自具微孔聚合物/氨基修饰MOF混合基质膜应用于CO<Sub>2</Sub>的分离选择。本发明通过非极性有机溶剂对MIL-101的氨化,提高了此MOF对CO<Sub>2</Sub>的吸附分离选择性,并与PIM-1混合制得自支撑的混合基质膜,显著提高了膜对CO<Sub>2</Sub>的分离选择性。(the invention discloses a self-microporous polymer/amino modified MOF mixed matrix membrane and a preparation method and application thereof, wherein the preparation method comprises the following steps: carrying out amination treatment on the metal organic framework MIL-101(Cr) to obtain an aminated metal organic framework MIL-101 (Cr); dissolving a self-microporous polymer in an organic solvent A to obtain a solution A with the concentration of the self-microporous polymer being 0.01-0.2 g/mL, dissolving aminated metal-organic framework MIL-101(Cr) in an organic solvent B to obtain a solution B with the concentration of the aminated metal-organic framework MIL-101(Cr) being 0.005-0.1 g/mL, mixing and stirring the solution A and the solution B uniformly, and slowly performing phase conversion and evaporation at room temperature to obtain a mixed matrix membrane. According to the inventionApplication of self-microporous polymer/amino modified MOF mixed matrix membrane to CO 2 and (4) separation and selection. The invention improves the effect of MOF on CO through ammoniation of the nonpolar organic solvent on MIL-101 2 The selectivity of adsorption separation is combined with PIM-1 to prepare a self-supporting mixed matrix membrane, and the CO pair of the membrane is obviously improved 2 Selectivity of separation of (1).)
1. a MOF mixed matrix membrane modified with a microporous polymer/amino group, comprising: the mixed matrix membrane is prepared according to the following method:
(1) Carrying out amination treatment on the metal organic framework MIL-101(Cr) to obtain an aminated metal organic framework MIL-101 (Cr);
(2) Dissolving a self-microporous polymer in an organic solvent A to obtain a solution A with the concentration of the self-microporous polymer being 0.01-0.2 g/mL, dissolving aminated metal-organic framework MIL-101(Cr) in an organic solvent B to obtain a solution B with the concentration of the aminated metal-organic framework MIL-101(Cr) being 0.005-0.1 g/mL, mixing and stirring the solution A and the solution B uniformly, and slowly performing phase conversion and evaporation at room temperature to obtain a mixed matrix membrane; the volume ratio of the solution A to the solution B is 1:1.
2. The self-microporous polymer/amino modified MOF mixed matrix membrane of claim 1, wherein: in the step (1), the preparation method of MIL-101(Cr) comprises the following steps: adding 2-methylimidazole into deionized water, uniformly stirring to obtain a 2-methylimidazole water solution with the concentration of 0.0067-0.0125 g/mL, then adding terephthalic acid into the 2-methylimidazole water solution, and continuously and uniformly stirring to obtain a mixed solution; dissolving chromium nitrate nonahydrate in water to obtain a chromium nitrate nonahydrate aqueous solution with the concentration of 0.053g/mL, uniformly mixing the mixed solution with the chromium nitrate nonahydrate aqueous solution, keeping the mixture in an oven at the constant temperature of 170 ℃ for 24 hours, carrying out centrifugal separation, washing the obtained centrifugal precipitate with absolute ethyl alcohol and dimethylformamide, and drying to obtain MIL-101 (Cr); the mass ratio of the 2-methylimidazole to the terephthalic acid to the chromium nitrate nonahydrate is 1: 4: 9.76.
3. The self-microporous polymer/amino modified MOF mixed matrix membrane of claim 1, wherein: in the step (1), the amination treatment process comprises the following steps: dispersing DETA or TAEA in anhydrous cyclohexane to prepare alkylamine solution, activating MIL-101 for 4-48 hours under a vacuum condition to obtain activated MIL-101(Cr), then adding the activated MIL-101(Cr) into the alkylamine solution to obtain suspension, uniformly stirring the suspension at room temperature, washing the solid obtained by centrifugation with anhydrous cyclohexane, and drying and activating under the vacuum of 55 ℃; the volume ratio of DETA to anhydrous cyclohexane is 1: 55-75, wherein the volume ratio of the TAEA to the anhydrous cyclohexane is 1: 40-60; the mass ratio of alkylamine solution to activated MIL-101(Cr) was 7.6: 1.
4. The self-microporous polymer/amino modified MOF mixed matrix membrane of claim 1, wherein: in the step (2), the polymer with micropores comprises PIM-1, PIM-7, carboxylated PIM-1, aminated PIM-1, carboxylated PIM-7 or aminated PIM-7.
5. The self-microporous polymer/amino modified MOF mixed matrix membrane of claim 1, wherein: in the step (2), the solvent A is chloroform, dichloromethane or tetrahydrofuran.
6. The self-microporous polymer/amino modified MOF mixed matrix membrane of claim 1, wherein: in the step (2), the solvent B is chloroform, dichloromethane, tetrahydrofuran or N, N-dimethylformamide.
7. The self-microporous polymer/amino modified MOF mixed matrix membrane of claim 1, wherein: in the step (2), the evaporation time is 12-72 h.
8. Application of the self-microporous polymer/amino modified MOF mixed matrix membrane of claim 1 to CO2And (4) separation and selection.
Technical Field
The invention relates to a self-microporous polymer/amino modified MOF mixed matrix membrane and a preparation method and application thereof, belonging to the technical field of functional membrane preparation and separation application.
Background
The separation and the capture of the carbon dioxide are efficiently realized, and the method has great significance for slowing down the emission of greenhouse gases in industrial production. Flue gas is a gaseous substance which is generated when fossil fuels such as coal and the like are combusted and has pollution to the environment, and the main components of the flue gas are nitrogen, carbon dioxide, sulfide and the like. The ultra-thin porous material membrane can be one of the research hotspots in the field of current gas separation materials because of the high efficiency of separating carbon dioxide from flue gas.
In 2004, Budd synthesizes rigid chain-like self-microporous polymers PIM-1-6 containing a twisted structure, and the main chain of the polymers cannot rotate freely, so that effective accumulation among molecular chains can be well hindered, continuous micropores are formed in the membrane, and the obtained membrane material has good permeability and selectivity and presents certain superiority in gas separation. Due to its CO pairing2Unique dissolution and diffusion effect, so that the catalyst is applied to CO2The selective adsorption separation field shows great citation potential.
The MOFs are also a series of advantages of large specific surface area, pore volume, adjustable pore size, easy functionalization and the like. So far, many reports have been made on the use of metal organic framework materials as carbon dioxide adsorbents, and the metal organic framework materials mainly achieve CO through two ways2/N2Selective separation and adsorption. One is a chemisorption method in which a basic functional group such as an amino group is introduced into a pore, and the other is a physisorption method in which the pore size/window size is adjusted.
The current effect of the alkylamine on MOF (MIL-101) modification of the resulting material is much worse than other MOF materials, in order to further increase CO2The non-polar solvent is used as the ammoniation solvent, so that the ammoniation effect of the membrane is improved, and the separation selectivity of the obtained mixed matrix membrane is greatly improved.
Disclosure of Invention
To solve the problems of the prior art, the object of the present invention is to prepare a polymer/amino-modification having self-contained microporesMOF mixed matrix membrane, mainly CO, for gas separation2/N2Separation of (4).
The technical scheme of the invention is as follows:
First, MOF particles (MIL-101) were prepared; secondly, preparing aminated MOF particles by taking a low-polarity solvent as a dispersion medium; and finally, mixing the polymer with the micropores and the amino-modified MOF, and carrying out phase conversion to obtain the high-efficiency gas separation membrane.
the invention relates to a self-microporous polymer/amino modified MOF mixed matrix membrane, which is prepared by the following method:
(1) Carrying out amination treatment on the metal organic framework MIL-101(Cr) to obtain an aminated metal organic framework MIL-101 (Cr);
(2) Dissolving a self-microporous polymer in an organic solvent A to obtain a solution A with the concentration of the self-microporous polymer being 0.01-0.2 g/mL, dissolving aminated metal-organic framework MIL-101(Cr) in an organic solvent B to obtain a solution B with the concentration of the aminated metal-organic framework MIL-101(Cr) being 0.005-0.1 g/mL, mixing and stirring the solution A and the solution B uniformly, and slowly performing phase conversion and evaporation at room temperature to obtain a mixed matrix membrane; the volume ratio of the solution A to the solution B is 1:1.
Further, in the step (1), the MIL-101(Cr) is prepared by a solvothermal method, and the preparation process comprises the following steps: adding 2-methylimidazole into deionized water, uniformly stirring to obtain a 2-methylimidazole water solution with the concentration of 0.0067-0.0125 g/mL, then adding terephthalic acid into the 2-methylimidazole water solution, and continuously and uniformly stirring to obtain a mixed solution; dissolving chromium nitrate nonahydrate in water to obtain a chromium nitrate nonahydrate aqueous solution with the concentration of 0.053g/mL, uniformly mixing the mixed solution with the chromium nitrate nonahydrate aqueous solution, keeping the mixture in an oven at the constant temperature of 170 ℃ for 24 hours, carrying out centrifugal separation, washing the obtained centrifugal precipitate with absolute ethyl alcohol and dimethylformamide, and drying to obtain MIL-101 (Cr); the mass ratio of the 2-methylimidazole to the terephthalic acid to the chromium nitrate nonahydrate is 1: 4: 9.76.
Further, in the step (1), the amination process comprises the following steps: dispersing DETA or TAEA in anhydrous cyclohexane to prepare alkylamine solution, activating MIL-101 for 4-48 hours under a vacuum condition to obtain activated MIL-101(Cr), then adding the activated MIL-101(Cr) into the alkylamine solution to obtain suspension, uniformly stirring the suspension at room temperature, washing the solid obtained by centrifugation with anhydrous cyclohexane, and drying and activating under the vacuum of 55 ℃; the volume ratio of DETA to anhydrous cyclohexane is 1: 55-75, wherein the volume ratio of the TAEA to the anhydrous cyclohexane is 1: 40-60; the mass ratio of alkylamine solution to activated MIL-101(Cr) was 7.6: 1.
Further, in the step (2), the solvent a may be chloroform, dichloromethane or tetrahydrofuran.
Further, in the step (2), the solvent B may be chloroform, dichloromethane, tetrahydrofuran or N, N-dimethylformamide.
Further, in the step (2), the polymer with micropores comprises PIM-1, PIM-7, carboxylated PIM-1, aminated PIM-1, carboxylated PIM-7 or aminated PIM-7.
Still further, in the step (2), the polymer with micropores is preferably PIM-1, and the PIM-1 is synthesized by mixing 5,5 ', 6,6 ' -tetrahydroxy-3, 3,3 ', 3 ' -tetramethyl-1, 1 ' -spirobiindane (TTSBI), tetrafluoroterephthalonitrile (DCTB), K, and K2CO3Dissolving the mixture in a mixed solution of DMAc and toluene, refluxing for 40min at 160 ℃, then pouring viscous fluid into methanol and stirring, wherein noodle-shaped solids are generated; filtering and washing with acetone, and drying in an oven to obtain solid PIM-1; the mass ratio of TTSBI to TFTN is 3: 1-2; the TTSBI and K2CO3The mass ratio is 1: 1-2; the adding amount of the DMAc is 4-6ml/g based on the mass of the TTSBI; the volume ratio of DMAc to toluene is 1-2: 1; the volume ratio of the methanol to the DMAc is 1: 1.5-2; the volume ratio of the acetone to the methanol is 1: 1-1.5; the oven temperature is 100-130 ℃.
Further, in the step (2), the reaction vessel used for the reaction is made of polyvinylidene fluoride.
Further, in the step (2), the evaporation time is 12-72 h.
The self-microporous polymer/amino modified MOF mixed matrix membrane is applied to CO2And (4) separation and selection.
Compared with the prior art, the invention has the advantages that: the amination of MIL-101 by a non-polar organic solvent improves the CO content of the MOF2The selectivity of adsorption separation is combined with PIM-1 to prepare a self-supporting mixed matrix membrane, and the CO pair of the membrane is obviously improved2Selectivity of separation of (1).
The invention is further illustrated by the following examples.
drawings
FIG. 1 is a surface SEM image of a MOF mixed matrix membrane with microporous polymer/amino modifications.
FIG. 2 is a sectional SEM image of a MOF mixed matrix membrane with microporous polymer/amino modifications.
Detailed Description
The present invention will be described in detail below with reference to specific examples, but the present invention is not limited to the following examples, and various modifications and implementations are included within the technical scope of the present invention without departing from the content and scope of the present invention.
The preparation method of the PIM-1 comprises the following steps: 12g of 5,5 ', 6,6 ' -tetrahydroxy-3, 3,3 ', 3 ' -tetramethyl-1, 1 ' -spirobiindane (TTSBI), 4g of tetrafluoroterephthalonitrile (DCTB), 12g K2CO3Placing the mixture in 60mL of DMAc and 60mL of toluene solution, refluxing for 40min at 160 ℃, pouring the obtained viscous fluid into 100mL of methanol, and stirring to obtain noodle-shaped solid; and (3) carrying out suction filtration and washing by using 120mL of acetone, and then drying in an oven at 120 ℃ to obtain the solid PIM-1.
Example 1
Preparation of MIL-101 (Cr): 2-methylimidazole (0.328g) is put into 40mL of deionized water, magnetically stirred for 5min at normal temperature, then 1.328 g of terephthalic acid is added, and stirred for 15 min; 3.2g of chromium nitrate nonahydrate is put into a small beaker, added into 60mL of deionized water and continuously stirred for 15 min; the resulting suspension (100mL) was mixed and held in an oven at a constant temperature of 170 ℃ for 24 hours. The liquid was then centrifuged at 3000 r/min. After washing with absolute ethanol and dimethylformamide, the green solid obtained by centrifugation was dried in an oven at 100 ℃ for 15h to obtain a green powder sample.
Preparation of aminated MOFs: 1.11mmol DETA (0.120mL) or TAEA (0.166mL) was dispersed in 8mL anhydrous Cyclohexane (CH) to prepare an alkylamine solution, activated MIL-101(Cr) (100mg, 0.146mmol) was added to the alkylamine solution, the resulting suspension was stirred at room temperature for 5min, the solid obtained by centrifugation was washed three times with anhydrous CH, dried under vacuum, and activated under vacuum at 55 ℃ before use.
Preparation of mixed matrix membrane: dissolving 1g of PIM-1 in 20mL of chloroform, and uniformly stirring for about 2 hours to obtain a solution A; 0.4g of aminated modified MIL-101(Cr) was dissolved in 20mL of DMF and stirred well for about 2h, called solution B; and (3) mixing the solution A, B, injecting the mixed solution into a polytetrafluoroethylene culture dish by using an injector after uniformly stirring, sealing the culture dish, and slowly evaporating to obtain the required mixed matrix membrane.
gas separation test: respectively testing the CO of the single component by adopting a single component measurement mode2And N2Permeability of (2), as a result of which the membrane is resistant to CO2Has a permeability of 15600barrer for N2Has a permeability of 450 barrer.
Example 2
Preparation of MIL-101 (Cr): 2-methylimidazole (0.328g) is put into 40mL of deionized water, magnetically stirred for 5min at normal temperature, then 1.328 g of terephthalic acid is added, and stirred for 15 min; 3.2g of chromium nitrate nonahydrate is put into a small beaker, added into 60mL of water and continuously stirred for 15 min; the resulting suspension (100mL) was mixed and held in an oven at a constant temperature of 170 ℃ for 24 hours. The liquid was then centrifuged at 3000 r/min. After washing with absolute ethanol and dimethylformamide, the green solid obtained by centrifugation was dried in an oven at 100 ℃ for 15h to obtain a green powder sample.
Preparation of aminated MOFs: 1.11mmol DETA (0.120mL) or TAEA (0.166mL) was dispersed in 8mL anhydrous Cyclohexane (CH) to prepare an alkylamine solution, activated MIL-101(Cr) (100mg, 0.146mmol) was added to the alkylamine solution, the resulting suspension was stirred at room temperature for 5min, the solid obtained by centrifugation was washed three times with anhydrous CH, dried under vacuum, and activated under vacuum at 55 ℃ before use.
Preparation of mixed matrix membrane: dissolving 1g of PIM-1 in 20mL of chloroform, and uniformly stirring for about 2 hours to obtain a solution A; 0.8g of aminated modified MIL-101(Cr) was dissolved in 20mL of DMF and stirred well for about 2h, called solution B; and (3) mixing the solution A, B, injecting the mixed solution into a polytetrafluoroethylene culture dish by using an injector after uniformly stirring, sealing the culture dish, and slowly evaporating to obtain the required mixed matrix membrane.
Gas separation test: respectively testing the CO of the single component by adopting a single component measurement mode2And N2Permeability of (2), as a result of which the membrane is resistant to CO2has a permeability of 18900barrer for N2Has a permeability of 495 barrer.