A method for preparing a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane

Abstract

This invention discloses a method for preparing a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane. First, porous polymer nanoparticles are composited with an amino polymer to synthesize core-shell porous polymer nanoparticles. Then, these nanoparticles are chemically crosslinked with the prepared aromatic heterocyclic polymer nanomaterials and a crosslinking agent to form a nanocomposite dispersion. Finally, the nanocomposite dispersion is directly coated onto the surface of a nonwoven fabric and then heat-treated to form a membrane. This invention is simple, controllable, and easy to scale up. The prepared membrane maintains high permeability selectivity and solvent resistance stability during long-term service, showing good prospects for industrial production and application.

Description

Technical Field

[0001] This invention belongs to the field of membrane separation technology, and particularly relates to a method for preparing a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane. Background Technology

[0002] In the fields of fine chemicals and pharmaceutical separation, particularly in key processes such as the separation of active pharmaceutical ingredients (APIs) and intermediates, the separation and purification of protein and peptide drugs, and the separation, concentration, and refining of antibiotics, organic solvents are widely used. Taking APIs as an example, their synthesis requires organic solvents as reaction media, and the purification and separation of APIs and oligomers also need to be carried out in organic solvents. Traditional methods such as multi-step extraction and evaporation concentration generally suffer from high energy consumption and significant organic solvent loss, and are prone to degradation and inactivation of heat-sensitive components. Therefore, developing efficient, low-energy-consumption, and environmentally friendly new separation technologies has become an urgent need for the pharmaceutical separation industry. Organic solvent nanofiltration (OSN) technology, with its excellent pore size sieving capability, low-energy operation characteristics, and green environmental protection advantages, provides an efficient solution for pharmaceutical separation scenarios in the aforementioned organic solvent systems.

[0003] Currently, commercially available OSN membranes are mainly prepared from traditional polymer materials such as polyimide and polyamide, which have advantages such as good film-forming properties and ease of processing. However, these polymer membranes generally suffer from problems such as high density, low permeability, and poor solvent stability, making it difficult to overcome the trade-off between solvent permeability and separation selectivity. Although traditional polymer materials can reduce membrane thickness to the nanometer scale through "thin-layer composite" (TFC) technology, which can improve membrane solvent permeability to some extent, it still cannot achieve a breakthrough in OSN separation performance. In contrast, porous organic polymers, with their high porosity, tunable pore size, and rigid framework structure, have become ideal materials for preparing high-performance OSN membranes. However, the preparation of existing porous organic polymer membranes still faces significant challenges: on the one hand, porous polymer materials such as covalent organic frameworks and conjugated microporous polymers have relatively large pore sizes (>2 nm), resulting in membranes with poor separation accuracy for smaller molecules, which is insufficient to meet the requirements of high-permeability selective OSN applications; on the other hand, membrane preparation processes are complex and demanding, and the interfacial interaction between the separation layer and the porous support layer is weak, making it difficult to prepare large-area membranes and scale up their application (Angew. Chem. Int. Ed. 2024, e202421661, Adv. Mater. 2017, 29, 1603945.). Therefore, it is urgent to explore novel porous organic polymer membrane materials and simple, controllable, and easily scalable methods for preparing solvent-resistant nanofiltration membranes to produce nanofiltration membranes with high permeability, high separation selectivity, and strong solvent resistance.

[0004] Based on the above analysis, integrating the excellent film-forming properties of traditional polymers and the tunable pore size of porous polymer materials can effectively overcome the shortcomings of membranes prepared separately, leveraging their advantages and improving the overall OSN performance of the membrane. Therefore, this invention innovatively proposes synthesizing core-shell porous polymer nanomaterials through a composite reaction of porous polymer nanoparticles and amino polymers, further combining them with rigid aromatic heterocyclic polymer nanomaterials to construct a nanocomposite membrane with high porosity, tunable pore size, and strong solvent resistance. A simple and easily controlled blade coating method is used for film formation, solving the problems of difficulty in large-area film formation of porous polymers and high membrane preparation costs. The prepared solvent-resistant nanofiltration membrane is defect-free, with pore size tunable at the sub-nanometer scale, exhibiting significant advantages in high solvent permeability and high solute separation selectivity, while also possessing excellent solvent resistance. This invention provides an effective separation technology and a high-performance solvent-resistant nanofiltration membrane for the precise separation of substances in organic solvent systems and efficient solvent recovery in fine chemical and pharmaceutical production. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane.

[0006] Therefore, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane includes the following steps:

[0008] 1) Dissolve 0.05-1 parts by mass of a polyamine monomer in 12-360 parts by mass of a mixed solvent containing an acid catalyst. After fully dissolving by magnetic stirring, a mixed solution is obtained. Then, 0.05-0.6 parts by mass of an aldehyde compound and 0.2-1.2 parts by mass of a 1,2-dicarbonyl compound are added to the above mixed solution. The polymerization reaction is carried out at 30-80°C for 1-5 hours to obtain a porous polymer nanoparticle aqueous dispersion. 1-5 parts by mass of the porous polymer nanoparticle aqueous dispersion are then reacted with 0.5-2.5 parts by mass of an amino polymer aqueous solution for 1-5 minutes to obtain a core-shell porous polymer nanoparticle dispersion.

[0009] 2) Mix 1-6 parts by weight of aromatic heterocyclic monomers with 0.1-1 parts by weight of surfactant and dissolve in 100 parts by weight of water. Then, dissolve 1-3 parts by weight of oxidant in 50-300 parts by weight of acidic aqueous solution. Subsequently, add the acidic aqueous solution containing oxidant dropwise to the aqueous solution containing aromatic heterocyclic monomers and oxidize and polymerize at 0°C-20°C for 2-8 hours to obtain an aqueous dispersion of aromatic heterocyclic polymer nanomaterials.

[0010] 3) Mix 1.5-7.5 parts by weight of core-shell porous polymer nanoparticle dispersion and 0.5-5 parts by weight of aromatic heterocyclic polymer nanomaterial aqueous dispersion and react at 15°C-35°C for 1-5 minutes; then add 0.05-0.5 parts by weight of crosslinking agent solution to the above mixed solution and carry out crosslinking reaction at 15°C-35°C and 400-1200 rpm for 5-60 minutes to obtain core-shell porous polymer / aromatic heterocyclic polymer nanocomposite dispersion. Subsequently, the above nanocomposite dispersion is coated onto the surface of nonwoven fabric, post-treated, and finally soaked and washed to obtain core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane.

[0011] In step 1), the polyamine monomer is selected from melamine, 1,3,5-tris(4-aminophenyl)benzene, 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, 2,7,14-triaminotriptene, or tetra(4-aminophenyl)methane, mixed in any proportion; the acid catalyst is selected from acetic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, or phosphoric acid; the aldehyde compound is selected from formaldehyde, 2-butenal, benzaldehyde, or terephthalaldehyde; the 1,2-dicarbonyl compound is selected from acetone aldehyde, butanedione, pentanedione, or glyoxal; and the amino polymer is selected from chitosan, polyethyleneimine, polyallylamine, ε-polylysine, or dendritic polyamide amine. One of the following: The aromatic heterocyclic monomer in step 2) is selected from aniline, p-phenylenediamine, o-phenylenediamine, 1,5-naphthyldiamine, pyrrole, or thiophene, mixed in any proportion; the surfactant is selected from sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, dodecyl dimethylamine oxide, or sodium dioctyl sulfosuccinate; the oxidant is selected from ammonium persulfate, cerium ammonium nitrate, sodium periodate, potassium chlorate, or potassium dichromate; the acid in the acidic aqueous solution is selected from acetic acid, sulfuric acid, hydrochloric acid, or phosphoric acid. The crosslinking agent solution in step 3) is selected from glutaraldehyde, glyoxal, polyethylene glycol diamine, or acetone aldehyde.

[0012] Preferably, the acid-containing catalyst described in step 1) has a mass percentage concentration of 1 to 10 wt% in the mixed solvent.

[0013] Preferably, the mixed solvent in step 1) is prepared by mixing one of acetonitrile, dioxane, dimethylacetamide or dimethyl sulfoxide and water in a mass ratio of 1:1 to 3:1.

[0014] Preferably, the magnetic stirring conditions described in step 1) are magnetic stirring at 500-1500 rpm for 0.5-2 hours at 15-35°C.

[0015] Preferably, the mass percentage concentration of the amino polymer aqueous solution in step 1) is 1~3wt%.

[0016] Preferably, the mass percentage concentration of the acidic aqueous solution in step 2) is 5~15wt%.

[0017] Preferably, the gradual addition in step 2) is performed with the dropping rate controlled at 5-10 g / min.

[0018] Preferably, the mass percentage concentration of the crosslinking agent solution in step 3) is 25~75 wt%.

[0019] Preferably, the post-treatment conditions described in step 3) are treatment at 40~80°C for 1~3 hours.

[0020] Preferably, the soaking and cleaning conditions in step 3) are soaking and cleaning for 5 to 10 hours in one of N,N-dimethylformamide, acetonitrile, tetrahydrofuran or acetone.

[0021] The aforementioned core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane can be used in fields such as the separation of organic drug molecules of different molecular weights.

[0022] The separation performance testing method of a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane of the present invention is as follows: The composite solvent-resistant nanofiltration membrane is placed in a dead-end filtration device in the art. Before testing, the membrane needs to be pre-pressurized and cleaned at an operating pressure of 0.2 MPa for 2 h. Then, under test conditions of 0.1 MPa and 25°C, the N,N-dimethylformamide permeate flux (J) and organic drug molecule rejection rate (R) of the membrane are measured. The calculation formulas are: J=V / (A·t); R=1-C p / C f Where V represents the volume of feed solution permeating the membrane, and A represents the effective area of ​​the membrane, which is 7.07 cm². 2 t – test runtime, C p - Osmotic concentration, C f - Feed solution concentration; The concentration of the organic drug molecule solution is obtained by measuring the ultraviolet absorbance of the solution using an ultraviolet spectrophotometer.

[0023] In this invention, the core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane can be optimized in terms of pore size, porosity, and hydrophilicity / hydrophobicity of the pore walls by controlling the chemical composition, concentration, ratio, and post-treatment temperature and time of the two polymer nanomaterials. This optimizes the rapid permeation of solvent molecules and the efficient separation of solute molecules in organic solvent systems. The core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane prepared in this invention generally has a permeation flux of N,N-dimethylformamide (DMF) higher than 20 L·m⁻¹. -2 ·h -1 ·bar -1 The membrane preparation method exhibits a retention rate of over 95% for organic drug molecules (molecular weight > 500 Da). This membrane preparation method is simple, controllable, and easily scaled up. The prepared membrane maintains high permeability selectivity and solvent stability during long-term service, demonstrating promising prospects for industrial production and application. Detailed Implementation

[0024] The following are embodiments of the present invention, but the present invention is not limited to the embodiments:

[0025] Example 1:

[0026] 0.05 g of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine monomer was dissolved in 12 g of a mixed solvent of acetonitrile and water in a 1:1 mass ratio containing 1 wt% acetic acid. After complete dissolution by magnetic stirring at 15°C and 500 rpm for 0.5 hours, a mixed solution was obtained. Then, 0.05 g of formaldehyde and 0.2 g of acetone aldehyde were added to the above mixed solution, and the polymerization reaction was carried out at 30°C for 1 hour to obtain a porous polymer nanoparticle aqueous dispersion. 1 g of the porous polymer nanoparticle aqueous dispersion was compounded with 0.5 g of 1 wt% chitosan aqueous solution for 1 minute to obtain a core-shell porous polymer nanoparticle dispersion. 1 g of aniline monomer was mixed with 0.1 g of sodium dodecylbenzenesulfonate and dissolved in 100 g of water. Then, 1 g of ammonium persulfate was dissolved in 50 g of 5wt% hydrochloric acid aqueous solution. Subsequently, the hydrochloric acid aqueous solution containing ammonium persulfate was added dropwise to the aqueous solution containing aniline monomer at a rate of 5 g / min. Oxidative polymerization was carried out at 0°C for 2 hours to obtain an aqueous dispersion of aromatic heterocyclic polymer nanomaterials. 1.5 g of core-shell porous polymer nanoparticle dispersion and 0.5 g of aromatic heterocyclic polymer nanomaterial aqueous dispersion were mixed and reacted at 15°C for 1 minute. Then, 0.05 g of 25wt% glutaraldehyde was added to the above mixed solution, and the crosslinking reaction was carried out at 15°C and 400 rpm under magnetic stirring for 5 minutes to obtain a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite dispersion. Subsequently, the above nanocomposite dispersion was coated onto the surface of a nonwoven fabric and post-treated at 40°C for 1 hour. Finally, after soaking and washing with N,N-dimethylformamide for 5 hours, a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane was obtained.

[0027] A core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane exhibits good performance at 25 °C and 0.1 MPa pressure for 0.02 g·L⁻¹. -1 Amphotericin B and 0.02 g·L -1 The solvent resistance nanofiltration performance of cefsulfonamide sodium in N,N-dimethylformamide solution was tested, and the membrane test results showed that the N,N-dimethylformamide flux was 23.6 L·m⁻¹. -2 ·h -1 ·bar -1 The retention rates for amphotericin B and cefsulfuron sodium were 98.1% and 96.1%, respectively.

[0028] Example 2:

[0029] 1 g of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine monomer was dissolved in 360 g of a mixed solvent containing acetonitrile and water at a mass ratio of 3:1 (10 wt% acetic acid). After complete dissolution by magnetic stirring at 1500 rpm for 2 hours at 35°C, a mixed solution was obtained. Then, 0.6 g of formaldehyde and 1.2 g of acetone aldehyde were added to the above mixed solution, and the polymerization reaction was carried out at 80°C for 5 hours to obtain an aqueous dispersion of porous polymer nanoparticles. 5 g of the aqueous dispersion of porous polymer nanoparticles was reacted with 2.5 g of 3 wt% chitosan aqueous solution for 5 minutes to obtain a core-shell porous polymer nanoparticle dispersion. 6 g of aniline monomer and 1 g of sodium dodecylbenzenesulfonate were mixed and dissolved in 100 g of water. Then, 3 g of ammonium persulfate was dissolved in 300 g of 15 wt% hydrochloric acid aqueous solution. Subsequently, the hydrochloric acid aqueous solution containing ammonium persulfate was added dropwise to the aqueous solution containing aniline monomer at a rate of 10 g / min. Oxidative polymerization was carried out at 20°C for 8 hours to obtain an aqueous dispersion of aromatic heterocyclic polymer nanomaterials. 7.5 g of core-shell porous polymer nanoparticle dispersion and 5 g of aromatic heterocyclic polymer nanomaterial aqueous dispersion were mixed and reacted at 35°C for 5 minutes. Then, 0.5 g of 75wt% glutaraldehyde was added to the above mixed solution, and the crosslinking reaction was carried out at 35°C and 1200 rpm under magnetic stirring for 60 minutes to obtain a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite dispersion. Subsequently, the above nanocomposite dispersion was coated onto the surface of a nonwoven fabric and post-treated at 80°C for 3 hours. Finally, after soaking and washing with N,N-dimethylformamide for 10 hours, a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane was obtained.

[0030] A core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane exhibits good performance at 25 °C and 0.1 MPa pressure for 0.02 g·L⁻¹. -1 Amphotericin B and 0.02 g·L -1 The solvent resistance nanofiltration performance of cefsulfonamide sodium in N,N-dimethylformamide solution was tested, and the membrane test results showed that the N,N-dimethylformamide flux was 20.1 L·m⁻¹. -2 ·h -1 ·bar -1 The retention rates for amphotericin B and cefsulfuron sodium were 98.8% and 96.4%, respectively.

[0031] Example 3:

[0032] 0.5 g of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine monomer was dissolved in 180 g of a mixed solvent of acetonitrile and water in a mass ratio of 3:1 containing 10 wt% acetic acid. After complete dissolution by magnetic stirring at 1000 rpm for 1 hour at 25°C, a mixed solution was obtained. Then, 0.3 g of formaldehyde and 0.6 g of acetone aldehyde were added to the above mixed solution, and the polymerization reaction was carried out at 30°C for 3 hours to obtain an aqueous dispersion of porous polymer nanoparticles. 3 g of the aqueous dispersion of porous polymer nanoparticles was reacted with 1.5 g of 2 wt% chitosan aqueous solution for 3 minutes to obtain a core-shell porous polymer nanoparticle dispersion. 3 g of aniline monomer and 0.5 g of sodium dodecylbenzenesulfonate were mixed and dissolved in 100 g of water. Then, 1.5 g of ammonium persulfate was dissolved in 100 g of 8wt% hydrochloric acid aqueous solution. Subsequently, the hydrochloric acid aqueous solution containing ammonium persulfate was added dropwise to the aqueous solution containing aniline monomer at a rate of 7 g / min. Oxidative polymerization was carried out at 5°C for 4 hours to obtain an aqueous dispersion of aromatic heterocyclic polymer nanomaterials. 4.5 g of core-shell porous polymer nanoparticle dispersion and 2.5 g of aromatic heterocyclic polymer nanomaterial aqueous dispersion were mixed and reacted at 25°C for 3 minutes. Then, 0.2 g of 50wt% glutaraldehyde was added to the above mixed solution, and the crosslinking reaction was carried out at 25°C and 800 rpm under magnetic stirring for 20 minutes to obtain a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite dispersion. Subsequently, the above nanocomposite dispersion was coated onto the surface of a nonwoven fabric and post-treated at 60°C for 2 hours. Finally, after soaking and washing with N,N-dimethylformamide for 7 hours, a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane was obtained.

[0033] A core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane exhibits good performance at 25 °C and 0.1 MPa pressure for 0.02 g·L⁻¹. -1 Amphotericin B and 0.02 g·L -1 The solvent resistance nanofiltration performance of cefsulfonamide sodium in N,N-dimethylformamide solution was tested, and the membrane test results showed that the N,N-dimethylformamide flux was 25.4 L·m⁻¹. -2 ·h -1 ·bar -1 The retention rates for amphotericin B and cefsulfuron sodium were 98.9% and 96.6%, respectively.

[0034] Comparative Example 1

[0035] Referring to the steps in Example 3, an amino polymer / aromatic heterocyclic polymer nanomaterial was directly used as raw material to form a nanocomposite dispersion, which was then coated onto the surface of a nonwoven fabric and post-treated (preparation conditions refer to Example 3) to prepare an amino polymer / aromatic heterocyclic polymer composite film.

[0036] Comparative Example 2

[0037] Following the steps in Example 3, core-shell porous polymer nanoparticles were directly coated onto the surface of nonwoven fabric and post-treated (preparation conditions as described in Example 3) to prepare a core-shell porous polymer composite membrane.

[0038] Comparative Example 3

[0039] Referring to the steps in Example 3, a nanocomposite dispersion was formed directly using porous polymer nanoparticles and aromatic heterocyclic polymer nanomaterials as raw materials, and then coated onto the surface of nonwoven fabric. After post-treatment (preparation conditions refer to Example 3), a porous polymer / aromatic heterocyclic polymer composite membrane was prepared.

[0040] Table 1. Membrane separation performance of the membranes prepared in Example 3 and Comparative Examples 1-3

[0041]

[0042] The results in Table 1 show that the retention rates of organic drug molecules and the flux of N,N-dimethylformamide for different types of membranes prepared by the four methods vary considerably, which is due to the different compositions and microstructures of the different membrane-forming materials.

[0043] In Comparative Example 1, a nanocomposite dispersion of amino polymer and aromatic heterocyclic polymer nanomaterials was directly formed and then post-treated to form a film. Due to the large steric hindrance of the aromatic heterocyclic polymer molecular chains, the resulting film typically has a loose pore structure. In this case, the amino polymer is unable to effectively fill or control these large gaps, resulting in poor pore modification effect. Ultimately, this leads to a large membrane flux and a reduced retention rate of organic drug molecules. In Comparative Example 2, a core-shell porous polymer nanoparticle dispersion was directly post-treated to form a film. The resulting core-shell porous polymer composite membrane had an excessively high flux. This is because the core-shell porous polymer nanoparticles are too small to form a tightly packed, continuous, dense layer on the nonwoven fabric surface, and large gaps easily form between the particles, resulting in a large membrane pore size. In Comparative Example 3, a nanocomposite dispersion was formed directly from porous polymer nanoparticles and aromatic heterocyclic polymer nanomaterials, followed by post-processing to form a film. The resulting porous polymer / aromatic heterocyclic polymer composite membrane had a high flux. This is because the interaction between the porous polymer and the aromatic heterocyclic polymer is weak and the degree of cross-linking is insufficient, resulting in a relatively loose membrane and thus a lower retention rate of drug molecules.

[0044] In Example 3, a nanocomposite dispersion was formed by cross-linking core-shell porous polymer nanoparticles and aromatic heterocyclic polymer nanomaterials. This dispersion was then coated onto a nonwoven fabric surface and post-treated to form a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane. By controlling the chemical composition, concentration, ratio of the two polymer nanomaterials, and the post-treatment temperature and time, the pore size, porosity, and hydrophilicity / hydrophobicity of the pore walls of the resulting composite membrane can be optimized, achieving rapid penetration of solvent molecules and efficient separation of solute molecules in organic solvent systems. The core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane shows promising application prospects in pharmaceutical separation, such as the extraction and purification of active pharmaceutical ingredients.

[0045] Example 4:

[0046] 0.2 g of 1,3,5-tris(4-aminophenyl)benzene monomer was dissolved in 48 g of a mixed solvent containing 5 wt% p-toluenesulfonic acid, acetonitrile, and water in a 1:1 mass ratio. After complete dissolution by magnetic stirring at 25°C and 500 rpm for 1 hour, a mixed solution was obtained. Then, 0.15 g of 2-butenal and 0.3 g of butanedione were added to the above mixed solution, and polymerization was carried out at 30°C for 3 hours to obtain a porous polymer nanoparticle aqueous dispersion. 2 g of the porous polymer nanoparticle aqueous dispersion was compounded with 1 g of 2 wt% polyethyleneimine aqueous solution for 2 minutes to obtain a core-shell porous polymer nanoparticle dispersion. 2 g of p-phenylenediamine monomer and 0.4 g of hexadecyltrimethylammonium bromide were mixed and dissolved in 100 g of water. Then, 1 g of cerium ammonium nitrate was dissolved in 50 g of 8wt% hydrochloric acid aqueous solution. Subsequently, the hydrochloric acid aqueous solution containing cerium ammonium nitrate was added dropwise to the aqueous solution containing p-phenylenediamine monomer at a rate of 10 g / min. Oxidative polymerization was carried out at 5°C for 4 hours to obtain an aqueous dispersion of aromatic heterocyclic polymer nanomaterials. 3 g of core-shell porous polymer nanoparticle dispersion and 1 g of aromatic heterocyclic polymer nanomaterial aqueous dispersion were mixed and reacted at 25°C for 2 minutes. Then, 0.1 g of 50wt% glyoxal was added to the above mixed solution, and the crosslinking reaction was carried out at 25°C and 600 rpm under magnetic stirring for 10 minutes to obtain a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite dispersion. Subsequently, the above nanocomposite dispersion was coated onto the surface of nonwoven fabric and post-treated at 60°C for 1.5 hours. Finally, after soaking and washing with N,N-dimethylformamide for 5 hours, a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane was obtained.

[0047] A core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane exhibits good performance at 25 °C and 0.1 MPa pressure for 0.02 g·L⁻¹. -1 Amphotericin B and 0.02 g·L -1The solvent resistance nanofiltration performance of cefsulfonamide sodium in N,N-dimethylformamide solution was tested, and the membrane test results showed that the N,N-dimethylformamide flux was 21.1 L·m⁻¹. -2 ·h -1 ·bar -1 The retention rates for amphotericin B and cefsulfuron sodium were 97.5% and 95.2%, respectively.

[0048] Example 5:

[0049] 0.5 g of melamine monomer was dissolved in 180 g of a mixed solvent containing 10 wt% dioxane (dioxane) and water in a 2:1 mass ratio. After thorough dissolution by magnetic stirring at 1000 rpm for 1 hour at 35°C, a mixed solution was obtained. Then, 0.3 g of benzaldehyde and 0.6 g of pentanedione were added to the above mixed solution, and the polymerization reaction was carried out at 80°C for 5 hours to obtain an aqueous dispersion of porous polymer nanoparticles. 5 g of the aqueous dispersion of porous polymer nanoparticles was then reacted with 2.5 g of 2 wt% polyethyleneimine aqueous solution for 3 minutes to obtain a core-shell porous polymer nanoparticle dispersion. 3 g of o-phenylenediamine monomer and 0.4 g of sodium dodecyl sulfate were mixed and dissolved in 100 g of water. Then, 2 g of sodium periodate was dissolved in 100 g of 8 wt% sulfuric acid aqueous solution. Subsequently, the sulfuric acid aqueous solution containing sodium periodate was added dropwise to the aqueous solution containing o-phenylenediamine monomer at a rate of 7 g / min. Oxidative polymerization was carried out at 10°C for 6 hours to obtain an aqueous dispersion of aromatic heterocyclic polymer nanomaterials. 7.5 g of core-shell porous polymer nanoparticle dispersion and 5 g of aromatic heterocyclic polymer nanomaterial aqueous dispersion were mixed and reacted at 25°C for 5 minutes. Then, 0.4 g of 75wt% polyethylene glycol diamine was added to the above mixed solution, and the crosslinking reaction was carried out at 25°C and 800 rpm under magnetic stirring for 30 minutes to obtain a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite dispersion. Subsequently, the above nanocomposite dispersion was coated onto the surface of nonwoven fabric and post-treated at 60°C for 2.5 hours. Finally, after soaking and washing with acetonitrile for 10 hours, a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane was obtained.

[0050] A core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane exhibits good performance at 25 °C and 0.1 MPa pressure for 0.02 g·L⁻¹. -1 Amphotericin B and 0.02 g·L -1 The solvent resistance nanofiltration performance of cefsulfonamide sodium in N,N-dimethylformamide solution was tested, and the membrane test results showed that the N,N-dimethylformamide flux was 20.6 L·m⁻¹. -2 ·h -1 ·bar -1The retention rates for amphotericin B and cefsulfuron sodium were 97.0% and 95.6%, respectively.

[0051] Example 6:

[0052] 0.05 g of 2,7,14-triaminotriptene monomer was dissolved in 12 g of a mixed solvent containing 5 wt% phosphoric acid, dimethylacetamide, and water in a 1:1 mass ratio. After thorough dissolution by magnetic stirring at 25°C and 500 rpm for 1 hour, a mixed solution was obtained. Then, 0.05 g of terephthalaldehyde and 0.2 g of glyoxal were added to the above mixed solution, and the polymerization reaction was carried out at 80°C for 3 hours to obtain a porous polymer nanoparticle aqueous dispersion. 3 g of the porous polymer nanoparticle aqueous dispersion was reacted with 1.5 g of 1 wt% polyallylamine aqueous solution for 3 minutes to obtain a core-shell porous polymer nanoparticle dispersion. 1 g of 1,5-naphthyldiamine monomer and 0.1 g of dodecyl dimethylamine oxide were mixed and dissolved in 100 g of water. Then, 1 g of potassium chlorate was dissolved in 50 g of 5 wt% acetic acid aqueous solution. Subsequently, the acetic acid aqueous solution containing potassium chlorate was added dropwise at 5 g / min to the aqueous solution containing 1,5-naphthyldiamine monomer. Oxidative polymerization was carried out at 20°C for 4 hours to obtain an aqueous dispersion of aromatic heterocyclic polymer nanomaterials. 4.5 g of core-shell porous polymer nanoparticle dispersion and 2.5 g of aromatic heterocyclic polymer nanomaterial aqueous dispersion were mixed and reacted at 25°C for 2 minutes. Then, 0.2 g of 25wt% acetone aldehyde was added to the above mixed solution, and the crosslinking reaction was carried out at 25°C and 600 rpm under magnetic stirring for 10 minutes to obtain a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite dispersion. Subsequently, the above nanocomposite dispersion was coated onto the surface of a nonwoven fabric and post-treated at 40°C for 2 hours. Finally, after being soaked and washed with tetrahydrofuran for 10 hours, a solvent-resistant nanofiltration membrane of core-shell porous polymer / aromatic heterocyclic polymer nanocomposite was obtained.

[0053] A core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane exhibits good performance at 25 °C and 0.1 MPa pressure for 0.02 g·L⁻¹. -1 Amphotericin B and 0.02 g·L -1 The solvent resistance nanofiltration performance of cefsulfonamide sodium in N,N-dimethylformamide solution was tested, and the membrane test results showed that the N,N-dimethylformamide flux was 23.1 L·m⁻¹. -2 ·h -1 ·bar -1 The retention rates for amphotericin B and cefsulfuron sodium were 97.1% and 95.8%, respectively.

[0054] Example 7:

[0055] 0.05 g of tetrakis(4-aminophenyl)methane monomer was dissolved in 12 g of a mixed solvent containing 5 wt% p-toluenesulfonic acid, dimethyl sulfoxide, and water in a mass ratio of 2:1. After complete dissolution by magnetic stirring at 25°C and 500 rpm for 2 hours, a mixed solution was obtained. Then, 0.05 g of formaldehyde and 0.2 g of dimethyl ethyl ketone were added to the above mixed solution, and the polymerization reaction was carried out at 30°C for 4 hours to obtain a porous polymer nanoparticle aqueous dispersion. 5 g of the porous polymer nanoparticle aqueous dispersion was reacted with 2.5 g of 1 wt% dendritic polyamide amine aqueous solution for 5 minutes to obtain a core-shell porous polymer nanoparticle dispersion. 1 g of pyrrole monomer was mixed with 0.1 g of sodium dioctyl sulfosuccinate and dissolved in 100 g of water. Then, 1 g of potassium dichromate was dissolved in 50 g of 15 wt% phosphoric acid aqueous solution. Subsequently, the phosphoric acid aqueous solution containing potassium dichromate was added dropwise to the aqueous solution containing pyrrole monomer at a rate of 6 g / min. Oxidative polymerization was carried out at 5°C for 6 hours to obtain an aqueous dispersion of aromatic heterocyclic polymer nanomaterials. 7.5 g of core-shell porous polymer nanoparticle dispersion and 2.5 g of aromatic heterocyclic polymer nanomaterial aqueous dispersion were mixed and reacted at 25°C for 3 minutes. Then, 0.2 g of 75wt% glutaraldehyde was added to the above mixed solution, and the crosslinking reaction was carried out at 25°C and 800 rpm under magnetic stirring for 20 minutes to obtain a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite dispersion. Subsequently, the above nanocomposite dispersion was coated onto the surface of nonwoven fabric and post-treated at 80°C for 2 hours. Finally, after soaking and washing with acetone for 8 hours, a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane was obtained.

[0056] A core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane exhibits good performance at 25 °C and 0.1 MPa pressure for 0.02 g·L⁻¹. -1 Amphotericin B and 0.02 g·L -1 The solvent resistance nanofiltration performance of cefsulfonamide sodium in N,N-dimethylformamide solution was tested, and the membrane test results showed that the N,N-dimethylformamide flux was 21.9 L·m⁻¹. -2 ·h -1 ·bar -1 The retention rates for amphotericin B and cefsulfuron sodium were 97.2% and 95.0%, respectively.

[0057] Example 8:

[0058] 0.2 g of tetrakis(4-aminophenyl)methane monomer was dissolved in 48 g of a mixed solvent containing 5 wt% phosphoric acid, dimethyl sulfoxide, and water in a mass ratio of 2:1. After complete dissolution by magnetic stirring at 800 rpm for 2 hours at 25°C, a mixed solution was obtained. Then, 0.05 g of formaldehyde and 0.2 g of acetone aldehyde were added to the above mixed solution, and the polymerization reaction was carried out at 80°C for 4 hours to obtain a porous polymer nanoparticle aqueous dispersion. 3 g of the porous polymer nanoparticle aqueous dispersion was reacted with 1.5 g of 2 wt% ε-polylysine aqueous solution for 3 minutes to obtain a core-shell porous polymer nanoparticle dispersion. 6 g of thiophene monomer and 1 g of sodium dodecylbenzenesulfonate were mixed and dissolved in 100 g of water. Then, 3 g of ammonium persulfate was dissolved in 300 g of 10 wt% aqueous phosphoric acid solution. Subsequently, the aqueous phosphoric acid solution containing ammonium persulfate was added dropwise to the aqueous solution containing thiophene monomer at a rate of 8 g / min. Oxidative polymerization was carried out at 5°C for 8 hours to obtain an aqueous dispersion of aromatic heterocyclic polymer nanomaterials. 7.5 g of core-shell porous polymer nanoparticle dispersion and 5 g of aromatic heterocyclic polymer nanomaterial aqueous dispersion were mixed and reacted at 25°C for 5 minutes. Then, 0.5 g of 50wt% glutaraldehyde was added to the above mixed solution, and the crosslinking reaction was carried out at 25°C and 800 rpm under magnetic stirring for 60 minutes to obtain a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite dispersion. Subsequently, the above nanocomposite dispersion was coated onto the surface of a nonwoven fabric and post-treated at 60°C for 3 hours. Finally, after soaking and washing with N,N-dimethylformamide for 8 hours, a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane was obtained.

[0059] A core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane exhibits good performance at 25 °C and 0.1 MPa pressure for 0.02 g·L⁻¹. -1 Amphotericin B and 0.02 g·L -1 The solvent resistance nanofiltration performance of cefsulfonamide sodium in N,N-dimethylformamide solution was tested, and the membrane test results showed that the N,N-dimethylformamide flux was 22.7 L·m⁻¹. -2 ·h -1 ·bar -1 The retention rates for amphotericin B and cefsulfuron sodium were 97.0% and 95.5%, respectively.

Claims

1. A method for preparing a core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane, characterized in that: Includes the following steps: 1) Dissolve 0.05-1 parts by mass of a polyamine monomer in 12-360 parts by mass of a mixed solvent containing an acid catalyst. After fully dissolving by magnetic stirring, a mixed solution is obtained. Then, 0.05-0.6 parts by mass of an aldehyde compound and 0.2-1.2 parts by mass of a 1,2-dicarbonyl compound are added to the above mixed solution. The polymerization reaction is carried out at 30-80°C for 1-5 hours to obtain a porous polymer nanoparticle aqueous dispersion. 1-5 parts by mass of the porous polymer nanoparticle aqueous dispersion are then reacted with 0.5-2.5 parts by mass of an amino polymer aqueous solution for 1-5 minutes to obtain a core-shell porous polymer nanoparticle dispersion. 2) Mix 1-6 parts by weight of aromatic heterocyclic monomers with 0.1-1 parts by weight of surfactant and dissolve in 100 parts by weight of water, then dissolve 1-3 parts by weight of oxidant in 50-300 parts by weight of acidic aqueous solution; Subsequently, an acidic aqueous solution containing an oxidant was added dropwise to an aqueous solution containing aromatic heterocyclic monomers, and oxidative polymerization was carried out at 0°C to 20°C for 2 to 8 hours to obtain an aqueous dispersion of aromatic heterocyclic polymer nanomaterials. 3) Mix 1.5-7.5 parts by weight of core-shell porous polymer nanoparticle dispersion and 0.5-5 parts by weight of aromatic heterocyclic polymer nanomaterial aqueous dispersion and react at 15°C-35°C for 1-5 minutes; then add 0.05-0.5 parts by weight of crosslinking agent solution to the above mixed solution and carry out crosslinking reaction at 15°C-35°C and 400-1200 rpm for 5-60 minutes to obtain core-shell porous polymer / aromatic heterocyclic polymer nanocomposite dispersion. Subsequently, the above nanocomposite dispersion is coated onto the surface of nonwoven fabric, post-treated, and finally soaked and washed to obtain core-shell porous polymer / aromatic heterocyclic polymer nanocomposite solvent-resistant nanofiltration membrane.

2. The preparation method according to claim 1, characterized in that: The polyamine monomer in step 1) is selected from melamine, 1,3,5-tris(4-aminophenyl)benzene, 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, 2,7,14-triaminotriphenylene, or tetra(4-aminophenyl)methane, or a mixture thereof in any proportion; the acid catalyst is selected from acetic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, or phosphoric acid; the aldehyde compound is selected from formaldehyde, 2-butenal, benzaldehyde, or terephthalaldehyde; the 1,2-dicarbonyl compound is selected from acetone aldehyde, butanedione, pentanedione, or glyoxal; the amino polymer is selected from chitosan, polyethyleneimine, polyallylamine, ε-polylysine, or dendritic polyamide amine; the aromatic heterocyclic monomer in step 2) is... The solution is composed of one or more of aniline, p-phenylenediamine, o-phenylenediamine, 1,5-naphthyldiamine, pyrrole, or thiophene, mixed in any proportion; the surfactant is selected from sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, dodecyl dimethylamine oxide, or sodium dioctyl sulfosuccinate; the oxidant is selected from ammonium persulfate, cerium ammonium nitrate, sodium periodate, potassium chlorate, or potassium dichromate; the acid in the acidic aqueous solution is selected from acetic acid, sulfuric acid, hydrochloric acid, or phosphoric acid; and the crosslinking agent solution in step 3) is selected from glutaraldehyde, glyoxal, polyethylene glycol diamine, or acetone aldehyde.

3. The preparation method according to claim 2, characterized in that: The acid-containing catalyst mentioned in step 1) has a mass percentage concentration of 1-10 wt% in the mixed solvent; the mixed solvent is prepared by mixing water with one of acetonitrile, dioxane, dimethylacetamide or dimethyl sulfoxide in a mass ratio of 1:1 to 3:1; the magnetic stirring conditions are 500-1500 rpm at 15-35°C for 0.5-2 hours; the amino polymer aqueous solution has a mass percentage concentration of 1-3 wt%.

4. The preparation method according to claim 2, characterized in that: The acidic aqueous solution in step 2) has a mass percentage concentration of 5-15 wt%; the gradual addition is achieved by controlling the dropping rate at 5-10 g / min.

5. The preparation method according to claim 2, characterized in that: The mass percentage concentration of the crosslinking agent solution mentioned in step 3) is 25~75 wt%; the post-treatment conditions are treatment at 40~80°C for 1~3 hours; the soaking and cleaning conditions are soaking and cleaning in one of N,N-dimethylformamide, acetonitrile, tetrahydrofuran or acetone for 5~10 hours.

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