Polyether block polyamide hybrid membrane filled based on modified hydrogen bond organic framework as well as preparation method and application of polyether block polyamide hybrid membrane

Abstract

The invention discloses a polyether block polyamide hybrid membrane filled based on a modified hydrogen bond organic framework, the membrane comprises a base membrane and a functional layer, the functional layer takes polyether block polyamide as a polymer main body and takes the hydrogen bond organic framework subjected to surface modification by polyvinylpyrrolidone and the like as a filler, and the mass ratio of the polyether block polyamide to the hydrogen bond organic framework is 90: (1-10). The preparation method comprises the following steps: self-assembling 1, 3, 6, 8-tetra (4-carboxybenzene) pyrene and the like in a solvent to obtain a hydrogen bond organic framework with a stick-shaped structure, and modifying the surface of the hydrogen bond organic framework by utilizing polyvinylpyrrolidone and the like; dispersing in a mixed solution of ethanol and water, blending with polyether block polyamide to obtain a membrane casting solution, spin-coating the surface of a base membrane with the membrane casting solution, and volatilizing a solvent to obtain the hybrid membrane. The operation is simple and convenient, the controllability is strong, and the universality is realized. Hydrophilic chain segments and macromolecular chain segments on the surface of the filler are mutually wound, so that the interface defect between the hydrophilic chain segments and the macromolecular chain segments is effectively overcome, and the compactness and selectivity of the membrane are improved. The hybrid membrane is used for toluene / nitrogen separation and has high permeability, high selectivity and high stability.

Description

Technical Field

[0001] The invention belongs to polymer-organic hybrid membranes, and in particular relates to the preparation of a hybrid membrane filled with polyether block polyamide by modified hydrogen bond organic framework. Background Art

[0002] Volatile organic compounds are a typical type of polluting gas, mainly including aromatics, alkanes, olefins and aldehydes, which have serious negative impacts on people's lives, health and living environment. The laws of countries around the world have set very strict limit requirements for their emissions. At present, the main methods for recovering VOCs in industry are: absorption method, adsorption method, condensation method, etc. Among them, membrane separation method 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 block copolymer that has been commercially produced and consists 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 selectivity and permeability from being improved at the same time. Hydrogen-bonded organic frameworks are self-assembled from organic units through hydrogen-bonding interactions. They have high porosity, large surface area, highly crystalline structure, good reproducibility, and mild synthesis conditions. These characteristics demonstrate the potential advantages of hydrogen-bonded organic frameworks as porous fillers for preparing mixed matrix membranes for gas separation. However, due to the differences in the inherent properties of fillers and polymers, interface defects and uneven dispersion of fillers are inevitable during the combination process, which seriously reduces the separation performance of hybrid membranes. Summary of the invention

[0003] In view of the above-mentioned prior art, in order to overcome the interface defects between the filler and the polymer and improve the separation performance of the hybrid membrane, the present invention provides a hybrid membrane based on a modified hydrogen-bonded organic framework filled with polyether block polyamide. The preparation of the hybrid membrane utilizes the fully organic characteristics of the hydrogen-bonded organic framework filler, and a hydrophilic segment such as polyvinyl pyrrolidone is added to the hydrogen-bonded organic framework skeleton or surface by a pre-design or post-grafting method to prepare a modified hydrogen-bonded organic framework. The hydrogen-bonded organic framework filler is a chemically stable mesoporous material formed by hydrogen bonds and interlayer π-π interactions. Its own π-conjugated large aromatic ring structure can produce π-π interactions with aromatic VOCs to promote the adsorption of VOCs molecules. In addition, the long-range ordered mesoporous structure of the hydrogen-bonded organic framework provides a regular channel for VOCs molecules, effectively reducing the mass transfer resistance of VOCs molecules. In the preparation process of the hybrid membrane of the present invention, the modified hydrogen-bonded organic framework is used as a filler, and the modification of polyvinyl pyrrolidone improves the hydrophilicity of the hydrogen-bonded organic framework filler, thereby promoting the uniform dispersion of the filler in the polyether block polyamide casting solution, and at the same time, the polyvinyl pyrrolidone segments adsorbed on the surface of the hydrogen-bonded organic framework filler can be mutually entangled with the polyether block polyamide block in the casting solution, effectively overcoming the interface defect problem between the filler and the polymer, and synergistically improving the permeability and selectivity of the membrane. The preparation method of the hybrid membrane of the present invention is simple to operate and the process is highly controllable. The prepared hybrid membrane has high density. The prepared membrane is applied to toluene / nitrogen separation and recovery, and has high permeation flux and separation factor and good stability.

[0004] In order to solve the above technical problems, the present invention proposes a hybrid membrane based on a modified hydrogen-bonded organic framework filled with polyether block polyamide, the hybrid membrane includes a base membrane and a functional layer, the functional layer includes a polymer body and a filler, the polymer body is a polyether block polyamide, the filler is a hydrogen-bonded organic framework whose surface is hydrophilically modified by a hydrophilic surface modifier, the hydrogen-bonded organic framework is self-assembled by carboxylic acid dimers in a solvent by intermolecular hydrogen bonding, the mass ratio of the modified hydrogen-bonded organic framework to the polyether block polyamide is 1 to 10:90, and the modified hydrogen-bonded organic framework is a stick-like structure with a length of 500 to 1000 nm.

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

[0006] The preparation method of the hybrid membrane comprises the following steps:

[0007] Step 1: Preparation of a modified hydrogen-bonded organic framework, comprising:

[0008] 1-1) preparing a hydrogen-bonded organic framework, which is self-assembled by carboxylic acid dimers in a solvent by intermolecular hydrogen bonding; the carboxylic acid dimers include any one of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, biphenyl-3,3',5,5'-tetrakis-(phenyl-4-carboxylic acid), 1,3,5-triphenyl(4-carboxyphenyl)pyrene and 1,3,5-tri(4-pyridyl)benzene; preferably 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene or biphenyl-3,3',5,5'-tetrakis-(phenyl-4-carboxylic acid);

[0009] 1-2) preparing a hydrophilic surface modifier aqueous solution with a mass volume ratio of 4 to 8 mg / mL, ultrasonically uniformly dispersing the hydrogen-bonded organic framework obtained in step 1-1) in the hydrophilic surface modifier aqueous solution at a mass volume ratio of 2 mg / 1 to 3 mL, stirring evenly, centrifuging and washing to obtain a yellow solid, vacuum drying and collecting, and the product after ball milling is a modified hydrogen-bonded organic framework; the hydrophilic surface modifier is any one of polyvinyl pyrrolidone, polyvinyl alcohol, polyacrylamide and polyethylene oxide, preferably polyvinyl pyrrolidone;

[0010] Step 2: Preparation of hybrid membrane, comprising:

[0011] 2-1) dispersing the modified hydrogen-bonded organic framework obtained in step 1 in an ethanol aqueous solution at a mass ratio of 1 to 10:900 and ultrasonically treating for 20 minutes to obtain a mixed solution, and sealing the polyether block polyamide particles in the mixed solution, wherein the mass ratio of the modified hydrogen-bonded organic framework to the polyether block polyamide is 1 to 10:90; mechanically stirring at 60 to 80° C. for 4 hours, disrupting the cells for 20 minutes, filtering the treated solution, and standing to degas, to obtain a casting solution;

[0012] 2-2) Using polyacrylonitrile ultrafiltration membrane as base membrane, the casting solution is evenly spin-coated on a polyacrylonitrile substrate flatly fixed on a glass plate, and the obtained membrane is dried at room temperature to finally obtain a hybrid membrane based on a modified hydrogen bonded organic framework filled with polyether block polyamide.

[0013] Furthermore, the preparation method of the present invention, wherein:

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

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

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

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

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

[0019] The hybrid membrane prepared by the present invention is used for toluene / nitrogen separation and recovery. At 25°C and 2.2 / 97.8 mol % toluene / nitrogen mixed gas, the permeation flux is 1.35×10 -6 ~1.51×10 -6 molμm m -2 s -1 Pa -1 , the separation factor is 632~954, and the separation performance remains stable within 120h.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] In the preparation method of the present invention, the hydrophilic segments on the surface of the modified hydrogen-bonded organic framework filler are tightly combined with the polyether block polyamide, which effectively improves the density of the membrane and thus improves the selectivity. The long-range ordered mesoporous structure of the hydrogen-bonded organic framework provides a regular channel for VOCs molecules, effectively reduces the mass transfer resistance of VOCs molecules in the hybrid membrane, and synergistically improves the selectivity and permeability of the hybrid membrane. The preparation method of the hybrid membrane of the present invention is simple, the process is highly controllable, and the method is universal. The prepared hybrid membrane is used for toluene / nitrogen separation and recovery, and has the characteristics of high permeability, high selectivity, and high stability. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0026] Figure 5 This is a cross-sectional electron micrograph of a comparative film obtained in a comparative example. DETAILED DESCRIPTION

[0027] The design idea of ​​the modified hydrogen-bonded organic framework filled polyether block polyamide hybrid membrane of the present invention is: utilizing the fully organic characteristics of the hydrogen-bonded organic framework filler, adding hydrophilic segments such as polyvinyl pyrrolidone, polyvinyl alcohol, polyacrylamide or polyethylene oxide to the hydrogen-bonded organic framework skeleton or surface by pre-design or post-grafting methods, and preparing a modified hydrogen-bonded organic framework to effectively improve the interface defects between the filler and the polymer, and improve the selectivity of the membrane. At the same time, the modified hydrogen-bonded organic framework provides an additional mass transfer channel with a sieving effect inside the dense polymer, improves the permeability of the membrane, and overcomes the "game effect" of selectivity and permeability in the polymer membrane. The hybrid membrane includes a base membrane and a functional layer, in which the rigid and flexible polyether block polyamide is used as the polymer body, and the surface hydrophilic modified hydrogen-bonded organic framework such as polyvinyl pyrrolidone is used as the filler. The modified hydrogen-bonded organic framework and the polyether block polyamide are in a mass ratio of 1 to 10:90, and the hydrogen bonding strength can be adjusted by adjusting the mass ratio of the filler to the polyether block polyamide to enhance the membrane separation performance. The hydrogen-bonded organic framework is self-assembled by intermolecular hydrogen bonding in a solvent, such as 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, biphenyl-3,3',5,5'-tetrakis-(phenyl-4-carboxylic acid), 1,3,5-triphenyl(4-carboxybenzene) or 1,3,5-tri(4-pyridyl)benzene, and the modified hydrogen-bonded organic framework is a stick-like structure with a length of 500 to 1000 nm. The preparation steps of the hybrid membrane are mainly as follows: first, a hydrogen-bonded organic framework is synthesized by a hydrogen-bonded self-assembly reaction of 1,3,6,8-tetra(4-carboxyphenyl)pyrene, etc., and then a hydrophilic surface modifier such as polyvinyl pyrrolidone is used to hydrophilically modify the surface of the hydrogen-bonded organic framework and then ball-mill to obtain a modified hydrogen-bonded organic framework of nanometer size, the modified hydrogen-bonded organic framework is a filler, the filler is mixed and heated with polyether block polyamide particles in an ethanol-water mixed solution to prepare a casting liquid, a polyacrylonitrile ultrafiltration membrane is used as a base membrane, the casting liquid is evenly spin-coated on a polyacrylonitrile substrate that is flatly fixed on a glass plate, and finally the obtained membrane is placed in a film drying box at room temperature for 12 to 24 hours, and finally a hybrid membrane based on a modified hydrogen-bonded organic framework filled with polyether block polyamide is obtained. The hybrid membrane preparation method of the present invention is simple, the process is highly controllable, and the method has universal applicability. The prepared hybrid membrane is used for toluene / nitrogen separation and recovery, and has the characteristics of high permeability, high selectivity, and high stability.

[0028] The technical solution of the present invention is further described in detail below in conjunction with specific examples and appendices. The specific implementation examples described are only used to explain 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 framework:

[0031] 200 mg of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene was ultrasonically dissolved in 30 mL of N,N-dimethylformamide, and then 300 mL of methanol was quickly poured into the above solution and stirred at room temperature for 24 hours. The yellow suspension formed was obtained under the action of a centrifuge, and then washed with methanol or deionized water for 3 times, and then dried in a vacuum oven at 80°C for one night. 8 mg / mL polyvinyl pyrrolidone aqueous solution was prepared, 200 mg of the above hydrogen-bonded organic framework was ultrasonically uniformly dispersed in 300 mL of polyvinyl pyrrolidone aqueous solution and stirred for 6 hours, centrifuged and washed 3 times to obtain a yellow solid, and finally the obtained yellow solid was placed in a vacuum oven at 100°C for 12 hours and dried before collection; the dried yellow solid was ball-milled at 3000 rpm for 30 to 60 minutes, and the ball-milled product was collected as the modified hydrogen-bonded organic framework.

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

[0033] Take 100 mg of the modified hydrogen-bonded organic framework obtained in step 1 and disperse it in 900 mg of 40% ethanol aqueous solution, ultrasonicate for 20 minutes, then seal 900 mg of polyether block polyamide particles in the above mixed solution, mechanically stir at 80°C for 4 hours, break the cells for 20 minutes, filter the obtained solution, let it stand for 1 hour to degas, and obtain the casting liquid; use the polyacrylonitrile ultrafiltration membrane as the base membrane, and evenly spin-coat the casting liquid on the polyacrylonitrile substrate fixed flat on the glass plate, and finally place the obtained membrane in a film drying box at room temperature for 24 hours, and finally obtain a hybrid membrane based on the modified hydrogen-bonded organic framework filled with polyether block polyamide. This membrane is denoted as membrane 1, and the cross-sectional electron micrograph of membrane 1 is shown in the figure. Figure 1 shown.

[0034] Membrane 1 was used for toluene / nitrogen separation and recovery. At 25°C and 2.2 / 97.8 mol% toluene / nitrogen mixed gas, the permeation flux was 1.51×10 -6 molμm m -2 s -1 Pa -1 , the separation factor is 954, and the separation performance remains stable within 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 that of Example 1, except that the amount of modified hydrogen-bonded organic framework in step 2 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 hybrid membrane finally obtained is recorded as membrane 2, and the cross-sectional electron micrograph of membrane 2 is shown in FIG. Figure 2 shown.

[0037] Membrane 2 was used for toluene / nitrogen separation and recovery. At 25 °C and 2.2 / 97.8 mol % toluene / nitrogen mixed gas, the permeation flux was 1.49 × 10 -6 molμmm -2 s -1 Pa -1 , the separation factor is 886, and the separation performance remains 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 that of Example 1, except that in step 1, 200 mg of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene is replaced by 200 mg of biphenyl-3,3',5,5'-tetrakis-(phenyl-4-carboxylic acid) to change the pore size of the hydrogen-bonded organic framework; the hybrid membrane finally obtained is recorded as membrane 3, and the cross-sectional electron micrograph of membrane 3 is shown in FIG. Figure 3 shown.

[0040] Membrane 3 was used for toluene / nitrogen separation and recovery. At 25 °C and 2.2 / 97.8 mol % toluene / nitrogen mixed gas, the permeation flux was 1.42 × 10 -6 molμmm -2 s -1 Pa -1 , the separation factor is 795, and the separation performance remains 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 that of Example 1, except that in step 1, 300 mL of 8 mg / mL polyvinyl pyrrolidone aqueous solution is replaced by 300 mL of 8 mg / mL polyvinyl alcohol aqueous solution. The hybrid membrane finally obtained is recorded as membrane 4. The cross-sectional electron micrograph of membrane 4 is shown in FIG. Figure 4 shown.

[0043] Membrane 4 was used for toluene / nitrogen separation and recovery. At 25°C and 2.2 / 97.8 mol% toluene / nitrogen mixed gas, the permeation flux was 1.39×10 -6 molμm m -2 s -1 Pa -1 , the separation factor is 709, and the separation performance remains stable within 120 hours. As shown in Table 1.

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

[0045] 1000 mg of polyether block polyamide particles were sealed in an ethanol aqueous solution and mechanically stirred at 80°C for 4 hours. The obtained solution was filtered and allowed to stand for 1 hour for degassing to obtain a casting liquid. Using a polyacrylonitrile ultrafiltration membrane as a base membrane, the casting liquid was evenly spin-coated on a polyacrylonitrile substrate flatly fixed on a glass plate. Finally, the obtained membrane was placed in a film drying box at room temperature for 24 hours to obtain a pure ether block polyamide membrane, which was recorded as a comparison membrane.

[0046] The comparative membrane was used for toluene / nitrogen separation and recovery. At 25°C and 2.2 / 97.8 mol% toluene / nitrogen mixed gas, the permeation flux was 1.35×10 -6 molμm m -2 s -1 Pa -1 , the separation factor is 632, and the separation performance remains stable within 120 hours. As shown in Table 1.

[0047] Table 1 shows the permeation flux and separation factor of the comparative example and Examples 1 to 4 at 25° C. and 2.2 / 97.8 mol % toluene / nitrogen mixed gas.

[0048]

[0049] By comparing the above comparative examples with Examples 1 to 4, it can be seen that the addition of the modified hydrogen-bonded organic framework can effectively improve the separation performance of the polyether block polyamide membrane for toluene / nitrogen mixed gas; in the above Examples 1, 2 and the comparative example, by controlling the mass ratio of the modified hydrogen-bonded organic framework to the polyether block polyamide, the strength of the hydrogen bond interaction can be effectively regulated. As the amount of addition increases, the hydrogen bond interaction is enhanced, and the affinity of the membrane for toluene molecules is improved, which ultimately manifests as the enhanced separation performance of the hybrid membrane; in the above Examples 3, 4 and the comparative example, by changing the monomers of the synthetic hydrogen-bonded organic framework and the type of hydrophilic modification, the separation performance of the hybrid membrane is also improved compared to the pure polyether block polyamide membrane. It can be seen that the modified hydrogen-bonded organic framework filled polyether block polyamide hybrid membrane for toluene / nitrogen separation proposed by the present 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 above-mentioned specific embodiments, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can make many improvements and changes without departing from the purpose of the present invention, which are all within the protection of the present invention.

Claims

1. A hybrid membrane based on a modified hydrogen-bonded organic framework filled with polyether block polyamide, characterized in that: The hybrid membrane comprises a base membrane and a functional layer, wherein the functional layer comprises a polymer body and a filler, wherein the polymer body is a polyether block polyamide, and the filler is a hydrogen-bonded organic framework whose surface is hydrophilically modified by a hydrophilic surface modifier, wherein the hydrogen-bonded organic framework is self-assembled by carboxylic acid dimers in a solvent through intermolecular hydrogen bonding, wherein the mass ratio of the modified hydrogen-bonded organic framework to the polyether block polyamide is 1 to 10:90, and the modified hydrogen-bonded organic framework is a stick-shaped structure with a length of 500 to 1000 nm.

2. The modified hydrogen bond organic framework filled polyether block polyamide hybrid membrane according to claim 1, characterized in that: The hydrophilic surface modifier is any one of polyvinyl pyrrolidone, polyvinyl alcohol, polyacrylamide and polyethylene oxide; the carboxylic acid dimer includes any one of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, biphenyl-3,3',5,5'-tetrakis-(phenyl-4-carboxylic acid), 1,3,5-triphenyl(4-carboxybenzene) and 1,3,5-tri(4-pyridyl)benzene.

3. A method for preparing a hybrid membrane based on a modified hydrogen-bonded organic framework filled with polyether block polyamide as claimed in claim 1, characterized in that: The following steps are involved: Step 1: Preparation of a modified hydrogen-bonded organic framework, comprising: 1-1) preparing a hydrogen-bonded organic framework, wherein the hydrogen-bonded organic framework is self-assembled by carboxylic acid dimers in a solvent by intermolecular hydrogen bonding; the carboxylic acid dimers include any one of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, biphenyl-3,3',5,5'-tetrakis-(phenyl-4-carboxylic acid), 1,3,5-triphenyl(4-carboxybenzene) and 1,3,5-tri(4-pyridyl)benzene; 1-2) preparing a hydrophilic surface modifier aqueous solution with a mass volume ratio of 4 to 8 mg / mL, ultrasonically uniformly dispersing the hydrogen-bonded organic framework obtained in step 1-1) in the hydrophilic surface modifier aqueous solution at a mass volume ratio of 2 mg / 1 to 3 mL, stirring evenly, centrifuging and washing to obtain a yellow solid, vacuum drying and collecting, and the product after ball milling is a modified hydrogen-bonded organic framework; the hydrophilic surface modifier is any one of polyvinyl pyrrolidone, polyvinyl alcohol, polyacrylamide and polyethylene oxide; Step 2: Preparation of hybrid membrane, comprising: 2-1) dispersing the modified hydrogen-bonded organic framework obtained in step 1 in an ethanol aqueous solution at a mass ratio of 1 to 10:900 and ultrasonically treating for 20 minutes to obtain a mixed solution, and sealing the polyether block polyamide particles in the mixed solution, wherein the mass ratio of the modified hydrogen-bonded organic framework to the polyether block polyamide is 1 to 10:90; mechanically stirring at 60 to 80° C. for 4 hours, disrupting the cells for 20 minutes, filtering the treated solution, and standing to degas, to obtain a casting solution; 2-2) Using polyacrylonitrile ultrafiltration membrane as base membrane, the casting solution is evenly spin-coated on a polyacrylonitrile substrate flatly fixed on a glass plate, and the obtained membrane is dried at room temperature to finally obtain a hybrid membrane based on a modified hydrogen bonded organic framework filled with polyether block polyamide.

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

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

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

7. The preparation method according to claim 3, characterized in that: In step 2-1), the concentration of the ethanol aqueous solution is 30-40%.

8. The preparation method according to claim 3, characterized in that: In step 2-2), the obtained film is dried at room temperature by placing the obtained film in a film drying box for 12 to 24 hours.

9. An application of a polyether block polyamide hybrid membrane filled with a modified hydrogen bonded organic framework, characterized in that: The hybrid membrane prepared by the preparation method according to any one of claims 3 to 8 was used for toluene / nitrogen separation. At 25°C and 2.2 / 97.8 mol% toluene / nitrogen mixed gas, the permeation flux was 1.39×10 -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 120h.

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