A high-load hydrogen-bonded organic framework mixed matrix membrane based on a solvent bridging strategy and its preparation method and application

Abstract

The present invention provides a high-load hydrogen-bonded organic framework mixed matrix membrane based on a solvent bridging strategy, as well as a preparation method and application thereof. The invention uses a quaternary ammonium anion exchange membrane AEM as a base membrane, a polyaminotriazine hydrogen-bonded organic framework HOFs as a modifier, and an asymmetric structure disubstituted halogenated acid as a bridging solvent. By utilizing the characteristics that the acid radical of the bridging solvent and the quaternary ammonium group of the AEM base membrane undergo electrostatic interaction, and the halogen and the amino group of the HOFs undergo hydrogen bonding, effective bridging between the quaternary ammonium anion exchange membrane AEM and the polyaminotriazine hydrogen-bonded organic framework HOFs is achieved, thereby increasing the loading amount of HOFs on the AEM base membrane and preparing a high-load HOFs mixed matrix membrane.

Description

Technical Field

[0001] The present invention relates to the technical field of anionic separation membranes, and in particular to a high-load hydrogen-bonded organic framework mixed matrix membrane based on a solvent bridging strategy, and a preparation method and application thereof. Background Art

[0002] Membrane separation technology has attracted widespread attention due to its high efficiency, energy conservation, and environmental friendliness. It holds broad application prospects in areas such as ion resource extraction and recovery, environmental remediation, and industrial wastewater treatment. The realization of efficient membrane separation processes depends largely on the careful selection of membrane materials.

[0003] The ion-sieving performance of polymer membranes is limited by their wide channel size distribution and low porosity, making it difficult to overcome the "trade-off" effect between permeability and selectivity. While porous crystalline membranes, such as covalent organic frameworks (COFs), metal-organic frameworks (MOFs), and hydrogen-bonded organic frameworks (HOFs), possess rich, regular pore structures, they suffer from weak mechanical strength and the difficulty of producing large, defect-free membranes, limiting their widespread use. Incorporating crystalline porous materials with uniform pore sizes into polymer matrices to create mixed-matrix membranes offers an effective approach to addressing the current challenges of efficient ion sieving.

[0004] Desalination, 2024, 576, 117352 reported a MOFs mixed matrix membrane prepared by a blending method. Due to the poor compatibility between MOFs and the matrix, an interfacial gap appeared in the membrane when the MOFs loading was 7.5%. In addition, due to the low content of MOFs, the additional ion transport path introduced into the membrane was less, and Cl - The transport rate is only 0.504 mol m -2 h -1 .

[0005] Chinese patent CN115869791A discloses a method for preparing and applying a porous organic cage mixed matrix membrane. Using a cosolvent method, porous organic cages CC3 and polymers are dissolved in a mixed solvent to prepare a mixed matrix membrane with good compatibility. The CC3 loading can reach up to 30%. However, due to the slow crystallization rate of CC3 during solvent evaporation, the resulting porous structure has an uneven size distribution, and the cage-like CC3 is in an amorphous state. - / SO4 2- The maximum separation performance is only 10.8.

[0006] Therefore, under the premise of high loading, ensuring the stability of the filler framework structure and compatibility with the matrix is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0007] To address the shortcomings of this field, the present invention proposes a high-HOF-loading mixed-matrix membrane based on a solvent-bridging strategy. By leveraging the asymmetric disubstituted groups at both ends of the solvent to form hydrogen bonds and electrostatic interactions with the HOF modifier and the AEM base membrane, this bridges the gap and promotes uniform distribution of HOFs across the membrane. Furthermore, HOFs crystallize confined within the membrane, forming a small, flake-like morphology, further improving compatibility with the polymer matrix. This results in a high-HOF-loading mixed-matrix membrane with superior mono- and divalent anion sieving performance.

[0008] The present invention provides a high-load HOFs mixed matrix membrane based on a solvent bridging strategy, which uses AEM as a base membrane, polyaminotriazine hydrogen-bonded organic frameworks (HOFs) as a modifier, and an asymmetric disubstituted halogenated acid as a bridging solvent. The acid groups of the bridging solvent are electrostatically interacted with the quaternary ammonium groups of the AEM base membrane, and the halogens are hydrogen-bonded with the amino groups of the HOFs, thereby achieving effective bridging between the AEM base membrane and the HOFs, increasing the loading of HOFs on the AEM base membrane, and preparing a high-load HOFs mixed matrix membrane.

[0009] In the present invention, the basic principle of the solvent bridging strategy is:

[0010] The basic principle of the solvent bridging strategy is to utilize the electrostatic interaction between the acid groups in the asymmetric disubstituted halogenated acid molecules and the quaternary ammonium groups of the AEM base membrane, and the hydrogen bonding between the halogen and the amino groups of HOFs to achieve the bridging between the AEM base membrane and HOFs.

[0011] In the present invention, the AEM base film has the following structural formula:

[0012]

[0013] Wherein, R2 is H or an alkyl group having 1 to 7 carbon atoms.

[0014] Ar1 is an aromatic hydrocarbon group, and the aromatic hydrocarbon group has the following structure

[0015] 、 、 and One of them.

[0016] In the present invention, the polyaminotriazine hydrogen bond organic framework HOFs modifier has the following structure:

[0017] 、 、 and One of the following;

[0018] Wherein, R3 is H or an alkyl group having 1-2 C atoms.

[0019] Ar2 is an aromatic hydrocarbon group, and the aromatic hydrocarbon group has the following structure

[0020] 、 and One of the following;

[0021] DAT1 and DAT2 have the following structural formulas:

[0022]

[0023] In the present invention, the halogenated acid bridging solvent has the following structural characteristics:

[0024] X n —R1—AH m

[0025] Wherein X is one or a combination of two or more of F, Cl, Br, and I, and n is 1-3;

[0026] R1 is an alkyl group having 1 to 20 carbon atoms;

[0027] AH is an acidic functional group such as a carboxylic acid group, a sulfonic acid group or a phosphoric acid group, and m is 1-3.

[0028] The halogenated acid bridging solvent includes but is not limited to trifluoroacetic acid (TFA), trifluoromethanesulfonic acid (TFSA), trifluoropropionic acid, dichloroacetic acid, trichloroacetic acid, and the like.

[0029] In the present invention, the preparation method of the HOFs mixed matrix membrane is briefly described as follows:

[0030] S1: AEM base film and halogenated acid are mixed in a mass ratio of 1:(1-20), homogenized and allowed to stand for 1-6 hours until the bonding between the functional groups is completed. This is referred to as solution A.

[0031] S2: HOFs and halogenated acid are mixed in a mass ratio of 1:(1-20), homogenized and allowed to stand for 1-6 hours until the bonding between the functional groups is completed, which is recorded as solution B;

[0032] S3: Mix solution A and solution B at a mass ratio of A:B = 1:(0.1-0.5), homogenize, and let stand for 1-6 hours to complete interfunctional group bridging, resulting in a clear, transparent film solution. Apply the clear film solution to a glass plate and evaporate the solvent at 20°C-80°C to prepare a high-HOF-loading mixed matrix membrane based on the solvent-bridging strategy.

[0033] The second aspect of the present invention provides a high-load HOFs mixed matrix membrane based on a solvent bridging strategy obtained according to the above preparation method.

[0034] The third aspect of the present invention provides the high-load HOFs mixed matrix membrane based on the solvent bridging strategy for anion separation, wherein the anion is Cl - / SO4 2- , F - / SO4 2- , Br - / SO4 2- , NO3 - / SO4 2- One or more of the above, wherein the anion separation is carried out by electrodialysis, and the electrodialysis current density is 0.1-20 mA cm -2 , preferably 5 mA cm -2 .

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The HOFs used in the present invention have regular and orderly ion transport channels and a pore structure formed by self-assembly of flexible hydrogen bonds. The pore size can be adaptively adjusted during the ion transport process, thereby reducing the ion transport energy barrier and improving the ion transport rate.

[0037] (2) The present invention utilizes asymmetric halogenated acid to form hydrogen bonds with HOFs and electrostatic interactions with the AEM base membrane, thereby promoting the uniform distribution of HOFs on the base membrane, enhancing the compatibility between HOFs and the matrix, further increasing the loading capacity, increasing the ion transport path within the membrane, and improving the ion transport rate.

[0038] (3) The present invention utilizes the cation-π interaction between the quaternary ammonium group and the aromatic ring to confine the HOFs structural unit to the vicinity of the quaternary ammonium group for in situ crystallization, thereby producing smaller HOFs crystals with a flake-like morphology in the membrane, thereby improving the compatibility between the polymer and the filler and the filler loading capacity, and enhancing the ion screening effect.

[0039] (4) The preparation method of the present invention is simple, and the HOFs loading of the prepared membrane can reach up to 50%. At the same time, it has excellent ion transmission rate and screening effect, breaking the "trade-off" effect between permeability and selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of the bridging principle of the solvent bridging strategy;

[0041] Figure 2These are digital photos of TFA dissolving H1OFs (A), TFA dissolving QPAB-E (B), and the two blended (C) in Example 1. The images show that QPAB-E and H1OFs are uniformly mixed.

[0042] The structural formula of H1OFs is as follows:

[0043]

[0044] The structural formula of QPAB-E is as follows:

[0045] .

[0046] Figure 3 The infrared spectra of H1OFs powder (A) and H1OFs solution in TFA (B) in Example 1 are shown. It can be seen from the figure that TFA is partially deprotonated to form carboxylate groups, while the amino groups in H1OFs are protonated in the solution.

[0047] Figure 4 The X-ray diffraction comparison diagram of the mixed matrix membranes with different H1OFs contents in Comparative Example 1 and Example 3. It can be seen from the figure that H1OFs crystallize in the membrane after the solvent evaporates.

[0048] Figure 5 The infrared spectra of the mixed matrix membranes with different H1OFs contents in Comparative Example 1 and Example 3 are compared. As can be seen from the figure, the mixed matrix membranes show characteristic diffraction peaks of H1OFs and polymers, indicating that both H1OFs and polymers can be stably present in the mixed matrix membranes.

[0049] Figure 6 Scanning electron micrographs (SEM) of the surface (A) and cross-section (B) of a 50% H1-QPAB-E membrane prepared using the solvent-bridging strategy in Example 3, and of the surface (C) and cross-section (D) of a 50% H1+QPAB-E membrane prepared using the traditional blending method. The images demonstrate that the membrane prepared using the solvent-bridging strategy is dense and defect-free, with H1OFs uniformly distributed throughout the membrane.

[0050] Figure 7 Scanning electron micrographs (SEM) of H1OFs in a solvent-bridging strategy membrane (A) and a conventional blend membrane (B) show the structural morphology of H1OFs within the membrane, obtained by washing away the QPAB-E matrix with dimethyl sulfoxide. The images show that H1OFs crystallize within the membrane in a smaller, flake-like form, contributing to increased H1OF loading within the membrane. DETAILED DESCRIPTION

[0051] In order to facilitate the understanding of the present invention, the preparation method and application of a high-load HOFs mixed matrix membrane based on a solvent bridging strategy provided by the present invention are described in detail below with reference to the accompanying drawings and specific examples. Obviously, the described embodiments are only part of the embodiments of the present invention and they should not be understood as limiting the scope of protection of the present invention.

[0052] Comparative Example 1

[0053] 1. In this comparative example, no hydrogen-bonding organic frameworks (HOFs) were added, and the membrane was a pure polymer membrane.

[0054] The preparation method of pure polymer membrane is briefly described as follows:

[0055] S1: Dissolve 0.1 g of QPAB-E in 1 mL of TFA solution, mix well, and let stand for 2 h to obtain a clear and transparent membrane solution. Then, apply the membrane solution to a glass plate and evaporate the solvent at 30°C to obtain a pure polymer anion separation membrane.

[0056] 2. The QPAB-E separation membrane prepared in this comparative example was applied to electrodialysis to separate Cl from the mixed solution. - / SO4 2- , F - / SO4 2- , Br - / SO4 2- and NO3 - / SO4 2- .

[0057] The QPAB-E anion separation membrane prepared in this comparative example was placed between the concentrating and desalting compartments of an electrodialysis device. The two outermost compartments contained a 0.3 M Na2SO4 buffer solution, while the two middle compartments served as the desalting and concentrating compartments, respectively. The desalting compartment contained 0.1 M NaCl / Na2SO4, NaF / Na2SO4, NaBr / Na2SO4, and NaNO3 / Na2SO4 mixed solutions, respectively, while the concentrating compartment contained a 0.01 M NaNO3 solution with a volume of 200 mL. The commercial cation exchange membrane used was a CMX membrane manufactured by ASTOM of Japan. The test lasted for 1 hour, and anion concentrations in the concentrating compartment were measured using an IC 6000 ion chromatograph. The transport rate and selectivity of each anion were calculated based on the concentrations.

[0058] The test results show that QPAB-E membrane Cl - The transport rate is 3.4 mol m -2 h -1 , corresponding to Cl - / SO4 2- The selectivity is 8.7; F -The transport rate is 2.9 mol m -2 h -1 , corresponding to F - / SO4 2- The selectivity is 7.1; Br - The transport rate is 3.7 mol m -2 h -1 , corresponding to Br - / SO4 2- Selectivity is 13.2; NO3 - The transport rate is 3.6 mol m -2 h -1 , corresponding to NO3 - / SO4 2- The selectivity is 10.3.

[0059] Comparative Example 2

[0060] 1. In this comparative example, no hydrogen-bonding organic frameworks (HOFs) were added, and the membrane was a pure polymer membrane.

[0061] The preparation method of pure polymer membrane is briefly described as follows:

[0062] S1: Dissolve 0.1 g of QPAB-H in 1 mL of TFA solution, mix well, and let stand for 2 h to obtain a clear, transparent membrane solution. Then, apply the membrane solution to a glass plate and evaporate the solvent at 30°C to obtain a pure polymer anion separation membrane. The structural formula of QPAB-H is as follows:

[0063]

[0064] 2. The QPAB-H separation membrane prepared in this comparative example was applied to electrodialysis to separate Cl - / SO4 2- , F - / SO4 2- , Br - / SO4 2- and NO3 - / SO4 2- .

[0065] The electrodialysis method was the same as that in Comparative Example 1.

[0066] The test results show that QPAB-H membrane Cl - The transport rate is 3.7 mol m -2 h -1 , corresponding to Cl - / SO4 2- The selectivity is 6.5; F - The transport rate is 3.1 mol m -2 h-1 , corresponding to F - / SO4 2- The selectivity is 5.3; Br - The transport rate is 3.9 mol m -2 h -1 , corresponding to Br - / SO4 2- Selectivity is 10.2; NO3 - The transport rate is 3.8 mol m -2 h -1 , corresponding to NO3 - / SO4 2- The selectivity is 8.6.

[0067] Example 1

[0068] 1. A method for preparing a high-load HOFs mixed matrix membrane based on a solvent bridging strategy. The brief steps are as follows:

[0069] S1: Dissolve 0.1 g of QPAB-E in 1 g of TFA solution and mix homogenously. Let it stand for 2 h until the bonding between functional groups is completed. This solution is called solution A.

[0070] S2: Dissolve 0.1 g of H1OFs in 1 g of TFA solution and mix homogeneously. Let it stand for 2 h until the bonding between the functional groups is completed. This solution is called solution B.

[0071] S3: Solution A and solution B were mixed at a mass ratio of A:B = 1:0.1 and allowed to stand for 2 h until the bridging between the functional groups was completed to obtain a clear and transparent membrane liquid. Finally, the membrane liquid was scraped onto a glass plate and the solvent was evaporated at 30°C to obtain a high-loading HOFs mixed matrix membrane based on the solvent bridging strategy, which was recorded as 10% H1-QPAB-E.

[0072] 2. The 10% H1-QPAB-E anion separation membrane prepared in this example was applied to electrodialysis to separate Cl - / SO4 2- .

[0073] The electrodialysis method was the same as that in Comparative Example 1.

[0074] The test results show that 10% H1-QPAB-E anion separation membrane Cl - The transport rate is 3.3 mol m -2 h -1 , corresponding to Cl - / SO4 2- The selectivity is 26.5. Compared with the pure polymer membrane in Comparative Example 1, the 10% H1-QPAB-E anion separation membrane prepared in this example has a higher selectivity for Cl- / SO4 2- The selectivity was increased by about 3.0 times. In summary, the anion separation membrane prepared in this embodiment achieved a significant improvement in ion separation efficiency.

[0075] Example 2

[0076] 1. In this example, the same method as in Example 1 was used to adjust the H1OFs content to prepare a 30% H1-QPAB-E anion separation membrane.

[0077] 2. The 30% H1-QPAB-E anion separation membrane prepared in this example was applied to electrodialysis to separate Cl from the mixed solution. - / SO4 2- .

[0078] The electrodialysis method was the same as that in Comparative Example 1.

[0079] The test results show that 30% H1-QPAB-E anion separation membrane Cl - The transport rate is 3.2 mol m -2 h -1 , corresponding to Cl - / SO4 2- The selectivity is 60.4. Compared with the pure polymer membrane in Comparative Example 1, the 30% H1-QPAB-E anion separation membrane prepared in this example has a higher selectivity for Cl - / SO4 2- The selectivity was increased by about 6.9 times. In summary, the anion separation membrane prepared in this embodiment achieved a significant improvement in ion separation efficiency.

[0080] Example 3

[0081] 1. In this example, the same method as in Example 1 was used to adjust the H1OFs content to prepare a 50% H1-QPAB-E anion separation membrane.

[0082] 2. The 50% H1-QPAB-E anion separation membrane prepared in this example was applied to electrodialysis to separate Cl - / SO4 2- .

[0083] The electrodialysis method was the same as that in Comparative Example 1.

[0084] The test results show that 50% H1-QPAB-E anion separation membrane Cl - The transport rate is 3.0 mol m -2 h -1 , corresponding to Cl - / SO4 2-The selectivity is 86.8. Compared with the pure polymer membrane in Comparative Example 1, the 50% H1-QPAB-E anion separation membrane prepared in this example has a higher selectivity for Cl - / SO4 2- The selectivity was increased by about 10.0 times. In summary, the anion separation membrane prepared in this embodiment achieved a significant improvement in ion separation efficiency.

[0085] Example 4

[0086] 1. In this example, the same method as in Example 3 was used, except that the quaternary ammonium AEM matrix membrane was replaced with QPAB-H to prepare a mixed matrix membrane, which was designated as 50% H1-QPAB-H.

[0087] 2. The 50% H1-QPAB-H anion separation membrane prepared in this example was applied to electrodialysis to separate Cl - / SO4 2- .

[0088] The electrodialysis method was the same as that in Comparative Example 1.

[0089] The test results show that 50% H1-QPAB-H anion separation membrane Cl - The transport rate is 3.2 mol m -2 h -1 , corresponding to Cl - / SO4 2- The selectivity is 63.5. Compared with the pure polymer membrane in Comparative Example 2, the 50% H1-QPAB-H anion separation membrane prepared in this example has a higher selectivity for Cl - / SO4 2- The selectivity was increased by about 7.3 times. In summary, the anion separation membrane prepared in this example achieved a significant improvement in ion separation efficiency.

[0090] Example 5

[0091] 1. In this example, the same method as in Example 3 was used to prepare an anion separation membrane by replacing the HOFs modifier with H2OFs, which was recorded as 50% H2-QPAB-E:

[0092]

[0093] 2. The 50% H2-QPAB-E anion separation membrane prepared in this example was applied to electrodialysis to separate Cl - / SO4 2- .

[0094] The electrodialysis method was the same as that in Comparative Example 1.

[0095] The test results show that 50% H2-QPAB-E anion separation membrane Cl -The transport rate is 3.7 mol m -2 h -1 , corresponding to Cl - / SO4 2- The selectivity is 64.9. Compared with the pure polymer membrane in Comparative Example 1, the 50% H2-QPAB-E anion separation membrane prepared in this example has a higher selectivity for Cl - / SO4 2- The selectivity was increased by about 7.5 times. In summary, the anion separation membrane prepared in this embodiment achieved a significant improvement in ion separation efficiency.

[0096] Example 6

[0097] 1. In this example, the same method as in Example 3 was used to prepare a 50% H1-QPAB-E anion separation membrane by changing the halogenated acid bridging solvent to TFSA.

[0098] 2. The 50% H1-QPAB-E anion separation membrane prepared in this example was applied to electrodialysis to separate Cl - / SO4 2- .

[0099] The electrodialysis method was the same as that in Comparative Example 1.

[0100] The test results show that 50% H1-QPAB-E anion separation membrane Cl - The transport rate is 3.1 mol m -2 h -1 , corresponding to Cl - / SO4 2- The selectivity is 84.5. Compared with the pure polymer membrane in Comparative Example 1, the 50% H1-QPAB-E anion separation membrane prepared in this example has a higher selectivity for Cl - / SO4 2- The selectivity was increased by about 9.7 times. In summary, the anion separation membrane prepared in this embodiment achieved a significant improvement in ion separation efficiency.

[0101] Example 7

[0102] 1. This example uses the same method as in Example 3 to prepare a 50% H1-QPAB-E anion separation membrane.

[0103] 2. The 50% H1-QPAB-E anion separation membrane prepared in this example was applied to the electrodialysis separation of F - / SO4 2- , Br - / SO4 2- , NO3 - / SO4 2- .

[0104] The electrodialysis method was the same as that in Comparative Example 1.

[0105] The test results are shown in the following table:

[0106]

[0107] In summary, the anion separation membrane prepared in this embodiment achieves a significant improvement in ion separation efficiency.

[0108] As demonstrated in the above examples, the high-load HOFs mixed-matrix membrane prepared by the present invention based on a solvent-bridging strategy exhibits excellent anion separation performance and is adaptable to a variety of anion separation systems, achieving superior separation performance and significantly improving the efficiency of target ion separation. This membrane has broad application prospects in the extraction and recovery of high-value-added ion resources, environmental remediation, and high-salinity wastewater treatment.

[0109] The specific embodiment described above is merely a preferred example of the present invention and should not limit the scope of protection of the present invention. Any person skilled in the art with relevant technical knowledge in the technical field of the present invention may make equivalent substitutions or reasonable changes to the technical content disclosed in the present invention without departing from the core concept and technical solution of the present invention. Such substitutions and changes should be deemed to be included in the scope of protection of the present invention.

Claims

1. A high-load hydrogen-bonded organic framework mixed matrix membrane based on a solvent bridging strategy, characterized in that: Using quaternary ammonium anion exchange membrane (AEM) as the base membrane, polyaminotriazine hydrogen-bonded organic frameworks (HOFs) as the modifier, and asymmetric disubstituted halogenated acid as the bridging solvent, the authors used the principle that the acid radicals in the asymmetric disubstituted halogenated acid molecules electrostatically interact with the quaternary ammonium groups of the AEM base membrane and that the halogens hydrogen-bond with the amino groups of the HOFs. This facilitated the compatibility of the AEM base membrane with HOFs and increased the loading of HOFs on the AEM base membrane, resulting in the preparation of a high-loading HOFs mixed matrix membrane. The polyaminotriazine hydrogen bond organic framework HOFs modifier has the following structure 、 、 and One of the following; Wherein, R3 is H or an alkyl group with 1-2 C atoms; Ar2 is an aromatic hydrocarbon group, and the aromatic hydrocarbon group has the following structure 、 and One of the following; DAT1 and DAT2 have the following structures: 。 2. The high-load hydrogen-bonded organic framework mixed matrix membrane based on the solvent bridging strategy according to claim 1, characterized in that The quaternary ammonium anion exchange membrane AEM has the following structural formula: ； Wherein, R2 is H or an alkyl group with 1-7 C atoms; Ar1 is an aromatic hydrocarbon group, and the aromatic hydrocarbon group has the following structure 、 、 and One of them.

3. The high-load hydrogen-bonded organic framework mixed matrix membrane based on solvent bridging strategy according to claim 1, characterized in that The asymmetric disubstituted halogenated acid bridging solvent has the following structural characteristics: X n —R1—AH m Wherein X is one or a combination of two or more of F, Cl, Br, and I, and n is 1-3; R1 is an alkyl group having 1 to 20 carbon atoms; AH is a carboxylic acid group, a sulfonic acid group or a phosphoric acid group, and m is 1-3.

4. The high-load hydrogen-bonded organic framework mixed matrix membrane based on solvent bridging strategy according to claim 1, characterized in that The asymmetric disubstituted halogenated acid bridging solvent includes but is not limited to trifluoroacetic acid, trifluoromethanesulfonic acid, trifluoropropionic acid, dichloroacetic acid, and trichloroacetic acid.

5. The high-load hydrogen-bonded organic framework mixed matrix membrane based on the solvent bridging strategy according to claim 1, wherein the preparation method thereof comprises the following steps: S1: AEM and halogenated acid are mixed in a mass ratio of 1:(1-20), homogenized, and allowed to stand for 1-6 hours until the bonding between the functional groups is completed. This is referred to as solution A. S2: HOFs and halogenated acid are mixed in a mass ratio of 1:(1-20), homogenized and allowed to stand for 1-6 h until the bonding between the functional groups is completed, which is recorded as solution B; S3: Mix solution A and solution B in a mass ratio of A:B=1:(0.1-0.5), homogenize and let stand for 1-6 hours until the bridging between the functional groups is completed to obtain a clear transparent film liquid. Smear the transparent film liquid on a glass plate and evaporate the solvent at 20℃-80℃ to obtain a high-load HOFs mixed matrix membrane based on the solvent bridging strategy.

6. A high-load hydrogen-bonded organic framework mixed matrix membrane based on a solvent bridging strategy as claimed in any one of claims 1 to 5 for anion separation; The anion is Cl - / SO4 2- , F - / SO4 2- , Br - / SO4 2- , NO3 - / SO4 2- One or more of the above, wherein the anion separation is carried out by electrodialysis, and the electrodialysis current density is 0.1-20 mA cm -2 .

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