Metal organic framework glass gas separation membrane and preparation method and application thereof

Abstract

The application discloses a kind of metal organic framework glass gas separation membranes and its preparation method and application, belong to membrane material field, the preparation method of metal organic framework glass gas separation membrane provided by the present application is pre-coated with the mixed solution of nano zinc oxide and polymer on carrier ultrasonic, then crystal membrane is synthesized with solvent thermal method, finally melt quenching into glass membrane, specifically includes the following steps: S1: nano zinc oxide-polymer mixed solution is coated on the surface of carrier;S2: preparation precursor solution;S3: after the carrier treated in step S1 is placed in precursor solution, solvent thermal treatment is carried out and cooling, obtain metal organic framework crystal membrane;S4: the metal organic framework crystal membrane prepared in step S3 is melt quenching, and metal organic framework glass gas separation membrane is prepared.The method is simple to operate, while not using zinc nitrate hexahydrate, the permeability and porosity of glass membrane are improved.

Description

Technical Field

[0001] The present invention relates to the field of membrane materials, and in particular to a metal organic framework glass gas separation membrane and a preparation method and application thereof. Background Art

[0002] Metal-organic frameworks (MOFs) have become a hot topic in membrane material research due to their unique structure and multifunctionality. The polycrystalline nature of MOF membranes poses a severe challenge to their fabrication and application. Scientists have worked hard to reduce grain boundary defects and cracks in MOF membranes. Although improvements have been made, the grain boundary problem remains unresolved.

[0003] Preparing metal-organic framework polycrystalline membranes into metal-organic framework glass membranes is a good way to eliminate intercrystalline defects. However, as the crystalline phase transforms to the amorphous glass phase, the pores of the MOF will collapse, thereby reducing the porosity of the MOF itself. For gas separation, the corresponding permeability will also decrease with the reduction of porosity, thus affecting the performance of the metal-organic framework glass membrane.

[0004] In addition, zinc nitrate hexahydrate is one of the main raw materials for the preparation of metal-organic framework glass membranes. However, zinc nitrate hexahydrate is toxic and a controlled chemical that is easily explosive, which makes the preparation of metal-organic framework glass membranes relatively cumbersome.

[0005] Based on this, it is necessary to develop a method for preparing a metal organic framework glass membrane that improves the porosity of the metal organic framework glass membrane while ensuring the gas separation performance of the metal organic framework glass membrane. Summary of the Invention

[0006] The object of the present invention is to provide a metal organic framework glass membrane with high porosity and high permeability and a preparation method thereof.

[0007] Based on this, the first aspect of the present invention provides a method for preparing a metal organic framework glass gas separation membrane, comprising the following steps:

[0008] S1: coating the nano zinc oxide-polymer mixed solution on the carrier surface;

[0009] S2: Mixing the organic ligand and the organic solvent to prepare a precursor solution;

[0010] S3: placing the support treated in step S1 in a precursor solution, performing solvent thermal treatment and cooling to obtain a metal organic framework crystal film;

[0011] S4: melt-quenching the metal organic framework crystal membrane obtained in step S3 to obtain a metal organic framework glass gas separation membrane.

[0012] The application provides a new preparation method of a high-porosity and high-permeability metal organic framework glass gas separation membrane, which comprises the following steps: pre-coating a mixed solution of nano-zinc oxide and a polymer on a carrier by ultrasonic coating, then synthesizing a metal organic framework crystal membrane by a conventional solvothermal method, and finally melting and quenching into a glass membrane.

[0013] Preferably, the carrier is selected from one of an aluminum carrier, a silicon carrier and a titanium carrier.

[0014] More preferably, the carrier is one of an alumina flaky carrier, an alumina tubular carrier, an alumina plate carrier, a silicon dioxide carrier, a titanium dioxide carrier and a stainless steel carrier.

[0015] Preferably, in the step S4, the metal organic framework crystal membrane is melted and quenched in a tubular furnace.

[0016] Preferably, in the step S4, the metal organic framework crystal membrane is melted and quenched in an inert gas atmosphere.

[0017] Preferably, in the step S1, the coating method is ultrasonic coating, and the ultrasonic coating time is 1-30 min.

[0018] Preferably, in the step S1, the polymer is one or more of polyethyleneimine, polydimethylsiloxane, polysulfone and polyethersulfone.

[0019] Preferably, the concentration of the polymer in the nano-zinc oxide-polymer mixed solution is 2-20 wt%, and the concentration of the nano-zinc oxide in the nano-zinc oxide-polymer mixed solution is 2-40 wt%.

[0020] Preferably, the organic ligand is any one or more of imidazole, benzimidazole, 2-methylbenzimidazole, 5-methylbenzimidazole, 5,6-dimethylbenzimidazole, 5-chlorobenzimidazole and 5-hydroxybenzimidazole; and the organic solvent is N,N-dimethylformamide.

[0021] Preferably, in the step S2, the molar ratio of the organic ligand to the organic solvent in the precursor solution is (1-30):(20-200).

[0022] Preferably, in the step S3, the heating temperature is 100-180℃.

[0023] More preferably, the heating time in the step S3 is 8-16h.

[0024] Preferably, the temperature of the melt quenching in the step S4 is 350-600℃.

[0025] More preferably, the time of the melt quenching in the step S4 is 10-50min.

[0026] Further, the second aspect of the present application provides a metal organic framework glass gas separation membrane prepared by the aforementioned preparation method.

[0027] Further, the third aspect of the present application provides an application of the aforementioned metal organic framework glass gas separation membrane, and the application is: using the metal organic framework glass gas separation membrane for the separation of carbon dioxide gas.

[0028] The metal organic framework glass gas separation membrane provided by the present application is prepared by the following steps: firstly, ultrasonic coating a mixed solution of nano zinc oxide and polymer on a carrier; secondly, synthesizing a metal organic framework crystal membrane by a conventional solvothermal method; and finally, melt quenching the metal organic framework crystal membrane into a metal organic framework glass membrane. The mixed solution is obtained by mixing the nano zinc oxide dispersion liquid and the polymer. Because the contents of the zinc oxide and the polymer are different, the consistencies of the mixed solution are different. According to the different consistencies, the thickness of the zinc oxide modified carrier penetrating into the carrier can be controlled, so that the thickness of the crystal membrane can be controlled. In addition, the polymer will be decomposed in the process of melt quenching the crystal membrane, and a large number of pores suitable for gas molecules to pass through are prepared.

[0029] The present application has the following beneficial effects: different from the prior art, the preparation method of the metal organic framework glass gas separation membrane provided by the present application does not need to use regulated reagents such as zinc nitrate hexahydrate, but only needs the cheap and easily obtained nano zinc oxide dispersion liquid to generate a continuous and dense metal organic framework glass gas separation membrane in a short time. The whole method has the advantages of simple operation, good repeatability and strong economy. The prepared metal organic framework glass gas separation membrane is dense and defect-free, and has excellent carbon dioxide gas separation selectivity and stability. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is an X-ray diffraction characterization result graph of the product M3 in the specific embodiment of the present application;

[0031] Figure 2 It is a scanning electron microscope characterization result graph of the product M3 in the specific embodiment of the present application;

[0032] Figure 3 It is an X-ray energy spectrum characterization result graph of the pretreated carrier in Example 1 and Comparative Example 1 in the specific embodiment of the present application;

[0033] Figure 4 X-ray diffraction characterization results of the product M 21 of the present application. DETAILED DESCRIPTION

[0034] In order to make the above objectives, features and advantages of the present application more apparent, the following will describe the specific embodiments of the present application in detail. It should be noted that the following embodiments are only used to illustrate the implementation methods and typical parameters of the present application, and are not used to limit the parameter ranges described in the present application, and any reasonable changes derived therefrom are still within the protection scope of the claims of the present application.

[0035] It should be noted that the endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and the values stated are approximate values. Ranges between the endpoints are also intended to be encompassed. Any single value in a range can be combined with any other value in a range to form a new range. The new range can be included in the present application.

[0036] To solve the problem of low porosity, low permeability and instability of the metal organic framework glass membrane in the prior art, the embodiment of the present application provides a metal organic framework glass gas separation membrane and a preparation method thereof. In the preparation method, a mixed solution of nano zinc oxide and polymer is pre-coated on the carrier by ultrasonic coating, and then a metal organic framework crystal membrane is synthesized by conventional solvothermal synthesis in a precursor solution with various concentrations. Finally, the metal organic framework crystal membrane is melted and quenched into a glass membrane. The technical means characterized by the preparation of the high-flux metal organic framework glass membrane by coating the mixed solution of nano zinc oxide and polymer on the carrier. The synthesis process of the metal organic framework glass membrane product is simple and controllable, has good repeatability, excellent performance and strong economy.

[0037] The preparation method comprises the following steps:

[0038] S1: coating a mixed solution of nano zinc oxide and polymer on the surface of the carrier by ultrasonic coating;

[0039] S2: mixing an organic ligand and an organic solvent to prepare a precursor solution;

[0040] S3: placing the carrier treated in step S1 in the precursor solution, performing solvothermal treatment and cooling to obtain a metal organic framework crystal membrane;

[0041] S4: melting and quenching the metal organic framework crystal membrane prepared in step S3 to obtain a metal organic framework glass gas separation membrane.

[0042] In the above embodiment, the ultrasonic coating time is 1-30 min.

[0043] In the above embodiment, in the nano zinc oxide-polymer mixed solution, the concentration of the polymer is 2 to 20 wt %, and the concentration of the nano zinc oxide is 2 to 40 wt %.

[0044] In the above embodiment, the polymer is selected from one or more of polyethyleneimine, polydimethylsiloxane, polysulfone, and polyethersulfone.

[0045] In the above embodiment, the organic solvent in the precursor solution is N,N-dimethylformamide, and the organic ligand is selected from any one or more of imidazole, benzimidazole, 2-methylbenzimidazole, 5-methylbenzimidazole, 5,6-dimethylbenzimidazole, 5-chlorobenzimidazole, and 5-hydroxybenzimidazole.

[0046] The preparation method of the metal-organic framework glass gas separation membrane provided in the specific embodiment of the present invention has a simple and controllable preparation process, and creatively does not use the controlled chemical zinc nitrate hexahydrate. In the preparation method provided in the specific embodiment of the present invention, different metal-organic framework materials can be prepared by changing the combination of organic ligands in the precursor solution. The aforementioned metal-organic framework materials include ZIF-4 (the organic ligand is only imidazole), ZIF-62 (the organic ligand is a combination of imidazole and benzimidazole), ZIF-76 (the organic ligand is a combination of imidazole and 5-chlorobenzimidazole), and TIF-4 (the organic ligand is a combination of imidazole and 5-methylbenzimidazole).

[0047] In some embodiments, the method for preparing a metal-organic framework glass gas separation membrane provided by the present invention can be used to prepare a metal-organic framework glass membrane supported by a sheet-shaped, tubular, or plate-shaped carrier of aluminum oxide.

[0048] The specific technical solutions of the present invention are described clearly and completely below in conjunction with specific embodiments. Unless otherwise specified, the CO2 / CH4 and CO2 / N2 mixed gas separation selectivity described in the present invention refers to the ratio of methane permeability to carbon dioxide permeability and the ratio of nitrogen permeability to carbon dioxide permeability; the methane, carbon dioxide and nitrogen permeabilities are the permeabilities of gases passing through a unit membrane area (m2) per unit time (s) and a unit pressure (Pa). 2 The above two parameters in this specification are measured according to the method in J. Membr. Sci. (2010, 354, 48-54.).

[0049] Comparative Example 1

[0050] Preparation of TIF-4 glass membrane without the presence of polymer

[0051] Pre-treatment of the support: Two alumina tubular supports were placed in a 20 wt% dispersion of nano-sized zinc oxide and sonicated for 5 min. The supports were removed and allowed to air dry until the surface was dry for use.

[0052] Preparation of the precursor solution: Imidazole and 5-methylbenzimidazole were dissolved in DMF in the ratio of 1 :9.2:41.6 (5-methylbenzimidazole:imidazole:DMF) and mixed well.

[0053] Preparation of the TIF-4 crystalline film: The pre-treated alumina support was immersed in the precursor solution. The film was crystallized in a forced air oven at 130°C for 12 h. The TIF-4 crystalline film was obtained after drying in a vacuum oven at 100°C for 1 h.

[0054] Preparation of the TIF-4 glass film: The TIF-4 crystalline film was wrapped in aluminium foil and heated in a tube furnace under argon at a rate of 5°C / min to 100°C for 30 min to remove the solvent DMF. The temperature was then increased at a rate of 10°C / min to 470°C and held at 470°C for 30 min. The TIF-4 glass film was obtained after cooling to room temperature (denoted a g TIF-4), and the product obtained is denoted M1, M2.

[0055] Example 1

[0056] Preparation of the TIF-4 glass film in the presence of a polymer

[0057] Pre-treatment of the support: Two alumina tubular supports were placed in a 20 wt% dispersion of nano-sized zinc oxide and PEI and sonicated for 5 min. The supports were removed and allowed to air dry until the surface was dry for use.

[0058] Preparation of the precursor solution: Imidazole and 5-methylbenzimidazole were dissolved in DMF in the ratio of 1 :9.2:41.6 (5-methylbenzimidazole:imidazole:DMF) and mixed well.

[0059] Preparation of the TIF-4 crystalline film: The pre-treated alumina support was immersed in the precursor solution. The film was crystallized in a forced air oven at 130°C for 12 h. The TIF-4 crystalline film was obtained after drying in a vacuum oven at 100°C for 1 h.

[0060] Preparation of the TIF-4 glass film: The TIF-4 crystalline film was wrapped in aluminium foil and heated in a tube furnace under argon at a rate of 5°C / min to 100°C for 30 min to remove the solvent DMF. The temperature was then increased at a rate of 10°C / min to 470°C and held at 470°C for 30 min. The TIF-4 glass film was obtained after cooling to room temperature (denoted a g TIF-4), and the product obtained is denoted M3, M4.

[0061] The M3 crystal film and glass film prepared in Example 1 were subjected to X-ray diffraction detection, and the results were as follows: Figure 1 As shown;

[0062] The M3 glass film obtained in Example 1 was observed by scanning electron microscopy. Figure 2 As shown;

[0063] The alumina tubular carriers pretreated in Example 1 and Comparative Example 1 were subjected to X-ray energy spectrum detection. The results are as follows: Figure 3 As shown;

[0064] The CO2 / CH4 separation selectivity and permeability of the products M1, M2, M3, and M4 obtained in Comparative Example 1 and Example 1 were tested, and the test results are shown in Table 1.

[0065] Table 1

[0066]

[0067] As shown in Table 1, products M1, M2, M3, and M4 all have certain selectivity for separating CO2 from CO2 / CH4 mixed gas. The CO2 permeabilities of M3 and M4 are significantly higher than those of M1 and M2.

[0068] Figure 1 is the XRD test result of M3 crystal film and glass film, Figure 1 The XRD structure of M3 crystal film and glass film shows that the product successfully prepared TIF-4 crystal film in the absence of zinc nitrate hexahydrate and with PEI doping, and after melt quenching, it became a g TIF-4, the crystal structure disappears and transforms into an amorphous structure.

[0069] Figure 2 This is the SEM characterization result of M3 glass film, where the left picture is a g The surface of TIF-4, the right picture is a g Cross-section of TIF-4, by Figure 2 It can be seen that a after melt quenching g A continuous glass film layer forms on the surface of TIF-4, and from the cross-section, it can be seen that TIF-4 glass is also formed inside the carrier.

[0070] Figure 3 The EDX test results of the pretreated tubular carriers in Example 1 and Comparative Example 1 are shown, wherein: Figure 3 A in FIG is the EDX detection result of the pretreated tubular carrier in Comparative Example 1, Figure 3 B in the figure is the EDX detection result of the pretreated tubular carrier in Example 1. Figure 3It can be seen that in the presence of PEI, most of the zinc oxide can be retained near the surface of the carrier, and in the absence of polymer, most of the zinc oxide penetrates deep into the carrier, so that most of the crystals grow inside the carrier, and the penetration rate is extremely low.

[0071] Example 2

[0072] Pre-treatment of the carrier: First, place two alumina tubular carriers in a 20wt% nano-zinc oxide and PEI mixed solution, ultrasonic for 5 min, and take out to dry naturally until the surface is dry for use.

[0073] Preparation of the precursor solution: Imidazole and 5-methylbenzimidazole are dissolved in DMF in a certain proportion and mixed uniformly. Different concentrations of precursor solutions are prepared. The molar ratio of imidazole and 5-methylimidazole is fixed at 23:2.5, and the molar amount of solvent DMF is changed to obtain 0.5U precursor solution (5-methylimidazole:imidazole:DMF = 1:9.2:83.2).

[0074] Preparation of TIF-4 crystal film: immerse the alumina carrier in the precursor solution. Crystallize into a film in a blast oven at 130°C for 12h, and dry in a vacuum oven at 100°C for 1h to obtain a TIF-4 crystal film. Finally, products M5 and M6 at a concentration of 0.5U precursor solution are obtained.

[0075] Preparation of TIF-4 glass film: wrap the TIF-4 crystal film in aluminum foil, and in an argon atmosphere, raise the temperature to 100°C at a rate of 5°C / min in a tubular furnace and maintain for 30min, then raise the temperature to 470°C at a rate of 10°C / min and maintain at 470°C for 30min, and after cooling to room temperature, a TIF-4 glass film (denoted as a g TIF-4) is obtained.

[0076] Example 3

[0077] Pre-treatment of the carrier: First, place two alumina tubular carriers in a 20wt% nano-zinc oxide and PEI mixed solution, ultrasonic for 5 min, and take out to dry naturally until the surface is dry for use.

[0078] Preparation of the precursor solution: Imidazole and 5-methylbenzimidazole are dissolved in DMF in a certain proportion and mixed uniformly. Different concentrations of precursor solutions are prepared. The molar ratio of imidazole and 5-methylimidazole is fixed at 23:2.5, and the molar amount of solvent DMF is changed to obtain 0.5U precursor solution (5-methylimidazole:imidazole:DMF = 1:9.2:83.2).

[0079] Preparation of TIF-4 crystal film: The alumina support was immersed in the precursor solution. The film was crystallized at 130 °C for 12 h in a blast oven, and dried at 100 °C for 1 h in a vacuum oven to obtain the TIF-4 crystal film. The products M7 and M8 were obtained at a final concentration of 0.75 U of the precursor solution.

[0080] Preparation of TIF-4 glass film: The TIF-4 crystal film was wrapped in aluminum foil and heated in a tube furnace under an argon atmosphere at a rate of 5 °C / min to 100 °C for 30 min, then at a rate of 10 °C / min to 470 °C and kept at 470 °C for 30 min. After cooling to room temperature, the TIF-4 glass film (denoted as a g TIF-4) was obtained.

[0081] Example 4

[0082] Pre-treatment of the support: First, two alumina supports were placed in a 20 wt% nano-zinc oxide and PEI mixed solution with both ends plugged, and ultrasonic treatment was performed for 5 min. The supports were naturally air-dried until the surface was dry for use.

[0083] Preparation of the precursor solution: Imidazole and 5-methylbenzimidazole were dissolved in DMF in a certain proportion and mixed uniformly. The precursor solution was prepared according to different concentrations. The molar ratio of imidazole and 5-methylimidazole was fixed at 23:2.5, and the molar amount of the solvent DMF was changed to obtain a 1.0 U precursor solution (5-methylimidazole:imidazole:DMF = 1:9.2:41.6).

[0084] Preparation of TIF-4 crystal film: The alumina support was immersed in the precursor solution. The film was crystallized at 130 °C for 12 h in a blast oven, and dried at 100 °C for 1 h in a vacuum oven to obtain the TIF-4 crystal film. The products M7 and M8 were obtained at a final concentration of 0.75 U of the precursor solution. 10 .

[0085] Preparation of TIF-4 glass film: The TIF-4 crystal film was wrapped in aluminum foil and heated in a tube furnace under an argon atmosphere at a rate of 5 °C / min to 100 °C for 30 min, then at a rate of 10 °C / min to 470 °C and kept at 470 °C for 30 min. After cooling to room temperature, the TIF-4 glass film (denoted as a g TIF-4) was obtained.

[0086] Example 5

[0087] Pre-treatment of the support: First, two alumina supports were placed in a 20 wt% nano-zinc oxide and PEI mixed solution with both ends plugged, and ultrasonic treatment was performed for 5 min. The supports were naturally air-dried until the surface was dry for use.

[0088] Preparation of precursor solution: imidazole and 5-methylbenzimidazole were dissolved in DMF in proportion and mixed uniformly. The precursor solution was prepared according to different concentrations. The molar ratio of imidazole and 5-methylbenzimidazole was fixed at 23:2.5, and the molar amount of solvent DMF was changed to obtain 1.5U precursor solution (5-methylbenzimidazole:imidazole:DMF = 1:9.2:34.6).

[0089] Preparation of TIF-4 crystal film: the alumina carrier was immersed in the precursor solution. The film was crystallized in a blast oven at 130°C for 12h, and dried in a vacuum oven at 100°C for 1h to obtain the TIF-4 crystal film. The product M 11 and M 12 .

[0090] Preparation of TIF-4 glass film: the TIF-4 crystal film was wrapped in aluminum foil paper, and was heated in a tube furnace under argon atmosphere at a rate of 5°C / min to 100°C for 30min, then at a rate of 10°C / min to 470°C and kept at 470°C for 30min. After cooling to room temperature, the TIF-4 glass film was obtained (denoted as a g TIF-4).

[0091] Example 6

[0092] M5~M 12 Glass film characterization

[0093] The products M5~M 12 obtained in Examples 2~6 were subjected to determination of CO2 / CH4 separation selectivity and permeation rate, and the determination results are shown in Table 2.

[0094] Table 2

[0095]

[0096] Example 7

[0097] Preparation of polymer-containing TIF-4 glass film with different growth time

[0098] Preparation of TIF-4 glass film: according to the method of Example 4, the precursor solution was prepared at the optimal 1U concentration, and 3 alumina plate carriers were selected and modified with 10wt% nano-zinc oxide and PEI mixed solution for 5min. The modified plate carriers were placed horizontally in the 1U precursor solution at 130°C, and heated for 24h, 12h and 6h, respectively. The TIF-4 crystal film was obtained after drying at 100°C for 1h. The crystal film was subjected to glass transition according to the glass film preparation method in Example 2, and the 3 plate crystal films were subjected to glass transition to obtain the product M 13 obtained after 24h reaction, the product M 14 obtained after 12h reaction, and the product M15 .

[0099] Characterization of TIF-4 glass membranes: The product M 13 ~M 15 was subjected to separation selectivity and permeability determination. The results of the CO2 / CH4 separation selectivity and permeability determination of the product M 13 ~M 15 are shown in Table 3.

[0100] Table 3

[0101]

[0102] Example 8

[0103] Preparation of different polymer TIF-4 glass membranes

[0104] Pre-treatment of the support: A mixed solution of nano-zinc oxide and polymer was prepared, the polymer including PEI (mixed solution I), PDMS (mixed solution II), PSF (mixed solution III), PES (mixed solution IV), the alumina tube support was placed in the mixed solution (I-IV) of 20 wt% nano-zinc oxide and polymer, and was subjected to ultrasonic treatment for 5 min, and was taken out and naturally air-dried until the surface was dry for use.

[0105] Preparation of the precursor solution: imidazole and 5-methylbenzimidazole were dissolved in DMF in a proportion to mix uniformly (the molar ratio in the precursor solution was 5-methylbenzimidazole:imidazole:DMF = 1:9.2:41.6).

[0106] Preparation of TIF-4 crystal membranes: the pre-treated alumina support was immersed in the precursor solution. Crystallization into a film was carried out in a blast oven at 130°C for 12 h, and after drying in a vacuum oven at 100°C for 1 h, a TIF-4 crystal membrane was obtained.

[0107] Preparation of TIF-4 glass membranes: the TIF-4 crystal membrane was wrapped in aluminum foil paper, and was raised to 100°C at a rate of 5°C / min in a tube furnace under an argon atmosphere for 30 min to remove the solvent DMF, and was then raised to 470°C at a rate of 10°C / min and was kept at 470°C for 30 min, and after cooling to room temperature, a TIF-4 glass membrane (denoted as a g TIF-4) was obtained. The product obtained by adding PEI was denoted as M 16 , the product obtained by adding PDMS was denoted as M 17 , the product obtained by adding PSF was denoted as M 18 , and the product obtained by adding PES was denoted as M 19 .

[0108] Characterization of TIF-4 glass membranes: The product M 16~M 19 The CO2 / CH4 separation selectivity and permeance were determined. The M 16 ~M 19 The CO2 / CH4 separation selectivity and permeance detection results are shown in Table 5.

[0109] Table 5

[0110]

[0111] From the gas permeability in Table 5, the degree of increase in gas flux is different in the presence of different polymers, among which the increase in flux is most obvious in the presence of PEI, and it has better gas separation performance.

[0112] Example 9

[0113] Preparation of ZIF-62 glass membrane in the presence of polymer:

[0114] Preparation of ZIF-62 glass membrane in the presence of polymer:

[0115] Preparation of ZIF-62 crystal membrane: Benzimidazole, imidazole, DMF, uniformly mixed according to the molar ratio of 1:4.2:67, recorded as precursor solution. The pretreated alumina carrier was placed in the precursor solution and then heated in an oven at 100°C for 48h for crystallization and growth, and then dried at 100°C overnight to obtain the ZIF-62 polycrystalline membrane.

[0116] Preparation of ZIF-62 glass membrane: Under an argon atmosphere, the tubular crystal membrane was wrapped with aluminum foil and placed in a tube furnace for heating. The temperature was increased from 25°C to 440°C at a rate of 10°C / min, and then kept at 440°C for 10-30 minutes. Subsequently, it was naturally cooled to room temperature to obtain the ZIF-62 glass membrane, recorded as M 20 , M 21 .

[0117] The product M 20 , M 21 obtained in Example 10 was subjected to XRD detection and determination of separation selectivity and permeance. The XRD characterization results of the product M 21 are shown in Figure 4 , and it can be seen from Figure 4 that this method can successfully prepare ZIF-62 crystals, and after melting and quenching, it becomes a g ZIF-62, the crystal structure disappears, and changes into an amorphous structure.

[0118] The product M 20, M 21 The CO2 / N2 separation selectivity and permeance detection results of M

[0119] Table 6

[0120]

[0121] From the detection results in Table 6, it can be seen that the synthesized product M 20 , M 21 has high separation performance for CO2 / N2, which proves that the prepared ZIF-62 glass membrane is dense and defect-free, and the increase of the polymer can improve the porosity of the metal organic framework glass.

[0122] Example 10

[0123] Preparation of ZIF-76 glass membrane in the presence of polymer:

[0124] Pre-treatment of the carrier: two alumina tubular carriers were placed in a 20wt% nano-zinc oxide and PEI mixed solution, and were ultrasonically treated for 5 min, and were naturally air-dried until the surface was dry for use.

[0125] Preparation of ZIF-76 crystal membrane: imidazole, 5-methylbenzimidazole, DMF, were uniformly mixed and stirred overnight according to the molar ratio (5-methylbenzimidazole:imidazole:DMF = 1:1.75:185) to be recorded as a precursor solution. The pre-treated carrier was vertically placed in the precursor solution, and then heated in an oven at 130°C for 24h to crystallize the membrane. After that, the carrier was dried at 100°C for 2h to obtain a ZIF-76 polycrystalline membrane.

[0126] Preparation of ZIF-76 glass membrane: under an argon atmosphere, the crystal membrane was placed in a tubular furnace for heating, and the temperature was increased from 25°C to 500°C at a rate of 10°C / min, and then kept at 500°C for 10 min. Subsequently, it was naturally cooled to room temperature to obtain a ZIF-76 glass membrane M 22 M 23 .

[0127] The CO2 / N2 separation selectivity and permeance of the product M 22 M 23 prepared above were determined, and the results are shown in Table 7.

[0128] Table 7

[0129]

[0130] From Table 7, it can be seen that M 22 M 23All of them have certain CO2 / N2 mixed gas separation selectivity. It is proved that the prepared ZIF-76 glass membrane is dense and defect-free, and the increase of polymer can improve the porosity of metal organic framework glass.

[0131] Unless otherwise defined, all terms, symbols and other scientific terminology used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. In some instances, terms are defined herein for the sake of clarity and convenience only. Such definitions are not intended to be limiting in scope unless otherwise expressly stated. The techniques described or referenced herein are generally well known and are practiced in a conventional manner, as is appreciated by those skilled in the art, unless otherwise indicated. Unless otherwise indicated, the use of commercially available reagents, instruments, and the like are in accordance with the manufacturer's instructions and parameters.

[0132] Although the present disclosure discloses the above, the protection scope of the present disclosure is not limited to this. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and these changes and modifications will fall within the protection scope of the present disclosure.

Claims

1. A method for preparing a metal organic framework glass gas separation membrane, characterized in that: The following steps are involved: S1: Ultrasonic coating of a nano zinc oxide-polymer mixed solution on a carrier surface, wherein the concentration of the polymer in the nano zinc oxide-polymer mixed solution is 2-20 wt %, the concentration of nano zinc oxide in the nano zinc oxide-polymer mixed solution is 2-40 wt %, and the carrier is selected from one of an aluminum carrier, a silicon carrier, and a titanium carrier, and the ultrasonic coating time is 1-30 min; S2: Mixing the organic ligand and the organic solvent to prepare a precursor solution; S3: placing the support treated in step S1 in a precursor solution, performing solvent thermal treatment and cooling to obtain a metal organic framework crystal film; S4: melt-quenching the metal organic framework crystal membrane obtained in step S3, wherein the polymer decomposes during the melt-quenching to obtain a metal organic framework glass gas separation membrane.

2. The preparation method according to claim 1, wherein In step S1, the polymer is selected from one or more of polyethyleneimine, polydimethylsiloxane, polysulfone, and polyethersulfone.

3. The preparation method according to claim 1, wherein The organic ligand is selected from any one or more of imidazole, benzimidazole, 2-methylbenzimidazole, 5-methylbenzimidazole, 5,6-dimethylbenzimidazole, 5-chlorobenzimidazole, and 5-hydroxybenzimidazole; and the organic solvent is N,N-dimethylformamide.

4. The preparation method according to claim 1, wherein In step S2, the molar ratio of the organic ligand to the organic solvent in the precursor solution is (1-30): (20-200).

5. The preparation method according to claim 1, wherein In step S3, the heating temperature is 100-180°C.

6. The preparation method according to claim 1, wherein In the step S4, the temperature of the melt quenching is 350-600°C.

7. A metal organic framework glass gas separation membrane, characterized in that: The method is prepared by any one of claims 1 to 6.

8. A use of the metal organic framework glass gas separation membrane according to claim 7, characterized in that: The application is: using the metal organic framework glass gas separation membrane for separating carbon dioxide gas.

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