In-situ polymerization modified polyethersulfone ultrafiltration membrane as well as preparation method and application thereof

Abstract

The invention provides an in-situ polymerization modified polyethersulfone ultrafiltration membrane as well as a preparation method and application thereof. The in-situ polymerization modified polyethersulfone ultrafiltration membrane is prepared from the following raw materials in parts by weight: 15 to 26 parts of membrane framework material PES, 30 to 80 parts of organic solvent, 1 to 5 parts of hydrophilic monomer, 0.1 to 0.5 part of initiator, 0.5 to 3.5 parts of cross-linking agent, 0.1 to 3 parts of pore-forming agent and 5 to 35 parts of non-solvent. According to the in-situ polymerization modified polyethersulfone ultrafiltration membrane provided by the invention, the polyethersulfone ultrafiltration membrane is subjected to in-situ polymerization modification by utilizing a hydrophilic monomer through a cross-linking reaction, so that the problems of easiness in loss, weak combination, complex process and poor anti-pollution effect in the existing ultrafiltration membrane modification technology are solved, and low protein adsorption, high hydrophilicity, high flux and long-acting stability are realized; and the preparation process is simple, and industrial large-scale production can be realized.

Description

Technical Field

[0001] This invention belongs to the field of polymer separation membrane material technology, specifically relating to an in-situ polymerized modified polyethersulfone ultrafiltration membrane, its preparation method, and its application. Background Technology

[0002] Polyethersulfone (PES) possesses excellent chemical stability, thermal stability, mechanical strength, and film-forming properties, making it one of the most commonly used materials in the ultrafiltration membrane field. It is widely applied in industries such as biomedicine, food fermentation, and industrial water treatment. However, conventional PES membranes have a strong hydrophobic surface, making them highly susceptible to non-specific protein adsorption when processing protein-containing systems. This leads to membrane pore blockage, rapid flux decline, frequent cleaning, and shortened lifespan, severely limiting their application in biomedicine and protein separation.

[0003] The main methods to improve the antifouling properties of PES membranes are: blending with hydrophilic polymers such as PVP, but PVP is easily dissolved and lost, and the hydrophilicity cannot be sustained; coating the surface with a hydrophilic layer, but the bonding force is weak and the resistance to scouring and chemical cleaning is poor; surface grafting polymerization is a complex process with high equipment requirements and is difficult to scale up.

[0004] CN107081079A discloses a method for preparing and applying a highly efficient hydrophilic-modified antifouling polyethersulfone (PES) membrane. The method includes two parts: physical blending hydrophilic modification and chemical grafting hydrophilic modification of a pure PES membrane. A hydrophilic block polymer is synthesized via surface-initiated reversible addition-fragmentation chain transfer polymerization (RAFT), and then physically blended with PES to prepare a PES / PAA-F127-PAA membrane. A strongly hydrophilic substance, NH2-PDMAPS, is synthesized using electron transfer activated regeneration catalyst-atom transfer radical polymerization (ARGET ATRP). Based on the blending modification, a highly efficient hydrophilic-modified antifouling PES membrane is prepared using a chemical grafting method. This invention uses the efficient and green RAFT and ARGET ATRP polymerization methods to design molecules with novel structures and mild reaction conditions. The hydrophilic modification method shows more significant effects and has broad application prospects in the field of oil-water separation. However, the grafting process used causes difficulties in production.

[0005] CN101259387A discloses a controllable flux, protein-fouling-resistant polyethersulfone ultrafiltration membrane and its preparation method. It uses polyethersulfone and Pluronic F127 as raw materials, with a mass percentage of 21.6-36%. The preparation method involves adding Pluronic F127 to a polyethersulfone solution of N,N-dimethylformamide, stirring thoroughly to form a casting solution; after standing to remove bubbles, cooling, pouring the casting solution onto a glass plate, scraping a membrane, placing it in a water bath to solidify, and then immersing it in water. This invention offers a simple preparation method, significantly improved antifouling performance, and excellent protein retention characteristics. The maximum flux of the controllable flux, protein-fouling-resistant polyethersulfone ultrafiltration membrane prepared by this invention can reach over 200 L / (m²h).

[0006] CN108479432A discloses a method for preparing a hydrophilic phenolphthalein polyethersulfone (PES-C) composite nanofiber ultrafiltration membrane, comprising: dissolving phenolphthalein polyethersulfone (PES-C) in an organic solvent to obtain a spinning solution; performing solution jet spinning; drying to obtain a PES-C nanofiber membrane; spraying a cross-linked polyvinylpyrrolidone (PVPP) solution onto the surface of the PES-C nanofiber membrane; and hot-pressing to obtain the final product. This invention uses solution jet spinning to prepare composite nanofiber ultrafiltration membranes, which, compared to the widely used electrospinning technology, offers advantages such as high production efficiency, low energy consumption, wide applicability, and suitability for industrial production. The prepared phenolphthalein polyethersulfone composite nanofiber ultrafiltration membrane exhibits high hydrophilicity, thermal stability, and resistance to acid and alkali corrosion, as well as high antifouling ability. Furthermore, its hydrophilicity is durable, which is beneficial for industrial production and has broad application prospects in microfiltration and ultrafiltration. However, the PVPP structure on its surface suffers from weak bonding, poor erosion resistance, and poor chemical cleaning resistance.

[0007] In summary, the problem of PES membrane antifouling properties has not yet been effectively solved. Therefore, how to provide a PES membrane with good antifouling performance, long-lasting effect, and simple preparation process has become an urgent problem to be solved. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide an in-situ polymerized modified polyethersulfone ultrafiltration membrane, its preparation method, and its applications. The in-situ polymerized modified polyethersulfone ultrafiltration membrane provided by this invention utilizes hydrophilic monomers modified in-situ through a crosslinking reaction. This solves the problems of easy leaching, weak bonding, complex processes, and poor antifouling effects in existing ultrafiltration membrane modification technologies. It achieves low protein adsorption, high hydrophilicity, high flux, and long-term stability, and the preparation process is simple, allowing for large-scale industrial production.

[0009] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides an in-situ polymerized modified polyethersulfone ultrafiltration membrane, wherein the raw materials for preparing the in-situ polymerized modified polyethersulfone ultrafiltration membrane include, by weight, 15-26 parts of membrane skeleton material PES, 30-80 parts of organic solvent, 1-5 parts of hydrophilic monomer, 0.1-0.5 parts of initiator, 0.5-3.5 parts of crosslinking agent, 0.1-3 parts of pore-forming agent, and 5-35 parts of non-solvent.

[0010] The proportions of the membrane skeleton material PES can be 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or 26 parts, etc.; the proportions of the organic solvent can be 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, or 80 parts, etc.; the proportions of the hydrophilic monomer can be 1, 2, 3, 4, or 5 parts, etc.; and the proportions of the initiator can be 0.1 or 0.2 parts. The amounts of the crosslinking agent can be 0.5, 1, 1.5, 2, 2.5, 3, or 3.5 parts, etc.; the amounts of the pore-forming agent can be 0.1, 0.5, 1, 1.5, 2, 2.5, or 3 parts, etc.; and the amounts of the non-solvent can be 5, 10, 15, 20, 25, 30, or 35 parts, etc., but are not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0011] The above-mentioned scheme utilizes polyethersulfone ultrafiltration membranes modified by in-situ polymerization of hydrophilic monomers through cross-linking reactions, which solves the problems of easy loss, weak binding, complex process and poor anti-fouling effect of existing ultrafiltration membrane modification technologies. It achieves low protein adsorption, high hydrophilicity, high throughput and long-term stability, and the preparation process is simple and can be industrialized for large-scale production.

[0012] Preferably, the organic solvent includes any one or a combination of at least two of N,N-dimethylformamide, N,N-dimethylacetamide, or N-methylpyrrolidone, with N-methylpyrrolidone being the most preferred.

[0013] Preferably, the hydrophilic monomer comprises N-vinylpyrrolidone; Preferably, the initiator includes any one or a combination of at least two of azobisisobutyronitrile, azobisisoheptanenitrile, or benzoyl peroxide, with azobisisobutyronitrile being the most preferred.

[0014] Preferably, the crosslinking agent includes a primary crosslinking agent and a secondary crosslinking agent.

[0015] Preferably, the main crosslinking agent includes any one or a combination of at least two of sodium divinylbenzenesulfonate, sodium methacryloyloxyethyl sulfonate, sulfobutyl diacrylate or carboxylated diacrylate, with sodium methacryloyloxyethyl sulfonate being the most preferred.

[0016] Preferably, the co-crosslinking agent includes any one or a combination of at least two of divinylbenzene, N,N-methylenebisacrylamide, or ethylene glycol dimethacrylate, with N,N-methylenebisacrylamide being the most preferred.

[0017] Preferably, the mass ratio of the primary crosslinking agent to the secondary crosslinking agent is (4-6):1, such as 4:1, 4.5:1, 5:1, 5.5:1 or 6:1, but not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0018] The above specific crosslinking agent combination Preferably, the pore-forming agent includes any one or a combination of at least two of PVP (polyvinylpyrrolidone) K17, PVP K30, PVP K90 or LiCl, with PVP K90 being the most preferred.

[0019] Preferably, the non-solvent includes any one or a combination of at least two of glycerol, DEG (diethylene glycol), TEG (triethylene glycol), PEG (polyethylene glycol), or water, with PEG being preferred.

[0020] The aforementioned non-solvents refer to solvents that cannot dissolve polyethersulfone.

[0021] Secondly, the present invention provides a method for preparing the in-situ polymerized modified polyethersulfone ultrafiltration membrane as described above, the method comprising the following steps: The membrane framework material and organic solvent are mixed, and then reacted with hydrophilic monomers, initiators and crosslinking agents to obtain a modified PES solution. A pore-forming agent, a non-solvent, and a modified PES solution are mixed and allowed to stand to obtain a PES casting solution. The PES casting solution was coated onto the substrate, and then left to stand at a constant temperature and humidity to obtain a pre-phase-separated coating solution. The pre-phase-separated coating solution was placed in a coagulation bath and water in sequence to obtain the in-situ polymerized modified polyethersulfone ultrafiltration membrane.

[0022] The above method uses PES as the membrane skeleton material. An initiator and hydrophilic monomers are added to the casting solution system. During the film formation process, in-situ polymerization is carried out to generate a three-dimensional network structure with strong hydrophilicity, high negative charge and stable structure. This network forms a semi-interpenetrating / interpenetrating polymer network with the PES material, forming a stable hydration layer on the membrane surface and the inner wall of the pores. This layer does not dissolve or peel off, thus inhibiting protein adsorption from a mechanistic perspective. At the same time, it maintains membrane flux and retention performance, achieving excellent antifouling effect, acid and alkali resistance, washability and no leakage. The preparation process is simple and compatible with existing production lines.

[0023] Preferably, the mixing reaction is carried out under a nitrogen atmosphere.

[0024] Preferably, the temperature of the mixing reaction is 50-70℃ and the time is 2-4 h. The temperature can be 50℃, 55℃, 60℃, 65℃ or 70℃, etc., and the time can be 2 h, 2.5 h, 3 h, 3.5 h or 4 h, etc., but is not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0025] Thirdly, the present invention also provides the application of the in-situ polymerized modified polyethersulfone ultrafiltration membrane as described above in the preparation of separation membranes.

[0026] Compared with the prior art, the present invention has the following beneficial effects: This invention provides an in-situ polymerized modified polyethersulfone ultrafiltration membrane. Utilizing hydrophilic monomers, the polyethersulfone ultrafiltration membrane is modified in-situ through a crosslinking reaction. This solves the problems of easy leaching, weak binding, complex processes, and poor antifouling effects in existing ultrafiltration membrane modification technologies. It achieves low protein adsorption, high hydrophilicity, high flux, and long-term stability, and the preparation process is simple, allowing for large-scale industrial production. Specific benefits include: 1. An in-situ polymerization process is used to form a stable hydrophilic network within the membrane, which does not dissolve or delaminate; the surface and pores are doubly hydrophilic, forming a stable hydration layer, which significantly improves membrane flux and reduces protein adsorption; the hydrophilic modification occurs within the membrane preparation solution system, the process is simple and compatible with existing production lines; 2. The water contact angle is significantly reduced, and the hydrophilicity is greatly improved; the adsorption of model protein (BSA) is reduced by 60%-85%; the pure water flux is increased by 30%-50%; the flux recovery rate is ≥90%, and the anti-fouling ability is significantly improved; the hydrophilic structure is stable, resistant to acids and alkalis, resistant to washing, and does not leak. Detailed Implementation

[0027] To further illustrate the technical means and effects of the present invention, the following describes the technical solution of the present invention in conjunction with preferred embodiments of the present invention. However, the present invention is not limited to the scope of the embodiments.

[0028] In the following example, the polyethersulfone was purchased from BASF, model number 28212-68-2; The PVP K90 was purchased from Inokay 9003-39-8, model number 9003-39-8; The PEG200 was purchased from Aladdin, model number 25322-68-3.

[0029] Example 1 This embodiment provides an in-situ polymerized modified polyethersulfone ultrafiltration membrane, prepared from the following raw materials (in parts by weight): 20 parts polyethersulfone, 60 parts N-methylpyrrolidone, 3 parts N-vinylpyrrolidone, 0.3 parts azobisisobutyronitrile, 2 parts sodium methacryloyloxyethyl sulfonate, 0.4 parts N,N-methylenebisacrylamide, 1.5 parts PVP K90, and 20 parts PEG200.

[0030] The preparation method is as follows: (1) Add PES to N-methylpyrrolidone and stir at 60°C for 2 hours; (2) Add N-vinylpyrrolidone, azobisisobutyronitrile, sodium methacryloyloxyethyl sulfonate, and N,N-methylenebisacrylamide to the PES solution in step (1), and stir at 60°C under nitrogen protection for 3 h to obtain the modified PES solution. (3) Add PVP K90 and PEG200 to the modified PES solution in step (2), stir at 60°C for 3 hours to obtain a mixed PES solution.

[0031] (4) The PES mixed solution from step (3) was left to stand at 40°C for 12 hours to obtain the PES casting solution; (5) The PES casting solution from step (4) is uniformly coated onto a clean glass plate to obtain a PES coating solution with a thickness of 150 μm. (6) Place the PES coating solution from step (5) in a constant temperature and humidity chamber for 20 s. The temperature of the constant temperature and humidity chamber is 40℃ and the humidity is 60%, to obtain the pre-phase separation coating solution. (7) Place the pre-phase-separated coating solution from step (6) into a coagulation bath (50% N-methylpyrrolidone aqueous solution) to obtain a PES membrane; (8) Place the PES membrane from step (7) in deionized water to obtain an in-situ polymerized modified PES ultrafiltration membrane.

[0032] Example 2 This embodiment provides an in-situ polymerized modified polyethersulfone ultrafiltration membrane, prepared from the following raw materials (in parts by weight): 15 parts polyethersulfone, 30 parts N,N-dimethylformamide, 1 part N-vinylpyrrolidone, 0.1 part azobisisobutyronitrile, 0.4 parts sodium divinylbenzenesulfonate, 0.1 part N,N-methylenebisacrylamide, 0.1 part PVP K90, and 5 parts PEG200.

[0033] The preparation method is the same as in Example 1.

[0034] Example 3 This embodiment provides an in-situ polymerized modified polyethersulfone ultrafiltration membrane, prepared from the following raw materials (in parts by weight): 26 parts polyethersulfone, 80 parts N-methylpyrrolidone, 5 parts N-vinylpyrrolidone, 0.5 parts azobisisoheptanenitrile, 3 parts sodium methacryloyloxyethyl sulfonate, 0.5 parts divinylbenzene, 3 parts PVP K90, and 35 parts glycerin.

[0035] The preparation method is the same as in Example 1.

[0036] Example 4 This embodiment provides an in-situ polymerized modified polyethersulfone ultrafiltration membrane. The raw materials used in its preparation are the same as in Example 1, except that sodium methacryloyloxyethyl sulfonate is not added and a portion is reduced for N,N-methylenebisacrylamide.

[0037] Example 5 This embodiment provides an in-situ polymerized modified polyethersulfone ultrafiltration membrane. The raw materials used in its preparation are the same as in Example 1, except that N,N-methylenebisacrylamide is not added and a portion is allocated to sodium methacryloyloxyethyl sulfonate.

[0038] Example 6 This embodiment provides an in-situ polymerized modified polyethersulfone ultrafiltration membrane. Except for sodium methacryloyloxyethyl sulfonate (1.8 parts) and N,N-methylenebisacrylamide (0.6 parts), the raw materials are the same as in Example 1.

[0039] Example 7 This embodiment provides an in-situ polymerized modified polyethersulfone ultrafiltration membrane. Except for sodium methacryloyloxyethyl sulfonate (2.1 parts) and N,N-methylenebisacrylamide (0.3 parts), the raw materials are the same as in Example 1.

[0040] Example 8 This embodiment provides an in-situ polymerized modified polyethersulfone ultrafiltration membrane. The raw materials used in its preparation are the same as in Example 1, except that sodium methacryloyloxyethyl sulfonate is replaced with an equal amount of sodium divinylbenzene sulfonate.

[0041] Example 9 This embodiment provides an in-situ polymerized modified polyethersulfone ultrafiltration membrane. The raw materials used in its preparation are the same as in Example 1, except that N,N-methylenebisacrylamide is replaced with an equal amount of ethylene glycol dimethacrylate.

[0042] Example 10 This embodiment provides a polyethersulfone ultrafiltration membrane, and the raw materials used in its preparation are the same as those in Example 1.

[0043] The preparation method is as follows: (1) PES, N-methylpyrrolidone, N-vinylpyrrolidone, azobisisobutyronitrile, sodium methacryloyloxyethyl sulfonate, N,N-methylenebisacrylamide, PVP K90 and PEG200 were mixed and stirred at 60°C for 3 h to obtain a PES mixed solution.

[0044] (2) The PES mixed solution from step (1) was allowed to stand at 40°C for 12 hours to obtain the PES casting solution; (3) The PES casting solution from step (2) is uniformly coated onto a clean glass plate to obtain a PES coating solution with a thickness of 150 μm. (4) Place the PES coating solution from step (3) in a constant temperature and humidity chamber for 20 s. The temperature of the constant temperature and humidity chamber is 40℃ and the humidity is 60%, to obtain the pre-phase separation coating solution. (5) Place the pre-phase-separated coating solution from step (4) into a coagulation bath (50% N-methylpyrrolidone aqueous solution) to obtain a PES membrane; (6) Place the PES membrane from step (5) in deionized water to obtain a PES ultrafiltration membrane.

[0045] Comparative Example 1 This comparative example provides a polyethersulfone ultrafiltration membrane. The raw materials used in its preparation are identical to those in Example 1, except that they do not contain sodium methacryloyloxyethyl sulfonate or N,N-methylenebisacrylamide.

[0046] The preparation method is as follows: (1) Add PES to N-methylpyrrolidone and stir at 60°C for 2 hours; (2) Add N-vinylpyrrolidone and azobisisobutyronitrile to the solution in step (1), stir at 60°C under nitrogen protection for 3 h to obtain PES solution; (3) Add PVP K90 and PEG200 to the PES solution in step (2), stir at 60°C for 3 h to obtain a PES mixed solution.

[0047] (4) The PES mixed solution from step (3) was left to stand at 40°C for 12 hours to obtain the PES casting solution; (5) The PES casting solution from step (4) is uniformly coated onto a clean glass plate to obtain a PES coating solution with a thickness of 150 μm. (6) Place the PES coating solution from step (5) in a constant temperature and humidity chamber for 20 s. The temperature of the constant temperature and humidity chamber is 40℃ and the humidity is 60%, to obtain the pre-phase separation coating solution. (7) Place the pre-phase-separated coating solution from step (6) into a coagulation bath (50% N-methylpyrrolidone aqueous solution) to obtain a PES membrane; (8) Place the PES membrane from step (7) in deionized water to obtain an in-situ polymerized modified PES ultrafiltration membrane.

[0048] Effect test: The polyethersulfone ultrafiltration membrane provided in the above example was tested using the following method: 1. Pure water flux test The ultrafiltration membranes prepared in each embodiment and comparative example were cut to a diameter of 5.3 cm (effective area 2.2 cm²). 2 The membrane was pre-wetted with deionized water for 30 minutes and then loaded into the ultrafiltration test apparatus. The test pressure was adjusted to 0.1 MPa and the temperature to 25°C. After stable operation for 30 minutes, the amount of pure water permeated within 10 minutes was collected, and the pure water flux was calculated using the following formula: Jw = V / (S×t) Where: Jw is the pure water flux (L•m) -2 •h -1 (abbreviated as LMH); V is the permeate water volume (L); S is the effective membrane area (m²). 2 ); t is the collection time (h). Three parallel samples were tested in each group, and the average value was taken.

[0049] 2. Contact Angle Test The membrane was fixed flat on the sample stage, with no wrinkles or air bubbles on the surface. Using the seat-drop method, 3 μL of deionized water was drawn up with a microsyringe and gently dropped onto the membrane surface. After the droplet stabilized for 5 seconds, an image was automatically captured and the water contact angle was calculated. Five points were randomly tested at different locations for each sample, and the maximum and minimum values ​​were removed before taking the average value.

[0050] 3. Protein Retention Rate Test Using bovine serum albumin (BSA, molecular weight 67 kDa) as the model protein, a BSA solution with a concentration of 1000 mg / L was prepared (solvent: 10 mM PBS buffer, pH 7.4). The BSA solution was filtered through the membrane to be tested at 0.1 MPa and 25 °C. After stabilizing the filtration for 10 min, the raw material solution and permeate were collected separately. The absorbance of both solutions was measured using the UV-280 nm method. The corresponding concentrations were obtained by referring to the BSA standard curve, and the rejection rate was calculated using the following formula: R = (1 - Cp / C0) × 100% Where: R is the protein retention rate (%); Cp is the BSA concentration in the permeate (mg / L); C0 is the BSA concentration in the feed solution (mg / L). Three parallel samples were tested in each group, and the average value was taken.

[0051] 4. Protein Static Adsorption Test Cut the membrane sheet to 2.5cm × 2.5cm, wet with ethanol, rinse with deionized water, and vacuum dry to constant weight. Pre-wet with 10mM PBS buffer (pH=7.4) for 30min. Immerse the membrane sheet completely in 20mL of 100mg / L BSA solution and incubate at 25℃ and 120rpm for 24h until adsorption equilibrium is reached. Take the supernatant after equilibrium, filter through a 0.22μm filter membrane, determine the concentration using the BCA method, and calculate the adsorption capacity per unit area using the following formula: Q = (C0 - Ce) × V / S Where: Q is the protein adsorption capacity per unit area (μg / cm²) 2 C0 is the initial concentration of BSA (mg / L); Ce is the concentration of BSA after adsorption equilibrium (mg / L); V is the volume of BSA solution (L); S is the effective membrane area (cm²). 2 Three parallel samples were tested in each group, and the average value was taken.

[0052] 5. Pore size analysis test The average pore size and pore size distribution of the membrane were determined using the liquid-liquid displacement method. Isopropanol was used as the wetting fluid, and deionized water was used as the displacement fluid. After the membrane was completely wetted, it was placed in the test cell. The water pressure was gradually increased under constant pressure, and the displacement fluid flux at different pressures was recorded. The membrane pore size was calculated using the Laplace equation. d=4γcosθ / P Where: d is the average pore size (nm); γ is the isopropanol-water interfacial tension (mN / m); θ is the contact angle (taken as 0°, since isopropanol completely wets the membrane); P is the bubble point pressure (kPa).

[0053] 6. Flux recovery rate test after alkaline washing First, the initial pure water flux Jw1 of the membrane was measured; then, the membrane was used to filter a 1000 mg / L BSA solution for 2 h (0.1 MPa, 25 °C), and the flux after fouling Jw2 was measured; subsequently, the membrane was flushed with 0.1 mol / L NaOH solution at 0.1 MPa for 30 min under cross-flow conditions at a cross-flow rate of 70 L / h, and flushed with deionized water until neutral, and the pure water flux Jw3 was measured again. The flux recovery rate was calculated using the following formula: FRR = Jw3 / Jw1 × 100% Where: FRR is the flux recovery rate (%) after alkaline washing; Jw1 is the initial pure water flux; Jw3 is the pure water flux after alkaline washing. Three parallel samples were tested in each group, and the average value was taken.

[0054] The results are as follows: The data above shows that the in-situ polymerized modified polyethersulfone ultrafiltration membrane provided by this invention can effectively solve the problems of easy loss, weak bonding, complex process, and poor antifouling effect of existing ultrafiltration membrane modification technologies, and achieves the effects of low protein adsorption, high hydrophilicity, high flux, and long-term stability. Comparative examples 1-9 show that this invention can effectively improve the product effect by selecting specific primary and secondary crosslinking agents and controlling relevant parameters. Comparative examples 1 and 10 show that this invention can effectively improve the product effect by first performing in-situ polymerization during the film formation process to generate a strongly hydrophilic, highly negatively charged, and structurally stable three-dimensional network structure, and then forming a semi-interpenetrating / interpenetrating polymer network with PES material.

[0055] The applicant declares that this invention illustrates the in-situ polymerized modified polyethersulfone ultrafiltration membrane, its preparation method, and its application through the above embodiments. However, this invention is not limited to the above embodiments, meaning that this invention does not necessarily rely on the above embodiments for implementation. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product, additions of auxiliary components, and selection of specific methods all fall within the protection and disclosure scope of this invention.

[0056] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0057] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. An in-situ polymerized modified polyethersulfone ultrafiltration membrane, characterized in that, The raw materials for preparing the in-situ polymerized modified polyethersulfone ultrafiltration membrane include, by weight, 15-26 parts of membrane skeleton material PES, 30-80 parts of organic solvent, 1-5 parts of hydrophilic monomer, 0.1-0.5 parts of initiator, 0.5-3.5 parts of crosslinking agent, 0.1-3 parts of pore-forming agent, and 5-35 parts of non-solvent.

2. The in-situ polymerized modified polyethersulfone ultrafiltration membrane according to claim 1, characterized in that, The organic solvent includes any one or a combination of at least two of N,N-dimethylformamide, N,N-dimethylacetamide, or N-methylpyrrolidone, preferably N-methylpyrrolidone.

3. The in-situ polymerized modified polyethersulfone ultrafiltration membrane according to claim 1 or 2, characterized in that, The hydrophilic monomer includes N-vinylpyrrolidone; Preferably, the initiator includes any one or a combination of at least two of azobisisobutyronitrile, azobisisoheptanenitrile, or benzoyl peroxide, with azobisisobutyronitrile being the most preferred.

4. The in-situ polymerized modified polyethersulfone ultrafiltration membrane according to any one of claims 1-3, characterized in that, The crosslinking agent includes a primary crosslinking agent and a secondary crosslinking agent; Preferably, the main crosslinking agent includes any one or a combination of at least two of sodium divinylbenzenesulfonate, sodium methacryloyloxyethyl sulfonate, sulfobutyl diacrylate or carboxylated diacrylate, preferably sodium methacryloyloxyethyl sulfonate; Preferably, the co-crosslinking agent includes any one or a combination of at least two of divinylbenzene, N,N-methylenebisacrylamide, or ethylene glycol dimethacrylate, with N,N-methylenebisacrylamide being the most preferred.

5. The in-situ polymerized modified polyethersulfone ultrafiltration membrane according to claim 4, characterized in that, The mass ratio of the primary crosslinking agent to the secondary crosslinking agent is (4-6):

1.

6. The in-situ polymerized modified polyethersulfone ultrafiltration membrane according to any one of claims 1-5, characterized in that, The pore-forming agent includes any one or a combination of at least two of PVP K17, PVP K30, PVP K90 or LiCl, preferably PVP K90; Preferably, the non-solvent includes any one or a combination of at least two of glycerol, DEG, TEG, PEG, or water, with PEG being preferred.

7. A method for preparing an in-situ polymerized modified polyethersulfone ultrafiltration membrane according to any one of claims 1-6, characterized in that, The preparation method includes the following steps: The membrane framework material and organic solvent are mixed, and then reacted with hydrophilic monomers, initiators and crosslinking agents to obtain a modified PES solution. A pore-forming agent, a non-solvent, and a modified PES solution are mixed and allowed to stand to obtain a PES casting solution. The PES casting solution was coated onto the substrate, and then left to stand at a constant temperature and humidity to obtain a pre-phase-separated coating solution. The pre-phase-separated coating solution was placed in a coagulation bath and water in sequence to obtain the in-situ polymerized modified polyethersulfone ultrafiltration membrane.

8. The preparation method according to claim 7, characterized in that, The mixing reaction was carried out under a nitrogen atmosphere.

9. The preparation method according to claim 7 or 8, characterized in that, The mixing reaction is carried out at a temperature of 50-70℃ for 2-4 hours.

10. The application of an in-situ polymerized modified polyethersulfone ultrafiltration membrane according to any one of claims 1-6 in the preparation of separation membranes.

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