Template-induced MOFs synthesis-modified polyaniline-based composite filler-doped pervaporation membrane and its preparation method and application

Abstract

The present invention discloses a pervaporation membrane doped with a polyaniline-based composite filler modified by template-induced MOFs synthesis, and a preparation method and application thereof. The present invention uses polyethylene glycol-modified polyaniline as an active site for in-situ growth of MOFs, and uses hydrophobic organic matter for grafting modification to obtain a MOFs-modified polyaniline material. PDMS is dispersed in n-heptane, and the MOFs-modified polyaniline material, a cross-linking agent, and a catalyst are added. After stirring and standing, a membrane is prepared by spin coating, and after drying, a composite pervaporation membrane is obtained. On the one hand, the multilayer flaky polyaniline and the final hydrophobic modification effectively improve the hydrophobicity and organic compatibility of the filler, enhance the selectivity of the composite membrane, and avoid the large-scale generation of interface defects. On the other hand, the in-situ growth of MOFs effectively solves the problem of easy agglomeration between MOFs and can also give play to the characteristic of porous materials of preferential alcohol permeability.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional membranes and their preparation and separation applications, and particularly relates to a pervaporation membrane doped with a polyaniline-based composite filler modified by template-induced MOFs synthesis, and a preparation method and application thereof. Background Art

[0002] Mixed matrix membranes are recognized as one of the important ways to solve the current difficulties encountered in pervaporation membrane separation of alcohol and water mixtures. The most popular filler at present is metal organic framework (MOFs) material, which has both organic and inorganic properties. However, MOFs still have some inevitable problems: (1) MOFs themselves are prone to agglomeration, which greatly limits their loading capacity in the membrane and thus the performance of the membrane; (2) MOFs have poor compatibility with the polymer matrix, which greatly affects the separation performance of the membrane; (3) MOFs are expensive, which is not conducive to cost reduction.

[0003] Therefore, finding a better and faster solution to these problems has become a hot topic of research. One popular approach is to combine MOFs with other materials to create composite fillers for use in pervaporation membranes. This approach not only addresses the inherent agglomeration and high cost issues of MOFs, but also cleverly combines the strengths of both materials, further enhancing the separation performance of the composite membrane.

[0004] Previous studies have shown that combining MOFs with two-dimensional materials can not only address inherent MOF issues but also leverage the strengths of both materials to enhance membrane separation performance. Therefore, this study used hydrophobic polyethylene glycol-modified polyaniline sheets as templates to induce the synthesis of MOFs. This yielded a novel composite material for the preparation of mixed-matrix membranes and their application in the permeation separation of alcohol-water solutions. Summary of the Invention

[0005] In order to overcome the problems of poor compatibility and easy agglomeration when doping MOFs materials in the prior art, the present invention provides a pervaporation membrane doped with a polyaniline-based composite filler modified by template-induced MOFs synthesis, and a preparation method and application thereof.

[0006] The technical solutions of the present invention are as follows:

[0007] A pervaporation membrane doped with a polyaniline-based composite filler modified by template-induced MOFs synthesis is prepared as follows:

[0008] S1: Disperse polyaniline sheets uniformly in deionized water, add polyethylene glycol solid, react at room temperature for 5-10 hours (preferably 8 hours), filter, wash (with deionized water), and dry (50°C, 12 hours) to obtain polyethylene glycol-modified polyaniline sheets;

[0009] The mass ratio of deionized water to polyaniline sheet is 50 to 2000:1, preferably 800:1;

[0010] The mass ratio of polyaniline sheet to polyethylene glycol solid is 1:0.1 to 10, preferably 1:2;

[0011] The molecular weight of the polyethylene glycol solid is 10,000 to 40,000, preferably 20,000;

[0012] S2: Add polyethylene glycol-modified polyaniline sheets to solvent A and mix them by ultrasonic mixing (30 min), then add the metal source and stir evenly (30 min), which is recorded as solution A; add the ligand to solvent B and stir to dissolve, which is recorded as solution B; pour solution B into solution A, stir and react at room temperature, then filter, wash, and dry (80°C, 12 h), then add the obtained solid product to the pre-hydrolyzed solution of silane coupling agent, stir and react, then filter, wash with water, and dry (80°C, 12 h) to obtain MOFs-modified polyaniline;

[0013] In this step, the metal source reacts with the ligand to synthesize MOFs, which are grown in situ on the polyethylene glycol-modified polyaniline sheet. The MOFs-modified polyaniline is then hydrophobically modified with a silane coupling agent to obtain the MOFs-modified polyaniline. The reaction time, solvent used for MOFs synthesis, and silane coupling agent modification time can be determined based on the material selection.

[0014] MOFs are selected from ZIF-8, ZIF-90, ZIF-67, ZIF-91, ZIF-71, MOF-808, MOF-199, etc.;

[0015] The mass ratio of polyethylene glycol-modified polyaniline sheet, metal source, and solvent A is 1:5-15:200-1500;

[0016] The mass ratio of ligand to solvent B is 1:200-1500;

[0017] The pre-hydrolysis solution of the silane coupling agent is composed of the silane coupling agent, water and ethanol in a mass ratio of 0.1-5:1-10:80-99;

[0018] The silane coupling agent is selected from γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropyloxy)propyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, anilinemethyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, etc.

[0019] In this step, "solvent A", "solvent B", "solution A", and "solution B" have no special meanings. They are marked as "A" and "B" only to distinguish the solvents or solutions involved in different operations;

[0020] S3: PDMS (polydimethylsiloxane) is evenly dispersed in n-heptane, and the MOFs-modified polyaniline, a crosslinker, and a catalyst obtained in S2 are added, dispersed evenly, and allowed to stand (10 to 30 minutes) to obtain a casting solution; the casting solution is spin-coated on a PVDF (polyvinylidene fluoride) membrane, and after drying, a pervaporation membrane doped with a polyaniline-based composite filler modified by the template-induced MOFs synthesis is obtained;

[0021] The volume mass ratio of n-heptane to PDMS is 2.9 to 14.6:1, mL / g; preferably 5.85:1, mL / g;

[0022] The mass ratio of PDMS, crosslinking agent, catalyst, and MOFs-modified polyaniline is 1:0.05-0.2:0.005-0.03:0.01-0.3, preferably 1:0.1:0.01:0.2;

[0023] Specifically, the crosslinking agent is ethyl orthosilicate, the catalyst is dibutyltin dilaurate, and the viscosity of PDMS at 25°C is 50,000 cst;

[0024] The molecular weight cut-off of the PVDF membrane is 20,000 to 100,000. The PVDF membrane is pretreated as follows before use: the PVDF membrane is soaked in an ethanol aqueous solution with a volume fraction of 20 to 70% (preferably 50%) for 3 to 6 hours, then taken out and rinsed with deionized water to complete the pretreatment of the PVDF membrane (placed in deionized water for later use);

[0025] When forming the membrane, the amount of the casting solution applied to the PVDF membrane is 0.05 to 0.3 g / cm 2 , preferably 0.1 g / cm 2 .

[0026] In the present invention, the preparation method of the polyaniline sheet is as follows:

[0027] Aniline is dissolved in 0.2-2M (preferably 1M) hydrochloric acid to obtain an aniline solution; an aqueous ammonium persulfate solution is (quickly) added to the aniline solution at 0-5°C (preferably 0-2°C), stirred for 0.5-2h (preferably 1h), filtered, and the filter cake is washed with water and methanol in sequence (until the filtrate is colorless), dried, and the obtained solid is stirred in a 3-15wt% (preferably 5wt%) ammonia aqueous solution for 16-30h (preferably 24h), filtered, and the filter cake is washed with water and methanol in sequence, and dried to obtain the polyaniline sheet;

[0028] The molar ratio of aniline to ammonium persulfate is 1.5 to 2.8:1, preferably 2:1;

[0029] The concentration of aniline in the aniline solution is 0.005 to 2 M, preferably 1 M;

[0030] The concentration of the ammonium persulfate aqueous solution is 0.002 to 2 M, preferably 0.5 M;

[0031] Specifically, the aniline solution and the ammonium persulfate aqueous solution are cooled to 0-5° C. and then mixed;

[0032] The volume mass ratio of the ammonia solution to the solid is 50 to 500:1, mL / g, preferably 100:1, mL / g.

[0033] The template-induced MOFs synthesis-modified polyaniline-based composite filler-doped pervaporation membrane of the present invention can be used for the pervaporation separation of alcohol-water mixtures; the alcohol in the alcohol-water mixture is, for example, one or both of butanol and ethanol.

[0034] Compared with the prior art, the beneficial effects of the present invention are embodied in:

[0035] (1) Polyaniline is a two-dimensional material. Multilayers facilitate the permeation of alcohols and extend the path of water molecules, thereby enhancing the separation performance of the membrane. In addition, polyaniline is a hydrophobic material, which can further enhance the separation performance of the membrane.

[0036] (2) Different MOF materials can be selected during the filler compounding process. On the one hand, the advantages of MOF porous materials can be brought into play, such as the preferential permeability of alcohol; on the other hand, the dispersion of MOF materials can be improved, and their agglomeration in PDMS can be inhibited. This improves the filler loading in the membrane and makes it easier to obtain high-performance, uniform, and defect-free mixed matrix pervaporation membranes.

[0037] (3) The hydrophobically modified composite filler has abundant hydrophobic organic functional groups, which effectively enhances the compatibility between the filler and PDMS. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 : Diagram of pervaporation apparatus. DETAILED DESCRIPTION

[0039] The present invention is further described below by means of specific examples, but the protection scope of the present invention is not limited thereto.

[0040] In the following examples,

[0041] The viscosity of polydimethylsiloxane (PDMS) is 50,000 cst, model XC-107-50,000, and the manufacturer is Jinan Xingchi Chemical Co., Ltd.

[0042] Example 1:

[0043] (1) Treatment of PVDF bottom membrane: Soak the PVDF bottom membrane with a molecular weight cutoff of 50,000 in a 50% volume fraction ethanol / water mixed solution for 5 hours, then take it out and rinse it with deionized water, and then place it in deionized water for use.

[0044] (2) Synthesis of layered polyaniline: Add 9.313 g of aniline to 100 mL of 1 M hydrochloric acid and stir for 30 minutes to mix evenly. This is referred to as solution A and is set aside. Add 11.41 g of ammonium persulfate to 100 mL of deionized water and stir for 30 minutes to dissolve and mix evenly. This is referred to as solution B and is set aside. After cooling solution A and solution B to 0-5°C respectively, quickly pour solution B into solution A. Maintain the temperature between 0-2°C and stir for 1 hour. After the reaction is complete, filter, wash with water and methanol until the filtrate is colorless, and dry in an oven at 80°C for 12 hours to obtain layered polyaniline powder - doped state (doped HCl molecules, layered polyaniline is a type of polyaniline morphology, which is related to the ratio of raw materials and experimental conditions during synthesis). Then, 5 g of layered polyaniline powder-doped state was added to 500 mL of 5 wt% ammonia solution, stirred for 24 h, filtered, washed with water and methanol twice in sequence, and dried in an oven at 80° C. for 12 h to obtain layered polyaniline.

[0045] (3) Preparation of polyethylene glycol-modified polyaniline: 0.1 g of polyaniline flakes were evenly dispersed in 80 g of deionized water, and 0.2 g of polyethylene glycol solid was added. The mixture was reacted at room temperature for 8 h, then filtered, washed with deionized water three times, and dried in an oven at 50°C for 12 h to obtain polyethylene glycol-modified polyaniline.

[0046] (4) ZIF-90 modified polyaniline: 0.1 g of polyethylene glycol-modified polyaniline sheet material was added to 50 mL of methanol, ultrasonicated for 30 min and stirred evenly, then 1 g of zinc nitrate hexahydrate was added and stirred for 30 min. The mixture was set aside as solution A. 1.7 g of 2-imidazole carboxaldehyde was weighed and added to 50 mL of N,N-dimethylformamide, stirred and dissolved, and set aside as solution B. Subsequently, solution B was poured into solution A, stirred at room temperature for 1 h, filtered and washed with methanol 3 times, and dried in an oven at 80°C for 12 h to obtain polyaniline preliminarily modified with ZIF-90. Finally, 0.2 g of this material was added to 50 mL of pre-hydrolysis solution (1 wt% KH550, 2 wt% water, 97 wt% ethanol), stirred at room temperature for 5 h, filtered and washed with water 3 times, and dried in an oven at 80°C for 12 h to obtain polyaniline modified with ZIF-90.

[0047] (5) Preparation of template-induced ZIF-90 synthesis-modified polyaniline-based pervaporation membrane: 0.855 g of polydimethylsiloxane (PDMS) was added to 5 mL of n-heptane, stirred at room temperature for 30 min, and then 0.128 g of ZIF-90-modified polyaniline powder was added and stirred for 30 min; the steps of stirring for 30 min and ultrasonication for 30 min were repeated for 3 h; then 0.0855 g of cross-linking agent tetraethyl orthosilicate was added and stirred for 15 min, 0.0086 g of catalyst dibutyltin dilaurate was added and stirred for 30 min, and after standing for 20 min (standing to remove bubbles), 2 mL of the obtained casting solution was taken and a membrane was formed on the above-mentioned PVDF membrane (radius 2 cm disc) by spin coating, and dried in an 80°C oven for 12 h to obtain a template-induced ZIF-90 synthesis-modified polyaniline-based pervaporation membrane.

[0048] The obtained template-induced ZIF-90 modified polyaniline-based pervaporation membrane has a permeation flux of 2777 g / m at 40 ° C, 5 wt% ethanol / water, a flow rate of 400 mL / min, and a filtration vacuum of less than 200 Pa. 2 h, and the separation factor is 15.1.

[0049] Example 2:

[0050] (1) Treatment of PVDF bottom membrane: Soak the PVDF bottom membrane with a molecular weight cutoff of 50,000 in a 50% volume fraction ethanol / water mixed solution for 5 hours, then take it out and rinse it with deionized water, and then place it in deionized water for use.

[0051] (2) Synthesis of layered polyaniline: Add 9.313 g of aniline to 100 mL of 1 M hydrochloric acid and stir for 30 minutes to mix evenly. This is referred to as solution A and is set aside. Add 11.41 g of ammonium persulfate to 100 mL of deionized water and stir for 30 minutes to dissolve and mix evenly. This is referred to as solution B and is set aside. After cooling solution A and solution B to 0-5°C respectively, quickly pour solution B into solution A. Maintain the temperature between 0-2°C and stir for 1 hour. After the reaction is complete, filter, wash with water and methanol until the filtrate is colorless, and dry in an oven at 80°C for 12 hours to obtain layered polyaniline powder - doped state (doped HCl molecules, layered polyaniline is a type of polyaniline morphology, which is related to the ratio of raw materials and experimental conditions during synthesis). Then, 5 g of layered polyaniline powder-doped state was added to 500 mL of 5 wt% ammonia solution, stirred for 24 h, filtered, washed with water and methanol twice in sequence, and dried in an oven at 80° C. for 12 h to obtain layered polyaniline.

[0052] (3) Preparation of polyethylene glycol-modified polyaniline: 0.1 g of polyaniline flakes were evenly dispersed in 80 g of deionized water, and 0.2 g of polyethylene glycol solid was added. The mixture was reacted at room temperature for 8 h, then filtered, washed with deionized water three times, and dried in an oven at 50°C for 12 h to obtain polyethylene glycol-modified polyaniline.

[0053] (4) ZIF-90 modified polyaniline: 0.1 g of polyethylene glycol-modified polyaniline sheet material was added to 50 mL of methanol, ultrasonicated for 30 min, and then stirred evenly. Then, 1 g of zinc nitrate hexahydrate was added and stirred for 30 min. The mixture was set aside as solution A. 1.7 g of 2-imidazole carboxaldehyde was weighed and added to 50 mL of N,N-dimethylformamide, stirred and dissolved, and set aside as solution B. Subsequently, solution B was poured into solution A, stirred at room temperature for 1 h, filtered and washed with methanol 3 times, and dried in an oven at 80°C for 12 h to obtain polyaniline preliminarily modified with ZIF-90. Finally, 0.2 g of this material was added to 50 mL of pre-hydrolysis solution (1 wt% KH560, 2 wt% water, 97 wt% ethanol), stirred at 45°C for 5 h, filtered and washed with water 3 times, and dried in an oven at 80°C for 12 h to obtain polyaniline modified with ZIF-90.

[0054] (5) Preparation of template-induced ZIF-90 synthesis-modified polyaniline-based pervaporation membrane: 0.855 g of polydimethylsiloxane (PDMS) was added to 5 mL of n-heptane, stirred at room temperature for 30 min, and then 0.128 g of ZIF-90-modified polyaniline powder was added and stirred for 30 min; the steps of stirring for 30 min and ultrasonication for 30 min were repeated for 3 h; then 0.0855 g of cross-linking agent tetraethyl orthosilicate was added and stirred for 15 min, 0.0086 g of catalyst dibutyltin dilaurate was added and stirred for 30 min, and after standing for 20 min (standing to remove bubbles), 2 mL of the obtained casting solution was taken and a membrane was formed on the above-mentioned PVDF membrane (radius 2 cm disc) by spin coating, and dried in an 80°C oven for 12 h to obtain a template-induced ZIF-90 synthesis-modified polyaniline-based pervaporation membrane.

[0055] The obtained template-induced ZIF-90 modified polyaniline-based pervaporation membrane had a permeation flux of 2210 g / m at 40 ° C, 5 wt% ethanol / water, a flow rate of 400 mL / min, and a filtration vacuum of less than 200 Pa. 2 h, and the separation factor is 17.8.

[0056] Example 3:

[0057] (1) Treatment of PVDF bottom membrane: Soak the PVDF bottom membrane with a molecular weight cutoff of 50,000 in a 50% volume fraction ethanol / water mixed solution for 5 hours, then take it out and rinse it with deionized water, and then place it in deionized water for use.

[0058] (2) Synthesis of layered polyaniline: Add 9.313 g of aniline to 100 mL of 1 M hydrochloric acid and stir for 30 minutes to mix evenly. This is referred to as solution A and is set aside. Add 11.41 g of ammonium persulfate to 100 mL of deionized water and stir for 30 minutes to dissolve and mix evenly. This is referred to as solution B and is set aside. After cooling solution A and solution B to 0-5°C respectively, quickly pour solution B into solution A. Maintain the temperature between 0-2°C and stir for 1 hour. After the reaction is complete, filter, wash with water and methanol until the filtrate is colorless, and dry in an oven at 80°C for 12 hours to obtain layered polyaniline powder - doped state (doped HCl molecules, layered polyaniline is a type of polyaniline morphology, which is related to the ratio of raw materials and experimental conditions during synthesis). Then, 5 g of layered polyaniline powder-doped state was added to 500 mL of 5 wt% ammonia solution, stirred for 24 h, filtered, washed with water and methanol twice in sequence, and dried in an oven at 80° C. for 12 h to obtain layered polyaniline.

[0059] (3) Preparation of polyethylene glycol-modified polyaniline: 0.1 g of polyaniline flakes were evenly dispersed in 80 g of deionized water, and 0.2 g of polyethylene glycol solid was added. The mixture was reacted at room temperature for 8 h, then filtered, washed with deionized water three times, and dried in an oven at 50°C for 12 h to obtain polyethylene glycol-modified polyaniline.

[0060] (4) ZIF-8 modified polyaniline: 0.1 g of polyethylene glycol-modified polyaniline sheet material was added to 50 mL of methanol, ultrasonicated for 30 minutes and stirred evenly, then 1 g of zinc nitrate hexahydrate was added and stirred for 30 minutes, which was set aside as solution A; 2.22 g of 2-methylimidazole was weighed and added to 50 mL of methanol, stirred and dissolved, and set aside as solution B. Subsequently, solution B was poured into solution A, stirred at room temperature for 40 minutes, filtered and washed with methanol three times, and dried in an oven at 80°C for 12 hours to obtain ZIF-8 preliminarily modified polyaniline. Finally, 0.2 g of this material was added to 50 mL of pre-hydrolysis solution (1 wt% KH550, 2 wt% water, 97 wt% ethanol), stirred at room temperature for 5 hours, filtered and washed with water three times, and dried in an oven at 80°C for 12 hours to obtain ZIF-8 modified polyaniline.

[0061] (5) Preparation of template-induced ZIF-8 synthesis-modified polyaniline-based pervaporation membrane: 0.855 g of polydimethylsiloxane (PDMS) was added to 5 mL of n-heptane, stirred at room temperature for 30 min, and then 0.154 g of ZIF-8-modified polyaniline powder was added and stirred for 30 min; the steps of stirring for 30 min and ultrasonication for 30 min were repeated for 3 h; then 0.0855 g of cross-linking agent tetraethyl orthosilicate was added and stirred for 15 min, 0.0086 g of catalyst dibutyltin dilaurate was added and stirred for 30 min, and after standing for 20 min (standing to remove bubbles), 2 mL of the obtained casting solution was taken and a membrane was formed on the above-mentioned PVDF membrane (radius 2 cm disc) by spin coating, and dried in an 80°C oven for 12 h to obtain a template-induced ZIF-8 synthesis-modified polyaniline-based pervaporation membrane.

[0062] The obtained template-induced ZIF-8 modified polyaniline-based pervaporation membrane has a permeation flux of 2611 g / m at 40 ° C, 1 wt% butanol / water, a flow rate of 400 mL / min, and a filtration vacuum of less than 200 Pa. 2 h, the separation factor is 58.3; the permeation flux is 2393 g / m at 40 ° C, 5 wt% ethanol / water, flow rate 400 mL / min, and filtration vacuum less than 200 Pa. 2 h, and the separation factor is 17.4.

[0063] Example 4:

[0064] (1) Treatment of PVDF bottom membrane: Soak the PVDF bottom membrane with a molecular weight cutoff of 50,000 in a 50% volume fraction ethanol / water mixed solution for 5 hours, then take it out and rinse it with deionized water, and then place it in deionized water for use.

[0065] (2) Synthesis of layered polyaniline: Add 9.313 g of aniline to 100 mL of 1 M hydrochloric acid and stir for 30 minutes to mix evenly. This is referred to as solution A and is set aside. Add 11.41 g of ammonium persulfate to 100 mL of deionized water and stir for 30 minutes to dissolve and mix evenly. This is referred to as solution B and is set aside. After cooling solution A and solution B to 0-5°C respectively, quickly pour solution B into solution A. Maintain the temperature between 0-2°C and stir for 1 hour. After the reaction is complete, filter, wash with water and methanol until the filtrate is colorless, and dry in an oven at 80°C for 12 hours to obtain layered polyaniline powder - doped state (doped HCl molecules, layered polyaniline is a type of polyaniline morphology, which is related to the ratio of raw materials and experimental conditions during synthesis). Then, 5 g of layered polyaniline powder-doped state was added to 500 mL of 5 wt% ammonia solution, stirred for 24 h, filtered, washed with water and methanol twice in sequence, and dried in an oven at 80° C. for 12 h to obtain layered polyaniline.

[0066] (3) Preparation of polyethylene glycol-modified polyaniline: 0.1 g of polyaniline flakes were evenly dispersed in 80 g of deionized water, and 0.2 g of polyethylene glycol solid was added. The mixture was reacted at room temperature for 8 h, then filtered, washed with deionized water three times, and dried in an oven at 50°C for 12 h to obtain polyethylene glycol-modified polyaniline.

[0067] (4) ZIF-8 modified polyaniline: 0.1 g of polyethylene glycol-modified polyaniline sheet material was added to 50 mL of water, ultrasonicated for 30 minutes and stirred evenly. Then, 1 g of zinc nitrate hexahydrate was added and stirred for 30 minutes. The mixture was set aside as solution A. 2.22 g of 2-methylimidazole was weighed and added to 50 mL of water. After stirring and dissolving, the mixture was set aside as solution B. Subsequently, solution B was poured into solution A, stirred at room temperature for 40 minutes, filtered and washed with water three times, and dried in an oven at 80°C for 12 hours to obtain polyaniline preliminarily modified with ZIF-8. Finally, 0.2 g of this material was added to 50 mL of pre-hydrolysis solution (1 wt% KH550, 2 wt% water, 97 wt% ethanol), stirred at room temperature for 5 hours, filtered and washed with water three times, and dried in an oven at 80°C for 12 hours to obtain polyaniline modified with ZIF-8.

[0068] (5) Preparation of template-induced ZIF-8 synthesis-modified polyaniline-based pervaporation membrane: 0.855 g of polydimethylsiloxane (PDMS) was added to 5 mL of n-heptane, stirred at room temperature for 30 min, and then 0.154 g of ZIF-8-modified polyaniline powder was added and stirred for 30 min; the steps of stirring for 30 min and ultrasonication for 30 min were repeated for 3 h; then 0.0855 g of cross-linking agent tetraethyl orthosilicate was added and stirred for 15 min, 0.0086 g of catalyst dibutyltin dilaurate was added and stirred for 30 min, and after standing for 20 min (standing to remove bubbles), 2 mL of the obtained casting solution was taken and a membrane was formed on the above-mentioned PVDF membrane (radius 2 cm disc) by spin coating, and dried in an 80°C oven for 12 h to obtain a template-induced ZIF-8 synthesis-modified polyaniline-based pervaporation membrane.

[0069] The obtained template-induced ZIF-8 modified polyaniline-based pervaporation membrane has a permeation flux of 3503 g / m at 40 ° C, 1 wt% butanol / water, a flow rate of 400 mL / min, and a filtration vacuum of less than 200 Pa. 2 h, the separation factor is 49.2; the permeation flux is 2819 g / m at 40 ° C, 5 wt% ethanol / water, flow rate 400 mL / min, and filtration vacuum less than 200 Pa. 2 h, and the separation factor is 14.8.

[0070] Example 5:

[0071] (1) Treatment of PVDF bottom membrane: Soak the PVDF bottom membrane with a molecular weight cutoff of 50,000 in a 50% volume fraction ethanol / water mixed solution for 5 hours, then take it out and rinse it with deionized water, and then place it in deionized water for use.

[0072] (2) Synthesis of layered polyaniline: Add 9.313 g of aniline to 100 mL of 1 M hydrochloric acid and stir for 30 minutes to mix evenly. This is referred to as solution A and is set aside. Add 11.41 g of ammonium persulfate to 100 mL of deionized water and stir for 30 minutes to dissolve and mix evenly. This is referred to as solution B and is set aside. After cooling solution A and solution B to 0-5°C respectively, quickly pour solution B into solution A. Maintain the temperature between 0-2°C and stir for 1 hour. After the reaction is complete, filter, wash with water and methanol until the filtrate is colorless, and dry in an oven at 80°C for 12 hours to obtain layered polyaniline powder - doped state (doped HCl molecules, layered polyaniline is a type of polyaniline morphology, which is related to the ratio of raw materials and experimental conditions during synthesis). Then, 5 g of layered polyaniline powder-doped state was added to 500 mL of 5 wt% ammonia solution, stirred for 24 h, filtered, washed with water and methanol twice in sequence, and dried in an oven at 80° C. for 12 h to obtain layered polyaniline.

[0073] (3) Preparation of polyethylene glycol-modified polyaniline: 0.1 g of polyaniline flakes were evenly dispersed in 80 g of deionized water, and 0.2 g of polyethylene glycol solid was added. The mixture was reacted at room temperature for 8 h, then filtered, washed with deionized water three times, and dried in an oven at 50°C for 12 h to obtain polyethylene glycol-modified polyaniline.

[0074] (4) ZIF-67 modified polyaniline: 0.1 g of polyethylene glycol-modified polyaniline sheet material was added to 50 mL of methanol, ultrasonicated for 30 min and stirred evenly, then 1 g of cobalt nitrate hexahydrate was added and stirred for 30 min, which was set aside as solution A; 2.24 g of 2-methylimidazole was weighed and added to 50 mL of methanol, stirred and dissolved, and set aside as solution B. Subsequently, solution B was poured into solution A, stirred at room temperature for 45 min, filtered and washed with methanol 3 times, and dried in an oven at 80°C for 12 h to obtain polyaniline preliminarily modified with ZIF-67. Finally, 0.2 g of this material was added to 50 mL of pre-hydrolysis solution (1 wt% KH590, 2 wt% water, 97 wt% ethanol), stirred at 60°C for 5 h, filtered and washed with water 3 times, and dried in an oven at 80°C for 12 h to obtain ZIF-67 modified polyaniline.

[0075] (5) Preparation of template-induced ZIF-67 synthesis-modified polyaniline-based pervaporation membrane: 0.855 g of polydimethylsiloxane (PDMS) was added to 5 mL of n-heptane, stirred at room temperature for 30 min, and then 0.0855 g of ZIF-67-modified polyaniline powder was added and stirred for 30 min; the steps of stirring for 30 min and ultrasonication for 30 min were repeated for 3 h; then 0.0855 g of cross-linking agent tetraethyl orthosilicate was added and stirred for 15 min, 0.0086 g of catalyst dibutyltin dilaurate was added and stirred for 30 min, and after standing for 20 min (standing to remove bubbles), 2 mL of the obtained casting solution was taken and a membrane was formed on the above-mentioned PVDF membrane (radius 2 cm disc) by spin coating, and dried in an 80°C oven for 12 h to obtain a template-induced ZIF-67 synthesis-modified polyaniline-based pervaporation membrane.

[0076] The obtained template-induced ZIF-67 modified polyaniline-based pervaporation membrane had a permeation flux of 2579 g / m at 40 ° C, 1 wt% butanol / water, a flow rate of 400 mL / min, and a filtration vacuum of less than 200 Pa. 2 h, separation factor is 53;

[0077] Example 6:

[0078] (1) Treatment of PVDF bottom membrane: Soak the PVDF bottom membrane with a molecular weight cutoff of 50,000 in a 50% volume fraction ethanol / water mixed solution for 5 hours, then take it out and rinse it with deionized water, and then place it in deionized water for use.

[0079] (2) Synthesis of layered polyaniline: Add 9.313 g of aniline to 100 mL of 1 M hydrochloric acid and stir for 30 minutes to mix evenly. This is referred to as solution A and is set aside. Add 11.41 g of ammonium persulfate to 100 mL of deionized water and stir for 30 minutes to dissolve and mix evenly. This is referred to as solution B and is set aside. After cooling solution A and solution B to 0-5°C respectively, quickly pour solution B into solution A. Maintain the temperature between 0-2°C and stir for 1 hour. After the reaction is complete, filter, wash with water and methanol until the filtrate is colorless, and dry in an oven at 80°C for 12 hours to obtain layered polyaniline powder - doped state (doped HCl molecules, layered polyaniline is a type of polyaniline morphology, which is related to the ratio of raw materials and experimental conditions during synthesis). Then, 5 g of layered polyaniline powder-doped state was added to 500 mL of 5 wt% ammonia solution, stirred for 24 h, filtered, washed with water and methanol twice in sequence, and dried in an oven at 80° C. for 12 h to obtain layered polyaniline.

[0080] (3) Preparation of polyethylene glycol-modified polyaniline: 0.1 g of polyaniline flakes were evenly dispersed in 80 g of deionized water, and 0.2 g of polyethylene glycol solid was added. The mixture was reacted at room temperature for 8 h, then filtered, washed with deionized water three times, and dried in an oven at 50°C for 12 h to obtain polyethylene glycol-modified polyaniline.

[0081] (4) ZIF-71 modified polyaniline: 0.1 g of polyethylene glycol-modified polyaniline sheet material was added to 50 mL of methanol, ultrasonicated for 30 min and stirred evenly, then 1 g of zinc acetate dihydrate was added and stirred for 30 min. The mixture was set aside as solution A. 2.5 g of 4,5-dichloroimidazole was weighed and added to 50 mL of methanol, stirred and dissolved, and set aside as solution B. Subsequently, solution B was slowly added dropwise to solution A, stirred at room temperature for 120 min, filtered and washed with methanol three times, and dried in an oven at 80 ° C for 12 h to obtain polyaniline preliminarily modified with ZIF-67. Finally, 0.2 g of this material was added to 50 mL of pre-hydrolysis solution (1 wt% KH590, 2 wt% water, 97 wt% ethanol), stirred at room temperature for 5 h, filtered and washed with water three times, and dried in an oven at 80 ° C for 12 h to obtain ZIF-71 modified polyaniline.

[0082] (5) Preparation of template-induced ZIF-71 synthesis-modified polyaniline-based pervaporation membrane: 0.855 g of polydimethylsiloxane (PDMS) was added to 5 mL of n-heptane, stirred at room temperature for 30 min, and then 0.103 g of ZIF-71-modified polyaniline powder was added and stirred for 30 min; the steps of stirring for 30 min and ultrasonication for 30 min were repeated for 3 h; then 0.0855 g of cross-linking agent tetraethyl orthosilicate was added and stirred for 15 min, 0.0086 g of catalyst dibutyltin dilaurate was added and stirred for 30 min, and after standing for 20 min (standing to remove bubbles), 2 mL of the obtained casting solution was taken and a membrane was formed on the above-mentioned PVDF membrane (radius 2 cm disc) by spin coating, and dried in an 80°C oven for 12 h to obtain a template-induced ZIF-71 synthesis-modified polyaniline-based pervaporation membrane.

[0083] The obtained template-induced ZIF-71 modified polyaniline-based pervaporation membrane had a permeation flux of 2810 g / m at 40 °C, 1 wt% butanol / water, a flow rate of 400 mL / min, and a filtration vacuum of less than 200 Pa. 2 h, separation factor is 46.7;

[0084] Comparative Example 1: No MOF material

[0085] (1) Treatment of PVDF bottom membrane: Soak the PVDF bottom membrane with a molecular weight cutoff of 50,000 in a 50% volume fraction ethanol / water mixed solution for 5 hours, then take it out and rinse it with deionized water, and then place it in deionized water for use.

[0086] (2) Synthesis of layered polyaniline: Add 9.313 g of aniline to 100 mL of 1 M hydrochloric acid and stir for 30 minutes to mix evenly. This is referred to as solution A and is set aside. Add 11.41 g of ammonium persulfate to 100 mL of deionized water and stir for 30 minutes to dissolve and mix evenly. This is referred to as solution B and is set aside. After cooling solution A and solution B to 0-5°C respectively, quickly pour solution B into solution A. Maintain the temperature between 0-2°C and stir for 1 hour. After the reaction is complete, filter, wash with water and methanol until the filtrate is colorless, and dry in an oven at 80°C for 12 hours to obtain layered polyaniline powder - doped state (doped HCl molecules, layered polyaniline is a type of polyaniline morphology, which is related to the ratio of raw materials and experimental conditions during synthesis). Then, 5 g of layered polyaniline powder-doped state was added to 500 mL of 5 wt% ammonia solution, stirred for 24 h, filtered, washed with water and methanol twice in sequence, and dried in an oven at 80° C. for 12 h to obtain layered polyaniline.

[0087] (3) Preparation of polyethylene glycol-modified polyaniline: 0.1 g of polyaniline flakes were evenly dispersed in 80 g of deionized water, and 0.2 g of polyethylene glycol solid was added. The mixture was reacted at room temperature for 8 h, then filtered, washed with deionized water three times, and dried in an oven at 50°C for 12 h to obtain polyethylene glycol-modified polyaniline.

[0088] (4) Silane-modified polyaniline: 0.2 g of polyethylene glycol-modified polyaniline was added to 50 mL of a pre-hydrolysis solution (1 wt% KH550, 2 wt% water, 97 wt% ethanol), stirred at room temperature for 5 h, filtered, washed with water three times, and dried in an oven at 80°C for 12 h to obtain silane-modified polyaniline.

[0089] (5) Preparation of silane-modified polyaniline-based pervaporation membrane: 0.855 g of polydimethylsiloxane (PDMS) was added to 5 mL of n-heptane, stirred at room temperature for 30 min, and then 0.154 g of silane-modified polyaniline powder was added and stirred for 30 min; the steps of stirring for 30 min and ultrasonication for 30 min were repeated for 3 h; then 0.0855 g of cross-linking agent ethyl orthosilicate was added and stirred for 15 min, and 0.0086 g of catalyst dibutyltin dilaurate was added and stirred for 30 min. After standing for 20 min (standing to remove bubbles), 2 mL of the obtained casting solution was taken and a membrane was formed on the above-mentioned PVDF membrane (2 cm radius disc) by spin coating, and dried in an oven at 80°C for 12 h. Finally, a silane-modified polyaniline-based pervaporation membrane was obtained.

[0090] The permeation flux of the obtained silane-modified polyaniline-based pervaporation membrane at 40°C, 1 wt% butanol / water, flow rate 400 mL / min, and filtration vacuum less than 200 Pa was 1149 g / m 2h, the separation factor is 51; the permeation flux is 1098 g / m at 40 ° C, 5 wt% ethanol / water, flow rate 400 mL / min, and filtration vacuum less than 200 Pa. 2 h, and the separation factor is 13.3. (The presence of MOF provides the membrane with a certain degree of alcohol selectivity and a large amount of flux, so the absence of porous MOF will cause a significant decrease in the flux of the composite membrane)

[0091] Comparative Example 2: No silane modification

[0092] (1) Treatment of PVDF bottom membrane: Soak the PVDF bottom membrane with a molecular weight cutoff of 50,000 in a 50% volume fraction ethanol / water mixed solution for 5 hours, then take it out and rinse it with deionized water, and then place it in deionized water for use.

[0093] (2) Synthesis of layered polyaniline: Add 9.313 g of aniline to 100 mL of 1 M hydrochloric acid and stir for 30 minutes to mix evenly. This is referred to as solution A and is set aside. Add 11.41 g of ammonium persulfate to 100 mL of deionized water and stir for 30 minutes to dissolve and mix evenly. This is referred to as solution B and is set aside. After cooling solution A and solution B to 0-5°C respectively, quickly pour solution B into solution A. Maintain the temperature between 0-2°C and stir for 1 hour. After the reaction is complete, filter, wash with water and methanol until the filtrate is colorless, and dry in an oven at 80°C for 12 hours to obtain layered polyaniline powder - doped state (doped HCl molecules, layered polyaniline is a type of polyaniline morphology, which is related to the ratio of raw materials and experimental conditions during synthesis). Then, 5 g of layered polyaniline powder-doped state was added to 500 mL of 5 wt% ammonia solution, stirred for 24 h, filtered, washed with water and methanol twice in sequence, and dried in an oven at 80° C. for 12 h to obtain layered polyaniline.

[0094] (3) Preparation of polyethylene glycol-modified polyaniline: 0.1 g of polyaniline flakes were evenly dispersed in 80 g of deionized water, and 0.2 g of polyethylene glycol solid was added. The mixture was reacted at room temperature for 8 h, then filtered, washed with deionized water three times, and dried in an oven at 50°C for 12 h to obtain polyethylene glycol-modified polyaniline.

[0095] (4) ZIF-8 modified polyaniline: 0.1 g of polyethylene glycol-modified polyaniline sheet material was added to 50 mL of methanol, ultrasonicated for 30 min, and stirred until uniform. 1 g of zinc nitrate hexahydrate was then added and stirred for 30 min. This was set aside as solution A. 2.22 g of 2-methylimidazole was weighed and added to 50 mL of methanol. After stirring and dissolving, this was set aside as solution B. Subsequently, solution B was poured into solution A, stirred at room temperature for 40 min, filtered, washed with methanol three times, and dried in an oven at 80°C for 12 h to obtain ZIF-8 modified polyaniline.

[0096] (5) Preparation of template-induced ZIF-8 synthesis-modified polyaniline-based pervaporation membrane: 0.855 g of polydimethylsiloxane (PDMS) was added to 5 mL of n-heptane, stirred at room temperature for 30 min, and then 0.154 g of ZIF-8-modified polyaniline powder was added and stirred for 30 min; the steps of stirring for 30 min and ultrasonication for 30 min were repeated for 3 h; then 0.0855 g of cross-linking agent tetraethyl orthosilicate was added and stirred for 15 min, 0.0086 g of catalyst dibutyltin dilaurate was added and stirred for 30 min, and after standing for 20 min (standing to remove bubbles), 2 mL of the obtained casting solution was taken and a membrane was formed on the above-mentioned PVDF membrane (radius 2 cm disc) by spin coating, and dried in an 80°C oven for 12 h to obtain a template-induced ZIF-8 synthesis-modified polyaniline-based pervaporation membrane.

[0097] The permeation flux of the obtained template-induced ZIF-8 modified polyaniline pervaporation membrane at 40 ° C, 1 wt% butanol / water, flow rate 400 mL / min, and filtration vacuum less than 200 Pa was 2937 g / m 2 h, the separation factor is 45.2; the permeation flux is 2444 g / m at 40 ° C, 5 wt% ethanol / water, flow rate 400 mL / min, and filtration vacuum less than 200 Pa. 2 h, and the separation factor is 12.5. (The presence of silane modification can improve the hydrophobicity of the filler, thereby increasing the membrane's selectivity for alcohols. On the other hand, it grafts a large number of hydrophobic organic functional groups onto the filler and enhances the compatibility between the filler and PDMS, avoiding the occurrence of large-scale defects. Therefore, the absence of silane modification causes the separation factor of the composite membrane to decrease, while the flux increases slightly due to compatibility reasons.)

[0098] Comparative Example 3: No polyethylene glycol

[0099] (1) Treatment of PVDF bottom membrane: Soak the PVDF bottom membrane with a molecular weight cutoff of 50,000 in a 50% volume fraction ethanol / water mixed solution for 5 hours, then take it out and rinse it with deionized water, and then place it in deionized water for use.

[0100] (2) Synthesis of layered polyaniline: Add 9.313 g of aniline to 100 mL of 1 M hydrochloric acid and stir for 30 minutes to mix evenly. This is referred to as solution A and is set aside. Add 11.41 g of ammonium persulfate to 100 mL of deionized water and stir for 30 minutes to dissolve and mix evenly. This is referred to as solution B and is set aside. After cooling solution A and solution B to 0-5°C respectively, quickly pour solution B into solution A. Maintain the temperature between 0-2°C and stir for 1 hour. After the reaction is complete, filter, wash with water and methanol until the filtrate is colorless, and dry in an oven at 80°C for 12 hours to obtain layered polyaniline powder - doped state (doped HCl molecules, layered polyaniline is a type of polyaniline morphology, which is related to the ratio of raw materials and experimental conditions during synthesis). Then, 5 g of layered polyaniline powder-doped state was added to 500 mL of 5 wt% ammonia solution, stirred for 24 h, filtered, washed with water and methanol twice in sequence, and dried in an oven at 80° C. for 12 h to obtain layered polyaniline.

[0101] (3) ZIF-71 modified polyaniline: 0.1 g of polyaniline sheet material was added to 50 mL of methanol, ultrasonicated for 30 minutes and stirred evenly, then 1 g of zinc acetate dihydrate was added and stirred for 30 minutes. The mixture was set aside as solution A. 2.5 g of 4,5-dichloroimidazole was weighed and added to 50 mL of methanol, stirred and dissolved, and set aside as solution B. Subsequently, solution B was slowly added dropwise to solution A, stirred at room temperature for 120 minutes, filtered and washed with methanol three times, and dried in an oven at 80°C for 12 hours to obtain polyaniline preliminarily modified with ZIF-67. Finally, 0.2 g of this material was added to 50 mL of pre-hydrolysis solution (1 wt% KH590, 2 wt% water, 97 wt% ethanol), stirred at room temperature for 5 hours, filtered and washed with water three times, and dried in an oven at 80°C for 12 hours to obtain ZIF-71 modified polyaniline.

[0102] (5) Preparation of template-induced ZIF-71 synthesis-modified polyaniline-based pervaporation membrane: 0.855 g of polydimethylsiloxane (PDMS) was added to 5 mL of n-heptane, stirred at room temperature for 30 min, and then 0.103 g of ZIF-71-modified polyaniline powder was added and stirred for 30 min; the steps of stirring for 30 min and ultrasonication for 30 min were repeated for 3 h; then 0.0855 g of cross-linking agent tetraethyl orthosilicate was added and stirred for 15 min, 0.0086 g of catalyst dibutyltin dilaurate was added and stirred for 30 min, and after standing for 20 min (standing to remove bubbles), 2 mL of the obtained casting solution was taken and a membrane was formed on the above-mentioned PVDF membrane (radius 2 cm disc) by spin coating, and dried in an 80°C oven for 12 h to obtain a template-induced ZIF-71 synthesis-modified polyaniline-based pervaporation membrane.

[0103] The obtained template-induced ZIF-71 modified polyaniline-based pervaporation membrane had a permeation flux of 3676 g / m at 40 °C, 1 wt% butanol / water, a flow rate of 400 mL / min, and a filtration vacuum of less than 200 Pa. 2 h, with a separation factor of 40.1. (The presence of polyethylene glycol provides continuous active sites for the in-situ growth of MOF. Without polyethylene glycol, MOF cannot grow regularly on the polyaniline surface, resulting in large-scale agglomeration between fillers. As a result, the composite membrane has a large number of interfacial defects, and the membrane flux is greatly increased.)

[0104] Comparative Example 4: No polyaniline

[0105] (1) Treatment of PVDF bottom membrane: Soak the PVDF bottom membrane with a molecular weight cutoff of 50,000 in a 50% volume fraction ethanol / water mixed solution for 5 hours, then take it out and rinse it with deionized water, and then place it in deionized water for use.

[0106] (2) Silane-modified ZIF-90: 0.1 g of polyethylene glycol was added to 50 mL of methanol, ultrasonicated for 30 min, and then stirred evenly. Then, 1 g of zinc nitrate hexahydrate was added and stirred for 30 min. The mixture was set aside as solution A. 1.7 g of 2-imidazolecarboxaldehyde was weighed and added to 50 mL of N,N-dimethylformamide, stirred and dissolved, and set aside as solution B. Subsequently, solution B was poured into solution A, stirred at room temperature for 1 h, filtered and washed with methanol 3 times, and dried in an oven at 80°C for 12 h to obtain ZIF-90. Finally, 0.2 g of this material was added to 50 mL of pre-hydrolysis solution (1 wt% KH550, 2 wt% water, 97 wt% ethanol), stirred at room temperature for 5 h, filtered and washed with water 3 times, and dried in an oven at 80°C for 12 h to obtain silane-modified ZIF-90.

[0107] (3) Preparation of silane-modified ZIF-90-based pervaporation membrane: 0.855 g of polydimethylsiloxane (PDMS) was added to 5 mL of n-heptane, stirred at room temperature for 30 min, and then 0.128 g of silane-modified ZIF-90 powder was added and stirred for 30 min; the steps of stirring for 30 min and ultrasonication for 30 min were repeated for 3 h; then 0.0855 g of cross-linking agent ethyl orthosilicate was added and stirred for 15 min, and 0.0086 g of catalyst dibutyltin dilaurate was added and stirred for 30 min. After standing for 20 min (standing to remove bubbles), 2 mL of the obtained casting solution was taken and a membrane was formed on the above-mentioned PVDF membrane (2 cm radius disc) by spin coating, and dried in an oven at 80°C for 12 h. Finally, a silane-modified ZIF-90-based pervaporation membrane was obtained.

[0108] The permeation flux of the obtained silane-modified ZIF-90-based pervaporation membrane at 40°C, 5 wt% ethanol / water, flow rate 400 mL / min, and filtration vacuum less than 200 Pa was 1906 g / m 2 h, with a separation factor of 10.2. (The presence of ZIF-90 alone results in insufficient active sites during silane modification, resulting in low hydrophobicity of the filler; in addition, insufficient compatibility also makes the filler prone to agglomeration.)

[0109] Comparative Example 5: Polydimethylsiloxane film (no filler)

[0110] (1) Treatment of PVDF membrane: Soak the PVDF membrane with a molecular weight cutoff of 50,000 in a 50% volume fraction ethanol / water mixed solution for 5 hours, then take it out and rinse it with deionized water, dry it in a 60°C oven for 10 hours, and then place it in deionized water for use.

[0111] (2) Preparation of polydimethylsiloxane membrane: 0.855 g of polydimethylsiloxane was added to 5 mL of n-heptane and stirred at room temperature for 30 min; then the steps of stirring for 30 min and ultrasonicating for 30 min were repeated for 3 h; then 0.0855 g of cross-linking agent ethyl orthosilicate was added and stirred for 15 min, 0.0086 g of catalyst dibutyltin dilaurate was added and stirred for 30 min, ultrasonicated for 10 min, and allowed to stand for 20 min. 2 mL of the obtained casting solution was taken and a membrane was formed on the above-mentioned PVDF membrane (2 cm radius disc) by spin coating, and dried in an oven at 80°C for 12 h to obtain a polydimethylsiloxane pervaporation membrane.

[0112] The permeation flux of the obtained polydimethylsiloxane pervaporation membrane at 40°C and 1 wt% butanol / water was 1239 g / m 2 h, the separation factor is 26; the permeation flux is 1120 g / m at 40 ° C, 5 wt% ethanol / water, flow rate 400 mL / min, and filtration vacuum less than 200 Pa. 2 h, the separation factor is 6.5.

Claims

1. A pervaporation membrane doped with a polyaniline-based composite filler modified by template-induced MOFs synthesis, characterized in that: Prepare as follows: S1: Disperse polyaniline sheets uniformly in deionized water, add polyethylene glycol solid, react at room temperature for 5-10 hours, filter, wash, and dry to obtain polyethylene glycol-modified polyaniline sheets; S2: Add polyethylene glycol-modified polyaniline sheets to solvent A, mix them by ultrasonication, then add the metal source and stir evenly, which is recorded as solution A; add the ligand to solvent B and stir to dissolve, which is recorded as solution B; pour solution B into solution A, stir and react at room temperature, then filter, wash and dry, and then add the obtained solid product to the pre-hydrolyzed solution of silane coupling agent, stir and react, then filter, wash with water and dry to obtain MOFs-modified polyaniline; The metal source reacts with the ligand to synthesize MOFs, which are in situ grown on a polyethylene glycol-modified polyaniline sheet. The MOFs are selected from one or more of ZIF-8, ZIF-90, ZIF-67, ZIF-91, ZIF-71, MOF-808, and MOF-199. The pre-hydrolysis solution of the silane coupling agent is composed of: a silane coupling agent, water, and ethanol; the silane coupling agent is selected from one or more of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, anilinemethyltriethoxysilane, and γ-mercaptopropyltrimethoxysilane; S3: PDMS is evenly dispersed in n-heptane, and the MOFs-modified polyaniline, a crosslinking agent, and a catalyst obtained in S2 are added, and the mixture is evenly dispersed and allowed to stand to obtain a casting solution; the casting solution is spin-coated on a PVDF membrane, and after drying, a pervaporation membrane doped with a polyaniline-based composite filler modified by the template-induced MOFs synthesis is obtained; The crosslinking agent is ethyl orthosilicate and the catalyst is dibutyltin dilaurate.

2. The pervaporation membrane doped with polyaniline-based composite fillers modified by template-induced MOFs synthesis as claimed in claim 1, characterized in that: In S1, the mass ratio of the polyaniline sheet to the polyethylene glycol solid is 1:0.1-10.

3. The pervaporation membrane doped with polyaniline-based composite fillers modified by template-induced MOFs synthesis as claimed in claim 1, characterized in that: In S2, the mass ratio of the polyethylene glycol-modified polyaniline sheet, the metal source, and the solvent A is 1:5-15:200-1500.

4. The pervaporation membrane doped with polyaniline-based composite fillers synthesized and modified by template-induced MOFs according to claim 1, characterized in that: In S2, the mass ratio of the ligand to the solvent B is 1:200-1500.

5. The pervaporation membrane doped with polyaniline-based composite fillers modified by template-induced MOFs synthesis as claimed in claim 1, characterized in that: In S2, the pre-hydrolysis solution of the silane coupling agent is composed of: silane coupling agent, water, and ethanol in a mass ratio of 0.1-5:1-10:80-99.

6. The pervaporation membrane doped with polyaniline-based composite fillers modified by template-induced MOFs synthesis as claimed in claim 1, characterized in that: In S3, the volume mass ratio of n-heptane to PDMS is 2.9-14.6:1, mL / g.

7. The pervaporation membrane doped with polyaniline-based composite fillers modified by template-induced MOFs synthesis as claimed in claim 1, characterized in that: In S3, the mass ratio of PDMS, cross-linking agent, catalyst, and MOFs-modified polyaniline is 1:0.05-0.2:0.005-0.03:0.01-0.

3.

8. The pervaporation membrane doped with polyaniline-based composite fillers modified by template-induced MOFs synthesis as claimed in claim 1, characterized in that: In S3, when forming the membrane, the amount of the casting solution applied to the PVDF membrane by spin coating is 0.05 to 0.3 g / cm 2 .

9. The pervaporation membrane doped with polyaniline-based composite fillers synthesized and modified by template-induced MOFs according to claim 1, characterized in that: The preparation method of the polyaniline sheet is as follows: Aniline is dissolved in 0.2-2M hydrochloric acid to obtain an aniline solution; an aqueous ammonium persulfate solution is added to the aniline solution at 0-5°C, stirred for 0.5-2 hours, filtered, the filter cake is washed with water and methanol in sequence, and dried; the resulting solid is stirred in a 3-15wt% ammonia solution for 16-30 hours, filtered, the filter cake is washed with water and methanol in sequence, and dried to obtain the polyaniline sheet; The molar ratio of aniline to ammonium persulfate is 1.5 to 2.8:1; The concentration of aniline in the aniline solution is 0.005 to 2 M; The concentration of the ammonium persulfate aqueous solution is 0.002 to 2 M; The volume mass ratio of the ammonia solution to the solid is 50-500:1, mL / g.

10. Use of a pervaporation membrane doped with a polyaniline-based composite filler modified by template-induced MOFs synthesis as claimed in claim 1 in the pervaporation separation of an alcohol-water mixture.

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