Defect-free polysulfon / MIL-160 / CAU-10-F composite membrane material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of gas separation membrane materials, in particular to a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material and a preparation method and application thereof.Polysulfone serves as a support and is compounded with MIL-160 / CAU-10-F to form the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material or a composite membrane, and the defect-free polysulfone in the composite membrane material has the advantages that the defect-free polysulfone in the composite membrane material can be separated from the MIL-160 / CAU-10-F composite membrane material at a high temperature; good mechanical property and oxidation resistance can be maintained, and meanwhile, the gas flux is relatively high; meanwhile, a hydrogen bond network structure formed at the interface of polysulfone and MIL-160 / CAU-10-F can further enhance the intersolubility with the interface of MIL-160 / CAU-10-F, and the performance stability and the plasticizing resistance of the composite membrane material are further improved. The flawless polysulfone / MIL-160 / CAU-10-F composite membrane disclosed by the invention has excellent plasticizing resistance and durability.

Description

Technical Field

[0001] This invention relates to the field of gas separation membrane material technology, and in particular to defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material, its preparation method and application. Background Technology

[0002] Helium plays a crucial role in defense and military applications. It is used not only to cool superconducting magnets in military equipment but also as a key component of the breathing mixture (oxygen + helium) in deep-sea submarines and submersibles. Currently, extracting and concentrating helium from natural gas is the only method for large-scale industrial production of helium. Industrial helium extraction primarily relies on the following technological methods:

[0003] (1) Cryogenic separation method. This method has significant advantages in industrial applications. It can handle large-scale gas flow rates and extract high-purity helium. However, its disadvantages are that it requires expensive cryogenic equipment and consumes a lot of energy to maintain the cryogenic conditions.

[0004] (2) Adsorption method, which is favored for its simple equipment, flexible operation and customizable adsorbents. Nevertheless, the capacity and selectivity of the adsorbent limit its efficiency in large-scale industrial production, and regular regeneration of the adsorbent is also required.

[0005] (3) Gas membrane separation technology, which is highly regarded for its high efficiency and energy saving. Its advantages include simple operation, compact equipment, relatively low energy consumption, and the ability to operate at room temperature, thereby reducing the impact on the environment. In addition, by adjusting the membrane material and structure, its selectivity and permeability can be optimized, making it suitable for the efficient separation of various gas mixtures.

[0006] Although gas membrane separation technology is favored for its high efficiency, energy saving, and environmental friendliness, it still faces some challenges in practical applications, including the "trade-off" effect, low selectivity, and poor stability. Literature [J. Am. Chem. Soc. 2021, 143, 17716-17723] discloses a polycrystalline metal-organic framework (MOF)-MIL-160 and its fluorinated variant membrane for CO2 / CH4 separation. The fluorinated MIL-160 / CAU-10-F membrane improves the CO2 / CH4 separation selectivity by 10.7% and CO2 permeability by 31.2%, but this patent literature does not mention the mechanical stability of the membrane. Patent CN115672062 A discloses a graphene-assisted ZIF-8 membrane material and its preparation method. This material can effectively extract helium from natural gas, but its selectivity for helium in mixtures such as He / N2 and He / CH4 is only 14, and its helium permeability is only 7.6 mol·m⁻¹. -2 ·s -1 ·MPa -1 It has low selectivity and the preparation method is relatively complicated, which is not conducive to industrialization.

[0007] Therefore, it is particularly important to find a membrane separation material with good stability and excellent selectivity for helium extraction and separation. Summary of the Invention

[0008] In view of this, the purpose of the present invention is to provide a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material, its preparation method and application, wherein the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane has good performance stability and anti-plasticization properties, as well as high gas flux and excellent selectivity.

[0009] The present invention solves the above-mentioned technical problems through the following technical means:

[0010] In a first aspect, embodiments of this application provide a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material. By weight, the raw materials for preparing the composite membrane material include: 3-10 parts of 2,5-furandicarboxylic acid, 1-2 parts of 5-fluoroisophthalic acid, 1-5 parts of aluminum chloride hexahydrate, 1-5 parts of sodium oxalate, and 0.1-1 parts of defect-free polysulfone powder.

[0011] Furthermore, by weight, the raw materials for preparing the composite membrane material include 6 parts of 2,5-furandicarboxylic acid, 1.7 parts of 5-fluoroisophthalic acid, 3 parts of aluminum chloride hexahydrate, 4 parts of sodium oxalate, and 0.6 parts of defect-free polysulfone powder.

[0012] Furthermore, by weight, the raw materials for preparing the defect-free polysulfone powder include: 1-5 parts of hexafluorobisphenol A, 1-5 parts of 4,4-dichlorodiphenyl sulfone, 1-5 parts of anhydrous K2CO3, 10-30 parts of N-methylpyrrolidone, and 10-30 parts of toluene.

[0013] Secondly, embodiments of this application also provide a method for preparing a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material, comprising the following steps:

[0014] 2,5-furandicarboxylic acid, 5-fluoroisophthalic acid, aluminum chloride hexahydrate and sodium oxalate were weighed and added to deionized water. Then, defect-free polysulfone powder was added, stirred and mixed, and placed in an oven at 100~120℃ for 24~48 hours to react. After naturally cooling to room temperature, the mixture was washed and dried to obtain defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material.

[0015] Furthermore, the method for preparing the defect-free polysulfone powder is as follows:

[0016] Hexafluorobisphenol A and 4,4-dichlorodiphenyl sulfone were weighed separately, mixed, and anhydrous K2CO3 was added. Then, N-methylpyrrolidone reaction solvent and toluene reflux agent were added. The mixture was heated to 100-250℃ under nitrogen protection and stirred. After cooling to room temperature, the product was transferred to distilled water, filtered, and the solid product was washed with deionized water and dried at 60-90℃ for 12-24 h to obtain defect-free polysulfone powder.

[0017] Furthermore, the specific steps of heating to 100~250℃ and stirring under nitrogen protection are as follows: heating to 100~200℃ under nitrogen protection and holding the reaction at this temperature for 2~4 hours, then heating to 150~250℃ and holding the reaction at this temperature for 6~12 hours.

[0018] Furthermore, in the method for preparing the defect-free polysulfone powder, the amounts of each raw material are as follows, by weight: 1-5 parts of hexafluorobisphenol A, 1-5 parts of 4,4-dichlorodiphenyl sulfone, 1-5 parts of anhydrous K2CO3, 10-30 parts of N-methylpyrrolidone, and 10-30 parts of toluene.

[0019] Thirdly, embodiments of this application also provide a method for preparing a defect-free polysulfone / MIL-160 / CAU-10-F composite film, comprising the following steps:

[0020] Hexafluorobisphenol A and 4,4-dichlorodiphenyl sulfone were weighed separately, mixed, and anhydrous K2CO3 was added. Then, N-methylpyrrolidone reaction solvent and toluene reflux agent were added. The mixture was stirred and heated to 100-200℃ under nitrogen protection and kept at this temperature for 2-4 h. The mixture was then heated to 150-250℃ and kept at this temperature for 6-12 h. After cooling to room temperature, the product was transferred to distilled water. The solid product was filtered, washed with deionized water, and dried at 60-90℃ for 12-24 h to obtain defect-free polysulfone powder.

[0021] In a reaction vessel, 2,5-furandicarboxylic acid, 5-fluoroisophthalic acid, aluminum chloride hexahydrate, and sodium oxalate were weighed and added, followed by deionized water and defect-free polysulfone powder. The mixture was stirred and mixed to obtain a mixed solution. α-Al2O3 sheets were placed horizontally at the bottom of the reaction vessel and immersed in the mixed solution. The reaction was carried out at 100°C to 120°C for 10 to 48 hours. After naturally cooling to room temperature, the α-Al2O3 sheets were removed, rinsed with acetone, and dried to obtain a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane.

[0022] Fourthly, the embodiments of this application also provide the application of the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane prepared by the preparation method described in the third aspect above in helium extraction and separation.

[0023] Fifthly, the embodiments of this application also provide the application of the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material described in the first aspect above or the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material prepared by the preparation method described in the second aspect above in the preparation of helium separation membranes.

[0024] This invention uses polysulfone as a support to form a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material or composite membrane. The defect-free polysulfone in this composite membrane material maintains good mechanical properties and oxidation resistance at high temperatures, while also exhibiting high gas flux. Furthermore, the hydrogen bond network structure formed at the interface between polysulfone and MIL-160 / CAU-10-F further enhances the interfacial miscibility with MIL-160 / CAU-10-F, further improving the performance stability and plasticization resistance of the composite membrane material. The defect-free polysulfone / MIL-160 / CAU-10-F composite membrane of this invention possesses excellent plasticization resistance and durability.

[0025] Testing revealed that the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane of this invention exhibits high helium flux and selectivity, with a helium flux reaching 378 GPU and He / CH4 and He / N2 selectivities reaching 386 and 371 respectively, making it suitable for helium separation and extraction. Attached Figure Description

[0026] Figure 1 The graph shows the anti-plasticization properties of the composite film prepared in Example 6.

[0027] Figure 2 The image shows the anti-plasticization properties of the composite film prepared in Comparative Example 1.

[0028] Figure 3 The graph shows the lifetime stability test results of the composite membranes prepared in Example 6 and Comparative Example 1. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] The terms "first" and "second," etc., used in the specification and claims herein are used to distinguish different objects, not to describe a specific order of objects. In the description of embodiments of this application, unless otherwise stated, "a plurality of" means two or more, for example, "a plurality of processing units" means two or more processing units, "a plurality of elements" means two or more elements, etc.

[0031] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0032] The English definitions in this invention are as follows:

[0033] 6FpDA: Bisphenol A hexafluorofluoropolymer; DDS: 4,4-dichlorodiphenyl sulfone; NMP: N-methylpyrrolidone; PSF: polysulfone.

[0034] This application uses polysulfone as a support to form a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material. The defect-free polysulfone in this composite membrane material can maintain good mechanical properties and oxidation resistance at high temperatures, while also having a high gas flux. At the same time, the hydrogen bond network structure formed at the interface between polysulfone and MIL-160 / CAU-10-F can further enhance the interfacial miscibility with MIL-160 / CAU-10-F, thereby further improving the performance stability and plasticization resistance of the composite membrane material.

[0035] The defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material of this application comprises, by weight, the following raw materials: 3-10 parts of 2,5-furandicarboxylic acid, 1-2 parts of 5-fluoroisophthalic acid, 1-5 parts of aluminum chloride hexahydrate, 1-5 parts of sodium oxalate, and 0.1-1 parts of defect-free polysulfone powder.

[0036] The preparation method of the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material of this application is as follows:

[0037] (1) Weigh out hexafluorobisphenol A and 4,4-dichlorodiphenyl sulfone separately, mix them, add anhydrous K2CO3 and mix, then add N-methylpyrrolidone reaction solvent and toluene reflux agent, stir and heat to 100~200℃ under nitrogen protection, keep the reaction temperature for 2~4h, then heat to 150~250℃, keep the reaction temperature for 6~12h, cool to room temperature, transfer the obtained product to distilled water, filter, wash the obtained solid product with deionized water, and dry at 60~90℃ for 12~24h to obtain defect-free polysulfone powder. In this step, the amount of each raw material by weight is as follows: hexafluorobisphenol A 1~5 parts, 4,4-dichlorodiphenyl sulfone 1~5 parts, anhydrous K2CO3 1~5 parts, N-methylpyrrolidone 10~30 parts and toluene 10~30 parts.

[0038] (2) Weigh 2,5-furandicarboxylic acid, 5-fluoroisophthalic acid, aluminum chloride hexahydrate and sodium oxalate respectively and add them to deionized water. Then add defect-free polysulfone powder, stir and mix well, place in an oven at 100~120℃ and heat for 24~48 hours. Cool naturally to room temperature, wash and dry to obtain defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material.

[0039] The method for preparing the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane of this application is as follows:

[0040] (1) Weigh out hexafluorobisphenol A and 4,4-dichlorodiphenyl sulfone separately, mix them, add anhydrous K2CO3 and mix, then add N-methylpyrrolidone reaction solvent and toluene reflux agent, stir and heat to 100~200℃ under nitrogen protection, keep the reaction temperature for 2~4h, then heat to 150~250℃, keep the reaction temperature for 6~12h, cool to room temperature, transfer the obtained product to distilled water, filter, wash the obtained solid product with deionized water, and dry at 60~90℃ for 12~24h to obtain defect-free polysulfone powder. In this step, the amount of each raw material by weight is as follows: hexafluorobisphenol A 1~5 parts, 4,4-dichlorodiphenyl sulfone 1~5 parts, anhydrous K2CO3 1~5 parts, N-methylpyrrolidone 10~30 parts and toluene 10~30 parts.

[0041] (2) In the reaction vessel, weigh and add 2,5-furandicarboxylic acid, 5-fluoroisophthalic acid, aluminum chloride hexahydrate and sodium oxalate, then add deionized water and defect-free polysulfone powder, stir and mix to obtain a mixed solution, take α-Al2O3 sheet and place it horizontally at the bottom of the reaction vessel, immerse the α-Al2O3 sheet in the mixed solution, heat at 100°C~120°C for 10h~48h, cool naturally to room temperature, take out the α-Al2O3 sheet, rinse with acetone, dry, and obtain defect-free polysulfone / MIL-160 / CAU-10-F composite membrane.

[0042] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0043] Example 1

[0044] The defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material of this embodiment is prepared as follows:

[0045] (1) Preparation of defect-free polysulfone

[0046] In a three-necked round-bottom flask, 3.3623 g of hexafluorobisphenol A (6FpDA) and 2.8716 g of 4,4-dichlorodiphenyl sulfone (DDS) were added, followed by 1.518 g of anhydrous K₂CO₃ catalyst, 23 mL of N-methylpyrrolidone (NMP) reaction solvent, and 13 mL of toluene reflux agent. The mixture was heated and stirred at 143 °C for 4 h under nitrogen protection, then the temperature was adjusted to 183 °C and maintained for 12 h. After cooling to room temperature, the product was transferred to distilled water to obtain a light white solid. After washing with deionized water five times and filtering to remove impurities, the solid was dried at 85 °C for 12 h to obtain defect-free polysulfone powder.

[0047] (2) Preparation of defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material

[0048] A solid mixture of 5 g 2,5-furandicarboxylic acid, 1.5 g 5-fluoroisophthalic acid, 3.0 g aluminum chloride hexahydrate, and 3.0 g sodium oxalate was dissolved in 100 ml deionized water by ultrasonic treatment. Then, 0.1 g of defect-free polysulfone powder was added. After stirring the solution until homogeneous, it was heated in an oven at 110°C for 25 hours. After natural cooling to room temperature and crystallization, the product was collected by filtration and washed three times each with dimethylformamide and acetone. After drying at room temperature, the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material was obtained.

[0049] Example 2

[0050] The defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material of this embodiment is prepared as follows:

[0051] (1) Preparation of defect-free polysulfone

[0052] In a three-necked round-bottom flask, 1.0 g of hexafluorobisphenol A (6FpDA) and 1.0 g of 4,4-dichlorodiphenyl sulfone (DDS) were added, followed by 1.0 g of anhydrous K₂CO₃ catalyst, 10 mL of N-methylpyrrolidone (NMP) reaction solvent, and 11.5 mL of toluene reflux agent. The mixture was heated and stirred to 100 °C under nitrogen protection for 3 h, then the temperature was adjusted to 150 °C and maintained for 12 h. After cooling to room temperature, the product was transferred to distilled water to obtain a light white solid. After washing with deionized water five times and filtering to remove impurities, the solid was dried at 60 °C for 24 h to obtain defect-free polysulfone powder.

[0053] (2) Preparation of defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material

[0054] A solid mixture of 5 g 2,5-furandicarboxylic acid, 1.5 g 5-fluoroisophthalic acid, 3.0 g aluminum chloride hexahydrate, and 3.0 g sodium oxalate was dissolved in 100 ml deionized water by ultrasonic treatment. Then, 0.4 g defect-free polysulfone powder was added. After stirring the solution until homogeneous, it was heated in an oven at 110°C for 25 hours. After natural cooling to room temperature and crystallization, the product was collected by filtration and washed three times each with dimethylformamide and acetone. After drying at room temperature, the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material was obtained.

[0055] Example 3

[0056] The defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material of this embodiment is prepared as follows:

[0057] (1) Preparation of defect-free polysulfone

[0058] In a three-necked round-bottom flask, 5.0 g of hexafluorobisphenol A (6FpDA) and 5.0 g of 4,4-dichlorodiphenyl sulfone (DDS) were added, followed by 5.0 g of anhydrous K₂CO₃ catalyst, 29 mL of N-methylpyrrolidone (NMP) reaction solvent, and 34.5 mL of toluene reflux agent. The mixture was heated and stirred at 200 °C for 2 h under nitrogen protection, then the temperature was adjusted to 250 °C and maintained for 6 h. After cooling to room temperature, the product was transferred to distilled water to obtain a light white solid. After washing with deionized water five times and filtering to remove impurities, the solid was dried at 90 °C for 15 h to obtain defect-free polysulfone powder.

[0059] (2) Preparation of defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material

[0060] A solid mixture of 5 g 2,5-furandicarboxylic acid, 1.5 g 5-fluoroisophthalic acid, 3.0 g aluminum chloride hexahydrate, and 3.0 g sodium oxalate was dissolved in 100 ml deionized water by ultrasonic treatment. Then, 0.7 g defect-free polysulfone powder was added. After stirring the solution until homogeneous, it was heated in an oven at 110°C for 25 hours. After natural cooling to room temperature and crystallization, the product was collected by filtration and washed three times each with dimethylformamide and acetone. After drying at room temperature, the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material was obtained.

[0061] Example 4

[0062] The defect-free polysulfone / MIL-160 / CAU-10-F composite membrane of this embodiment is prepared as follows:

[0063] (1) Preparation of defect-free polysulfone

[0064] This step is the same as in Example 1.

[0065] (2) Preparation of defect-free polysulfone / MIL-160 / CAU-10-F composite membrane

[0066] A solid mixture of 5g 2,5-furandicarboxylic acid, 1.5g 5-fluoroisophthalic acid, 3.0g aluminum chloride hexahydrate, and 3.0g sodium oxalate was dissolved in 100ml deionized water by ultrasonic treatment. Then, 0.1g of defect-free polysulfone powder was added. After the synthesis solution was stirred until homogeneous, a 5cm*5cm α-Al2O3 substrate was placed horizontally in a stainless steel high-pressure reactor lined with Teflon and heated in an oven at 110°C for 25 hours. After the solvothermal reaction, the substrate was cooled to room temperature, and the α-Al2O3 sheet was removed. The film formed on the α-Al2O3 substrate was rinsed multiple times with acetone and then dried overnight in air at 100°C to obtain a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane.

[0067] Example 5

[0068] The defect-free polysulfone / MIL-160 / CAU-10-F composite membrane of this embodiment is prepared as follows:

[0069] (1) Preparation of defect-free polysulfone

[0070] This step is the same as in Example 1.

[0071] (2) Preparation of defect-free polysulfone / MIL-160 / CAU-10-F composite membrane

[0072] A solid mixture of 5g 2,5-furandicarboxylic acid, 1.5g 5-fluoroisophthalic acid, 3.0g aluminum chloride hexahydrate, and 3.0g sodium oxalate was dissolved in 100ml deionized water by ultrasonic treatment. Then, 0.4g of defect-free polysulfone powder was added. After the synthesis solution was stirred until homogeneous, a 5cm*5cm α-Al2O3 substrate was horizontally placed in a stainless steel high-pressure reactor lined with Teflon and heated in an oven at 110°C for 25 hours. After the solvothermal reaction, the substrate was cooled to room temperature, and the α-Al2O3 sheet was removed. The film formed on the α-Al2O3 substrate was rinsed multiple times with acetone and then dried overnight in air at 100°C to obtain a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane.

[0073] Example 6

[0074] The defect-free polysulfone / MIL-160 / CAU-10-F composite membrane of this embodiment is prepared as follows:

[0075] (1) Preparation of defect-free polysulfone

[0076] This step is the same as in Example 1.

[0077] (2) Preparation of defect-free polysulfone / MIL-160 / CAU-10-F composite membrane

[0078] A solid mixture of 5g 2,5-furandicarboxylic acid, 1.5g 5-fluoroisophthalic acid, 3.0g aluminum chloride hexahydrate, and 3.0g sodium oxalate was dissolved in 100ml deionized water by ultrasonic treatment. Then, 0.7g of defect-free polysulfone powder was added. After the synthesis solution was stirred until homogeneous, a 5cm*5cm α-Al2O3 substrate was horizontally placed in a stainless steel high-pressure reactor lined with Teflon and heated in an oven at 110°C for 25 hours. After the solvothermal reaction, the substrate was cooled to room temperature, and the α-Al2O3 sheet was removed. The film formed on the α-Al2O3 substrate was rinsed multiple times with acetone and then dried overnight in air at 100°C to obtain a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane.

[0079] Example 7

[0080] The defect-free polysulfone / MIL-160 / CAU-10-F composite membrane of this embodiment is prepared as follows:

[0081] (1) Preparation of defect-free polysulfone

[0082] This step is the same as in Example 1.

[0083] (2) Preparation of defect-free polysulfone / MIL-160 / CAU-10-F composite membrane

[0084] A solid mixture of 5g 2,5-furandicarboxylic acid, 1.5g 5-fluoroisophthalic acid, 3.0g aluminum chloride hexahydrate, and 3.0g sodium oxalate was dissolved in 100ml deionized water by ultrasonic treatment. Then, 1.0g defect-free polysulfone powder was added. After the synthesis solution was stirred until homogeneous, a 5cm*5cm α-Al2O3 substrate was placed horizontally in a stainless steel high-pressure reactor lined with Teflon and heated in an oven at 110°C for 25 hours. After the solvothermal reaction, the substrate was cooled to room temperature, and the α-Al2O3 sheet was removed. The film formed on the α-Al2O3 substrate was rinsed multiple times with acetone and then dried overnight in air at 100°C to obtain a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane.

[0085] Example 8

[0086] The defect-free polysulfone / MIL-160 / CAU-10-F composite membrane of this embodiment is prepared as follows:

[0087] (1) Preparation of defect-free polysulfone

[0088] This step is the same as in Example 2.

[0089] (2) Preparation of defect-free polysulfone / MIL-160 / CAU-10-F composite membrane

[0090] A solid mixture of 3.0 g 2,5-furandicarboxylic acid, 1.0 g 5-fluoroisophthalic acid, 1.00 g aluminum chloride hexahydrate, and 1.0 g sodium oxalate was dissolved in 100 ml deionized water by ultrasonic treatment. Then, 0.5 g defect-free polysulfone powder was added. After the synthesis solution was stirred until homogeneous, a 5 cm * 5 cm α-Al2O3 substrate was placed horizontally in a stainless steel high-pressure reactor lined with Teflon and heated in an oven at 100°C for 48 hours. After the solvothermal reaction, the substrate was cooled to room temperature, and the α-Al2O3 sheet was removed. The film formed on the α-Al2O3 substrate was rinsed multiple times with acetone and then dried overnight in air at 100°C to obtain a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane.

[0091] Example 9

[0092] The defect-free polysulfone / MIL-160 / CAU-10-F composite membrane of this embodiment is prepared as follows:

[0093] (1) Preparation of defect-free polysulfone

[0094] This step is the same as in Example 2.

[0095] (2) Preparation of defect-free polysulfone / MIL-160 / CAU-10-F composite membrane

[0096] A solid mixture of 10.0 g 2,5-furandicarboxylic acid, 2.0 g 5-fluoroisophthalic acid, 5.00 g aluminum chloride hexahydrate, and 5.0 g sodium oxalate was dissolved in 100 ml deionized water by ultrasonic treatment. Then, 0.5 g defect-free polysulfone powder was added. After the synthesis solution was stirred until homogeneous, a 5 cm * 5 cm α-Al2O3 substrate was placed horizontally in a stainless steel high-pressure reactor with a Teflon lining and heated in an oven at 120°C for 10 hours. After the solvothermal reaction, the substrate was cooled to room temperature, and the α-Al2O3 sheet was removed. The film formed on the α-Al2O3 substrate was rinsed multiple times with acetone and then dried overnight in air at 100°C to obtain a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane.

[0097] Comparative Example 1

[0098] The composite membrane in this comparative example did not contain defect-free polysulfone powder, but the other steps were the same as in Example 6. Specifically, its preparation method is as follows:

[0099] A solid mixture of 5g 2,5-furandicarboxylic acid, 1.5g 5-fluoroisophthalic acid, 3.0g aluminum chloride hexahydrate, and 3.0g sodium oxalate was dissolved in 100ml deionized water by ultrasonic treatment. After stirring until homogeneous, a 5cm*5cm α-Al2O3 substrate was placed horizontally in a stainless steel high-pressure reactor lined with Teflon and heated in an oven at 110°C for 25 hours. After the solvothermal reaction, the substrate was cooled to room temperature, and the α-Al2O3 sheet was removed. The film formed on the α-Al2O3 substrate was rinsed multiple times with acetone and then dried overnight in air at 100°C to obtain a composite membrane.

[0100] Comparative Example 2

[0101] The composite membrane in this comparative example did not contain 5-fluoroisophthalic acid and sodium oxalate, but 3.5g of sodium formate was newly added. The other steps were the same as in Example 6. Specifically, its preparation method is as follows:

[0102] (1) Preparation of defect-free polysulfone

[0103] This step is the same as in Example 1.

[0104] (2) Preparation of composite membrane

[0105] A solid mixture of 5g 2,5-furandicarboxylic acid, 3.0g aluminum chloride hexahydrate, and 3.5g sodium formate was dissolved in 100ml deionized water by ultrasonic treatment. Then, 0.7g defect-free polysulfone powder was added. After the synthesis solution was stirred until homogeneous, a 5cm*5cm α-Al2O3 substrate was placed horizontally in a stainless steel high-pressure reactor lined with Teflon and heated in an oven at 110°C for 25 hours. After the solvothermal reaction, the substrate was cooled to room temperature, and the α-Al2O3 sheet was removed. The film formed on the α-Al2O3 substrate was rinsed multiple times with acetone and then dried overnight in air at 100°C to obtain the composite membrane.

[0106] Performance testing

[0107] The test pressure was set at 0.4 MPa and the temperature at 90 °C. Argon gas was used to purge the permeate side and the osmotic side. The test gases were CH4, He and N2. The gas separation performance of the composite membranes prepared in Examples 4-9 and Comparative Examples 1-2 were tested respectively. The test results are shown in Table 1.

[0108]

[0109] Table 1

[0110] As shown in Table 1, the composite membrane with defect-free polysulfone / MIL-160 / CAU-10-F exhibits high helium flux and selectivity, reaching a helium flux of 378 GPU and He / CH4 and He / N2 selectivities of 386 and 371, respectively. In contrast, the composite membrane in Comparative Example 1 without defect-free polysulfone has a lower helium flux (only 270 GPU) and lower He / CH4 and He / N2 selectivities compared to Example 6. This indicates that defect-free polysulfone can efficiently transport helium at high temperatures and possesses excellent gas selectivity. In Comparative Example 2, without 5-fluoroisophthalic acid and sodium oxalate, and using only MIL-160, the helium flux is only 98 GPU and the selectivity is only 81. This is because the un-F-treated MIL-160 has lower gas adsorption capacity.

[0111] Figure 1 The graph shows the anti-plasticization properties of the composite film prepared in Example 6. Figure 2 The image shows the anti-plasticization properties of the composite film prepared in Comparative Example 1. (From...) Figure 1 It can be seen that as the feed pressure increases, the helium selectivity does not decrease significantly (the decrease is 3), while from... Figure 2The significant decrease in helium selectivity (by 10) indicates that the introduction of defect-free polysulfone gives MIL-160 / CAU-10-F excellent anti-plasticization properties at high temperatures.

[0112] The composite membranes prepared in Example 6 and Comparative Example 1 were used as test samples. Ternary gas mixtures He / CO2 / CH4 and He / CO2 / N2 were used as feed gases, and the membranes were tested for 260 hours at 0.4 MPa and 90°C. Their lifetime stability was then tested. The test results can be found in [link to test results]. Figure 3 .from Figure 3 As can be seen, in the 260h lifetime test of defect-free polysulfone / MIL-160 / CAU-10-F, the He flux decay rate was only 3.4%, which is far lower than that of the composite membrane without defect-free polysulfone in Comparative Example 1 (decay rate: 11.7%). This further illustrates that the addition of defect-free polysulfone can improve the durability of the composite membrane and help extend its service life.

[0113] In summary, the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane of this application can be used in helium extraction and separation, and the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane of this application can also be made into a membrane for helium separation and extraction.

[0114] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention. Technical aspects, shapes, and structures not described in detail in this invention are all well-known technologies.

Claims

1. A defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material, characterized in that, The raw materials for preparing the composite membrane material, by weight, include: 3-10 parts of 2,5-furandicarboxylic acid, 1-2 parts of 5-fluoroisophthalic acid, 1-5 parts of aluminum chloride hexahydrate, 1-5 parts of sodium oxalate, and 0.1-1 parts of defect-free polysulfone powder.

2. The defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material according to claim 1, characterized in that, The raw materials for preparing the composite membrane material, by weight, include 6 parts of 2,5-furandicarboxylic acid, 1.7 parts of 5-fluoroisophthalic acid, 3 parts of aluminum chloride hexahydrate, 4 parts of sodium oxalate, and 0.6 parts of defect-free polysulfone powder.

3. The defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material according to claim 1, characterized in that, The raw materials for preparing the defect-free polysulfone powder, by weight, include: 1-5 parts of hexafluorobisphenol A, 1-5 parts of 4,4-dichlorodiphenyl sulfone, 1-5 parts of anhydrous K2CO3, 10-30 parts of N-methylpyrrolidone, and 10-30 parts of toluene.

4. A method for preparing a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material, characterized in that, Includes the following steps: 2,5-furandicarboxylic acid, 5-fluoroisophthalic acid, aluminum chloride hexahydrate and sodium oxalate were weighed and added to deionized water. Then, defect-free polysulfone powder was added, stirred and mixed, and placed in an oven at 100~120℃ for 24~48 hours to react. After naturally cooling to room temperature, the mixture was washed and dried to obtain defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material.

5. The method for preparing the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material according to claim 4, characterized in that, The method for preparing the defect-free polysulfone powder is as follows: Hexafluorobisphenol A and 4,4-dichlorodiphenyl sulfone were weighed separately, mixed, and anhydrous K2CO3 was added. Then, N-methylpyrrolidone reaction solvent and toluene reflux agent were added. The mixture was heated to 100-250℃ under nitrogen protection and stirred. After cooling to room temperature, the product was transferred to distilled water, filtered, and the solid product was washed with deionized water and dried at 60-90℃ for 12-24 hours to obtain defect-free polysulfone powder.

6. The method for preparing the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material according to claim 5, characterized in that, The specific steps of heating to 100-250°C and stirring under nitrogen protection are as follows: heating to 100-200°C under nitrogen protection and holding the temperature for 2-4 hours, then heating to 150-250°C and holding the temperature for 6-12 hours.

7. The method for preparing the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material according to claim 5, characterized in that, In the preparation method of the defect-free polysulfone powder, the amounts of each raw material are as follows, by weight: 1-5 parts of hexafluorobisphenol A, 1-5 parts of 4,4-dichlorodiphenyl sulfone, 1-5 parts of anhydrous K2CO3, 10-30 parts of N-methylpyrrolidone, and 10-30 parts of toluene.

8. A method for preparing a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane, characterized in that, Includes the following steps: Hexafluorobisphenol A and 4,4-dichlorodiphenyl sulfone were weighed separately, mixed, and anhydrous K2CO3 was added. Then, N-methylpyrrolidone reaction solvent and toluene reflux agent were added. The mixture was stirred and heated to 100-200℃ under nitrogen protection and kept at this temperature for 2-4 h. The mixture was then heated to 150-250℃ and kept at this temperature for 6-12 h. After cooling to room temperature, the product was transferred to distilled water. The solid product was filtered, washed with deionized water, and dried at 60-90℃ for 12-24 h to obtain defect-free polysulfone powder. In a reaction vessel, 2,5-furandicarboxylic acid, 5-fluoroisophthalic acid, aluminum chloride hexahydrate, and sodium oxalate were weighed and added, followed by deionized water and defect-free polysulfone powder. The mixture was stirred and mixed to obtain a mixed solution. α-Al2O3 sheets were placed horizontally at the bottom of the reaction vessel and immersed in the mixed solution. The reaction was carried out at 100°C to 120°C for 10 to 48 hours. After naturally cooling to room temperature, the α-Al2O3 sheets were removed, rinsed with acetone, and dried to obtain a defect-free polysulfone / MIL-160 / CAU-10-F composite membrane.

9. The application of the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane prepared by the method according to claim 8 in helium extraction and separation.

10. The application of the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material according to any one of claims 1-3 or the defect-free polysulfone / MIL-160 / CAU-10-F composite membrane material prepared by the preparation method according to any one of claims 4-7 in the preparation of helium separation membrane.

Images