A high-flux, high-selectivity solvent-resistant nanofiltration membrane based on telage base polyamide@polyimide and its preparation method

Abstract

This invention discloses a high-flux, high-selectivity telage-based polyamide@polyimide solvent-resistant nanofiltration membrane and its preparation method, comprising: firstly, preparing a monomer—3,3'-diamino-telage base (DATB)—using a recrystallization method; then, adding it sequentially with an organic acid and polyimide to an organic solvent to prepare a casting solution; coating this solution onto a nonwoven fabric; and then preparing a polyimide-supported substrate membrane rich in DATB through a solvent-induced phase inversion; subsequently, contacting this substrate with a polyacrylamide chloride organic phase; and preparing a nascent telage-based polyamide@polyimide nanofiltration membrane through an interfacial polymerization reaction; and finally, using an aliphatic polyamine for post-crosslinking and solvent activation to obtain the high-flux, high-selectivity telage-based polyamide@polyimide solvent-resistant nanofiltration membrane. The nanofiltration membrane prepared by this invention can withstand most conventional polar, nonpolar, and aprotic strongly polar solvents, has a narrow pore size distribution, and combines high flux and high selectivity, showing broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of various organic solvent separation membrane technologies, specifically to a high-flux, high-selectivity Teleg base polyamide@polyimide solvent-resistant nanofiltration membrane and its preparation method. Background Technology

[0002] Chemical and pharmaceutical production, food processing, and other processes all involve the separation, purification, and concentration of large quantities of small molecule compounds. Traditional methods such as distillation, evaporation, extraction, and chromatography are energy-intensive, inefficient, and account for approximately 40-70% of production costs, while also polluting the environment. Nanofiltration, a pressure-driven membrane separation technology between ultrafiltration and reverse osmosis, offers advantages such as high separation precision, a wide range of separation targets, high efficiency and energy saving, simple and safe operation, and easy integration. In particular, nanofiltration can replace traditional energy-intensive processes such as distillation and evaporation for the separation, purification, and solvent recovery of products in organic solvent systems.

[0003] The core of applying nanofiltration technology for the long-term separation and concentration of organic solvent systems lies in developing solvent-resistant nanofiltration membranes (SRNs). However, conventional polypiperazine amide nanofiltration membranes are not solvent-resistant, and their polysulfone support layer swells or even dissolves. Conventional solvent-resistant nanofiltration membranes such as polyimide and polyacrylonitrile have poor permeation selectivity, making them unsuitable for practical applications. Therefore, attempts have been made to introduce nanomaterials such as graphene oxide (GO), metal-organic frameworks (MOFs), carbon nanotubes (CNTs), and two-dimensional transition metal materials (MXenes) into the membrane to improve its permeation flux. For example, Zhan et al. (J. Membr. Sci., 2023, 666: 121168) introduced two-dimensional MXene (u-Ti3C2Tx) into a polyimide membrane, which slightly increased the membrane's ethanol flux (approximately 3.97 Lm). -2 .h -1 .bar -1 Although Guo et al. (AIChE J., 2017, 63: 1303-1312) found that introducing MOF materials into the polypiperazine amide separation layer could improve the solvent flux of the membrane, it did not significantly improve the membrane's solvent resistance. Self-polymerizing microporous polymers (PIMs) have unique rigid twisted chains and continuous microporous structures, and are therefore used to prepare solvent-resistant nanofiltration membranes. For example, Livingston et al. (J. Membr. Sci., 2018, 558: 52-63.) and Choi et al. (J. Membr. Sci., 2023, 671: 121370) prepared a series of composite nanofiltration membranes, PIM-1, PIM-7, PIM-8, and XPIM-1, by directly coating PAN or PI support layers. These membranes can withstand non-polar solvents such as heptane and toluene, and polar solvents such as ethanol and ketones, and have high solvent flux (approximately 4–18 Lm). -2 .h-1 .bar -1 However, it is intolerant to aprotic, strongly polar solvents such as N,N'-dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), and dimethyl sulfoxide (DMSO). Fu et al. (J. Mater. Chem. A, 2021, 9: 7180-7189) used 7,7'-OH-BINOL, which has a highly rotatable kinked unit and a rigid diaromatic alcohol ring structure, as an aqueous monomer, and interfacially polymerized it with TMC to prepare a nanofiltration membrane with fluxes of 28.7 Lm for acetone and methanol, respectively. -2 h - 1 bar -1 and 9.2 Lm -2 h -1 bar -1 However, its rejection rate for solutes such as tetracycline is relatively low (approximately 98.2%), and its separation selectivity needs further improvement.

[0004] In patent CN117959960A, the inventors developed a 3,3'-diamino-teleg base monomer with a unique V-shaped rigid structure. Introducing this monomer into a nanofiltration membrane can also construct a unique self-polymerizing microporous structure rich in teleg tertiary amines. This structure easily enhances the membrane's acid resistance through protonation reactions with acids. However, the column chromatography purification method used in the synthesis of this monomer is time-consuming, requires large amounts of solvent, and is costly. Therefore, this invention improves the purification process of this monomer to simplify the operation steps, increase efficiency, and reduce costs.

[0005] Therefore, there is an urgent need in this field to develop a solvent-resistant nanofiltration membrane and its preparation method that has excellent solvent resistance (especially resistance to aprotic strongly polar solvents) and permeation flux, high separation selectivity (applicable to both pure organic solvent systems and aqueous systems containing organic solvents), and is simple and inexpensive to prepare. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of poor solvent resistance, permeability, and solute separation selectivity of conventional polypiperazine amide nanofiltration membranes and solvent-resistant polyimide membranes. This invention proposes a high-flux, high-selectivity telage base-based polyamide@polyimide solvent-resistant nanofiltration membrane and its preparation method. The nanofiltration membrane is prepared by first using a two-step method and recrystallization to prepare the functional monomer—3,3'-diamino-telage base (DATB). Then, DATB is dissolved in a polar solvent with an organic acid for protonation pre-protection. Polyimide (PI) is then added to prepare a casting solution. After stirring, allowing it to stand and degas, the solution is coated onto a nonwoven fabric to form a liquid film. This film is then placed in a coagulation bath for non-solvent-induced phase inversion (NIPs) to prepare a DATB-rich porous polyimide support substrate. After washing the surface with deionized water, it undergoes interfacial polymerization by contacting one side with an organic phase solution containing acyl chloride monomers. After the reaction is complete, the remaining organic phase solution is removed, and the membrane is air-dried. Finally, it is cross-linked with diamine molecules (cross-linking agent) and activated with a polar solvent to obtain the final membrane.

[0007] Because DATB molecules contain a unique V-shaped rigid twisted structure, introducing a separation layer can enhance the rigidity of polyamide segments and increase the free volume between segments, thereby endowing the separation layer with excellent solvent resistance and permeability. At the same time, diamine molecules can chemically crosslink with residual acyl chloride monomers or functional groups on the membrane surface and the polyimide supporting substrate, improving the separation selectivity of the membrane while also significantly enhancing solvent resistance, thus enabling it to withstand aprotic strong polar solvents. Furthermore, the appropriate activation energy of polar solvents on nanofiltration membranes further enhances the solvent permeation flux of nanofiltration membranes.

[0008] This invention proposes to synthesize a telrogal base diamine monomer, pre-protect the amino group by adding acid to protonate the amino group, formulate it into a casting solution with polyimide, and introduce it onto the surface of the polyimide support layer by a non-solvent-induced phase inversion method. Then, through interfacial polymerization, chemical crosslinking and solvent activation, a polyamide@polyimide solvent-resistant nanofiltration membrane containing telrogal bases is prepared.

[0009] A high-flux, high-selectivity, solvent-resistant Teleg base polyamide@polyimide nanofiltration membrane is prepared according to the following method: (1) Preparation of 3,3'-diamino-teleger base monomer (i.e., teleger base diamine monomer): ① Dissolve 2-12 parts by weight of bromoaniline compound and 2-6 parts by weight of paraformaldehyde monomer in 100 parts by weight of trifluoroacetic acid. React at room temperature for 36-60 hours. After the reaction is complete, add 20-80 ml of dichloromethane to the reaction solution and stir for 5 mins. Then slowly add excess ice and ammonia water (NH3·H2O, 28%) to the mixed solution and stir thoroughly. Extract three times with 500-800 mL of dichloromethane. Add 500-1000 mL of hydrochloric acid solution with pH=1 to the extract, stir thoroughly, take the organic phase, add anhydrous sodium sulfate (Na2SO4), and filter under vacuum; after the filtrate is evaporated to dryness, add 500-1000 mL of ethyl acetate to dissolve it thoroughly, then add 5-15 g of 400 mesh activated carbon and stir thoroughly at 50 ℃ for 12-24 h, and filter to obtain the filtrate; after the filtrate is evaporated to dryness, crystallize it with 100-150 mL of dichloromethane and 300-500 mL of methanol, then filter and dry to obtain a white powdery solid, namely the intermediate 3,3'-dibromo-teleg base; ② Take 1-10 parts by weight of the 3,3'-dibromo-teleg base intermediate and disperse it in 20 parts by weight of toluene. Then, under inert gas protection, add 0.03-0.06 parts by weight of the catalyst tris(di-methylenebenzylacetone)dipalladium, 0.04-0.08 parts by weight of 1,1'-binaphthyl-2,2'-bis(diphenylphosphine), 0.8-1.2 parts by weight of sodium tert-butoxide, and 0.8-1.6 parts by weight of benzophenone imine. After mixing evenly, react at 80-120℃ for 12-48 hours. Then, react in a mixed solution of 4-16 parts by weight of tetrahydrofuran and 10-40 parts by weight of 1-3 mol / L hydrochloric acid for 1-6 hours to obtain a reaction solution containing 3,3'-diamino-teleg base. ③ The reaction solution containing the 3,3'-diamino-Tellerg base was allowed to stand and separate into layers. After removing the organic phase, ammonia (28% by mass) was added to the remaining aqueous phase to adjust the aqueous phase to alkalinity. Then, the solution was allowed to stand at room temperature for the first crystallization to obtain a dark yellow powdery solid, which is the initial DATB product. The initial DATB product was dissolved in hydrochloric acid, and then 100 mL of dichloromethane was used to extract trace residual impurities. After removing the dichloromethane organic phase, ammonia was added to the remaining aqueous phase again to adjust the aqueous phase to alkalinity. The solution was allowed to stand at room temperature for the second crystallization to obtain a light yellow powdery solid, which is the final DATB product.

[0010] (2) Add the 3,3'-diamino-Tellerg base monomer obtained in step (1) to a polar solvent, then add an organic acid, stir at -20~-5 ℃ for 30~120 minutes, add polyimide (PI) to the mixed solution, stir evenly and let stand to remove bubbles to obtain casting solution; (3) The casting solution from step (2) is scraped onto a nonwoven fabric and placed in a coagulation bath aqueous solution for non-solvent-induced phase transformation. The non-solvent-induced phase transformation time is 30-120 seconds. After that, the membrane surface is rinsed clean with deionized water and then air-dried to obtain a polyimide support substrate with a surface rich in telogen diamine monomer. (4) Pour the organic phase solution containing polyacrylamide chloride monomers onto the polyimide support substrate obtained in step (3) with a surface rich in 3,3'-diamino-Tellerg base monomers. After reacting for 30 to 300 seconds, remove the remaining organic phase solution. Then, heat-treat at 25 to 40 °C for 1 to 20 minutes. After that, soak and wash the obtained membrane in anhydrous ethanol to obtain the nascent Terellerg base polyamide@polyimide nanofiltration membrane. (5) The nascent Teleg base polyamide nanofiltration membrane obtained in step (4) is immersed in an alcohol solution containing aliphatic polyamine (i.e. crosslinking agent) for post-crosslinking, and then immersed in a strongly polar organic solvent for activation to obtain a high-flux and high-selectivity Teleg base polyamide@polyimide solvent-resistant nanofiltration membrane.

[0011] In step (1), the molar ratio of hydrochloric acid to crude DATB product is 2.5 to 4.0, and the volume ratio of dichloromethane to hydrochloric acid solution is 1:1; the aqueous phase is adjusted to alkalinity to pH ≥ 9, the first crystallization time is 6 to 10 hours, and the second crystallization time is 1 to 3 hours. Furthermore, the contents of the telrogallic diamine monomer, organic acid, polyimide, and polar solvent in step (2) are as follows: 0.5–5 wt% of telrogallodiamine monomer; Polyimide 12–20 wt%; Teregol diamine monomer: organic acid (molar ratio) 1:4 to 1:7; Balance of polar solvent; Further, the organic acid mentioned in step (2) is one or any combination of two of citric acid, trifluoroacetic acid, and glacial acetic acid; the polar solvent is one or any combination of two of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), or N-methylpyrrolidone (NMP); Further, the mixed solution described in step (2) is stirred at 20-40 °C for 12-24 hours until it is uniform and clear, and then allowed to stand for 12-24 hours to remove bubbles; Furthermore, in step (3), the amount of coagulation bath used is 1.2 to 2 L; the air-drying time is 10 to 60 minutes.

[0012] Further, the polyacrylamide chloride monomer mentioned in step (4) is isophthaloyl chloride, biphenyltetracarboxylic chloride, trimesoyl chloride or phthaloyl chloride, and the concentration of the polyacrylamide chloride monomer in the organic phase solution containing the polyacrylamide chloride monomer is 0.05 to 0.3 w / v; the organic solvent in the organic phase solution containing the polyacrylamide chloride monomer is one or any combination of two of Isopar G, n-hexane or n-heptane.

[0013] Further, the crosslinking agent mentioned in step (5) is one or any combination of two of ethylenediamine, propylenediamine, hexamethylenediamine, polyethyleneimine, and 2-hydroxypropyldiamine; the alcohol in the alcohol solution is one of isopropanol and ethylene glycol; the mass percentage concentration of the crosslinking agent is in the range of 1.0 to 20.0%, the post-crosslinking temperature is 20 to 80°C, and the crosslinking time is 1 to 20 minutes.

[0014] Further, the solvent mentioned in step (5) is one or any combination of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO) or N-methylpyrrolidone (NMP); the activation temperature is 20 to 60°C and the activation time is 1 to 10 minutes.

[0015] The present invention also proposes a high-flux, high-selectivity telreg base polyamide@polyimide solvent-resistant nanofiltration membrane prepared by the preparation method described above, comprising a polyimide porous support layer and a telreg base-containing polyamide separation layer bonded to its surface, wherein the separation layer is provided with V-shaped rigid twisted telreg base structural units, and aliphatic polyamine crosslinking bonds exist between the separation layer and the support layer and / or on the surface of the separation layer.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] ① Using a simple recrystallization method to replace the traditional column chromatography method for purifying DATB monomers can effectively improve the purity and purification efficiency of the functional monomer 3,3'-diamino-teleg base, reduce monomer purification costs and facilitate industrialization, while also improving the crosslinking degree and separation selectivity of nanofiltration membrane separation layers. ② Protonating the 3,3'-diamino-Tellerg base with an organic acid to form an ammonium salt can avoid the cross-linking reaction between the 3,3'-diamino-Tellerg base and polyimide in the casting solution, which would lead to the embrittlement of the substrate. It also facilitates the faster, more abundant and more uniform segregation and enrichment of the 3,3'-diamino-Tellerg base to the substrate surface during the phase transformation process, thereby improving the cross-linking degree and separation selectivity of the separation layer. At the same time, the abundant V-shaped rigid twisted Telleg base units on the chain segment endow the membrane with higher free volume, solvent permeability and tolerance. ③ By using aliphatic polyamines to perform overall post-crosslinking with polyimide substrate membrane and residual acyl chloride monomers or groups in the separation layer, the tolerance of the prepared nanofiltration membrane to non-protic strong polar solvents can be effectively improved, thus broadening the range of solvents that the nanofiltration membrane can tolerate. ④ Appropriate activation of the membrane using a highly polar solvent can further improve the solvent permeability of the prepared nanofiltration membrane; ⑤ The preparation of nanofiltration membranes by coupling non-solvent-induced phase transformation and interfacial polymerization processes not only solves the problem of membrane preparation by interfacial polymerization of sparingly soluble 3,3'-diamino-teleg base monomers, but also simplifies the membrane preparation process and reduces wastewater volume. Attached Figure Description

[0018] Figure 1 It is a DATB monomer obtained by recrystallization. 1 H NMR spectrum.

[0019] Figure 2 The blank polyimide (PI) porous support substrate (S) described in this invention PI ), PI porous support substrate with DATB monomer enriched on the surface (S PI-DATB ), Telger base polyamide@polyimide nanofiltration membrane (SRN) DATB-TMC Crosslinked activated Teleg base polyamide@polyimide solvent-resistant nanofiltration membrane (SRN) DATB-TMC@HDA@DMF ) and conventional polypiperazine amide solvent-resistant nanofiltration membranes (N PIP-TMC@HDA@DMF Fourier attenuated total reflectance infrared spectrum (ATR-FTIR) of ).

[0020] Figure 3 The Tellerig base polyamide@polyimide nanofiltration membrane (SRN) described in this invention DATB-TMC Post-crosslinked Teleg base polyamide@polyimide solvent-resistant nanofiltration membrane (SRN) DATB-TMC@HDA ), activated Teleg base polyamide@polyimide solvent-resistant nanofiltration membrane (SRN) DATB-TMC@HDA@DMF Images of the membrane before and after immersion in DMF solvent for 14 days. Detailed Implementation

[0021] The following detailed description, in conjunction with specific embodiments, further clarifies the invention. However, the scope and content of this application are not limited to the following embodiments. Any variations or implementations that do not depart from the scope and content of this invention should be included within the technical scope of this invention.

[0022] 1. Synthesis of Teleg diamine monomers

[0023] Example 1:

[0024] ① At -15 ℃, add 25.91 g of 4-bromoaniline, 9.18 g of paraformaldehyde, and 300 mL of trifluoroacetic acid to a three-necked flask. Stir the mixture to room temperature and continue stirring for 48 h. Add 50 mL of dichloromethane to the reaction mixture and stir for 5 mins. Slowly add excess ice and ammonia (NH3·H2O, 28%) to the mixture, stir thoroughly, and extract three times with 500 mL of dichloromethane. Add 1000 mL of hydrochloric acid solution with pH=1 to the extract, stir thoroughly, take the organic phase, add anhydrous sodium sulfate (Na2SO4), and filter under vacuum; after the filtrate is evaporated to dryness, add 500 mL of ethyl acetate to dissolve it thoroughly, then add 10 g of 400 mesh activated carbon and stir thoroughly at 50 ℃ for 24 hours, and filter to obtain the filtrate; after the filtrate is evaporated to dryness, crystallize it with 100 mL of dichloromethane and 300 mL of methanol, filter and dry to obtain 15.5 g of white powdery solid, namely the intermediate 3,3'-dibromo-teleg base.

[0025] ② Under nitrogen protection, 47.25 g of the obtained intermediate 3,3'-dibromo-teregol base was dispersed in 1000 mL of toluene, and 3 g of 1,1'-binaphthyl-2,2'-bis(diphenylphosphine), 36 g of sodium tert-butoxide, and 50 mL of benzophenone imine were added. Then, 1.5 g of tris(di-methylenebenzylacetone)dipalladium was added as a catalyst, and the mixture was refluxed for 24 h. The reaction solution was concentrated under vacuum. The residue was added to a mixed solution of 500 mL of tetrahydrofuran and 1000 mL of hydrochloric acid (2 mol / L) and reacted for 3 hours. After the reaction was completed, a homogeneous reaction solution containing DATB was obtained.

[0026] ③ The reaction solution containing the 3,3'-diamino-Tellerg base was allowed to stand and separate into layers. After removing the organic phase, ammonia (28% by mass) was added to the remaining aqueous phase to adjust the pH to 9. The solution was then allowed to stand at room temperature for 8 hours for the first crystallization, yielding a dark yellow powdery solid, which is the initial DATB product. 20g of the initial DATB product was dissolved in 100mL of 2mol / L hydrochloric acid solution, and then 100mL of dichloromethane was used to extract trace residual impurities. After removing the dichloromethane organic phase, ammonia (28% by mass) was added to the remaining aqueous phase again to adjust the pH to 9. The solution was allowed to stand at room temperature for 2 hours for the second crystallization, yielding 20.32g of a pale yellow powdery solid, which is the final DATB product.

[0027] The ¹H NMR spectrum of the obtained DATB product is as follows: Figure 1 As shown, the successful synthesis and high purity of DATB are confirmed.

[0028] Comparative Example 1:

[0029] The crystallization purification step in step ① of Example 1—"After the filtrate is evaporated to dryness, 500 mL of ethyl acetate is added to dissolve it completely, then 10 g of 400-mesh activated carbon is added and stirred thoroughly at 50 °C for 24 hours, and the filtrate is filtered; the filtrate is evaporated to dryness and crystallized with 100 mL of dichloromethane and 300 mL of methanol, and after filtration and drying, a white powdery solid, namely the intermediate 3,3'-dibromo-teleg base, is obtained"—is changed to a chromatography purification step—"The residual concentrate is purified by alkaline alumina column chromatography, after chromatography with 10 L of eluent dichloromethane and petroleum ether (volume ratio of 1:9) for 6 hours, the resulting eluent is evaporated to dryness to obtain the intermediate 3,3'-dibromo-teleg base."

[0030] The recrystallization purification step in step ③ of Example 1—"the first crystallization was performed by letting the aqueous phase (pH=9) stand at room temperature for 8 hours to obtain a dark yellow powdery solid, which is the initial DATB product; 20g of the initial DATB product was dissolved in 100mL of 2mol / L hydrochloric acid solution, and then the trace residual impurities were extracted with 100mL of dichloromethane. After removing the dichloromethane organic phase, ammonia water (28% by mass) was added to the remaining aqueous phase to adjust the pH of the aqueous phase to 9, and the second crystallization was performed by letting it stand at room temperature for 2 hours." The process of "crystallizing to obtain a pale yellow powdery solid, which is the final product DATB" was changed to a chromatography purification step: "Dichloromethane was added to the aqueous phase (pH=9) for extraction. After removing the aqueous phase, pure water and brine (NaCl) were added to the organic phase for washing. The phase was then dried with anhydrous magnesium sulfate and filtered. The organic phase was then concentrated under vacuum and purified by alkaline alumina column chromatography. The phase was chromatographically analyzed for 15 hours with 7.5 L of methanol and dichloromethane (volume ratio 1:20) as eluent. The eluent was evaporated to dryness to obtain the final product DATB."

[0031] Table 1: Effect of purification method on the preparation of DATB monomer

[0032] As shown in Table 1, the recrystallization method adopted in this invention significantly improves purification efficiency (10 hours vs. 15 hours) and greatly reduces purification costs (by about 16%) while ensuring a high yield. At the same time, the product purity is higher (99.5% vs. 98.2%), the operation is simpler, and it is more suitable for industrial production.

[0033] 2. Preparation of solvent-resistant nanofiltration membranes using Teleg base polyamide@polyimide

[0034] Example 2

[0035] ① Non-solvent-induced phase transformation Add 2.0 wt% DATB monomer and NMP to a round-bottom flask, then add 0.87 ml of trifluoroacetic acid (NMP). DATB :nTFA =1:5), stir thoroughly for a certain period of time, and finally add 17 wt% polyimide. Stir thoroughly at 25 ℃ and let stand for 12 hours to remove bubbles, obtaining a homogeneous, bubble-free casting solution. Pour the casting solution evenly onto nonwoven fabric S53, and then use a 200 μm doctor blade to scrape it into a uniform liquid film. Immerse the nonwoven fabric coated with the liquid film into 2 L of coagulation bath aqueous solution for non-solvent-induced phase transformation for 60 seconds to obtain a PI porous support substrate film with a surface rich in DATB monomer, named S. PI-DATB .

[0036] ②In-situ interface aggregation A 0.10 w / v% hexane solution of 1,3,5-benzenetricarboxylic chloride (TMC) was poured onto the surface of an air-dried PI porous support membrane rich in DATB monomer for interfacial polymerization for 60 seconds. After removing excess organic phase solution from the membrane surface, the membrane was heat-treated at 30 °C for 30 minutes to finally obtain a polyamide nanofiltration membrane containing telage bases, which was named SRN. DATB-TMC The prepared nanofiltration membrane was stored in anhydrous ethanol for later use.

[0037] ③ Post-crosslinking The prepared nanofiltration membrane SRN DATB-TMC Crosslinking was performed in a 6 wt% HDA / IPA solution at 60 °C for 30 mins, and the sample was named SRN. DATB-TMC@HDA .

[0038] ④ Solvent activation To further improve the membrane flux, the cross-linked nanofiltration membrane SRN DATB-TMC@HDA It was activated by immersion in DMF solution at 80 °C for 15 mins and named SRN. DATB-TMC@HDA@DMF .

[0039] Example 3: Change the DATB concentration in step ② from 2.0 wt% to 0.5 wt%, and trifluoroacetic acid (n DATB :n TFA The volume of the SRN (ratio 1:5) was changed from 0.87 ml to 0.22 ml, and other operations were the same as in Example 1. DATB-TMC Membrane performance data are listed in Table 2.

[0040] Example 4: Change the DATB concentration in step ② from 2.0 wt% to 1.0 wt%, and the trifluoroacetic acid (n DATB :n TFA The volume of the SRN (ratio 1:5) was changed from 0.87 ml to 0.43 ml, and other operations were the same as in Example 1. DATB-TMC Membrane performance data are listed in Table 2.

[0041] Example 5: Change the DATB concentration in step ② from 2.0 wt% to 1.5 wt%, and the trifluoroacetic acid (n DATB :n TFA The volume of the SRN (ratio 1:5) was changed from 0.87 ml to 0.65 ml, and other operations were the same as in Example 1. DATB-TMC Membrane performance data are listed in Table 2.

[0042] Example 6: Change the DATB concentration in step ② from 2.0 wt% to 2.5 wt%, and the trifluoroacetic acid (n... DATB :n TFA The volume of the SRN (ratio 1:5) was changed from 0.87 ml to 1.08 ml, and other operations were the same as in Example 1. DATB-TMC Membrane performance data are listed in Table 2.

[0043] Example 7: In step ④, the concentration of 1,3,5-benzenetricarboxylic acid chloride was changed from 0.10 wt% to 0.05 wt%, and other operations were the same as in Example 1, to prepare SRN. DATB-TMC Membrane performance data are listed in Table 3.

[0044] Example 8: In step ④, the concentration of 1,3,5-benzenetricarboxylic acid chloride was changed from 0.10 w / v% to 0.15 w / v%, and other operations were the same as in Example 1 to prepare SRN. DATB-TMC Membrane performance data are listed in Table 3.

[0045] Example 9: In step ④, the concentration of 1,3,5-benzenetricarboxylic acid chloride was changed from 0.10 w / v% to 0.2 w / v%, and other operations were the same as in Example 1 to prepare SRN. DATB-TMC Membrane performance data are listed in Table 3.

[0046] Example 10: The interface aggregation time in step ④ is changed from 60 s to 30 s, and other operations are the same as in Example 1, to produce the SRN. DATB-TMC Membrane performance data are listed in Table 4.

[0047] Example 11: Change the interface aggregation time in step ④ from 60 s to 90 s, and perform other operations as in Example 1 to produce the SRN. DATB-TMC Membrane performance data are listed in Table 4.

[0048] Example 12: Change the interface aggregation time in step ④ from 60 s to 120 s, and perform other operations as in Example 1 to produce the SRN. DATB-TMC Membrane performance data are listed in Table 4.

[0049] Table 2: Comparison of membrane properties prepared in Examples 2-6

[0050] Table 2 shows that DATB concentration has a significant impact on membrane performance. When the DATB concentration is 2.0 wt% (Example 2), the membrane maintains a high methanol flux (17.99 Lm). -2 h -1 bar -1 It also exhibits the best Eriochrome Black T rejection rate (98.6%). When the DATB concentration is too low (0.5 wt%), although the flux is the highest, the rejection rate decreases significantly; when the DATB concentration is too high (2.5 wt%), both flux and rejection rate decrease.

[0051] Table 3: Comparison of membrane properties prepared in Examples 7-9

[0052] As shown in Table 3, when the TMC concentration increased from 0.05 w / v% to 0.15 w / v%, the rejection rate significantly increased from 92.8% to 99.4%, while the flux increased from 22.74 Lm. -2 h -1 bar -1 Reduced to 10.72 Lm -2 h -1 bar -1 Increasing the TMC concentration further to 0.20 w / v% did not significantly change the performance. Considering both flux and rejection rate, 0.10–0.15 w / v% is the optimal TMC concentration range.

[0053] Table 4: Comparison of membrane properties prepared in Examples 10-12

[0054] As shown in Table 4, as the interfacial polymerization time increased from 30 s to 120 s, the Rhodamine B rejection rate increased from 96.2% to 99.2%, but the methanol flux decreased from 22.2 Lm. -2 h -1 bar -1 Reduced to 11.76 Lm -2 h -1 bar -1 An interface aggregation time of 60–90 s can achieve a good balance between throughput and rejection rate.

[0055] Selecting SRN in Example 2 DATB-TMC SRN DATB-TMC@HDA SRN DATB-TMC@HDA@DMF The mass retention rate was tested. The membrane was immersed in the polar aprotic solvent N,N-dimethylformamide (DMF) solution for 14 days. The mass retention rate results are shown in Table 5.

[0056] Table 5: SRN in Example 2 DATB-TMC SRN DATB-TMC@HDA SRN DATB-TMC@HDA@DMF Perform quality retention performance testing

[0057] As shown in Table 5, SRN without post-crosslinking DATB-TMC The membrane completely dissolved after only one day of immersion in DMF (mass retention rate of 0), indicating that the polyamide separation layer formed by interfacial polymerization could not effectively protect the overall structure of the membrane from the erosion of highly polar solvents. Meanwhile, the SRN crosslinked after HDA... DATB-TMC@HDA The membrane retained 97.4% of its mass after immersion in DMF for 14 days, and the activated SRN... DATB-TMC@HDA@DMF The membrane quality retention rate still reached 98.2%. This indicates that post-crosslinking with HDA significantly improved the overall structural stability of the membrane, enabling it to withstand aprotic strong polar solvents. Figure 3 The images of the membrane also visually confirm this conclusion.

[0058] Selecting SRN in Example 2 DATB-TMC SRN DATB-TMC@HDA SRN DATB-TMC@HDA@DMF Dye separation performance was tested. The separation test results of 50 ppm Eriochrome Black T / methanol solution at 25 ℃ and 0.6 MPa are shown in Table 6.

[0059] Comparative Example 2: In Example 2, the DATB monomer of the triglucopyranodiamine was replaced with piperazine. Using the same piperazine concentration as the aqueous phase solution and the same TMC concentration as the oil phase solution, N was obtained after aqueous amine immersion for 1 min and the same interfacial polymerization reaction time. PIP-TMC Then, through the same chemical crosslinking and solvent activation process, a polypiperazine amide solvent-resistant nanofiltration membrane SRN is obtained. PIP-TMC@HDA SRN PIP-TMC@HDA@DMF For comparative testing, the separation test results of 50 ppm Eriochrome Black T / methanol solution at 25 ℃ and 0.6 MPa are shown in Table 6.

[0060] Table 6: SRN in Example 2 DATB-TMC SRN DATB-TMC@HDA SRN DATB-TMC@HDA@DMFThe membrane and N in Comparative Example 2 PIP-TMC SRN PIP-TMC@HDA SRN PIP-TMC@HDA@DMF Membrane dye separation performance test

[0061] As shown in Table 6, the nanofiltration membrane (SRN) prepared by this invention using DATB as the aqueous monomer... DATB-TMC Methanol flux (17.99 Lm) from the membrane -2 h -1 bar -1 The efficiency is significantly higher than that of conventional polypiperazine amide nanofiltration membranes (N) with piperazine as the monomer. PIP-TMC ~membrane, 4.59 Lm - 2 h -1 bar -1 Furthermore, the retention rate of Chrome Black T was higher (98.6% vs 97.7%). After post-crosslinking and activation, SRN... DATB-TMC@HDA@DMF ~Methanol flux of the membrane (11.68 Lm) -2 h -1 bar -1 It is still significantly higher than SRN. PIP-TMC@HDA@DMF ~membrane (4.21 Lm) -2 h -1 bar -1 Both solvents maintained a rejection rate of over 99.5%. This indicates that DATB's unique V-shaped rigid twisted structure effectively increases the free volume of the separation layer, thereby significantly improving solvent permeation flux.

[0062] Selecting SRN in Example 2 DATB-TMC@HDA@DMF Membrane and SRN in Comparative Example 2 PIP-TMC@HDA@DMF The membrane was tested for separation performance with different dyes. The separation results of 50 ppm different dye / methanol solutions at 25 ℃ and 0.6 MPa are shown in Table 7.

[0063] Table 7: SRN in Example 2 DATB-TMC@HDA@DMF Membrane and SRN in Comparative Example 2 PIP-TMC@HDA@DMF Membrane separation performance tests for different dyes

[0064] As shown in Table 7, the SRN prepared in this invention... DATB-TMC@HDA@DMF The membrane exhibits excellent retention performance (≥98.2%) for dyes with molecular weights greater than 327 Da (such as MR, EBT, RDB, AC66, CR, MB, G250, EB, RB), and a flux (8.2–11.8 Lm). -2 h -1 bar -1The efficiency is significantly higher than that of conventional polypiperazine amide solvent-resistant nanofiltration membranes (2.9–4.2 μm). -2 h -1 bar -1 For MO (methyl orange, molecular weight 327 Da), which has a smaller molecular weight, the membrane rejection rate of the present invention is 69.3%, while that of the control membrane is 98.9%. This indicates that the pore size of the membrane of the present invention is slightly larger than that of the control membrane, which is consistent with its higher flux and also confirms that the V-shaped rigid structure of DATB does indeed increase the free volume of the membrane.

[0065] Selecting SRN in Example 2 DATB-TMC@HDA@DMF Membrane and SRN in Comparative Example 2 PIP-TMC@HDA@DMF The membrane was tested for flux performance with different pure solvents. The flux test results for different pure solvents (DMSO, NMP, DMF, DMAc, EtOH, MeOH, IPA, EA, THF, ACN) at 25 ℃ and 0.6 MPa are shown in Table 8.

[0066] Table 8: SRN in Example 2 DATB-TMC@HDA@DMF Membrane and SRN in Comparative Example 2 PIP-TMC@HDA@DMF Membrane for solvent flux performance testing

[0067] As shown in Table 8, the SRN prepared by this invention... DATB-TMC@HDA@DMF The membrane exhibits considerable flux to a variety of organic solvents, particularly methanol (11.9 Lm). -2 h -1 bar -1 ), ethyl acetate (5.7 Lm) -2 h -1 bar -1 ), tetrahydrofuran (13.1 Lm) -2 h -1 bar -1 ) and acetonitrile (23.1 Lm) -2 h -1 bar -1 The membrane exhibits excellent performance in various applications. Most importantly, it demonstrates good permeability to aprotic, strongly polar solvents such as DMF, DMAc, DMSO, and NMP (fluxes of 5.8, 2.6, 1.5, and 1.9 Lm, respectively). -2 h -1 bar -1 In contrast, conventional polypiperazine amide solvent-resistant nanofiltration membranes have a flux of 0 for these solvents, indicating that the membrane of the present invention has significant advantages in terms of tolerance and permeability to aprotic strongly polar solvents.

[0068] Selecting SRN in Example 2 DATB-TMC@HDA@DMFThe membrane was tested for separation performance with different polar aprotic solvents. The separation results of 50 ppm EBT / polar aprotic solutions (DMSO, DMF, DMAc, NMP) at 25 ℃ and 0.6 MPa are shown in Table 9.

[0069] Table 9: SRN in Example 2 DATB-TMC@HDA@DMF Membrane separation performance tests in different aprotic strongly polar solvent systems

[0070] As shown in Table 9, the SRN prepared in this invention... DATB-TMC@HDA@DMF The membrane exhibited excellent separation performance in four aprotic strongly polar solvent systems, with EBT rejection rates exceeding 97.9%, and rejection rates exceeding 99% in DMF, DMAc, and NMP systems. This demonstrates that the membrane not only withstands aprotic strongly polar solvents but also maintains excellent separation selectivity in these harsh solvent environments, indicating significant potential for separation applications in organic solvent systems.

[0071] Selecting SRN in Example 2 DATB-TMC@HDA@DMF Membrane and SRN in Comparative Example 2 PIP-TMC@HDA@DMF The membrane's solvent resistance was tested. The membrane was immersed in a polar aprotic solvent, N,N-dimethylformamide (DMF), at 25 °C and 0.6 MPa. The separation results for a 50 ppm EBT / methanol solution are shown in Table 10. Table 10: SRN in Example 2 DATB-TMC@HDA@DMF Membrane and SRN in Comparative Example 2 PIP-TMC@HDA@DMF Changes in dye rejection and solvent flux of the membrane before and after immersion in DMF

[0072] As shown in Table 10, the SRN prepared by this invention... DATB-TMC@HDA@DMF After being immersed in DMF for 14 days, the membrane consistently maintained an EBT rejection rate of over 99.3%, with a flux stable at 13–18 Lm. -2 h -1 bar -1 No significant performance degradation was observed between the two processes. Meanwhile, conventional polypiperazine amide solvent-resistant nanofiltration membranes (SRN) showed no performance degradation. PIP-TMC@HDA@DMF Although the membrane can maintain a certain degree of structural integrity in DMF (attributed to post-HDA crosslinking), its flux is only 3–6 Lm. -2 h -1 bar -1 The solvent permeation flux is significantly lower than that of the membrane of this invention. This indicates that the introduction of DATB not only improves the solvent permeation flux of the membrane, but also endows the membrane with superior long-term solvent resistance.

[0073] In summary, based on the above results, the present invention employs a simple recrystallization method that can effectively improve the purity and purification efficiency of the functional monomer 3,3'-diamino-teleg base, reduce monomer purification costs, and is easy to industrialize. Pre-protonation of the 3,3'-diamino-tellegag base with an organic acid to form an ammonium salt avoids cross-linking reactions between the 3,3'-diamino-tellegag base and polyimide in the casting solution, which could lead to substrate embrittlement. This also facilitates faster, more abundant, and more uniform segregation of the 3,3'-diamino-tellegag base onto the substrate surface during phase inversion, thereby improving the cross-linking degree and separation selectivity of the separation layer. Simultaneously, the abundant V-shaped rigid twisted tellegag base units on the chain segments endow the membrane with higher free volume, solvent permeability, and resistance. Post-crosslinking of the membrane using aliphatic polyamines such as HAD effectively enhances the resistance of the prepared nanofiltration membrane to aprotic strongly polar solvents, broadening the range of solvents the nanofiltration membrane can tolerate. Moderate activation of the membrane using strongly polar solvents further improves the solvent permeability of the prepared nanofiltration membrane. Therefore, the prepared SRN... DATB-TMC@HDA@DMF The membrane exhibits excellent retention performance for dyes with molecular weights greater than 327 Da, while maintaining a uniform flux of 10 Lm. -2 h -1 bar -1 In the pure solvent test, SRN DATB-TMC@HDA@DMF The membrane exhibits high fluxes for methanol, ethyl acetate, and acetonitrile, at 11.9, 13.1, and 21.1 Lm, respectively. -2 h -1 bar -1 The flux is significantly higher than that of conventional polypiperazine amide solvent-resistant nanofiltration membranes. In tests with four polar aprotic solvents, the membrane's rejection rate was consistently above 98%, demonstrating excellent solvent resistance and separation performance against various strongly polar aprotic solvents. Therefore, it holds great potential for applications in the recovery of dyes from organic solvents. After a 14-day long-term solvent resistance stability test, the prepared SRN... DATB-TMC@HDA@DMF The membrane exhibits excellent solvent resistance and separation performance. After 14 days, its rejection rate remained at 99.3%, with a slight increase in flux. This indicates that the membrane structure remained unchanged and can withstand these aprotic strong polar solvents for a long time. Therefore, this membrane has great potential for separation applications in organic solvent systems.

[0074] Depend on Figure 2 As can be seen from the ATR-FTIR images, the infrared spectral evidence of each membrane systematically verifies the feasibility and structural reproducibility of each key step of the present invention (DATB surface enrichment, interfacial polymerization to construct the separation layer, post-crosslinking and activation).

[0075] Figure 3 These are comparative images of various membranes before and after immersion in DMF solvent for 14 days. Figure 3The macroscopic physical morphology confirms that the uncrosslinked membrane completely disintegrated in DMF, while the crosslinked membrane remained intact after immersion in DMF for 14 days. This directly demonstrates the crucial role of the crosslinking step in resisting aprotic strong polar solvents, and also corroborates the rationality of the stepwise design strategy in this invention of "first constructing the separation layer through interfacial polymerization, and then strengthening it through overall crosslinking with polyamines".

[0076] This invention provides a high-throughput, high-selectivity Teleg-based polyamide@polyimide solvent-resistant nanofiltration membrane and its preparation method, which have significant industrial practical value. This invention employs a recrystallization method to purify DATB monomers, which is simple to operate, low in cost, and easy to scale up industrially. The membrane fabrication process, coupled with non-solvent-induced phase inversion and interfacial polymerization, is simple and produces less wastewater. The prepared nanofiltration membrane can withstand most organic solvents, including conventional polar solvents, non-polar solvents, and aprotic strongly polar solvents (such as DMF, DMAc, DMSO, NMP, etc.), while exhibiting both high throughput and high selectivity. This membrane has broad application prospects in the separation, purification, and solvent recovery of pure organic solvent systems and water systems containing organic solvents in chemical and pharmaceutical production, food processing, and other fields.

[0077] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a high-flux, high-selectivity, solvent-resistant telregruyl polyamide@polyimide nanofiltration membrane, characterized in that, Includes the following steps: (1) Preparation of 3,3'-diamino-Tellerg base monomer; (2) Add the 3,3'-diamino-Tellerg base monomer obtained in step (1) to a polar solvent, then add an organic acid, stir at -20~-5 ℃ for 30~120 minutes, add polyimide to the mixed solution, stir evenly and let stand to remove bubbles to obtain casting solution; (3) The casting solution from step (2) is scraped onto a nonwoven fabric and placed in a coagulation bath aqueous solution for non-solvent-induced phase transformation. The non-solvent-induced phase transformation time is 30-120 seconds. After that, the membrane surface is rinsed clean with deionized water and then air-dried to obtain a polyimide support substrate with a surface rich in telogen diamine monomer. (4) Pour the organic phase solution containing polyacrylamide chloride monomer onto the polyimide support substrate obtained in step (3) with a surface rich in 3,3'-diamino-Tellerg base monomer. After reacting for 30 to 300 seconds, remove the remaining organic phase solution. Then, heat-treat at 25 to 40°C for 1 to 20 minutes. After that, soak and wash the obtained membrane in anhydrous ethanol to obtain the nascent Terellerg base polyamide@polyimide nanofiltration membrane. (5) The nascent Teleg base polyamide@polyimide nanofiltration membrane obtained in step (4) is immersed in an alcohol solution containing a crosslinking agent for post-crosslinking, and then immersed in a highly polar organic solvent for activation to obtain a high-flux and high-selectivity Teleg base polyamide@polyimide solvent-resistant nanofiltration membrane, wherein the crosslinking agent is an aliphatic polyamine.

2. The method for preparing the high-flux, high-selectivity, solvent-resistant Teleg base polyamide@polyimide nanofiltration membrane as described in claim 1, characterized in that: The preparation process in step (1) includes the following steps: ① Dissolve 2-12 parts by weight of bromoaniline compound and 2-6 parts by weight of paraformaldehyde monomer in 100 parts by weight of trifluoroacetic acid. React at room temperature for 36-60 hours. After the reaction is complete, add 20-80 ml of dichloromethane to the reaction solution and stir for a period of time. Then slowly add excess ice and ammonia water to the mixed solution and stir thoroughly. Extract three times with 500-800 mL of dichloromethane. Add 500-1000 mL of hydrochloric acid solution with pH=1 to the extract and stir thoroughly. Take the organic phase, add anhydrous sodium sulfate, and filter under vacuum. After the filtrate is evaporated to dryness, add 500-1000 mL of ethyl acetate to dissolve it thoroughly. Then add 5-15 g of 400 mesh activated carbon and stir thoroughly at 50 ℃ for 12-24 h. Filter to obtain the filtrate. After the filtrate is evaporated to dryness, crystallize it with 100-150 mL of dichloromethane and 300-500 mL of methanol. Filter and dry to obtain a white powdery solid, namely the intermediate 3,3'-dibromo-teleg base. ② Take 1-10 parts by weight of the 3,3'-dibromo-teleg base intermediate and disperse it in 15-20 parts by weight of toluene. Then, under inert gas protection, add 0.03-0.06 parts by weight of the catalyst tris(di-methylenebenzylacetone)palladium, 0.04-0.08 parts by weight of 1,1'-binaphthyl-2,2'-bis(diphenylphosphine), 0.8-1.2 parts by weight of sodium tert-butoxide, and 0.8-1.6 parts by weight of benzophenone imine. After mixing evenly, react at 80-120℃ for 12-48 hours. Then, react in a mixed solution of 4-16 parts by weight of tetrahydrofuran and 10-40 parts by weight of 1-3 mol / L hydrochloric acid for 1-6 hours to obtain a reaction solution containing 3,3'-diamino-teleg base. ③ The reaction solution containing the 3,3'-diamino-Tellerg base was allowed to stand and separate into layers. After removing the organic phase, ammonia was added to the remaining aqueous phase to adjust the aqueous phase to alkalinity. Then, the solution was allowed to stand at room temperature for the first crystallization to obtain a dark yellow powdery solid, which is the initial DATB product. The initial DATB product was dissolved in hydrochloric acid, and then trace residual impurities were extracted with dichloromethane. After removing the dichloromethane organic phase, ammonia was added to the remaining aqueous phase again to adjust the aqueous phase to alkalinity. The solution was allowed to stand at room temperature for the second crystallization to obtain a light yellow powdery solid, which is the final DATB product.

3. The method for preparing the high-flux, high-selectivity, telage-based polyamide@polyimide solvent-resistant nanofiltration membrane as described in claim 2, characterized in that: In step ③, the molar ratio of hydrochloric acid to crude DATB product is 2.5~4.0, and the volume ratio of dichloromethane to hydrochloric acid solution is 1:1; the aqueous phase is adjusted to alkalinity to pH≥9, the first crystallization time is 6~10 hours, and the second crystallization time is 1~3 hours.

4. The method for preparing the high-flux, high-selectivity, telage-based polyamide@polyimide solvent-resistant nanofiltration membrane as described in claim 1, characterized in that: In step (2), the contents of 3,3'-diamino-teleg base monomer, organic acid, polyimide, and polar solvent are as follows: 0.5–5 wt% of 3,3'-diamino-teleg base monomer; Polyimide 12–20 wt%; The molar ratio of 3,3'-diamino-teleg base monomer to organic acid is 1:4 to 1:7; Balance of polar solvent.

5. The method for preparing the high-flux, high-selectivity, telage-based polyamide@polyimide solvent-resistant nanofiltration membrane as described in claim 1, characterized in that: In step (2), the organic acid is one or any combination of two of citric acid, trifluoroacetic acid, and glacial acetic acid; the polar solvent is one or any combination of two of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or N-methylpyrrolidone.

6. The method for preparing the high-flux, high-selectivity, telage-based polyamide@polyimide solvent-resistant nanofiltration membrane as described in claim 1, characterized in that: In step (2), the mixed solution after adding polyimide is stirred at 20-40°C for 12-24 hours until it is uniform and transparent, and then allowed to stand for 12-24 hours to remove bubbles; in step (3), the amount of coagulation bath is 1.2-2 L; the time for air drying is 10-60 minutes.

7. The method for preparing the high-flux, high-selectivity, telage-based polyamide@polyimide solvent-resistant nanofiltration membrane as described in claim 1, characterized in that: In step (4), the polyacrylamide chloride monomer is isophthaloyl chloride, biphenyltetracarboxylic chloride, trimesoyl chloride or phthaloyl chloride, and the concentration of the polyacrylamide chloride monomer in the organic phase solution containing the polyacrylamide chloride monomer is 0.05 to 0.3 w / v; the organic solvent in the organic phase solution containing the polyacrylamide chloride monomer is one or any combination of two of Isopar G, n-hexane or n-heptane.

8. The method for preparing the high-flux, high-selectivity, telage-based polyamide@polyimide solvent-resistant nanofiltration membrane as described in claim 1, characterized in that: In step (5), the crosslinking agent is one or any combination of two of ethylenediamine, propylenediamine, hexamethylenediamine, polyethyleneimine, and 2-hydroxypropyldiamine; the alcohol in the alcohol solution is one of isopropanol and ethylene glycol; the mass percentage concentration of the crosslinking agent is in the range of 1.0 to 20.0%, the post-crosslinking temperature is 20 to 80°C, and the crosslinking time is 1 to 20 minutes.

9. The method for preparing the high-flux, high-selectivity, telage-based polyamide@polyimide solvent-resistant nanofiltration membrane as described in claim 1, characterized in that: The strongly polar organic solvent mentioned in step (5) is one or any combination of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide or N-methylpyrrolidone; the activation temperature is 20 to 60°C and the activation time is 1 to 10 minutes.

10. A high-flux, high-selectivity Teleg-based polyamide@polyimide solvent-resistant nanofiltration membrane prepared by the preparation method according to any one of claims 1-9, characterized in that, It includes a porous polyimide support layer and a polyamide release layer containing telrog bases bonded to its surface. The release layer incorporates V-shaped rigid twisted telrog base structural units, and aliphatic polyamine crosslinks exist between the release layer and the support layer and / or on the surface of the release layer.

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