Method for optimizing performance of meta-aramid ultrafiltration membrane

Abstract

The invention relates to a method for optimizing the performance of a meta-aramid ultrafiltration membrane, in particular to an overall method for improving the crosslinking degree of the membrane and reducing the molecular cut-off by reacting EDC-HCl treated meta-aramid ultrafiltration membrane with an amine-containing monomer, which comprises the following steps: preparing the membrane, preparing an EDC-HCl solution, soaking and activating the membrane, preparing an amine-containing monomer solution, and reacting. According to the preparation method disclosed by the invention, the activation effect of EDC-HCl on carboxyl on the surface of the meta-aramid ultrafiltration membrane and the subsequent reaction with an amine-containing monomer are creatively utilized to construct a new cross-linked structure; the meta-aramid ultrafiltration membrane product with specific crosslinking degree and molecular weight cut-off prepared by the method is suitable for industrial production and has very strong practicability.

Description

A method for optimizing the performance of meta-aramid ultrafiltration membranes Technical Field

[0001] This invention belongs to the technical field of membrane materials, and particularly relates to a method for optimizing the performance of meta-aramid ultrafiltration membranes. Background Technology

[0002] Ultrafiltration membranes, as an important component of membrane separation technology, are widely used in various fields such as food, medicine, chemical industry, and environmental protection. Meta-aramid ultrafiltration membranes hold an important position among many ultrafiltration membrane materials due to their good chemical stability, mechanical properties, and certain separation performance. However, with the continuous improvement of performance requirements for ultrafiltration membranes in various industries, existing meta-aramid ultrafiltration membranes have gradually revealed some shortcomings in practical applications.

[0003] First, regarding the degree of crosslinking, existing meta-aramid ultrafiltration membranes have a relatively low degree of crosslinking. This low degree of crosslinking makes the membrane structure prone to changes when exposed to external environmental factors, such as use in solutions with higher temperatures or different pH levels. These structural changes can alter the membrane's pore size distribution, thus affecting its separation performance. For example, in the food industry, during ultrafiltration of protein solutions, insufficient membrane crosslinking leads to a gradual loosening of the membrane structure and an increase in pore size over prolonged filtration. This allows previously retained protein molecules to permeate through the membrane, reducing separation efficiency and product quality.

[0004] Secondly, regarding the molecular weight cutoff, existing meta-aramid ultrafiltration membranes have a relatively large molecular weight cutoff, which cannot meet the needs of some applications requiring efficient retention of small molecules. For example, in the biopharmaceutical field, when separating and purifying some small molecule drugs or bioactive components, ultrafiltration membranes with a smaller molecular weight cutoff are required to effectively retain and separate the target substances. However, existing meta-aramid ultrafiltration membranes, due to their large molecular weight cutoff, cannot accurately separate the desired small molecules, resulting in low product purity and affecting subsequent drug development and production.

[0005] Furthermore, traditional methods for increasing membrane crosslinking degree and reducing molecular weight cutoff have many drawbacks. Some physical methods, such as heat treatment, while increasing crosslinking degree to some extent, often negatively impact other membrane properties, such as membrane flexibility and flux, leading to membrane rupture during use, reduced flux, and consequently affecting overall filtration efficiency. Chemical methods, on the other hand, often use highly corrosive or toxic chemical reagents, posing a threat to operator health and potentially leaving residues that pollute the environment and affect the final membrane performance.

[0006] In summary, how to effectively improve the crosslinking degree of the membrane and reduce the molecular weight cutoff without affecting other excellent properties of meta-aramid ultrafiltration membranes has become a key technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] The technical problem to be solved by the present invention is that the existing meta-aramid ultrafiltration membrane has low crosslinking degree and large molecular weight cutoff. In order to improve its shortcomings, the present invention provides a method for optimizing the performance of meta-aramid ultrafiltration membrane, that is, by immersing the meta-aramid ultrafiltration membrane in EDC-HCl solution and then reacting it with amine-containing monomers, the crosslinking degree of the membrane can be significantly improved and the molecular weight cutoff can be reduced.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solution: a method for optimizing the performance of a meta-aramid ultrafiltration membrane, comprising the following steps: S1: membrane preparation; selecting a suitable meta-aramid ultrafiltration membrane, cutting it into appropriate sizes, and reserving it for later use; S2: EDC-HCl solution preparation; accurately weighing a certain amount of EDC-HCl solid, dissolving it in deionized water, and preparing an EDC-HCl solution with a concentration of 0.1-1.2%. S3: HCl solution preparation: During preparation, use a magnetic stirrer to thoroughly stir to ensure complete dissolution and obtain a homogeneous and stable solution; S4: Membrane activation: Completely immerse the cut meta-aramid ultrafiltration membrane in the prepared EDC-HCl solution for 2-3 hours. During immersion, the solution should be kept at room temperature, and the container should be gently shaken periodically to ensure full contact between the membrane and the solution, guaranteeing uniform activation of the carboxyl groups on the membrane surface; S5: Preparation of amine monomer solution: Select suitable amine monomers, such as ethylenediamine or hexamethylenediamine, and dissolve them in deionized water to prepare a 5%-8% amine monomer solution. Stir thoroughly during preparation to ensure complete dissolution of the amine monomer; S6: Reaction process: Remove the activated meta-aramid ultrafiltration membrane from the EDC-HCl solution... The membrane was removed from the Cl solution and gently rinsed with deionized water to remove residual EDC-HCl solution. Then, the membrane was quickly placed in the amine monomer solution and reacted at 35℃-45℃ for 1-1.5 hours. During the reaction, a constant temperature water bath was used to precisely control the reaction temperature, and the solution was stirred to ensure full contact between the membrane and the amine monomer, promoting the condensation reaction between amino and activated carboxyl groups to form a cross-linked structure. S6: Post-treatment. After the reaction, the membrane was removed from the amine monomer solution and rinsed with plenty of deionized water to remove unreacted amine monomers and byproducts generated during the reaction. After rinsing, the membrane was placed in a vacuum drying oven to achieve constant weight, yielding the treated meta-aramid ultrafiltration membrane.

[0009] As a preferred embodiment, the vacuum drying oven in step S6 is controlled at 40°C, and drying is performed at this temperature for 5-10 minutes.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention innovatively utilizes the activation effect of EDC-HCl on the carboxyl groups on the surface of meta-aramid ultrafiltration membrane, and the subsequent reaction with amine-containing monomers to construct a new cross-linked structure. By precisely controlling parameters such as EDC-HCl solution concentration, soaking time, amine-containing monomer concentration, reaction temperature and time, the meta-aramid ultrafiltration membrane product with specific cross-linking degree and molecular weight cutoff obtained by this method is suitable for industrial production and has strong practicality. Detailed Implementation

[0011] The technical solution of this application will be further described and illustrated below through embodiments.

[0012] A method for optimizing the performance of a meta-aramid ultrafiltration membrane includes the following steps: S1: Membrane preparation; selecting a suitable meta-aramid ultrafiltration membrane, cutting it to an appropriate size, and reserving it for later use; S2: EDC-HCl solution preparation; accurately weighing a certain amount of EDC-HCl solid, dissolving it in deionized water to prepare an EDC-HCl solution with a concentration of 0.1-1.2%. S3: HCl solution preparation: During preparation, use a magnetic stirrer to thoroughly stir to ensure complete dissolution and obtain a homogeneous and stable solution; S4: Membrane activation: Completely immerse the cut meta-aramid ultrafiltration membrane in the prepared EDC-HCl solution for 2-3 hours. During immersion, the solution should be kept at room temperature, and the container should be gently shaken periodically to ensure full contact between the membrane and the solution, guaranteeing uniform activation of the carboxyl groups on the membrane surface; S5: Preparation of amine monomer solution: Select suitable amine monomers, such as ethylenediamine or hexamethylenediamine, and dissolve them in deionized water to prepare a 5%-8% amine monomer solution. Stir thoroughly during preparation to ensure complete dissolution of the amine monomer; S6: Reaction process: Remove the activated meta-aramid ultrafiltration membrane from the EDC-HCl solution. Gently rinse the membrane surface with deionized water to remove residual EDC-HCl solution. Then, quickly immerse the membrane in the amine monomer solution and react at 35℃-45℃ for 1-1.5 hours. During the reaction, a constant temperature water bath can be used to precisely control the reaction temperature. Simultaneously, use a stirrer to stir the solution to ensure full contact between the membrane and the amine monomer, promoting the condensation reaction between amino and activated carboxyl groups to form a cross-linked structure. S6: Post-treatment. After the reaction, remove the membrane from the amine monomer solution and rinse the membrane surface with plenty of deionized water to remove unreacted amine monomers and byproducts generated during the reaction. After rinsing, place the membrane in a vacuum drying oven and dry at 40℃ for 5-10 minutes to achieve constant weight, obtaining the treated meta-aramid ultrafiltration membrane.

[0013] Based on some core parameter data in the above steps, the following adjustable range of parameters is proposed as the basis for the design of the embodiments: EDC-HCl solution concentration: 0.1%-1.2% Soaking time: 2-3h Amine monomer: 5%-8% Reaction temperature: 35-45℃ Reaction time: 1-1.5h Post-treatment method: uniformly adopt 40℃ vacuum drying for 10min.

[0014] Example 1: S1: Membrane preparation; S2: EDC-HCl solution preparation, prepared to a concentration of 0.1%; S3: Soaking time control, controlled at 2 hours; S4: Amine monomer solution preparation, prepared to a concentration of 5%; S5: Reaction temperature and reaction time control, the reaction is carried out at a temperature of 35°C for 1 hour; S6: The membrane is placed in a vacuum drying oven and dried at a temperature of 40°C for 10 minutes to achieve constant weight, thus obtaining the treated meta-aramid ultrafiltration membrane.

[0015] Conclusion: The meta-aramid ultrafiltration membrane produced by the above steps has a crosslinking degree of 55.2% and a molecular weight cutoff of 57840 Da. Using this set of data as a baseline control group, the concentration of EDC-HCl solution, soaking time, concentration of amine monomer, reaction temperature, and reaction time in this scheme were verified, and the influence of each parameter on the membrane crosslinking degree and molecular weight cutoff was comprehensively analyzed.

[0016] Example 2: S1: Membrane preparation; S2: EDC-HCl solution preparation, prepared to a concentration of 0.4%; S3: Soaking time control, controlled at 2 hours; S4: Amine monomer solution preparation, prepared to a concentration of 5%; S5: Reaction temperature and reaction time control, the reaction is carried out at a temperature of 35°C for 1 hour; S6: The membrane is placed in a vacuum drying oven and dried at a temperature of 40°C for 10 minutes to achieve constant weight, thus obtaining the treated meta-aramid ultrafiltration membrane.

[0017] Conclusion: The meta-aramid ultrafiltration membrane produced by the above steps has a crosslinking degree of 57.6% and a molecular weight cutoff of 55920 Da.

[0018] Example 3: S1: Membrane preparation; S2: EDC-HCl solution preparation, prepared to a concentration of 0.7%; S3: Soaking time control, controlled at 2 hours; S4: Amine monomer solution preparation, prepared to a concentration of 5%; S5: Reaction temperature and reaction time control, the reaction is carried out at a temperature of 35°C for 1 hour; S6: The membrane is placed in a vacuum drying oven and dried at a temperature of 40°C for 10 minutes to achieve constant weight, thus obtaining the treated meta-aramid ultrafiltration membrane.

[0019] Conclusion: The meta-aramid ultrafiltration membrane produced by the above steps has a crosslinking degree of 60.0% and a molecular weight cutoff of 54,000 Da.

[0020] Example 4: S1: Membrane preparation; S2: EDC-HCl solution preparation, prepared to a concentration of 1.0%; S3: Soaking time control, controlled at 2 hours; S4: Amine monomer solution preparation, prepared to a concentration of 5%; S5: Reaction temperature and reaction time control, the reaction is carried out at a temperature of 35°C for 1 hour; S6: The membrane is placed in a vacuum drying oven and dried at a temperature of 40°C for 10 minutes to achieve constant weight, thus obtaining the treated meta-aramid ultrafiltration membrane.

[0021] Conclusion: The meta-aramid ultrafiltration membrane produced by the above steps has a crosslinking degree of 62.4% and a molecular weight cutoff of 52080 Da.

[0022] Example 5: S1: Membrane preparation; S2: EDC-HCl solution preparation, prepared into a 1.2% EDC-HCl solution; S3: Soaking time control, controlled at 2 hours; S4: Amine monomer solution preparation, prepared into a 5% amine monomer solution; S5: Reaction temperature and reaction time control, the reaction is carried out at 35°C for 1 hour; S6: The membrane is placed in a vacuum drying oven and dried at 40°C for 10 minutes to achieve constant weight, thus obtaining the treated meta-aramid ultrafiltration membrane.

[0023] Conclusion: The meta-aramid ultrafiltration membrane produced by the above steps has a crosslinking degree of 64.0% and a molecular weight cutoff of 50,800 Da.

[0024] Example 6: S1: Membrane preparation; S2: EDC-HCl solution preparation, prepared to a concentration of 0.7%; S3: Soaking time control, controlled at 2.2h; S4: Amine monomer solution preparation, prepared to a concentration of 5%; S5: Reaction temperature and reaction time control, the reaction is carried out at a temperature of 35℃ for a reaction time of 1 hour; S6: The membrane is placed in a vacuum drying oven and dried at a temperature of 40℃ for 10 minutes to achieve constant weight, thus obtaining the treated meta-aramid ultrafiltration membrane.

[0025] Conclusion: The meta-aramid ultrafiltration membrane produced by the above steps has a crosslinking degree of 62.0% and a molecular weight cutoff of 52400 Da.

[0026] Example 7: S1: Membrane preparation; S2: EDC-HCl solution preparation, prepared to a concentration of 0.7%; S3: Soaking time control, controlled at 2.5h; S4: Amine monomer solution preparation, prepared to a concentration of 5%; S5: Reaction temperature and reaction time control, the reaction is carried out at a temperature of 35℃ for a reaction time of 1 hour; S6: The membrane is placed in a vacuum drying oven and dried at a temperature of 40℃ for 10 minutes to achieve constant weight, thus obtaining the treated meta-aramid ultrafiltration membrane.

[0027] Conclusion: The meta-aramid ultrafiltration membrane produced by the above steps has a crosslinking degree of 65.0% and a molecular weight cutoff of 50,000 Da.

[0028] Example 8: S1: Membrane preparation; S2: EDC-HCl solution preparation, prepared to a concentration of 0.7%; S3: Soaking time control, controlled at 2.8h; S4: Amine monomer solution preparation, prepared to a concentration of 5%; S5: Reaction temperature and reaction time control, the reaction is carried out at a temperature of 35℃ for 1 hour; S6: The membrane is placed in a vacuum drying oven and dried at a temperature of 40℃ for 10 minutes to achieve constant weight, thus obtaining the treated meta-aramid ultrafiltration membrane.

[0029] Conclusion: The meta-aramid ultrafiltration membrane produced by the above steps has a crosslinking degree of 68.0% and a molecular weight cutoff of 47,600 Da.

[0030] Example 9: S1: Membrane preparation; S2: EDC-HCl solution preparation, prepared to a concentration of 0.7%; S3: Soaking time control, controlled at 3.0h; S4: Amine monomer solution preparation, prepared to a concentration of 5%; S5: Reaction temperature and reaction time control, the reaction is carried out at a temperature of 35℃ for 1 hour; S6: The membrane is placed in a vacuum drying oven and dried at a temperature of 40℃ for 10 minutes to achieve constant weight, thus obtaining the treated meta-aramid ultrafiltration membrane.

[0031] Conclusion: The meta-aramid ultrafiltration membrane produced by the above steps has a crosslinking degree of 70.0% and a molecular weight cutoff of 46,000 Da.

[0032] Example 10: S1: Membrane preparation; S2: EDC-HCl solution preparation, prepared to a concentration of 0.7%; S3: Soaking time control, controlled at 2.5h; S4: Amine monomer solution preparation, prepared to a concentration of 6%; S5: Reaction temperature and reaction time control, the reaction is carried out at a temperature of 35℃ for a reaction time of 1.2h; S6: The membrane is placed in a vacuum drying oven and dried at a temperature of 40℃ for 10 minutes to achieve constant weight, thus obtaining the treated meta-aramid ultrafiltration membrane.

[0033] Conclusion: The meta-aramid ultrafiltration membrane produced by the above steps has a crosslinking degree of 72.0% and a molecular weight cutoff of 44400 Da.

[0034] Example 11: S1: Membrane preparation; S2: EDC-HCl solution preparation, prepared to a concentration of 0.7%; S3: Soaking time control, controlled at 2.5h; S4: Amine monomer solution preparation, prepared to a concentration of 7%; S5: Reaction temperature and reaction time control, the reaction is carried out at a temperature of 40℃ for a reaction time of 1.3h; S6: The membrane is placed in a vacuum drying oven and dried at a temperature of 40℃ for 10 minutes to achieve constant weight, thus obtaining the treated meta-aramid ultrafiltration membrane.

[0035] Conclusion: The meta-aramid ultrafiltration membrane produced by the above steps has a crosslinking degree of 84.5% and a molecular weight cutoff of 34400 Da.

[0036] Example 12: S1: Membrane preparation; S2: EDC-HCl solution preparation, prepared to a concentration of 0.7%; S3: Soaking time control, controlled at 2.5h; S4: Amine monomer solution preparation, prepared to a concentration of 8%; S5: Reaction temperature and reaction time control, the reaction is carried out at a temperature of 45℃ for a reaction time of 1.5h; S6: The membrane is placed in a vacuum drying oven and dried at a temperature of 40℃ for 10 minutes to achieve constant weight, thus obtaining the treated meta-aramid ultrafiltration membrane.

[0037] Conclusion: The meta-aramid ultrafiltration membrane produced by the above steps has a crosslinking degree of 90.0% and a molecular weight cutoff of 30,000 Da.

[0038] The above 12 sets of examples are summarized in the table below: The following conclusions can be drawn from the above data: 1. Effect of EDC-HCl concentration: Increasing the concentration from 0.1% to 1.2% increases the degree of crosslinking by 15.9% (55.2%→64.0%) and decreases the molecular weight cutoff by 12.2%. The main function of EDC-HCl is to activate carboxyl groups; a concentration of 0.7% is sufficient to meet basic activation requirements, and excessively high concentrations have limited effect on performance improvement. 2. Effect of soaking time: Extending the time from 2.0h to 3.0h increases the degree of crosslinking by 16.7% (60.0%→70.0%) and decreases the molecular weight cutoff by 14.8%. Setting the soaking time to 2.5h is the most cost-effective time point; after that, the reaction enters a plateau phase, and further extending the time reduces the benefit. 3. Effect of amine monomer concentration: As the concentration increases from 5.0% to 8.0%, the degree of crosslinking increases sharply by 38.5% (65.0%→90.0%), and the molecular weight cutoff decreases by 40.0%. The amine monomer, as a crosslinking agent, directly determines the density of crosslinking points and is the core parameter for controlling membrane pore size and retention performance. 4. Effect of reaction temperature and time: From 35℃ / 1.0h to 45℃ / 1.5h, the degree of crosslinking increases by 38.5%, and the molecular weight cutoff decreases by 40.0% simultaneously. The increase in temperature accelerates the condensation reaction, while the extension of time ensures the complete reaction. The synergistic effect of the two is significant.

[0039] Therefore, this invention has the following effects: It improves the degree of crosslinking and enhances membrane stability: By using the method of soaking in EDC-HCl and reacting with amine-containing monomers in this invention, the degree of crosslinking of the meta-aramid ultrafiltration membrane is successfully improved. A higher degree of crosslinking makes the membrane structure more stable and better resistant to the influence of external environmental factors. When used in solutions with different temperatures and pH levels, the membrane structure is less prone to change, thus ensuring a stable pore size distribution and extending the membrane's service life. For example, in the field of chemical wastewater treatment, when treating some corrosive wastewater, the meta-aramid ultrafiltration membrane treated by this method can operate stably for a long time, with a service life extended by 10%-15% compared to untreated membranes, reducing the increased costs caused by frequent membrane module replacements.

[0040] Reducing the molecular weight cutoff and improving separation precision: The newly formed cross-linked structure refines the membrane pore size, effectively reducing the molecular weight cutoff. This allows meta-aramid ultrafiltration membranes to more accurately retain small molecules, meeting the needs of the biopharmaceutical, food, and other industries for efficient separation of small molecules. In the biopharmaceutical field, when separating and purifying some small molecule drugs, the treated membrane can increase product purity by 5%-10%, significantly improving product quality and facilitating subsequent drug research and development and production.

[0041] Simple to operate and environmentally friendly: The method employed in this invention is relatively simple to operate, requiring no complex equipment or processes. Furthermore, the EDC-HCl and common amine-containing monomers used are relatively environmentally friendly, producing no large amounts of harmful byproducts during the reaction and leaving no difficult-to-treat residues afterward, resulting in minimal environmental pollution. Compared to some traditional methods for increasing membrane crosslinking and reducing molecular weight cutoff, this invention is more in line with the principles of green chemistry and sustainable development, and has promising application prospects.

[0042] Maintaining original excellent performance: While increasing the degree of crosslinking and reducing the molecular weight cutoff, the method of this invention does not significantly damage the original excellent properties of the meta-aramid ultrafiltration membrane, such as chemical stability and mechanical properties. The membrane can still maintain good chemical resistance and a certain mechanical strength, and can better exert its comprehensive performance advantages in practical applications.

[0043] Based on the above embodiments, this solution can be divided into the following multiple solutions: 1. High cross-linking degree solution (80%-90%) Applicable scenarios: chemical wastewater and other highly corrosive environments.

[0044] Parameter combination: EDC-HCl 0.7%-1.0%, soaking time 2.8-3.0h, amine monomer 7.5%-8.0%, temperature 42-45℃, time 1.4-1.5h.

[0045] Performance indicators: cross-linking degree 85%-90%, molecular weight cutoff 30000-33000 Da, service life extended by 15%.

[0046] 2. Medium crosslinking degree scheme (65%-75%) is suitable for the separation of small molecules in biopharmaceuticals.

[0047] Parameter combination: EDC-HCl 0.5%-0.8%, soaking time 2.4-2.6h, amine monomer content 5.8%-6.5%, temperature 37-40℃, time 1.2-1.3h.

[0048] Performance indicators: cross-linking degree 68%-75%, molecular weight cutoff 42000-48000 Da, product purity improved by 8%-10%.

[0049] 3. Low cross-linking solution (55%-65%) is suitable for protein separation in the food industry.

[0050] Parameter combination: EDC-HCl 0.2%-0.5%, soaking time 2.0-2.2h, amine monomer 5.0%-5.5%, temperature 35-36℃, time 1.0-1.1h.

[0051] Performance indicators: crosslinking degree 55%-62%, molecular weight cutoff 51000-57000 Da, balancing throughput and separation efficiency.

[0052] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.

Claims

1. A method for optimizing the performance of a meta-aramid ultrafiltration membrane, characterized in that, The process includes the following steps: S1: Membrane preparation; Select a suitable meta-aramid ultrafiltration membrane, cut it to an appropriate size, and set it aside for later use; S2: EDC-HCl solution preparation; Accurately weigh a certain amount of EDC-HCl solid, dissolve it in deionized water, and prepare an EDC-HCl solution with a concentration of 0.1-1.2%. During the preparation process, use a magnetic stirrer to stir thoroughly to ensure complete dissolution and obtain a homogeneous and stable solution; S3: Membrane immersion activation; Completely immerse the cut meta-aramid ultrafiltration membrane in the prepared EDC-HCl solution. The immersion time is controlled at 2-3 hours. During the immersion process, the solution should be kept at room temperature, and the container should be gently shaken periodically to ensure that the membrane and solution are in full contact and that the carboxyl groups on the membrane surface are uniformly activated. S4: Preparation of amine monomer solution; Select a suitable amine monomer, such as ethylenediamine or hexamethylenediamine, and dissolve it in deionized water to prepare an amine monomer solution with a concentration of 5%-8%. During the preparation process, stir thoroughly to ensure complete dissolution of the amine monomer. S5: Reaction process: Remove the activated meta-aramid ultrafiltration membrane from the EDC-HCl solution and gently rinse the membrane surface with deionized water to remove residual EDC-HCl solution. Then, quickly place the membrane into the amine monomer solution and react at a temperature of 35℃-45℃ for 1-1.5 hours. During the reaction, a constant temperature water bath can be used to precisely control the reaction temperature. At the same time, use a stirring device to stir the solution to ensure full contact between the membrane and the amine monomer, promoting the condensation reaction between amino groups and activated carboxyl groups to form a cross-linked structure. S6: Post-treatment. After the reaction is complete, the membrane is removed from the amine monomer solution and rinsed with a large amount of deionized water to remove unreacted amine monomers and byproducts generated during the reaction. After rinsing, the membrane is placed in a vacuum drying oven to achieve constant weight, thus obtaining the treated meta-aramid ultrafiltration membrane.

2. The method for optimizing the performance of a meta-aramid ultrafiltration membrane according to claim 1, characterized in that: In step S6, the vacuum drying oven is controlled at 40°C, and drying is performed at this temperature for 5-10 minutes.