Polyether block polyamide hybrid membrane based on modified hydrogen bond organic framework and its preparation method and application

Abstract

This invention discloses a hybrid membrane based on a modified hydrogen-bonded organic framework filled with polyether block polyamide. The membrane comprises a base membrane and a functional layer. The functional layer uses polyether block polyamide as the polymer host and a surface-modified hydrogen-bonded organic framework (HBOM) modified with polyvinylpyrrolidone (PVP) as the filler, with a mass ratio of 90:1 to 10. The preparation method involves: self-assembling a rod-shaped HBOM structure using 1,3,6,8-tetra(4-carboxyphenyl)pyrene in a solvent, and then surface-modifying it with PPVP; dispersing the HBOM in a mixed solution of ethanol and water, blending it with the polyether block polyamide to obtain a casting solution, spin-coating it onto the base membrane surface, and then evaporating the solvent to obtain the hybrid membrane. The process is simple, highly controllable, and universally applicable. The hydrophilic segments on the filler surface intertwine with the polymer segments, effectively overcoming interface defects and improving the membrane's density and selectivity. When used for toluene / nitrogen separation, this hybrid membrane exhibits high permeability, high selectivity, and high stability.

Description

Technical Field

[0001] This invention pertains to polymer-organic hybrid membranes, and particularly relates to the preparation of a polyether-block polyamide hybrid membrane filled with a modified hydrogen-bonded organic framework. Background Technology

[0002] Volatile organic compounds (VOCs) are a typical class of polluting gases, mainly including aromatics, alkanes, alkenes, and aldehydes. They have a serious negative impact on human health and the environment, and laws in various countries have set very strict limits on their emissions. Currently, industrial VOCs recovery methods mainly include absorption, adsorption, and condensation. Among these, membrane separation has great application prospects in the field of VOCs recovery due to its low energy consumption, significant separation effect, and simple operation. Polymer membranes have become common membrane materials in the field of VOCs separation and recovery due to their good mechanical properties and easy processing characteristics. Polyether block polyamide is a commercially produced block copolymer composed of polyamide hard segments and polyether soft segments. It has good stability, affinity, and high selectivity for VOCs, but its inherent trade-off limits the ability to simultaneously improve selectivity and permeability. Hydrogen-bonded organic frameworks (HORFORMs) are self-assembled from organic structural units through hydrogen bond interactions. They possess high porosity, large surface area, highly crystalline structure, good renewability, and mild synthesis conditions. These characteristics demonstrate the potential advantages of HORFORMs as porous packing materials for preparing hybrid matrix membranes for gas separation. However, due to the inherent differences in properties between the packing material and the polymer, interfacial defects and uneven packing material dispersion inevitably occur during the bonding process, which severely reduces the separation performance of the hybrid membrane. Summary of the Invention

[0003] To address the aforementioned shortcomings in existing technologies and improve the separation performance of hybrid membranes by overcoming interfacial defects between fillers and polymers, this invention provides a hybrid membrane based on a modified hydrogen-bonded organic framework (HBOF) filled with polyether block polyamide. The preparation of this hybrid membrane utilizes the all-organic nature of the HBOF filler. Hydrophilic segments, such as polyvinylpyrrolidone, are added to the HBOF framework framework or its surface through pre-design or post-grafting methods, thus preparing a modified HBOF. HBOF fillers are chemically stable mesoporous materials formed through hydrogen bonds and interlayer π-π interactions. Their inherent π-conjugated large aromatic ring structure can generate π-π interactions with aromatic VOCs, promoting the adsorption of VOC molecules. Furthermore, the long-range ordered mesoporous structure of the HBOF provides well-ordered channels for VOC molecules, effectively reducing the mass transfer resistance of VOC molecules. In the preparation process of the hybrid membrane of this invention, a modified hydrogen-bonded organic framework (HBR) is used as the filler. Modification with polyvinylpyrrolidone (PVP) improves the hydrophilicity of the HBR filler, thereby promoting uniform dispersion of the filler in the polyether-block polyamide casting solution. Simultaneously, the PVP segments adsorbed on the surface of the HBR filler can entangle with the polyether-block polyamide segments in the casting solution, effectively overcoming the interfacial defects between the filler and the polymer, and synergistically improving the membrane's permeability and selectivity. The preparation method of the hybrid membrane of this invention is simple to operate and highly controllable. The prepared hybrid membrane has high density. When applied to toluene / nitrogen separation and recovery, the prepared membrane exhibits high permeation flux and separation factor, as well as good stability.

[0004] To address the aforementioned technical problems, this invention proposes a hybrid membrane based on a modified hydrogen-bonded organic framework filled with polyether block polyamide. This hybrid membrane comprises a base membrane and a functional layer. The functional layer includes a polymer host and a filler. The polymer host is polyether block polyamide, and the filler is a hydrogen-bonded organic framework whose surface has been hydrophilically modified with a hydrophilic surface modifier. The hydrogen-bonded organic framework is self-assembled from carboxylic acid dimers in a solvent via intermolecular hydrogen bonding. The mass ratio of the modified hydrogen-bonded organic framework to the polyether block polyamide is 1–10:90, and the modified hydrogen-bonded organic framework has a rod-like structure with a length of 500–1000 nm.

[0005] Furthermore, in the hybrid membrane of the present invention, the hydrophilic surface modifier is any one of polyvinylpyrrolidone, polyvinyl alcohol, polyacrylamide, and polyethylene oxide; the carboxylic acid dimer includes any one of 1,3,6,8-tetra(4-carboxyphenyl)pyrene, biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid), 1,3,5-triphenyl(4-carboxyphenyl), and 1,3,5-tri(4-pyridyl)benzene.

[0006] The method for preparing this hybrid membrane includes the following steps:

[0007] Step 1, Preparation of modified hydrogen-bonded organic frameworks, including:

[0008] 1-1) Preparation of hydrogen-bonded organic frameworks, wherein the hydrogen-bonded organic frameworks are self-assembled from carboxylic acid dimers in a solvent by intermolecular hydrogen bonding; the carboxylic acid dimers include any one of 1,3,6,8-tetra(4-carboxyphenyl)pyrene, biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid), 1,3,5-triphenyl(4-carboxyphenyl) and 1,3,5-tris(4-pyridyl)benzene; preferably 1,3,6,8-tetra(4-carboxyphenyl)pyrene or biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid);

[0009] 1-2) Prepare an aqueous solution of hydrophilic surface modifier with a mass-to-volume ratio of 4-8 mg / mL. Disperse the hydrogen-bonded organic framework obtained in step 1-1) uniformly in the aqueous solution of the hydrophilic surface modifier at a mass-to-volume ratio of 2 mg / 1-3 mL using ultrasonication. Stir until homogeneous, centrifuge and wash to obtain a yellow solid. Collect the solid after vacuum drying. The product obtained after ball milling is the modified hydrogen-bonded organic framework. The hydrophilic surface modifier is any one of polyvinylpyrrolidone, polyvinyl alcohol, polyacrylamide, and polyethylene oxide, preferably polyvinylpyrrolidone.

[0010] Step 2, preparation of the hybrid membrane, including:

[0011] 2-1) The modified hydrogen-bonded organic framework obtained in step one is dispersed in an ethanol-water solution at a mass ratio of 1 to 10:900 and sonicated for 20 minutes to obtain a mixed solution. Polyether block polyamide particles are sealed in the above mixed solution, wherein the mass ratio of modified hydrogen-bonded organic framework to polyether block polyamide is 1 to 10:90. The mixture is mechanically stirred at 60 to 80°C for 4 hours, and the cells are disrupted for 20 minutes. The treated solution is filtered, allowed to stand to remove bubbles, and a casting solution is obtained.

[0012] 2-2) Using a polyacrylonitrile ultrafiltration membrane as the base membrane, the casting solution was uniformly spin-coated onto a polyacrylonitrile substrate that was flattened and fixed on a glass plate. The resulting membrane was dried at room temperature to finally obtain a polyether block polyamide hybrid membrane based on a modified hydrogen bond organic framework.

[0013] Furthermore, in the preparation method described in this invention, wherein:

[0014] In step 1-1), the hydrogen-bonded organic framework is self-assembled in a solvent by intermolecular hydrogen bonding of 1,3,6,8-tetra(4-carboxyphenyl)pyrene or biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid). The specific details are as follows: 1,3,6,8-tetra(4-carboxyphenyl)pyrene or biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid) is ultrasonically dissolved in N,N-dimethylformamide at a mass-to-volume ratio of 10-20 mg / 1-3 mL. Then, methanol is rapidly poured into the solution at a volume ratio of 10:1. The mixture is stirred evenly at room temperature, centrifuged to form a yellow suspension, washed 2-3 times with methanol or deionized water, and vacuum dried to obtain the hydrogen-bonded organic framework.

[0015] In step 1-1), the stirring time at room temperature is 4 to 24 hours; vacuum drying is performed in a vacuum oven at 80°C for 12 hours.

[0016] In steps 1-2), the stirring time is 2-6 hours, the centrifugal washing is performed 2-3 times, and the yellow solid is vacuum dried in a vacuum oven at 40-120℃ for 12 hours; the ball milling speed is 3000 rpm, and the ball milling time is 30-60 minutes.

[0017] In step 2-1), the concentration of the ethanol aqueous solution is 30-40%.

[0018] In step 2-2), drying the obtained film at room temperature means placing the obtained film in a drying box for 12-24 hours.

[0019] The hybrid membrane prepared according to this invention was used for toluene / nitrogen separation and recovery. At 25°C and with a toluene / nitrogen mixed gas of 2.2 / 97.8 mol%, the permeation flux was 1.35 × 10⁻⁶. -6 ~1.51×10 -6 molμm m -2 s -1 Pa -1 The separation factor ranged from 632 to 954, and the separation performance remained stable within 120 hours.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] In the preparation method of this invention, the hydrophilic segments on the surface of the modified hydrogen-bonded organic framework filler effectively enhance the membrane's density and thus improve selectivity by tightly binding with the polyether block polyamide. The long-range ordered mesoporous structure of the hydrogen-bonded organic framework provides regular channels for VOCs molecules, effectively reducing the mass transfer resistance of VOCs molecules within the hybrid membrane and synergistically improving the selectivity and permeability of the hybrid membrane. The hybrid membrane preparation method of this invention is simple, highly controllable, and universally applicable. The prepared hybrid membrane, used for toluene / nitrogen separation and recovery, exhibits high permeability, high selectivity, and high stability. Attached Figure Description

[0022] Figure 1 This is a cross-sectional electron microscope image of membrane 1 obtained in Example 1.

[0023] Figure 2 This is a cross-sectional electron microscope image of membrane 2 obtained in Example 2.

[0024] Figure 3 This is a cross-sectional electron microscope image of membrane 3 obtained in Example 3.

[0025] Figure 4 This is a cross-sectional electron microscope image of membrane 4 obtained in Example 4.

[0026] Figure 5 This is a cross-sectional electron microscope image of the contrast membrane obtained from the comparison. Detailed Implementation

[0027] The design concept of this invention, a modified hydrogen-bonded organic framework-filled polyether block polyamide hybrid membrane, is as follows: Utilizing the all-organic nature of the hydrogen-bonded organic framework filler, hydrophilic segments, such as polyvinylpyrrolidone, polyvinyl alcohol, polyacrylamide, or polyethylene oxide, are added to the framework or surface of the hydrogen-bonded organic framework through pre-design or post-grafting methods. This prepares a modified hydrogen-bonded organic framework that effectively improves the interfacial defects between the filler and the polymer, enhancing membrane selectivity. Simultaneously, the modified hydrogen-bonded organic framework provides additional mass transfer channels with sieving function within the dense polymer, improving membrane permeability and overcoming the "game effect" between selectivity and permeability in polymer membranes. This hybrid membrane includes a base membrane and a functional layer. The functional layer uses a rigid-flexible polyether block polyamide as the polymer host and a surface-modified hydrophilic hydrogen-bonded organic framework, such as polyvinylpyrrolidone, as the filler. The modified hydrogen-bonded organic framework and polyether block polyamide are in a mass ratio of 1–10:90. The strength of the hydrogen bond interaction can be controlled by adjusting the mass ratio of the filler to the polyether block polyamide, thereby enhancing the membrane separation performance. The hydrogen-bonded organic framework is formed by intermolecular hydrogen bonding in a solvent from substances such as 1,3,6,8-tetra(4-carboxyphenyl)pyrene, biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid), 1,3,5-triphenyl(4-carboxyphenyl) or 1,3,5-tri(4-pyridyl)benzene. The modified hydrogen-bonded organic framework is a rod-shaped structure with a length of 500-1000 nm. The preparation steps of this hybrid membrane are as follows: First, a hydrogen-bonded organic framework (HBO) is synthesized through a hydrogen-bonded self-assembly reaction of 1,3,6,8-tetra(4-carboxyphenyl)pyrene, etc. Then, the surface of the HBO is hydrophilically modified using a hydrophilic surface modifier such as polyvinylpyrrolidone, followed by ball milling to obtain nanoscale modified HBO. This modified HBO serves as a filler. The filler is then mixed with polyether block polyamide particles in an ethanol-water mixture and heated to prepare a casting solution. Using a polyacrylonitrile ultrafiltration membrane as the base membrane, the casting solution is uniformly spin-coated onto a polyacrylonitrile substrate that is flattened and fixed on a glass plate. Finally, the resulting membrane is placed in a drying oven at room temperature for 12–24 hours, ultimately yielding a polyether block polyamide hybrid membrane filled with a modified HBO. This invention provides a simple, highly controllable, and universally applicable method for preparing the hybrid membrane. The prepared hybrid membrane is used for toluene / nitrogen separation and recovery, exhibiting high permeability, high selectivity, and high stability.

[0028] The technical solution of the present invention will be further described in detail below with reference to specific examples and appendices. The specific implementation examples described are only for explanation and illustration of the present invention and are not intended to limit the present invention.

[0029] Example 1: Preparation of a modified hydrogen-bonded organic framework-filled polyether block polyamide hybrid membrane, the steps are as follows:

[0030] Step 1: Preparation of modified hydrogen-bonded organic frameworks:

[0031] 200 mg of 1,3,6,8-tetra(4-carboxyphenyl)pyrene was ultrasonically dissolved in 30 mL of N,N-dimethylformamide. Then, 300 mL of methanol was rapidly added to the solution, and the mixture was stirred at room temperature for 24 h. The resulting yellow suspension was obtained by centrifugation, followed by washing three times with methanol or deionized water, and then drying overnight in a vacuum oven at 80 °C. An 8 mg / mL polyvinylpyrrolidone aqueous solution was prepared. 200 mg of the aforementioned hydrogen-bonded organic framework was ultrasonically and uniformly dispersed in 300 mL of the polyvinylpyrrolidone aqueous solution and stirred for 6 h. After centrifugation and washing three times, a yellow solid was obtained. The obtained yellow solid was then dried in a vacuum oven at 100 °C for 12 h and collected. The dried yellow solid was ball-milled at 3000 rpm for 30–60 min, and the ball-milled product was collected as the modified hydrogen-bonded organic framework.

[0032] Step 2: Preparation of a dense polyether-block polyamide hybrid membrane:

[0033] 100 mg of the modified hydrogen-bonded organic framework obtained in step one was dispersed in 900 mg of a 40% ethanol aqueous solution and sonicated for 20 min. Then, 900 mg of polyether block polyamide particles were sealed in the above mixed solution and mechanically stirred at 80 °C for 4 h to disrupt cells for 20 min. The resulting solution was filtered and allowed to stand for 1 h to remove bubbles, yielding a casting solution. Using a polyacrylonitrile ultrafiltration membrane as the base membrane, the casting solution was uniformly spin-coated onto a polyacrylonitrile substrate that was flattened and fixed on a glass plate. Finally, the resulting membrane was placed in a drying oven at room temperature for 24 h to obtain a polyether block polyamide hybrid membrane based on the modified hydrogen-bonded organic framework. This membrane is designated as membrane 1, and the cross-sectional electron micrograph of membrane 1 is shown below. Figure 1 As shown.

[0034] Membrane 1 was used for toluene / nitrogen separation and recovery. At 25°C and with a toluene / nitrogen mixture of 2.2 / 97.8 mol%, the permeate flux was 1.51 × 10⁻⁶. -6 molμm m -2 s -1 Pa -1 The separation factor was 954, and the separation performance remained stable over 120 hours, as shown in Table 1.

[0035] Example 2: Preparation of a modified hydrogen-bonded organic framework-filled polyether block polyamide hybrid membrane, the steps are as follows:

[0036] The preparation process is basically the same as in Example 1, except that in step two, the amount of modified hydrogen-bonded organic framework is changed from 100 mg to 50 mg, and the amount of polyether block polyamide is changed from 900 mg to 950 mg, that is, the mass fraction of filler in the hybrid membrane is changed from 10% to 5%. The resulting hybrid membrane is designated as membrane 2. A cross-sectional electron microscope image of membrane 2 is shown. Figure 2 As shown.

[0037] Membrane 2 was used for toluene / nitrogen separation and recovery. At 25°C and with a toluene / nitrogen mixture of 2.2 / 97.8 mol%, the permeate flux was 1.49 × 10⁻⁶. -6 molμmm -2 s -1 Pa -1 The separation factor was 886, and the separation performance remained stable within 120 hours, as shown in Table 1.

[0038] Example 3: Preparation of a modified hydrogen-bonded organic framework-filled polyether block polyamide hybrid membrane, the steps are as follows:

[0039] The preparation process is basically the same as in Example 1, except that in step one, 200 mg of 1,3,6,8-tetra(4-carboxyphenyl)pyrene is replaced with 200 mg of biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid) to change the pore size of the hydrogen-bonded organic framework; the resulting hybrid membrane is designated as membrane 3, and the cross-sectional electron micrograph of membrane 3 is shown in Figure 3. Figure 3 As shown.

[0040] Membrane 3 was used for toluene / nitrogen separation and recovery. At 25°C and with a toluene / nitrogen mixture of 2.2 / 97.8 mol%, the permeate flux was 1.42 × 10⁻⁶. -6 molμmm -2 s -1 Pa -1 The separation factor was 795, and the separation performance remained stable within 120 hours, as shown in Table 1.

[0041] Example 4: Preparation of a modified hydrogen-bonded organic framework-filled polyether block polyamide hybrid membrane, the steps are as follows:

[0042] The preparation process is basically the same as in Example 1, except that in step one, 300 mL of 8 mg / mL polyvinylpyrrolidone aqueous solution is replaced with 300 mL of 8 mg / mL polyvinyl alcohol aqueous solution. The resulting hybrid membrane is designated as membrane 4, and the cross-sectional electron micrograph of membrane 4 is shown below. Figure 4 As shown.

[0043] Membrane 4 was used for toluene / nitrogen separation and recovery. At 25°C and with a toluene / nitrogen mixture of 2.2 / 97.8 mol%, the permeate flux was 1.39 × 10⁻⁶. -6 molμm m -2 s -1 Pa -1 The separation factor was 709, and the separation performance remained stable within 120 hours, as shown in Table 1.

[0044] Comparative example: Preparation of pure polyether block polyamide membrane, the steps are as follows:

[0045] 1000 mg of polyether block polyamide particles were sealed in an ethanol-water solution and mechanically stirred at 80 °C for 4 h. The resulting solution was filtered and allowed to stand for 1 h to remove bubbles, yielding a casting solution. Using a polyacrylonitrile ultrafiltration membrane as the base membrane, the casting solution was uniformly spin-coated onto a polyacrylonitrile substrate that was flattened and fixed on a glass plate. Finally, the resulting membrane was placed in a drying oven at room temperature for 24 h to obtain a pure ether block polyamide membrane, which was designated as the control membrane.

[0046] The control membrane was used for toluene / nitrogen separation and recovery. At 25°C and with a toluene / nitrogen mixture of 2.2 / 97.8 mol%, the permeation flux was 1.35 × 10⁻⁶. -6 molμm m -2 s -1 Pa -1 The separation factor was 632, and the separation performance remained stable over 120 hours, as shown in Table 1.

[0047] Table 1 shows the permeation flux and separation factor of comparative examples and Examples 1-4 at 25°C with a 2.2 / 97.8 mol% toluene / nitrogen mixture.

[0048]

[0049] The comparison between the comparative examples and Examples 1-4 shows that the addition of the modified hydrogen-bonded organic framework effectively improves the separation performance of the polyether block polyamide membrane for toluene / nitrogen mixed gases. In Examples 1, 2, and the comparative examples, by controlling the mass ratio of the modified hydrogen-bonded organic framework to the polyether block polyamide, the strength of hydrogen bond interactions can be effectively regulated. With increasing addition, the hydrogen bond interactions strengthen, and the membrane's affinity for toluene molecules increases, ultimately resulting in enhanced separation performance of the hybrid membrane. In Examples 3, 4, and the comparative examples, by changing the monomers used to synthesize the hydrogen-bonded organic framework and the type of hydrophilic modification, the separation performance of the hybrid membrane was also improved compared to the pure polyether block polyamide membrane. Therefore, the modified hydrogen-bonded organic framework-filled polyether block polyamide hybrid membrane for toluene / nitrogen separation proposed in this invention has broad application potential.

[0050] Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many improvements and changes under the guidance of the present invention without departing from the spirit of the present invention, and these improvements and changes are all within the protection scope of the present invention.

Claims

1. A polyether block polyamide hybrid membrane based on a modified hydrogen-bonded organic framework, characterized in that, The hybrid membrane includes a base membrane and a functional layer. The functional layer includes a polymer host and a filler. The polymer host is a polyether block polyamide, and the filler is a hydrogen-bonded organic framework that has been hydrophilically modified by a hydrophilic surface modifier. The hydrogen-bonded organic framework is self-assembled by carboxylic acid dimers in a solvent through intermolecular hydrogen bonding. The mass ratio of the modified hydrogen-bonded organic framework to the polyether block polyamide is 1 to 10:

90. The modified hydrogen-bonded organic framework has a rod-like structure with a length of 500 to 1000 nm. The hydrophilic surface modifier is any one of polyvinylpyrrolidone, polyvinyl alcohol, polyacrylamide, and polyethylene oxide; the carboxylic acid dimer includes any one of 1,3,6,8-tetra(4-carboxyphenyl)pyrene, biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid), 1,3,5-triphenyl(4-carboxyphenyl), and 1,3,5-tri(4-pyridyl)benzene.

2. A method for preparing a polyether block polyamide hybrid membrane based on a modified hydrogen-bonded organic framework as described in claim 1, characterized in that, Includes the following steps: Step 1, Preparation of modified hydrogen-bonded organic frameworks, including: 1-1) Preparation of hydrogen-bonded organic frameworks, which are self-assembled from carboxylic acid dimers in a solvent by intermolecular hydrogen bonding; 1-2) Prepare a hydrophilic surface modifier aqueous solution with a mass-volume ratio of 4-8 mg / mL. Disperse the hydrogen-bonded organic framework obtained in step 1-1) uniformly in the hydrophilic surface modifier aqueous solution by ultrasonication at a mass-volume ratio of 2 mg / 1-3 mL. Stir evenly, centrifuge and wash to obtain a yellow solid, vacuum dry and collect. The product after ball milling is the modified hydrogen-bonded organic framework. Step 2, preparation of the hybrid membrane, including: 2-1) The modified hydrogen-bonded organic framework obtained in step one is dispersed in an ethanol-water solution at a mass ratio of 1 to 10:900 and sonicated for 20 minutes to obtain a mixed solution. Polyether block polyamide particles are sealed in the above mixed solution, wherein the mass ratio of modified hydrogen-bonded organic framework to polyether block polyamide is 1 to 10:

90. The mixture is mechanically stirred at 60 to 80°C for 4 hours, and the cells are disrupted for 20 minutes. The treated solution is filtered, allowed to stand to remove bubbles, and a casting solution is obtained. 2-2) Using a polyacrylonitrile ultrafiltration membrane as the base membrane, the casting solution was uniformly spin-coated onto a polyacrylonitrile substrate that was flattened and fixed on a glass plate. The resulting membrane was dried at room temperature to finally obtain a polyether block polyamide hybrid membrane based on a modified hydrogen bond organic framework.

3. The preparation method according to claim 2, characterized in that, In step 1-1), the hydrogen-bonded organic framework is self-assembled in a solvent by intermolecular hydrogen bonding of 1,3,6,8-tetra(4-carboxyphenyl)pyrene or biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid). 1,3,6,8-tetra(4-carboxyphenyl)pyrene or biphenyl-3,3',5,5'-tetra-(phenyl-4-carboxylic acid) is ultrasonically dissolved in N,N-dimethylformamide at a mass-to-volume ratio of 10–20 mg / 1–3 mL. Then, methanol is rapidly added to the solution at a volume ratio of 10:1, and the mixture is stirred evenly at room temperature. After centrifugation, a yellow suspension is formed, which is washed 2–3 times with methanol or deionized water and then vacuum dried to obtain the hydrogen-bonded organic framework.

4. The preparation method according to claim 3, characterized in that, In step 1-1), the stirring time at room temperature is 4 to 24 hours; vacuum drying is performed in a vacuum oven at 80°C for 12 hours.

5. The preparation method according to claim 2, characterized in that, In steps 1-2), the stirring time is 2-6 hours, the centrifugal washing is performed 2-3 times, and the yellow solid is vacuum dried in a vacuum oven at 40-120℃ for 12 hours; the ball milling speed is 3000 rpm, and the ball milling time is 30-60 minutes.

6. The preparation method according to claim 2, characterized in that, In step 2-1), the concentration of the ethanol aqueous solution is 30-40%.

7. The preparation method according to claim 2, characterized in that, In step 2-2), drying the obtained film at room temperature involves placing the film in a drying box for 12-24 hours.

8. An application of a modified hydrogen-bonded organic framework-filled polyether block polyamide hybrid membrane, characterized in that, The hybrid membrane prepared according to any one of claims 2 to 7 was used for toluene / nitrogen separation, and the permeation flux was 1.39 × 10⁻⁶ at 25 °C and in a 2.2 / 97.8 mol% toluene / nitrogen mixed gas. -6 ~1.51×10 -6 molμm m -2 s -1 Pa -1 The separation factor is 709–954, and the separation performance remains stable within 120 hours.

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