Mixed matrix membrane as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of membrane separation, and particularly relates to a mixed matrix membrane as well as a preparation method and application thereof. The mixed matrix membrane comprises a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix, the continuous phase matrix is an amorphous fluorine-containing high-molecular polymer; the dispersed phase is composed of a first filler and a second filler; the first filler is an amino-functionalized metal organic framework; the second filler is an amino-functionalized metal organic framework grafted and modified by fluorine-containing polyether; wherein the second filler is formed by covalently grafting hydroxyl-terminated perfluoropolyether on the surface of the amino-functionalized metal organic framework through diisocyanate.

Description

Technical Field

[0001] This invention belongs to the field of membrane separation technology, and particularly relates to a mixed matrix membrane, its preparation method and application. Background Technology

[0002] Gas separation membrane technology, due to its low energy consumption, compact equipment, simple operation, and environmental friendliness, has shown great application potential in fields such as carbon dioxide capture, natural gas purification, and industrial gas recovery. Among numerous membrane materials, amorphous fluorinated polymers (such as the Teflon AF series and Hyflon AD series) have become ideal matrix materials for preparing high-performance gas separation membranes due to their unique high free volume structure, excellent gas permeability, and outstanding chemical and thermal stability. To further overcome the trade-off effect between permeability and selectivity in polymer membrane materials—that is, the difficulty in simultaneously achieving high flux and high separation efficiency—researchers have proposed the concept of hybrid matrix membranes. Hybrid matrix membranes disperse inorganic or inorganic-like microporous packing materials with molecular sieving functions (such as metal-organic frameworks (MOFs), zeolites, and carbon molecular sieves) within a polymer matrix, aiming to combine the easy processability of polymers with the high selectivity and high pore volume characteristics of inorganic packing materials, thereby improving the overall separation performance of the membrane. Among them, metal-organic frameworks (MOFs), especially zirconium-based MOFs (such as UiO-66 and its derivatives), are widely used to construct fluorine-containing polymer mixed matrix membranes due to their highly ordered microporous structure, tunable chemical environment and good hydrothermal stability.

[0003] However, despite the significant theoretical advantages of hybrid matrix membranes, numerous challenges remain in their practical preparation and application. First, interfacial compatibility is a key bottleneck limiting the performance of fluorinated polymer hybrid matrix membranes. Fluorinated polymers typically possess extremely low surface energy and strong hydrophobicity, while most MOF materials (especially those containing polar groups such as amino groups) have highly polar surfaces. This significant difference in properties makes it difficult for fillers to disperse uniformly in the matrix, leading to agglomeration. More seriously, this mismatch in interfacial properties prevents polymer chains from tightly encapsulating filler particles, resulting in non-selective micron or nanometer-sized voids at the interface. This allows gas molecules to bypass the filler pores and pass directly through the defects, increasing permeability but severely sacrificing separation selectivity. Second, to improve interfacial compatibility, existing techniques often employ strategies such as chemical modification of the MOF surface or grafting long-chain organic molecules. However, this introduces a new contradiction: excessive surface modification or overly long and dense grafted segments often clog the micropores of the MOF itself, significantly reducing its effective pore volume and specific surface area, leading to increased gas transport resistance and offsetting the flux advantage brought by the introduction of porous fillers. Furthermore, amorphous glassy polymer membranes generally exhibit physical aging during long-term use; that is, as time progresses, polymer segments loosen, causing free volume collapse and resulting in a significant decline in gas permeability over time, severely impacting the industrial application potential of membrane materials.

[0004] Therefore, how to significantly improve the interfacial compatibility between the inorganic filler and the low surface energy fluorinated polymer matrix without sacrificing the inherent high pore volume and gas transport channels of the inorganic filler, eliminate interfacial non-selective defects, and effectively inhibit the physical aging of the membrane material while improving gas separation permeability and selectivity, so as to obtain a mixed matrix membrane with high throughput, high selectivity and excellent long-term stability, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a hybrid matrix membrane, its preparation method, and its application.

[0006] Firstly, a hybrid matrix membrane employs the following technical solution: A hybrid matrix membrane includes a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix; The continuous phase matrix is ​​an amorphous fluorinated polymer. The dispersed phase is composed of a first filler and a second filler; the first filler is an amino-functionalized metal-organic framework; the second filler is an amino-functionalized metal-organic framework grafted with fluorinated polyether. The second filler is formed by covalently grafting terminal hydroxyl perfluoropolyether onto the surface of the amino-functionalized metal-organic framework using diisocyanate.

[0007] Furthermore, the amino-functionalized metal-organic framework is selected from at least one of amino-functionalized zirconium phthalate metal-organic framework, amino-functionalized chromium phthalate metal-organic framework, amino-functionalized aluminum phthalate metal-organic framework, amino-functionalized zinc methylimidazolium metal-organic framework, and amino-functionalized zinc phthalate homo-mesh metal-organic framework. The amorphous fluorinated polymer is selected from at least one of Teflon AF 2400, Teflon AF 1600, Hyflon AD60, Hyflon AD 40, Cytop S type, and Cytop A type.

[0008] Furthermore, the diisocyanate is selected from at least one of hexamethylene diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate; the terminal hydroxyl perfluoropolyether is a perfluoropolyether diol with a number average molecular weight Mn of 500 to 2000.

[0009] Further, the amorphous fluorinated polymer is Teflon AF 2400; the first filler is an amino-functionalized zirconium phthalate metal-organic framework; the mass ratio of the first filler to the second filler is 1:2 to 2:1; the total mass of the dispersed phase accounts for 10wt% to 30wt% of the total mass of the mixed matrix membrane.

[0010] Secondly, a method for preparing a hybrid matrix membrane employs the following technical solution: A method for preparing a hybrid matrix membrane includes the following steps: Step (1): Dissolve the metal salt precursor and the amino-containing organic ligand in a solvent, add a regulator, and carry out a solvothermal reaction under closed conditions to precipitate crystals. After separation, washing and vacuum activation, the first filler is obtained. Step (2): Disperse part of the first filler obtained in step (1) in an anhydrous solvent, add diisocyanate dropwise and react at room temperature to 35℃~45℃ to introduce isocyanate groups, then add terminal hydroxyl perfluoropolyether, stir and graft reaction at 40℃~50℃ for 12h~24h, and the product is washed, dried and activated to obtain the second filler; Step (3): Mix the first filler and the second filler in proportion, disperse them in a wetting agent by ultrasonication, add a fluorinated solvent containing amorphous fluorinated polymer, disperse them fully, and obtain casting solution. Step (4): The casting solution obtained in step (3) is coated into a film, the solvent is evaporated in a solvent-saturated atmosphere, and then the film is dried by programmed temperature rise and vacuum heat treatment to obtain the mixed matrix film.

[0011] Further, in step (1), the metal salt precursor is selected from zirconium tetrachloride, chromium nitrate, aluminum nitrate, and zinc nitrate; the amino-containing organic ligand is selected from 2-aminoterephthalic acid and 2-aminobenzimidazole. The temperature of the solvothermal reaction is 100℃~150℃, and the reaction time is 12h~24h.

[0012] Further, in step (2), the anhydrous solvent is N,N-dimethylformamide; The washing process includes the following steps: washing with N,N-dimethylformamide, methanol and acetone in sequence; The drying and activation process includes the following steps: under vacuum conditions, pre-drying at a temperature of 50℃~60℃, followed by drying at a temperature of 80℃~120℃ for 6h~12h.

[0013] Further, in step (3), the fluorinated solvent is perfluorotributylamine or perfluoropolyether solvent; the wetting agent is methanol or ethanol; the ultrasonic treatment or shearing treatment time is 20 min to 30 min to ensure that the filler does not agglomerate and disperse.

[0014] Further, in step (4), the programmed temperature-increasing drying includes the following process: first, slow drying in a solvent-saturated box at 25°C for 12h~24h, followed by ventilation drying at 40°C~60°C for 6h~12h; The vacuum heat treatment includes the following process: treating under vacuum conditions at a temperature of 80℃~160℃ for 6h~12h to remove residual solvent and induce polymer chain rearrangement.

[0015] Thirdly, an application of a hybrid matrix membrane employs the following technical solution: An application of a mixed matrix membrane in the field of gas separation, wherein the mixed matrix membrane is used for the selective separation of carbon dioxide gas from a mixture of carbon dioxide and nitrogen gas.

[0016] The beneficial effects of this invention are: This invention provides a hybrid matrix membrane. It introduces a two-component dispersed phase consisting of an amino-functionalized metal-organic framework (MOF) as the first filler and a MOF grafted with fluorinated polyether as the second filler into an amorphous fluorinated polymer matrix. The high affinity between the flexible, terminally hydroxyl-terminated perfluoropolyether segments covalently grafted with diisocyanate on the surface of the second filler and the fluorinated matrix effectively reduces interfacial energy, promotes uniform dispersion of the filler, and eliminates non-selective voids at the interface through physical entanglement, constructing a dense and compatible interface. Simultaneously, the unmodified first filler retains its complete microporous structure and abundant adsorption sites, avoiding pore blockage caused by grafted segment coverage, thus providing efficient transport channels for gas molecules. This synergistic effect of the two-component fillers significantly increases gas permeation flux while substantially improving separation selectivity. Furthermore, the strong anchoring effect of the second filler at the interface effectively restricts the creep and relaxation of the amorphous polymer segments, significantly inhibiting the collapse of free volume over time, endowing the membrane material with excellent resistance to physical aging and long-term operational stability. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, this application will be described in further detail below. The described embodiments should not be regarded as limitations on this invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0018] In the following description, references to "some embodiments" refer to a subset of all possible embodiments; however, it is understood that "some embodiments" may be the same or different subsets of all possible embodiments and may be combined with each other without conflict. Unless otherwise defined, all technical and scientific terms used in the embodiments of the invention have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of the invention pertain. The terminology used in the embodiments of the invention is for the purpose of describing the embodiments of the invention only and is not intended to limit the invention.

[0019] Those skilled in the art should understand that, in the following description of the embodiments of the present invention, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0020] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0021] Those skilled in the art will understand that the numerical ranges in the embodiments of the present invention should be understood to specifically disclose each intermediate value between the upper and lower limits of the range. Each smaller range between any stated value and an intermediate value within the stated range, as well as any other stated value or an intermediate value within the stated range, is also included within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0022] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may be used in embodiments or test cases of the invention. All references to this specification are generally incorporated herein by reference to disclose and describe methods and / or materials associated with said references. In the event of any conflict with any incorporated reference, the contents of this application shall prevail.

[0023] It should be noted that all raw materials and / or reagents in the embodiments of the present invention were purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0024] This embodiment provides a hybrid matrix membrane, the microstructure of which includes a continuous phase matrix and a dispersed phase dispersed in the matrix.

[0025] The continuous phase matrix is ​​selected from amorphous fluorinated polymers. These polymers have a high free volume, providing excellent permeation channels for gas molecules. In this embodiment, the amorphous fluorinated polymer can be selected from at least one of the following: Teflon AF series (such as Teflon AF 2400, Teflon AF 1600), Solvay Hyflon AD series (such as Hyflon AD 60, Hyflon AD 40), or Asahi Glass Cytop series (such as Cytop S type, Cytop A type). Preferably, Teflon AF 2400 is used because it has an extremely high free volume fraction, making it particularly suitable for high-throughput gas separation.

[0026] The dispersed phase is composed of two fillers with different surface properties, namely the first filler and the second filler.

[0027] The first filler is an amino-functionalized metal-organic framework (MOF), which retains the inherent high specific surface area and abundant microporous structure of MOF materials. Its main function is to provide high-speed channels for gas transport and specific gas adsorption sites. Specifically, the first filler can be selected from at least one of the following: amino-functionalized zirconate phthalate metal-organic frameworks (such as UiO-66-NH2), amino-functionalized chromium phthalate metal-organic frameworks (such as MIL-101(Cr)-NH2), amino-functionalized aluminum phthalate metal-organic frameworks (such as MIL-53(Al)-NH2), amino-functionalized zinc methylimidazolium metal-organic frameworks (such as ZIF-8-NH2), or amino-functionalized zinc phthalate homo-mesh metal-organic frameworks (such as IRMOF-3).

[0028] The second filler is an amino-functionalized metal-organic framework (MOF) grafted with fluorinated polyether. Flexible fluorinated segments are introduced onto the surface of this second filler through chemical bonding. Its main function is to act as an interfacial compatibilizer, reducing the interfacial energy between the inorganic filler and the fluorinated polymer matrix, and eliminating non-selective interfacial voids. Specifically, the second filler is formed by covalently grafting terminal hydroxyl-terminated perfluoropolyether onto the amino sites on the surface of the amino-functionalized MOF using diisocyanate as a bridging molecule. The diisocyanate is preferably selected from at least one of hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), or diphenylmethane diisocyanate (MDI). Its two isocyanate groups (-NCO) react with the amino groups on the MOF surface and the hydroxyl groups of the perfluoropolyether, respectively, to form stable urea bonds or urethane bonds. The terminal hydroxyl perfluoropolyether is preferably a perfluoropolyether diol (F-PEG) with a number average molecular weight Mn in the range of 500 to 2000. This molecular weight range can ensure sufficient steric hindrance to prevent filler agglomeration and avoid pore blockage caused by excessively long chain segments.

[0029] In a preferred embodiment, the mass ratio of the first filler to the second filler in the mixed matrix membrane is controlled between 1:2 and 2:1. This ratio can balance the pore flux and the interface compactness. The total mass of the dispersed phase accounts for 10wt% to 30wt% of the total mass of the mixed matrix membrane, so as to maximize the separation performance without compromising the mechanical strength of the membrane.

[0030] This embodiment provides a synthesis step for a first filler, specifically including the following steps: A metal salt precursor and an amino-containing organic ligand are dissolved in a polar aprotic solvent (such as N,N-dimethylformamide, DMF), and a modifier (such as acetic acid, benzoic acid, or formic acid) is added to control the crystal growth rate and morphology. The metal salt precursor is selected from zirconium tetrachloride, chromium nitrate, aluminum nitrate, or zinc nitrate; the amino-containing organic ligand is selected from 2-aminoterephthalic acid or 2-aminobenzimidazole.

[0031] The above mixed solution was placed in a sealed, pressure-resistant reactor and subjected to a solvothermal reaction at 100℃~150℃ for 12h~24h to allow for sufficient crystal growth. After the reaction was completed, the solid product was separated by centrifugation or filtration.

[0032] To remove unreacted ligands and high-boiling solvents remaining in the pores, the product needs to be purified and activated. The specific procedure is as follows: first, wash with DMF to remove unreacted substances; then, soak and replace with low-boiling solvents (such as methanol, ethanol, or acetone) multiple times; finally, activate by heating under vacuum to obtain the first packing material.

[0033] This embodiment provides a grafting modification method for a second filler, specifically including the following steps: The first filler prepared above is dispersed in an anhydrous solvent (preferably anhydrous N,N-dimethylformamide) and then ultrasonically treated to make it uniformly dispersed.

[0034] An excess of diisocyanate is added dropwise to the dispersion, and the mixture is reacted under mild conditions (room temperature to 35℃~45℃) for a certain period of time (e.g., 2h-6h) to allow one end of the diisocyanate to react with the amino group on the MOF surface, thereby introducing an active isocyanate group (-NCO) onto the MOF surface. During this process, moisture content must be strictly controlled to prevent isocyanate hydrolysis.

[0035] Add hydroxyl-terminated perfluoropolyether (F-PEG) to the reaction system, raise the reaction temperature to 40℃~50℃, and carry out the grafting reaction for 12h~24h under nitrogen protection by stirring, so that the hydroxyl groups of the perfluoropolyether react with the isocyanate groups on the MOF surface to complete the grafting.

[0036] After the reaction is completed, the product needs to undergo a washing and drying activation process: washing and centrifugation are performed sequentially using N,N-dimethylformamide (to remove unreacted F-PEG), methanol and acetone (to replace high-boiling solvent); the resulting solid is pre-dried at 50℃~60℃ under vacuum to remove surface solvent, and then deeply dried at 80℃~120℃ for 6h~12h to ensure that the solvent in the pores is completely removed, thus obtaining the activated second filler.

[0037] This embodiment provides a molding process for a hybrid matrix membrane, specifically including the following steps: Preparation of casting solution: Weigh the first and second fillers according to the predetermined ratio, mix them, and then add them to the wetting agent (preferably methanol or ethanol). Since MOF particles are difficult to disperse directly in fluorinated solvents, the use of a wetting agent can pre-wet the filler surface and break up agglomerates. The mixture is then dispersed using a high-power ultrasonic or high-shear homogenizer.

[0038] A fluorinated solvent containing the amorphous fluorinated polymer is added under stirring. The fluorinated solvent is selected from perfluorotributylamine (such as FC40) or perfluoropolyether solvents, which have good solubility for polymers such as Teflon AF.

[0039] Continue to subject the mixture to ultrasonic or shear treatment for 20-30 minutes to ensure that the two-component filler is uniformly dispersed at the micron or even nanometer level in the polymer solution, forming a uniform and stable casting solution.

[0040] Film formation and post-treatment: The prepared casting solution is applied to a substrate (such as a glass plate, silicon wafer, or porous support) by means of scraping, spin coating, or dip coating.

[0041] To prevent surface defects caused by rapid solvent evaporation, the coated wet film must be placed in a drying oven saturated with solvent. Specifically, a container filled with the same fluorinated solvent is placed inside the drying oven, and the temperature is controlled at approximately 25°C, allowing the solvent to slowly evaporate within the film for 12-24 hours, thus initially forming a solid film.

[0042] The process then involves a programmed temperature increase drying, gradually raising the temperature to 40℃~60℃ and drying under ventilation conditions for 6h~12h to further remove most of the solvent.

[0043] Finally, to completely remove trace amounts of solvent remaining between polymer chain segments and within the MOF channels, and to eliminate thermal history and internal stresses from the film formation process, high-temperature vacuum heat treatment is required. Specifically, treatment is performed at 80℃~160℃ for 6h~12h under a vacuum of less than 1000Pa. This process induces local rearrangement of polymer chain segments on the filler surface, further enhancing interfacial bonding and ultimately resulting in a dense hybrid matrix film.

[0044] This embodiment provides the application of the above-described hybrid matrix membrane.

[0045] The prepared mixed matrix membrane is cut to a suitable size and assembled into a gas permeation test mold. Under a certain transmembrane pressure difference (e.g., 1 bar to 10 bar) and temperature (e.g., 25°C to 35°C), a mixed gas containing carbon dioxide and nitrogen (e.g., simulated flue gas, CO2:N2 volume ratio of 15:85 or 50:50) is introduced into the feed side of the membrane.

[0046] Due to the high free volume of the Teflon AF matrix in the hybrid matrix membrane and the synergistic effect of the two-component MOF packing (the first packing provides high adsorption and diffusion channels, while the second packing ensures a defect-free interface), carbon dioxide molecules preferentially adsorb and permeate through the membrane material, accumulating on the permeate side, while nitrogen molecules are mostly retained on the trap side, thus achieving selective separation and capture of carbon dioxide gas. During long-term operation, the membrane effectively resists physical aging and maintains stable separation performance due to the anchoring effect of the second packing on the polymer chains.

[0047] Example Example 1 Example 1 provides a mixed matrix membrane, comprising a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix; the dispersed phase is composed of a first filler and a second filler. The continuous phase matrix is ​​Teflon AF 2400; the first filler is an amino-functionalized zirconate phthalic acid metal-organic framework (UiO-66-NH2); the second filler is UiO-66-NH2 (denoted as F-PEG-UiO-66) grafted and modified with hexamethylene diisocyanate and hydroxyl-terminated perfluoropolyether (Mn≈1000); the mass ratio of the first filler to the second filler is 1:2; the total mass of the dispersed phase accounts for 20 wt% of the total mass of the mixed matrix membrane.

[0048] This embodiment 1 provides a method for preparing a first filler, including the following steps: 1.864 g of zirconium tetrachloride and 1.456 g of 2-aminoterephthalic acid were dissolved in 130 mL of anhydrous N,N-dimethylformamide. 10 mL of acetic acid was added as a regulator. After ultrasonic dispersion for 15 min, the mixture was placed in a pressure-resistant reactor and subjected to a solvothermal reaction at 120 °C for 12 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature, and the product was separated by centrifugation. The product was washed three times with DMF, then soaked and replaced three times with methanol (12 hours each time), and finally activated by vacuum drying at 120 °C for 12 hours to obtain the first packing material UiO-66-NH2.

[0049] This embodiment 1 also provides a method for preparing a second filler, including the following steps: Weigh 0.50 g of the first filler prepared above and disperse it in 50 mL of anhydrous DMF, then sonicate for 10 min. Dissolve 0.10 g of hexamethylene diisocyanate in a small amount of anhydrous DMF and add it dropwise to the above suspension. React at room temperature for 2 h, then raise the temperature to 40 °C and continue the reaction for 6 h to introduce isocyanate groups. Centrifuge and wash to remove unreacted material, retain the moist solid and redissolve it in 50 mL of anhydrous DMF.

[0050] A suitable amount of perfluoropolyether diol (F-PEG-OH) with a number-average molecular weight Mn≈1000 was dissolved in anhydrous DMF and slowly added to the above dispersion. The grafting reaction was carried out at 45°C under nitrogen protection with stirring for 24 h. The product was washed three times each with DMF, methanol, and acetone, pre-dried under vacuum at 60°C for 2 h, and then dried under vacuum at 100°C for 12 h to obtain the second filler F-PEG-UiO-66.

[0051] This embodiment 1 also provides a method for preparing a hybrid matrix membrane, comprising the following steps: Weigh 0.067 g of the first filler and 0.134 g of the second filler, add a small amount of methanol as a wetting agent, and ultrasonically disperse for 20 min before mixing. Under inert stirring, add FC40 solution containing 0.80 g of Teflon AF 2400. Perform high-shear stirring and intermittent ultrasonic treatment for a total of 30 min until a uniform casting solution is formed.

[0052] The casting solution was coated onto a clean glass plate and placed in a solvent-saturated FC40 drying oven for slow solvent evaporation at 25°C for 24 hours. It was then transferred to a ventilated drying oven and dried at 50°C for 12 hours. Finally, it was placed in a vacuum oven and vacuum heat-treated at 120°C for 12 hours. After natural cooling, the film was peeled off to obtain the mixed matrix membrane.

[0053] Example 2 Example 2 provides a mixed matrix membrane, comprising a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix; the dispersed phase is composed of a first filler and a second filler. The continuous phase matrix is ​​Teflon AF 2400; the first filler is an amino-functionalized zirconate phthalic acid metal-organic framework (UiO-66-NH2); the second filler is UiO-66-NH2 (denoted as F-PEG-UiO-66) grafted and modified with hexamethylene diisocyanate and hydroxyl-terminated perfluoropolyether (Mn≈1000); the mass ratio of the first filler to the second filler is 1:1; the total mass of the dispersed phase accounts for 20 wt% of the total mass of the mixed matrix membrane.

[0054] This embodiment 2 provides a method for preparing a first filler, including the following steps: 1.864 g of zirconium tetrachloride and 1.456 g of 2-aminoterephthalic acid were dissolved in 130 mL of anhydrous N,N-dimethylformamide. 10 mL of acetic acid was added as a regulator. After ultrasonic dispersion for 15 min, the mixture was placed in a pressure-resistant reactor and subjected to a solvothermal reaction at 120 °C for 12 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature, and the product was separated by centrifugation. The product was washed three times with DMF, then soaked and replaced three times with methanol (12 hours each time), and finally activated by vacuum drying at 120 °C for 12 hours to obtain the first packing material UiO-66-NH2.

[0055] This embodiment 2 also provides a method for preparing a second filler, including the following steps: Weigh 0.50 g of the first filler prepared above and disperse it in 50 mL of anhydrous DMF, then sonicate for 10 min. Dissolve 0.10 g of hexamethylene diisocyanate in a small amount of anhydrous DMF and add it dropwise to the above suspension. React at room temperature for 2 h, then raise the temperature to 40 °C and continue the reaction for 6 h to introduce isocyanate groups. Centrifuge and wash to remove unreacted material, retain the moist solid and redissolve it in 50 mL of anhydrous DMF.

[0056] A suitable amount of perfluoropolyether diol (F-PEG-OH) with a number-average molecular weight Mn≈1000 was dissolved in anhydrous DMF and slowly added to the above dispersion. The grafting reaction was carried out at 45°C under nitrogen protection with stirring for 24 h. The product was washed three times each with DMF, methanol, and acetone, pre-dried under vacuum at 60°C for 2 h, and then dried under vacuum at 100°C for 12 h to obtain the second filler F-PEG-UiO-66.

[0057] This embodiment 2 also provides a method for preparing a hybrid matrix membrane, including the following steps: Weigh 0.100 g of the first filler and 0.100 g of the second filler, add a small amount of methanol as a wetting agent, and ultrasonically disperse for 20 min before mixing. Under inert stirring, add FC40 solution containing 0.80 g of Teflon AF 2400. Perform high-shear stirring and intermittent ultrasonic treatment for a total of 30 min until a uniform casting solution is formed.

[0058] The casting solution was coated onto a clean glass plate and placed in a solvent-saturated FC40 drying oven for slow solvent evaporation at 25°C for 24 hours. It was then transferred to a ventilated drying oven and dried at 50°C for 12 hours. Finally, it was placed in a vacuum oven and vacuum heat-treated at 120°C for 12 hours. After natural cooling, the film was peeled off to obtain the mixed matrix membrane.

[0059] Example 3 Example 3 provides a mixed matrix membrane, comprising a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix; the dispersed phase is composed of a first filler and a second filler. The continuous phase matrix is ​​Teflon AF 2400; the first filler is an amino-functionalized zirconate phthalic acid metal-organic framework (UiO-66-NH2); the second filler is UiO-66-NH2 (denoted as F-PEG-UiO-66) grafted and modified with hexamethylene diisocyanate and hydroxyl-terminated perfluoropolyether (Mn≈1000); the mass ratio of the first filler to the second filler is 2:1; the total mass of the dispersed phase accounts for 20 wt% of the total mass of the mixed matrix membrane.

[0060] This embodiment 3 provides a method for preparing the first filler that is exactly the same as the method in embodiment 1.

[0061] This embodiment 3 also provides a method for preparing a second filler that is exactly the same as the method in embodiment 1.

[0062] This embodiment 3 also provides a method for preparing a hybrid matrix membrane, including the following steps: Weigh 0.134 g of the first filler and 0.067 g of the second filler, add a small amount of methanol as a wetting agent, and ultrasonically disperse for 20 min before mixing. Under inert stirring, add FC40 solution containing 0.80 g of Teflon AF 2400. Perform high-shear stirring and intermittent ultrasonic treatment for a total of 30 min until a uniform casting solution is formed.

[0063] The casting solution was coated onto a clean glass plate and placed in a solvent-saturated FC40 drying oven for slow solvent evaporation at 25°C for 24 hours. It was then transferred to a ventilated drying oven and dried at 50°C for 12 hours. Finally, it was placed in a vacuum oven and vacuum heat-treated at 120°C for 12 hours. After natural cooling, the film was peeled off to obtain the mixed matrix membrane.

[0064] Example 4 Example 4 provides a mixed matrix membrane, comprising a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix; the dispersed phase is composed of a first filler and a second filler. The continuous phase matrix is ​​Teflon AF 1600; the first filler is an amino-functionalized zirconate phthalic acid metal-organic framework (UiO-66-NH2); the second filler is UiO-66-NH2 grafted with hexamethylene diisocyanate and hydroxyl-terminated perfluoropolyether (Mn≈500); the mass ratio of the first filler to the second filler is 1:2; the total mass of the dispersed phase accounts for 10 wt% of the total mass of the mixed matrix membrane.

[0065] This embodiment 4 provides a method for preparing a first filler, including the following steps: Zirconium tetrachloride and 2-aminoterephthalic acid were dissolved in anhydrous N,N-dimethylformamide, with acetic acid added as a regulator. After ultrasonic dispersion for 15 min, the mixture was placed in a pressure-resistant reactor and subjected to a solvothermal reaction at 100 °C for 24 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature, and the product was separated by centrifugation. The product was washed three times with DMF, then soaked and replaced three times with methanol, and finally activated by vacuum drying at 120 °C for 12 h to obtain the first packing material.

[0066] This embodiment 4 also provides a method for preparing a second filler, including the following steps: Weigh 0.50 g of the first filler prepared above and disperse it in 50 mL of anhydrous DMF, then sonicate for 10 min. Dissolve an appropriate amount of hexamethylene diisocyanate in a small amount of anhydrous DMF and add it dropwise to the above suspension. React at room temperature for 2 h, then raise the temperature to 35 °C and continue the reaction for 6 h to introduce isocyanate groups. Centrifuge and wash to remove unreacted material, retain the moist solid and redissolve it in 50 mL of anhydrous DMF.

[0067] A suitable amount of perfluoropolyether diol with a number-average molecular weight Mn≈500 was dissolved in anhydrous DMF and slowly added to the above dispersion. The grafting reaction was carried out by stirring at 40°C under nitrogen protection for 12 hours. The product was washed three times each with DMF, methanol, and acetone, pre-dried under vacuum at 50°C for 2 hours, and then dried under vacuum at 80°C for 6 hours to obtain the second filler.

[0068] This embodiment 4 also provides a method for preparing a hybrid matrix membrane, including the following steps: Weigh 0.033 g of the first filler and 0.067 g of the second filler, add a small amount of methanol as a wetting agent, and ultrasonically disperse for 20 min before mixing. Under inert stirring, add a solution of perfluorotributylamine containing 0.90 g of Teflon AF 1600. Perform high-shear stirring and intermittent ultrasonic treatment for a total of 30 min until a uniform casting solution is formed.

[0069] The casting solution was coated onto a clean glass plate and placed in a solvent-saturated drying oven to slowly evaporate the solvent at 25°C for 12 hours. It was then transferred to a ventilated drying oven and dried at 40°C for 6 hours. Finally, it was placed in a vacuum oven and vacuum heat-treated at 80°C for 6 hours. After natural cooling, the film was peeled off to obtain the mixed matrix membrane.

[0070] Example 5 Example 5 provides a mixed matrix membrane, comprising a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix; the dispersed phase is composed of a first filler and a second filler. The continuous phase matrix is ​​Hyflon AD 60; the first filler is an amino-functionalized zirconate phthalic acid metal-organic framework (UiO-66-NH2); the second filler is UiO-66-NH2 grafted with toluene diisocyanate (TDI) and hydroxyl-terminated perfluoropolyether (Mn≈2000); the mass ratio of the first filler to the second filler is 2:1; the total mass of the dispersed phase accounts for 30 wt% of the total mass of the mixed matrix membrane.

[0071] This embodiment 5 provides a method for preparing a first filler, including the following steps: Zirconium tetrachloride and 2-aminoterephthalic acid were dissolved in anhydrous N,N-dimethylformamide, with acetic acid added as a regulator. After ultrasonic dispersion for 15 min, the mixture was placed in a pressure-resistant reactor and subjected to a solvothermal reaction at 150 °C for 12 h. After the reaction, the mixture was allowed to cool naturally to room temperature, and the product was separated by centrifugation. The product was washed three times with DMF, then soaked and replaced three times with methanol, and finally activated by vacuum drying at 120 °C for 12 h to obtain the first packing material.

[0072] This embodiment 5 also provides a method for preparing a second filler, including the following steps: Weigh 0.50 g of the first filler prepared above and disperse it in 50 mL of anhydrous DMF, then sonicate for 10 min. Dissolve an appropriate amount of toluene diisocyanate in a small amount of anhydrous DMF and add it dropwise to the above suspension. React at room temperature for 2 h, then raise the temperature to 45 °C and continue the reaction for 6 h to introduce isocyanate groups. Centrifuge and wash to remove unreacted material, retain the moist solid and redissolve it in 50 mL of anhydrous DMF.

[0073] A suitable amount of perfluoropolyether diol with a number-average molecular weight (Mn) of approximately 2000 was dissolved in anhydrous DMF and slowly added to the above dispersion. The grafting reaction was carried out at 50°C under nitrogen protection with stirring for 24 hours. The product was washed three times each with DMF, methanol, and acetone, pre-dried under vacuum at 60°C for 2 hours, and then dried under vacuum at 120°C for 12 hours to obtain the second filler.

[0074] This embodiment 5 also provides a method for preparing a hybrid matrix membrane, comprising the following steps: Weigh 0.200 g of the first filler and 0.100 g of the second filler, add a small amount of ethanol as a wetting agent, and ultrasonically disperse for 30 min before mixing. Under inert stirring, add a perfluoropolyether solvent solution containing 0.70 g of Hyflon AD 60. Perform high-shear stirring and intermittent ultrasonic treatment for a total of 30 min until a uniform casting solution is formed.

[0075] The casting solution was coated onto a clean glass plate and placed in a solvent-saturated drying oven to slowly evaporate the solvent at 25°C for 24 hours. It was then transferred to a ventilated drying oven and dried at 60°C for 12 hours. Finally, it was placed in a vacuum oven and vacuum heat-treated at 160°C for 12 hours. After natural cooling, the film was peeled off to obtain the mixed matrix membrane.

[0076] Example 6 Example 6 provides a mixed matrix membrane, comprising a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix; the dispersed phase is composed of a first filler and a second filler. The continuous phase matrix is ​​Cytop S-type; the first filler is an amino-functionalized chromium phthalate metal-organic framework (MIL-101(Cr)-NH2); the second filler is MIL-101(Cr)-NH2 grafted with diphenylmethane diisocyanate (MDI) and hydroxyl-terminated perfluoropolyether (Mn≈1000); the mass ratio of the first filler to the second filler is 1:1; the total mass of the dispersed phase accounts for 15 wt% of the total mass of the mixed matrix membrane.

[0077] This embodiment 6 provides a method for preparing a first filler, including the following steps: Chromium nitrate and 2-aminoterephthalic acid were dissolved in a mixed solvent of water and DMF. Sodium hydroxide was added to adjust the pH. After ultrasonic dispersion for 15 min, the mixture was placed in a pressure-resistant reactor and subjected to a solvothermal reaction at 150 °C for 18 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature, and the product was separated by centrifugation. The product was washed three times alternately with DMF and ethanol, then soaked and replaced three times with methanol, and finally activated by vacuum drying at 120 °C for 12 h to obtain the first filler, MIL-101(Cr)-NH2.

[0078] This embodiment 6 also provides a method for preparing a second filler, including the following steps: Weigh 0.50 g of the first filler prepared above and disperse it in 50 mL of anhydrous DMF, then sonicate for 10 min. Take an appropriate amount of diphenylmethane diisocyanate (MDI) and dissolve it in a small amount of anhydrous DMF, then add it dropwise to the above suspension. After reacting at room temperature for 2 h, raise the temperature to 40 °C and continue the reaction for 6 h to introduce isocyanate groups. Centrifuge and wash to remove unreacted material, retain the moist solid and redissolve it in 50 mL of anhydrous DMF.

[0079] A suitable amount of perfluoropolyether diol with a number-average molecular weight (Mn) ≈ 1000 was dissolved in anhydrous DMF and slowly added to the above dispersion. The grafting reaction was carried out at 45°C under nitrogen protection with stirring for 18 hours. The product was washed three times each with DMF, methanol, and acetone, pre-dried under vacuum at 60°C for 2 hours, and then dried under vacuum at 100°C for 12 hours to obtain the second filler.

[0080] This embodiment 6 also provides a method for preparing a hybrid matrix membrane, comprising the following steps: Weigh 0.075 g of the first filler and 0.075 g of the second filler, add a small amount of methanol as a wetting agent, and ultrasonically disperse for 20 min before mixing. Under inert stirring, add a solution containing 0.85 g of Cytop S-type perfluorotributylamine. Perform high-shear stirring and intermittent ultrasonic treatment for a total of 30 min until a uniform casting solution is formed.

[0081] The casting solution was coated onto a clean glass plate and placed in a solvent-saturated drying oven to slowly evaporate the solvent at 25°C for 18 hours. It was then transferred to a ventilated drying oven and dried at 55°C for 10 hours. Finally, it was placed in a vacuum oven and vacuum heat-treated at 100°C for 10 hours. After natural cooling, the film was peeled off to obtain the mixed matrix membrane.

[0082] Example 7 Example 7 provides a mixed matrix membrane comprising a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix; the dispersed phase is composed of a first filler and a second filler. The continuous phase matrix is ​​Teflon AF 2400; the first filler is an amino-functionalized aluminum phthalate metal-organic framework (MIL-53(Al)-NH2); the second filler is MIL-53(Al)-NH2 grafted with hexamethylene diisocyanate and hydroxyl-terminated perfluoropolyether (Mn≈1500); the mass ratio of the first filler to the second filler is 1:2; the total mass of the dispersed phase accounts for 25 wt% of the total mass of the mixed matrix membrane.

[0083] This embodiment 7 provides a method for preparing a first filler, including the following steps: Aluminum nitrate and 2-aminoterephthalic acid were dissolved in a mixed solvent of DMF and water, ultrasonically dispersed for 15 min, and then placed in a pressure-resistant reactor for a solvothermal reaction at 130 °C for 24 h. After the reaction, the mixture was allowed to cool naturally to room temperature, and the product was separated by centrifugation. The product was washed three times with DMF, then soaked in ethanol three times, and finally activated by vacuum drying at 150 °C for 12 h to obtain the first filler, MIL-53(Al)-NH2.

[0084] This embodiment 7 also provides a method for preparing a second filler, including the following steps: Weigh 0.50 g of the first filler prepared above and disperse it in 50 mL of anhydrous DMF, then sonicate for 10 min. Dissolve an appropriate amount of hexamethylene diisocyanate in a small amount of anhydrous DMF and add it dropwise to the above suspension. React at room temperature for 2 h, then raise the temperature to 35 °C and continue the reaction for 6 h to introduce isocyanate groups. Centrifuge and wash to remove unreacted material, retain the moist solid and redissolve it in 50 mL of anhydrous DMF.

[0085] A suitable amount of perfluoropolyether diol with a number-average molecular weight Mn≈1500 was dissolved in anhydrous DMF and slowly added to the above dispersion. The grafting reaction was carried out at 45°C under nitrogen protection with stirring for 20 h. The product was washed three times each with DMF, methanol, and acetone, pre-dried under vacuum at 60°C for 2 h, and then dried under vacuum at 110°C for 12 h to obtain the second filler.

[0086] This embodiment 7 also provides a method for preparing a hybrid matrix membrane, comprising the following steps: Weigh 0.083 g of the first filler and 0.167 g of the second filler, add a small amount of methanol as a wetting agent, and ultrasonically disperse for 25 min before mixing. Under inert stirring, add FC40 solution containing 0.75 g of Teflon AF 2400. Perform high-shear stirring and intermittent ultrasonic treatment for a total of 30 min until a uniform casting solution is formed.

[0087] The casting solution was coated onto a clean glass plate and placed in a solvent-saturated drying oven to slowly evaporate the solvent at 25°C for 20 hours. It was then transferred to a ventilated drying oven and dried at 50°C for 10 hours. Finally, it was placed in a vacuum oven and vacuum heat-treated at 130°C for 10 hours. After natural cooling, the film was peeled off to obtain the mixed matrix membrane.

[0088] Example 8 Example 8 provides a hybrid matrix membrane comprising a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix; the dispersed phase is composed of a first filler and a second filler. The continuous phase matrix is ​​Hyflon AD 40; the first filler is an amino-functionalized zinc methylimidazolium metal-organic framework (ZIF-8-NH2); the second filler is ZIF-8-NH2 grafted with hexamethylene diisocyanate and hydroxyl-terminated perfluoropolyether (Mn≈800); the mass ratio of the first filler to the second filler is 1.5:1; the total mass of the dispersed phase accounts for 10 wt% of the total mass of the hybrid matrix membrane.

[0089] This embodiment 8 provides a method for preparing a first filler, including the following steps: Zinc nitrate and 2-aminobenzimidazole were dissolved in methanol and ultrasonically dispersed for 15 min. The mixture was then subjected to a solvothermal reaction at 100 °C for 6 h (or stirred at room temperature for 24 h). After the reaction, the product was separated by centrifugation. The product was washed three times with methanol, then soaked and replaced three times with methanol, and finally activated by vacuum drying at 100 °C for 12 h to obtain the first packing material ZIF-8-NH2.

[0090] This embodiment 8 also provides a method for preparing a second filler, comprising the following steps: Weigh 0.50 g of the first filler prepared above and disperse it in 50 mL of anhydrous DMF, then sonicate for 10 min. Dissolve an appropriate amount of hexamethylene diisocyanate in a small amount of anhydrous DMF and add it dropwise to the above suspension. React at room temperature for 2 h, then raise the temperature to 35 °C and continue the reaction for 6 h to introduce isocyanate groups. Centrifuge and wash to remove unreacted material, retain the moist solid and redissolve it in 50 mL of anhydrous DMF.

[0091] A suitable amount of perfluoropolyether diol with a number-average molecular weight Mn≈800 was dissolved in anhydrous DMF and slowly added to the above dispersion. The grafting reaction was carried out at 40°C under nitrogen protection with stirring for 16 hours. The product was washed three times each with DMF, methanol, and acetone, pre-dried under vacuum at 50°C for 2 hours, and then dried under vacuum at 90°C for 8 hours to obtain the second filler.

[0092] This embodiment 8 also provides a method for preparing a hybrid matrix membrane, comprising the following steps: Weigh 0.060 g of the first filler and 0.040 g of the second filler, add a small amount of methanol as a wetting agent, and ultrasonically disperse for 20 min before mixing. Under inert stirring, add a perfluorinated solvent solution containing 0.90 g of Hyflon AD 40. Perform high-shear stirring and intermittent ultrasonic treatment for a total of 30 min until a uniform casting solution is formed.

[0093] The casting solution was coated onto a clean glass plate and placed in a solvent-saturated drying oven to slowly evaporate the solvent at 25°C for 16 hours. It was then transferred to a ventilated drying oven and dried at 45°C for 8 hours. Finally, it was placed in a vacuum oven and vacuum heat-treated at 90°C for 12 hours. After natural cooling, the film was peeled off to obtain the mixed matrix membrane.

[0094] Comparative Example Comparative Example 1 Comparative Example 1 provides a hybrid matrix membrane, comprising a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix. The continuous phase matrix is ​​Teflon AF 2400; the dispersed phase consists only of a first filler, which is an amino-functionalized zirconium phthalate metal-organic framework (UiO-66-NH2); the total mass of the dispersed phase accounts for 20 wt% of the total mass of the hybrid matrix membrane.

[0095] Comparative Example 1 provides a method for preparing a first packing material, comprising the following steps: 1.864 g of zirconium tetrachloride and 1.456 g of 2-aminoterephthalic acid were dissolved in 130 mL of anhydrous N,N-dimethylformamide. 10 mL of acetic acid was added as a regulator. After ultrasonic dispersion for 15 min, the mixture was placed in a pressure-resistant reactor and subjected to a solvothermal reaction at 120 °C for 12 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature, and the product was separated by centrifugation. The product was washed three times with DMF, then soaked and replaced three times with methanol (12 hours each time), and finally activated by vacuum drying at 120 °C for 12 hours to obtain the first packing material UiO-66-NH2.

[0096] Comparative Example 1 also provides a method for preparing a hybrid matrix membrane, comprising the following steps: Weigh 0.20 g of the first filler and add a small amount of methanol as a wetting agent, then ultrasonically disperse for 20 min. Under inert stirring, add FC40 solution containing 0.80 g of Teflon AF 2400. Perform high-shear stirring and intermittent ultrasonic treatment for a total of 30 min until a uniform casting solution is formed.

[0097] The casting solution was coated onto a clean glass plate and placed in a solvent-saturated FC40 drying oven for slow solvent evaporation at 25°C for 24 hours. It was then transferred to a ventilated drying oven and dried at 50°C for 12 hours. Finally, it was placed in a vacuum oven and vacuum heat-treated at 120°C for 12 hours. After natural cooling, the film was peeled off to obtain the mixed matrix membrane.

[0098] Comparative Example 2 Comparative Example 2 provides a mixed matrix membrane comprising a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix. The continuous phase matrix is ​​Teflon AF 2400; the dispersed phase consists only of a second filler, which is UiO-66-NH2 (denoted as F-PEG-UiO-66) grafted and modified with hexamethylene diisocyanate and hydroxyl-terminated perfluoropolyether (Mn≈1000); the total mass of the dispersed phase accounts for 20 wt% of the total mass of the mixed matrix membrane.

[0099] Comparative Example 2 provides a method for preparing a first packing material that is exactly the same as the method in Example 1.

[0100] Comparative Example 2 also provides a method for preparing a second filler that is exactly the same as the method in Example 1.

[0101] Comparative Example 2 also provides a method for preparing a hybrid matrix membrane, comprising the following steps: Weigh 0.20 g of the second filler and add a small amount of methanol as a wetting agent. Disperse the mixture ultrasonically for 20 min. Under inert stirring, add FC40 solution containing 0.80 g of Teflon AF 2400. Perform high-shear stirring and intermittent ultrasonic treatment for a total of 30 min until a uniform casting solution is formed.

[0102] The casting solution was coated onto a clean glass plate and placed in a solvent-saturated FC40 drying oven for slow solvent evaporation at 25°C for 24 hours. It was then transferred to a ventilated drying oven and dried at 50°C for 12 hours. Finally, it was placed in a vacuum oven and vacuum heat-treated at 120°C for 12 hours. After natural cooling, the film was peeled off to obtain the mixed matrix membrane.

[0103] Comparative Example 3 Comparative Example 3 provides a mixed matrix membrane, comprising a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix; the dispersed phase is composed of a first filler and a second filler. The continuous phase matrix is ​​Teflon AF 2400; the first filler is UiO-66-NH2; the second filler is UiO-66-NH2 (denoted as PEG-UiO-66) grafted and modified with hexamethylene diisocyanate and hydroxyl-terminated polyethylene glycol (PEG, Mn≈1000); the mass ratio of the first filler to the second filler is 1:2; the total mass of the dispersed phase accounts for 20 wt% of the total mass of the mixed matrix membrane.

[0104] Comparative Example 3 provides a method for preparing a first packing material that is exactly the same as the method in Example 1.

[0105] Comparative Example 3 also provides a method for preparing a second filler (PEG-UiO-66), comprising the following steps: Weigh 0.50 g of the first filler prepared above and disperse it in 50 mL of anhydrous DMF, then sonicate for 10 min. Dissolve 0.10 g of hexamethylene diisocyanate in a small amount of anhydrous DMF and add it dropwise to the above suspension. React at room temperature for 2 h, then raise the temperature to 40 °C and continue the reaction for 6 h to introduce isocyanate groups. Centrifuge and wash to remove unreacted material, retain the moist solid and redissolve it in 50 mL of anhydrous DMF.

[0106] A suitable amount of polyethylene glycol diol (PEG-OH) with a number-average molecular weight Mn≈1000 was dissolved in anhydrous DMF and slowly added to the above dispersion. The grafting reaction was carried out at 45°C under nitrogen protection with stirring for 24 h. The product was washed three times each with DMF, methanol, and acetone, pre-dried under vacuum at 60°C for 2 h, and then dried under vacuum at 100°C for 12 h to obtain the second filler PEG-UiO-66.

[0107] Comparative Example 3 also provides a method for preparing a hybrid matrix membrane, comprising the following steps: Weigh 0.067 g of the first filler and 0.134 g of the second filler, add a small amount of methanol as a wetting agent, and ultrasonically disperse for 20 min before mixing. The remaining steps are exactly the same as in Example 1.

[0108] Comparative Example 4 Comparative Example 4 provides a hybrid matrix membrane composed of a Teflon AF 2400 matrix, a UiO-66-NH2 filler, and free perfluoropolyether diol (F-PEG-OH) as an additive. The mass of Teflon AF 2400 is 0.80 g, the total mass of UiO-66-NH2 is 0.20 g, and the mass of F-PEG-OH is equivalent to the amount grafted onto the second filler in Example 1.

[0109] Comparative Example 4 provides a method for preparing a first packing material, which is exactly the same as the method in Example 1.

[0110] Comparative Example 4 also provides a method for preparing a hybrid matrix membrane, comprising the following steps: Weigh 0.20 g of UiO-66-NH2, add a small amount of methanol as a wetting agent, and ultrasonically disperse for 20 min. Under inert stirring, add the dispersion to an FC40 solution containing 0.80 g of Teflon AF 2400. Subsequently, add free F-PEG-OH (Mn≈1000) equivalent to the amount of the second filler grafted in Example 1. Perform high-shear stirring and intermittent ultrasonic treatment for a total of 30 min until a uniform casting solution is formed.

[0111] The subsequent film formation and post-treatment steps are exactly the same as in Example 1.

[0112] Performance testing To verify the performance of the hybrid matrix membrane prepared by the present invention, the membrane samples obtained in Examples 1-8 and Comparative Examples 1-4 were subjected to the following tests: 1. Testing Methods (1) Gas permeation performance test The gas permeation performance of the membrane was determined using the constant volume-variable pressure (Time-lag method).

[0113] Testing instruments: Homemade gas permeation instrument or commercial gas permeation tester (such as VAC-V2 differential pressure gas permeation instrument).

[0114] Test gases: carbon dioxide (CO2) and nitrogen (N2) with a purity of 99.999%.

[0115] Test conditions: The test temperature was controlled at 25℃, and the transmembrane pressure difference was maintained at 2 bar (0.2 MPa).

[0116] Parameter calculation: Gas permeability coefficient: unit is Barrer. Ideal selectivity: calculation formula is... .

[0117] (2) Physical aging resistance test The prepared membrane sample was placed naturally in an environment of 25℃ and 50% relative humidity for 90 days. Then, its CO2 permeability coefficient was measured again according to the above gas permeability test method, and the retention rate of the permeability coefficient was calculated (retention rate = P after aging / initial P × 100%).

[0118] (3) Mechanical performance testing Tensile tests were performed on the membrane samples using a universal testing machine in accordance with ASTM D882 standard.

[0119] Spline specifications: dumbbell-shaped spline (4 mm wide, 20 mm gauge length).

[0120] Tensile rate: 5 mm / min. Recorded data: tensile strength and elongation at break.

[0121] 2. Test Results Table 1. Performance test results of the hybrid matrix membranes prepared in Examples 1-8 and Comparative Examples 1-4

[0122] 3. Results Analysis This study employed a dual-filler strategy of "high-throughput unmodified MOF + compatibility-modified F-PEG grafted MOF" to construct fluorinated polymer hybrid matrix membranes. Table 1 lists the comparison of CO2 permeability and ideal CO2 / N2 selectivity Young's modulus of pure fluorinated matrix, four comparative samples, and eight examples.

[0123] A single unmodified MOF (Comparative Example 1) significantly increases overall flux, but interface incompatibility leads to non-selective porosity, resulting in a lack of significant improvement in CO2 / N2 selectivity. Conversely, a single F-PEG-grafted MOF (Comparative Example 2) significantly improves interface compactness and selectivity, but partial occupation or blockage of pores leads to a relative decrease in flux. Therefore, unmodified MOFs provide a "flux-driving force," while F-PEG-grafted MOFs provide "interface conditioning / selectivity assurance."

[0124] By combining and optimizing the ratios of the two types of fillers (Examples 1–8), it became possible to significantly improve selectivity while maintaining or moderately increasing flux. The estimation results show that the CO2 permeability coefficients of the example population are generally in the range of 3900–5000 Barrer, and the CO2 / N2 selectivity is in the range of 21–29, balancing the requirements at both ends of flux and selectivity. The microscopic mechanism of this synergistic effect can be explained as follows: the unmodified MOF retains its open channels to provide rapid flux pathways; while the compatible segments of the F-PEG grafted MOF and the fluorinated matrix reduce interfacial porosity / non-selective pathways, enhancing the screening effect for small molecules (CO2).

[0125] The introduction of fillers and interfacial compatibility significantly affect the Young's modulus of the membrane. While unmodified MOFs may improve rigidity, stress concentration points are introduced due to interfacial defects, resulting in a negligible overall modulus improvement (Comparative Example 1). F-PEG grafting forms good molecular-level coupling with the fluorinated matrix, leading to generally higher Young's moduli in the compounded examples compared to the pure membrane. This indicates that the compounding strategy can improve rigidity and dimensional stability without sacrificing mechanical stability. Non-fluorinated PEG grafting (Comparative Example 3), due to poor compatibility, actually reduces mechanical properties.

[0126] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A hybrid matrix membrane, characterized in that, It includes a continuous phase matrix and a dispersed phase dispersed in the continuous phase matrix; The continuous phase matrix is ​​an amorphous fluorinated polymer. The dispersed phase is composed of a first filler and a second filler; the first filler is an amino-functionalized metal-organic framework; the second filler is an amino-functionalized metal-organic framework grafted with fluorinated polyether. The second filler is formed by covalently grafting terminal hydroxyl perfluoropolyether onto the surface of the amino-functionalized metal-organic framework using diisocyanate.

2. The hybrid matrix membrane according to claim 1, characterized in that, The amino-functionalized metal-organic framework is selected from at least one of amino-functionalized zirconium phthalate metal-organic framework, amino-functionalized chromium phthalate metal-organic framework, amino-functionalized aluminum phthalate metal-organic framework, amino-functionalized zinc methyl imidazole metal-organic framework, and amino-functionalized zinc phthalate homo-mesh metal-organic framework. The amorphous fluorinated polymer is selected from at least one of Teflon AF 2400, Teflon AF 1600, Hyflon AD 60, Hyflon AD 40, Cytop S type, and Cytop A type.

3. The hybrid matrix membrane according to claim 1, characterized in that, The diisocyanate is selected from at least one of hexamethylene diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate; the terminal hydroxyl perfluoropolyether is a perfluoropolyether diol with a number average molecular weight Mn of 500 to 2000.

4. The hybrid matrix membrane according to claim 2, characterized in that, The amorphous fluorinated polymer is Teflon AF 2400; the first filler is an amino-functionalized zirconium phthalate metal-organic framework; the mass ratio of the first filler to the second filler is 1:2 to 2:1; the total mass of the dispersed phase accounts for 10wt% to 30wt% of the total mass of the mixed matrix membrane.

5. A method for preparing a hybrid matrix membrane according to any one of claims 1 to 4, characterized in that, Includes the following steps: Step (1): Dissolve the metal salt precursor and the amino-containing organic ligand in a solvent, add a regulator, and carry out a solvothermal reaction under closed conditions to precipitate crystals. After separation, washing and vacuum activation, the first filler is obtained. Step (2): Disperse part of the first filler obtained in step (1) in an anhydrous solvent, add diisocyanate dropwise and react at room temperature to 35℃~45℃ to introduce isocyanate groups, then add terminal hydroxyl perfluoropolyether, stir and graft reaction at 40℃~50℃ for 12h~24h, and the product is washed, dried and activated to obtain the second filler; Step (3): Mix the first filler and the second filler in proportion, disperse them in a wetting agent by ultrasonication, add a fluorinated solvent containing amorphous fluorinated polymer, disperse them fully, and obtain casting solution. Step (4): The casting solution obtained in step (3) is coated into a film, the solvent is evaporated in a solvent-saturated atmosphere, and then the film is dried by programmed temperature rise and vacuum heat treatment to obtain the mixed matrix film.

6. The preparation method according to claim 5, characterized in that, In step (1), the metal salt precursor is selected from zirconium tetrachloride, chromium nitrate, aluminum nitrate, and zinc nitrate; the amino-containing organic ligand is selected from 2-aminoterephthalic acid and 2-aminobenzimidazole. The temperature of the solvothermal reaction is 100℃~150℃, and the reaction time is 12h~24h.

7. The preparation method according to claim 5, characterized in that, In step (2), the anhydrous solvent is N,N-dimethylformamide; The washing process includes the following steps: washing with N,N-dimethylformamide, methanol and acetone in sequence; The drying and activation process includes the following steps: under vacuum conditions, pre-drying at a temperature of 50℃~60℃, followed by drying at a temperature of 80℃~120℃ for 6h~12h.

8. The preparation method according to claim 5, characterized in that, In step (3), the fluorinated solvent is perfluorotributylamine or perfluoropolyether solvent; the wetting agent is methanol or ethanol; the ultrasonic treatment or shearing treatment time is 20 min to 30 min to ensure that the filler does not agglomerate and disperse.

9. The preparation method according to claim 5, characterized in that, In step (4), the programmed temperature rise drying includes the following process: first, slowly drying in a solvent saturation box at 25°C for 12h~24h, and then ventilating drying at 40°C~60°C for 6h~12h; The vacuum heat treatment The process includes the following steps: treating under vacuum at a temperature of 80℃~160℃ for 6h~12h to remove residual solvent and induce polymer chain rearrangement.

10. An application of a hybrid matrix membrane as described in any one of claims 1 to 4 in the field of gas separation, characterized in that, The mixed matrix membrane is used for the selective separation of carbon dioxide gas from a mixture of carbon dioxide and nitrogen.

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