Preparation method and detection method of anti-pollution anion exchange membrane
Antifouling anion exchange membranes were prepared by polymerization and amination of acrylic acid, chloromethylstyrene, and styrene monomers, followed by electrodeposition modification. This method solved the problems of easy fouling and poor performance of membranes, and achieved high-efficiency antifouling and improved strength of the membranes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HANGZHOU BLUETEC ENVIRONMENTAL TECH
- Filing Date
- 2023-03-23
- Publication Date
- 2026-06-19
AI Technical Summary
Existing anion exchange membranes are susceptible to fouling during electrodialysis, resulting in low separation efficiency, reduced membrane flux, and shortened lifespan. Furthermore, the modification of polystyrene skeletons is costly but has poor performance, making it difficult to meet commercial needs.
An antifouling anion exchange membrane was prepared by polymerizing acrylic acid, chloromethylstyrene, and styrene monomers to form a precursor, followed by amination, HCl transformation, and electrodeposition modification.
The preparation process is simple and controllable, and the resulting anion exchange membrane has stable performance, high anti-fouling properties and strength, making it suitable for industrial applications.
Abstract
Description
Technical Field
[0001] This invention relates to the field of ion exchange membrane technology, and in particular to a method for preparing and detecting an anti-fouling anion exchange membrane. Background Technology
[0002] Electrodialysis is an electrochemical selective separation osmosis process that uses ion exchange membranes as its core component. During electrodialysis, ions in water selectively pass through the ion exchange membrane under the influence of an electric field, while salts migrate from the desalination tank to the concentration tank, effectively reducing the discharge of saline wastewater. Compared to nanofiltration and reverse osmosis, electrodialysis has a higher water recovery rate because it is not limited by osmotic pressure.
[0003] In electrodialysis, ion exchange membranes are the core components of the equipment, enabling the directional migration of ions under the influence of an electric field. However, membrane fouling has always been a major challenge hindering the development of ion exchange membranes, leading to a series of problems such as low separation efficiency, reduced membrane flux, and shortened lifespan.
[0004] In existing technologies, the antifouling performance of ion exchange membranes is mainly improved through the following approaches:
[0005] 1. π-π conjugation between membrane matrix structure and aromatic pollutants: During membrane preparation, the chain segment length is changed by adjusting the degree of crosslinking, forming a special polymer network;
[0006] 2. Interaction between positively charged anion exchange membrane and negatively charged organic pollutants: By forming a thin anion exchange layer (negatively charged layer) on the surface of a common anion exchange membrane, the electrostatic repulsion between the anion exchange layer and organic macromolecules is utilized to reduce membrane fouling;
[0007] 3. Change the antifouling potential of the anion exchange membrane to reduce membrane fouling.
[0008] Therefore, membrane surface structure, such as hydrophilicity, charge, roughness, and membrane matrix (density, main chain structure), has a significant impact on the antifouling performance of ion exchange membranes. However, existing methods for improving the antifouling performance of ion exchange membranes often suffer from drawbacks such as complex and difficult-to-control conditions, difficulty in industrialization, limited improvement on the antifouling performance of ion exchange membranes, and the fact that the antifouling performance of ion exchange membranes still cannot meet the requirements.
[0009] In addition, during electrodialysis, ion exchange membranes should have good mechanical strength, low swelling degree, and high chemical stability. However, most ion exchange membranes currently use polystyrene as the skeleton. The modification cost of this skeleton is low, but its performance is poor, and its alkali resistance and mechanical properties are difficult to meet commercial requirements. Summary of the Invention
[0010] This invention designs a method for preparing and detecting an anti-fouling anion exchange membrane, in order to overcome the technical problems of existing anion exchange membranes having complex and difficult-to-control preparation processes, difficulty in industrialization, poor anti-fouling performance, low strength, and difficulty in meeting requirements.
[0011] To address the above problems, this invention discloses a method for preparing an antifouling anion exchange membrane, comprising the following steps:
[0012] S1, Preparation of the original membrane precursor: The original membrane precursor of the anion exchange membrane is formed by the polymerization reaction of three monomers: acrylic acid, chloromethylstyrene, and styrene.
[0013] S2, Amination reaction of the original membrane precursor: The original membrane precursor is immersed in a mixture of trimethylamine solution and methyl acetal to carry out the amination reaction of the original membrane precursor, and the original membrane is obtained after the amination reaction.
[0014] S3, HCl transformation of the original membrane: The original membrane obtained after the amination reaction is immersed in an HCl solution to carry out the HCl transformation of the original membrane.
[0015] S4, Surface charge modification of film: Sodium 4-styrenesulfonate or dopamine is deposited onto the surface of the HCl-converted film by electrodeposition.
[0016] Furthermore, in step S1, the addition ratio of acrylic acid, chloromethylstyrene, and styrene by weight is (0.5-2):(0.5-2):(6-10).
[0017] Furthermore, in step S1, the polymerization reaction process of the three monomers, acrylic acid, chloromethylstyrene, and styrene, is as follows: First, the three monomers, acrylic acid, chloromethylstyrene, and styrene, are weighed according to the proportion, and a crosslinking agent and an initiator are added. After mixing for 5 to 12 hours to make them uniform, the mixture is heated to 70 to 160°C to carry out the polymerization reaction, and the precursor of the anion exchange membrane is prepared.
[0018] Furthermore, in step S2, the amination reaction of the original membrane precursor is carried out as follows: First, methyl acetal is mixed with 20% to 40% trimethylamine solution to obtain a uniform mixture for later use. Then, the original membrane precursor prepared in step S1 is immersed in the mixture and soaked at 30 to 40°C for more than 10 hours to obtain the amination-reacted original membrane.
[0019] Furthermore, in step S3, the original membrane obtained after the amination reaction is immersed in an HCl solution and soaked at room temperature for more than 2 hours to obtain the original membrane after HCl conversion.
[0020] Further, in step S4, the electrodeposition process is as follows: First, sodium 4-styrene sulfonate or dopamine is dissolved in a Tris buffer solution with a pH of 8-8.5 and a concentration of 8-15 mmol / L. The amount of sodium 4-styrene sulfonate or dopamine added is 0.001-0.003 g / mL based on the volume of the Tris buffer solution. The electrodeposition time is 0.5-1 h, and the electrodeposition current density is 5-12 mA / cm². 2 .
[0021] Furthermore, in step S4, when dopamine is used for electrodeposition, FeCl3 is added to the Tris buffer solution, and the amount of FeCl3 added is 10% to 30% of the amount of dopamine added.
[0022] A method for detecting an antifouling anion exchange membrane, the method being used to detect the antifouling anion exchange membrane prepared by the above preparation method.
[0023] Furthermore, the detection method includes the following steps:
[0024] P1. The obtained antifouling anion exchange membrane is immersed in a 0.2-1 mol / L Na2SO4 aqueous solution for ≥2 hours and then washed with water.
[0025] P2, an anion exchange membrane is sandwiched between two chamber units with silver and silver chloride electrodes, and a 0.05-0.2 mol / L Na2SO4 aqueous solution is introduced into the anode chamber;
[0026] P3, a mixed solution containing sodium dodecylbenzenesulfonate, a high molecular weight organic compound, and Na2SO4, a low molecular weight electrolyte, is added to the cathode chamber.
[0027] P4, stir the anode and cathode chambers at 5-15 mA / cm 2 Electrodialysis was performed using the current density;
[0028] P5. Fix the platinum wire to both sides of the anion exchange membrane and measure the voltage E1 across the anion exchange membrane when the current is first applied.
[0029] P6. After energizing for a certain period of time, measure the voltage value E2 across the anion exchange membrane again.
[0030] P7, calculate the voltage difference ΔE = E2 - E1, and use the voltage difference ΔE as a parameter to measure the antifouling strength of the ion exchange membrane.
[0031] Furthermore, the detection method includes the following steps:
[0032] P1. The obtained antifouling anion exchange membrane was immersed in a 0.5 mol / L Na2SO4 aqueous solution for ≥2 h and then washed with water.
[0033] P2, an anion exchange membrane is sandwiched between two chamber units with silver and silver chloride electrodes, and a 0.1 mol / L Na2SO4 aqueous solution is introduced into the anode chamber;
[0034] P3, a mixed solution containing sodium dodecylbenzenesulfonate, a high molecular weight organic compound, and Na2SO4, a low molecular weight electrolyte, is added to the cathode chamber; wherein the mass concentration of sodium dodecylbenzenesulfonate in the mixed solution is 5%, and the molar concentration of Na2SO4 is 0.5 mol / L;
[0035] P4, stir the anode and cathode chambers at 10 mA / cm 2 Electrodialysis was performed using the current density;
[0036] P5. Fix the platinum wire to both sides of the anion exchange membrane and measure the voltage E1 across the anion exchange membrane when the current is first applied.
[0037] P6, after 3 hours of energization, the voltage value E2 across the anion exchange membrane was measured again;
[0038] P7, calculate the voltage difference ΔE = E2 - E1, and use the voltage difference ΔE as a parameter to measure the antifouling strength of the ion exchange membrane.
[0039] The preparation and detection methods of the antifouling anion exchange membrane described in this application have the advantages of simple preparation process, stable and controllable preparation process, stable and reliable performance of the obtained anion exchange membrane, and high antifouling performance and strength. Detailed Implementation
[0040] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, a detailed description is provided below in conjunction with specific embodiments of the present invention.
[0041] A method for preparing an antifouling anion exchange membrane, comprising the following steps:
[0042] S1, Preparation of the original membrane precursor: The original membrane precursor of the anion exchange membrane is formed by the polymerization reaction of three monomers: acrylic acid, chloromethylstyrene, and styrene.
[0043] S2, Amination reaction of the original membrane precursor: The original membrane precursor is immersed in a mixture of trimethylamine solution and methyl acetal to carry out the amination reaction of the original membrane precursor, and the original membrane is obtained after the amination reaction.
[0044] S3, HCl transformation of the original membrane: The original membrane obtained after the amination reaction is immersed in an HCl solution to carry out the HCl transformation of the original membrane.
[0045] S4, Surface charge modification of film: Sodium 4-styrenesulfonate or dopamine is deposited onto the surface of the HCl-converted film by electrodeposition.
[0046] Furthermore, in step S1, a hydrophilic anion exchange membrane precursor can be formed through the polymerization reaction of three monomers: acrylic acid, chloromethylstyrene, and styrene monomer.
[0047] Furthermore, in step S1, the addition ratio of acrylic acid, chloromethylstyrene, and styrene by weight is (0.5-2):(0.5-2):(6-10).
[0048] Preferably, in step S1, the amounts of acrylic acid and chloromethylstyrene added are the same by weight.
[0049] More preferably, in step S1, the ratio of acrylic acid, chloromethylstyrene, and styrene by weight is 1:1:8.
[0050] Furthermore, in step S1, the polymerization reaction process of the three monomers, acrylic acid, chloromethylstyrene, and styrene, is as follows: First, the three monomers, acrylic acid, chloromethylstyrene, and styrene, are weighed according to the proportion, and a crosslinking agent and an initiator are added. After mixing for 5 to 12 hours to make them uniform, the mixture is heated to 70 to 160°C to carry out the polymerization reaction, and the precursor of the anion exchange membrane is prepared.
[0051] As some embodiments of this application, in step S1, monomer mixing can be carried out by means of stirring or ultrasound.
[0052] In the preparation method of the antifouling ion exchange membrane described in this application, a hydrophilic anion exchange membrane precursor, namely a polymer framework, is formed by polymerizing three monomers: acrylic acid, chloromethylstyrene, and styrene. This polymer framework can effectively reduce the adsorption of the polymer framework, thereby reducing the van der Waals forces of the polymer framework adsorbing organic acids, ultimately reducing the adsorption rate of organic acids and improving its strength and antifouling performance.
[0053] Furthermore, in step S2, the chloromethyl group on the original membrane precursor can be reacted to generate a quaternary ammonium group by amination reaction of the original membrane precursor, thus obtaining an anion exchange membrane.
[0054] Furthermore, in step S2, the amination reaction of the original membrane precursor is carried out as follows: First, methyl acetal is mixed with 20% to 40% trimethylamine solution to obtain a uniform mixture for later use. Then, the original membrane precursor prepared in step S1 is immersed in the mixture and soaked at 30 to 40°C for more than 10 hours to obtain the amination-reacted original membrane.
[0055] Preferably, in step S2, a mixture is obtained by mixing methyl acetal with a 30% trimethylamine solution.
[0056] Furthermore, in step S2, there is no strict limitation on the weight ratio of methyl acetal to 30% trimethylamine solution. Preferably, the weight ratio of methyl acetal to 30% trimethylamine solution is (1:9) to (9:1).
[0057] Furthermore, in step S3, the OH-type strong basic anion exchange resin can be converted to Cl-type anion exchange resin by converting the original membrane with HCl. This is to avoid the acid-base neutralization reaction between the organic acid and the OH-type strong basic anion exchange resin, thereby reducing the chemical affinity of the ion exchange membrane and decreasing the binding force between the exchange membrane and the macromolecular organic matter containing carboxylic acid groups.
[0058] Preferably, in step S3, the original membrane obtained after the amination reaction is immersed in an HCl solution and soaked at room temperature for more than 2 hours to obtain the original membrane after HCl conversion.
[0059] Preferably, in step S3, the concentration of the HCl solution is 1.0 mol / L to 3.0 mol / L.
[0060] Preferably, in step S3, the soaking time of the original membrane in the HCl solution is 2 to 5 hours.
[0061] Further, in step S4, the electrodeposition process is as follows: First, sodium 4-styrene sulfonate or dopamine is dissolved in a Tris buffer solution with a pH of 8-8.5 and a concentration of 8-15 mmol / L. The amount of sodium 4-styrene sulfonate or dopamine added is 0.001-0.003 g / mL based on the volume of the Tris buffer solution. The electrodeposition time is 0.5-1 h, and the electrodeposition current density is 5-12 mA / cm². 2 .
[0062] Furthermore, in step S4, when dopamine is used for electrodeposition, FeCl3 is added to the Tris buffer solution, and the amount of FeCl3 added is 10% to 30% of the amount of dopamine added.
[0063] In this application, the FeCl3 contains Fe 3+ It can act as a catalyst in the dopamine polymerization process, promoting dopamine polymerization and enhancing the polymerization rate and strength. Meanwhile, Fe... 3+It can interact with -OH, NH2 groups, etc. in dopamine through hydrogen bonding, thereby increasing the stability of the dopamine-modified system and extending the mechanical strength and service life of the anti-fouling ion exchange membrane described in this application.
[0064] A method for detecting antifouling anion exchange membranes, comprising the following steps:
[0065] P1. The obtained antifouling anion exchange membrane is immersed in a 0.2-1 mol / L Na2SO4 aqueous solution for ≥2 hours and then washed with water.
[0066] P2, an anion exchange membrane is sandwiched between two chamber units with silver and silver chloride electrodes, and a 0.05-0.2 mol / L Na2SO4 aqueous solution is introduced into the anode chamber;
[0067] P3, a mixed solution containing sodium dodecylbenzenesulfonate, a high molecular weight organic compound, and Na2SO4, a low molecular weight electrolyte, is added to the cathode chamber.
[0068] P4, stir the anode and cathode chambers at 5-15 mA / cm 2 Electrodialysis was performed using the current density;
[0069] P5. Fix the platinum wire to both sides of the anion exchange membrane and measure the voltage E1 across the anion exchange membrane when the current is first applied.
[0070] P6. After energizing for a certain period of time, measure the voltage value E2 across the anion exchange membrane again.
[0071] P7, calculate the voltage difference ΔE = E2 - E1, and use the voltage difference ΔE as a parameter to measure the antifouling strength of the ion exchange membrane.
[0072] In this application, if the anion exchange membrane is contaminated with organic pollutants, the voltage across the membrane will increase, and the voltage difference ΔE will increase. Therefore, in this application, the voltage difference ΔE can be used to measure the anti-fouling strength of the ion exchange membrane. Generally, the smaller ΔE is, the higher the organic pollution resistance of the ion exchange membrane, and the higher the anti-fouling strength of the ion exchange membrane.
[0073] Preferably, in step P1, the obtained antifouling anion exchange membrane is immersed in a 0.5 mol / L Na2SO4 aqueous solution for ≥2 hours and then washed with water.
[0074] More preferably, in step P1, the obtained antifouling anion exchange membrane is immersed in a 0.5 mol / L Na2SO4 aqueous solution for 2-5 hours and then washed with water.
[0075] Preferably, in step P2, an anion exchange membrane is sandwiched between two chamber units having silver and silver chloride electrodes, and a 0.1 mol / L Na2SO4 aqueous solution is introduced into the anode chamber.
[0076] Preferably, in step P3, a mixed solution containing sodium dodecylbenzenesulfonate, a high molecular weight organic compound, and Na2SO4, a low molecular weight electrolyte, is added to the cathode chamber; wherein the mass concentration of sodium dodecylbenzenesulfonate in the mixed solution is 5%, and the molar concentration of Na2SO4 is 0.5 mol / L.
[0077] Preferably, in step P4, the anode chamber and the cathode chamber are stirred at a speed of 1000 rpm and at 10 mA / cm². 2 Electrodialysis is performed using a current density.
[0078] Preferably, in step P6, after energizing for 2 to 5 hours, the voltage value E2 across the anion exchange membrane is measured again.
[0079] More preferably, in step P6, after energizing for 3 hours, the voltage value E2 across the anion exchange membrane is measured again.
[0080] Furthermore, the detection method for the antifouling anion exchange membrane described in this application can be used not only for the antifouling anion exchange membrane prepared in this application, but also for the detection of other anion exchange membranes.
[0081] As some embodiments of this application, organic pollution tests were conducted on the obtained antifouling anion exchange membrane using the detection method described in this application. The results showed that the antifouling anion exchange membrane described in this application has good antifouling ability against humic acid in water and Rhodamine B in dyes.
[0082] The preparation and detection methods of the antifouling anion exchange membrane described in this application are illustrated below through specific embodiments:
[0083] Example 1
[0084] A method for preparing an antifouling anion exchange membrane, comprising the following steps:
[0085] S1, Preparation of the original membrane precursor: First, weigh out three monomers, acrylic acid, chloromethylstyrene and styrene, in a ratio of 0.5:0.5:6. Then mix the three monomers and add crosslinking agent and initiator. Mix for 5 hours to make it uniform. Then heat to 70°C to carry out polymerization reaction to prepare the original membrane precursor of anion exchange membrane.
[0086] S2, Amination reaction of the original membrane precursor: First, methyl acetal and 20% trimethylamine solution are mixed in a ratio of 1:9 to obtain a uniform mixture for later use. Then, the original membrane precursor prepared in step S1 above is immersed in the mixture and soaked at 30°C for 10 hours to obtain the original membrane after amination reaction.
[0087] S3, HCl transformation of the original membrane: The original membrane obtained after the amination reaction was immersed in an HCl solution with a concentration of 1.0 mol / L and soaked at room temperature for 2 hours to obtain the original membrane after HCl transformation.
[0088] S4, Surface charge modification of the film: First, sodium 4-styrene sulfonate was dissolved in a Tris buffer solution with a pH of 8–8.5 and a concentration of 8 mmol / L. The amount of sodium 4-styrene sulfonate added was 0.001 g / mL based on the volume of the Tris buffer solution. The electrodeposition time was 1 h, and the electrodeposition current density was 12 mA / cm². 2 .
[0089] Example 2
[0090] A method for preparing an antifouling anion exchange membrane, comprising the following steps:
[0091] S1, Preparation of the original membrane precursor: First, weigh three monomers, acrylic acid, chloromethylstyrene and styrene, in a ratio of 1:1:8. Then, mix the three monomers and add a crosslinking agent and an initiator. After mixing for 8 hours to make them uniform, heat to 1000℃ to carry out the polymerization reaction to prepare the original membrane precursor of the anion exchange membrane.
[0092] S2, Amination reaction of the original membrane precursor: First, methyl acetal and 30% trimethylamine solution are mixed in a 1:1 ratio to obtain a uniform mixture for later use. Then, the original membrane precursor prepared in step S1 above is immersed in the mixture and soaked at 38°C for 12 hours to obtain the original membrane after amination reaction.
[0093] S3, HCl conversion of the original membrane: The original membrane obtained after the amination reaction was immersed in a 2.0 mol / L HCl solution and soaked at room temperature for 2.5 h to obtain the HCl-converted original membrane;
[0094] S4, Surface charge modification of the film: First, dopamine was dissolved in a 10 mmol / L Tris buffer solution with a pH of 8–8.5. The amount of dopamine added was 0.002 g / mL based on the volume of the Tris buffer solution. The electrodeposition time was 0.8 h, and the electrodeposition current density was 10 mA / cm². 2 .
[0095] Example 3
[0096] A method for preparing an antifouling anion exchange membrane, comprising the following steps:
[0097] S1, Preparation of the original membrane precursor: First, weigh out three monomers, acrylic acid, chloromethylstyrene and styrene, in a ratio of 1:1:10. Then mix the three monomers and add crosslinking agent and initiator. Mix for 12 hours to make it uniform. Then heat to 160℃ to carry out polymerization reaction to prepare the original membrane precursor of anion exchange membrane.
[0098] S2, Amination reaction of the original membrane precursor: First, methyl acetal and 40% trimethylamine solution are mixed in a ratio of 9:1 to obtain a uniform mixture for later use. Then, the original membrane precursor prepared in step S1 above is immersed in the mixture and soaked at 40°C for 14 hours to obtain the original membrane after amination reaction.
[0099] S3, HCl transformation of the original membrane: The original membrane obtained after the amination reaction was immersed in a 3.0 mol / L HCl solution and soaked at room temperature for 5 hours to obtain the original membrane after HCl transformation.
[0100] S4, Surface charge modification of the film: First, dopamine and FeCl3 were dissolved in a 15 mmol / L Tris buffer solution with a pH of 8–8.5. The amount of dopamine added was 0.003 g / mL based on the volume of the Tris buffer solution. The amount of FeCl3 added was 20% of the amount of dopamine added by weight. The electrodeposition time was 0.5 h, and the electrodeposition current density was 5 mA / cm². 2 .
[0101] Example 4
[0102] A method for detecting antifouling anion exchange membranes is provided. The antifouling anion exchange membranes prepared in Examples 1-3 above are tested using this method. The test results are shown in Table 1 below. The detection method includes the following steps:
[0103] P1. The obtained antifouling anion exchange membrane was immersed in a 0.5 mol / L Na2SO4 aqueous solution for ≥2 h and then washed with water.
[0104] P2, an anion exchange membrane is sandwiched between two chamber units with silver and silver chloride electrodes, and a 0.1 mol / L Na2SO4 aqueous solution is introduced into the anode chamber;
[0105] P3, a mixed solution containing sodium dodecylbenzenesulfonate, a high molecular weight organic compound, and Na2SO4, a low molecular weight electrolyte, is added to the cathode chamber; wherein the mass concentration of sodium dodecylbenzenesulfonate in the mixed solution is 5%, and the molar concentration of Na2SO4 is 0.5 mol / L;
[0106] P4, stir the anode and cathode chambers at 10 mA / cm 2 Electrodialysis was performed using the current density;
[0107] P5. Fix the platinum wire to both sides of the anion exchange membrane and measure the voltage E1 across the anion exchange membrane when the current is first applied.
[0108] P6, after 3 hours of energization, the voltage value E2 across the anion exchange membrane was measured again;
[0109] P7, calculate the voltage difference ΔE = E2 - E1, and use the voltage difference ΔE as a parameter to measure the antifouling strength of the ion exchange membrane.
[0110] Table 1 shows the measured voltage difference ΔE values.
[0111] Sample source E1(mV) E2(mV) Voltage difference ΔE (mV) Example 1 153 456 303 Example 2 138 427 289 Example 3 147 401 254
[0112] While the present invention has been disclosed above, it is not limited thereto. In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.
Claims
1. A method for preparing an anti-fouling anion exchange membrane, characterized in that, Including the following steps: S1, Preparation of the original membrane precursor: The original membrane precursor of the anion exchange membrane is formed by the polymerization reaction of three monomers: acrylic acid, chloromethylstyrene, and styrene. S2, Amination reaction of the original membrane precursor: The original membrane precursor is immersed in a mixture of trimethylamine solution and methyl acetal to carry out the amination reaction of the original membrane precursor, and the original membrane is obtained after the amination reaction. S3, HCl transformation of the original membrane: The original membrane obtained after the amination reaction is immersed in an HCl solution to carry out the HCl transformation of the original membrane. S4, Surface charge modification of film: Sodium 4-styrenesulfonate or dopamine is deposited onto the surface of the HCl-converted film by electrodeposition. In step S2, the amination reaction of the original membrane precursor is carried out as follows: First, methyl acetal is mixed with 20%~40% trimethylamine solution to obtain a uniform mixture for later use. Then, the original membrane precursor prepared in step S1 is immersed in the mixture and soaked at 30~40℃ for more than 10 hours to obtain the amination-reacted original membrane. In step S4, the electrodeposition process is as follows: First, sodium 4-styrene sulfonate or dopamine is dissolved in a Tris buffer solution with a pH of 8-8.5 and a concentration of 8-15 mmol / L. The amount of sodium 4-styrene sulfonate or dopamine added is 0.001-0.003 g / mL based on the volume of the Tris buffer solution. The electrodeposition time is 0.5-1 h, and the electrodeposition current density is 5-12 mA / cm². 2 ; When dopamine is used for electrodeposition, FeCl3 is also added to the Tris buffer solution, and the amount of FeCl3 added is 10% to 30% of the amount of dopamine added.
2. The method for preparing the antifouling anion exchange membrane according to claim 1, characterized in that, In step S1, the addition ratio of acrylic acid, chloromethylstyrene, and styrene by weight is (0.5~2):(0.5~2):(6~10).
3. The method for preparing the antifouling anion exchange membrane according to claim 1 or 2, characterized in that, In step S1, the polymerization reaction process of the three monomers, acrylic acid, chloromethylstyrene, and styrene, is as follows: First, the three monomers, acrylic acid, chloromethylstyrene, and styrene, are weighed according to the proportion, and a crosslinking agent and an initiator are added. After mixing for 5 to 12 hours to make them uniform, the mixture is heated to 70 to 160°C to carry out the polymerization reaction, and the precursor of the anion exchange membrane is prepared.
4. The method for preparing the antifouling anion exchange membrane according to claim 1, characterized in that, In step S3, the original membrane obtained after the amination reaction is immersed in an HCl solution and soaked at room temperature for more than 2 hours to obtain the original membrane after HCl conversion.
5. A method for detecting antifouling anion exchange membranes, characterized in that, The detection method is used to detect the antifouling anion exchange membrane prepared by the preparation method according to any one of claims 1 to 4.
6. The detection method for the antifouling anion exchange membrane according to claim 5, characterized in that, The detection method includes the following steps: P1. The obtained antifouling anion exchange membrane is immersed in a 0.2~1mol / L Na2SO4 aqueous solution for ≥2h and then washed with water. P2, an anion exchange membrane is sandwiched between two chamber units with silver and silver chloride electrodes, and a 0.05~0.2mol / L Na2SO4 aqueous solution is introduced into the anode chamber; P3, a mixed solution containing sodium dodecylbenzenesulfonate, a high molecular weight organic compound, and Na2SO4, a low molecular weight electrolyte, is added to the cathode chamber. P4, stir the anode and cathode chambers at 5~15 mA / cm 2 Electrodialysis is performed using current density; P5. Fix the platinum wire to both sides of the anion exchange membrane and measure the voltage E1 across the anion exchange membrane when the current is first applied. P6. After energizing for a certain period of time, measure the voltage value E2 across the anion exchange membrane again. P7, calculate the voltage difference ΔE=E2-E1, and use the voltage difference ΔE as a parameter to measure the antifouling strength of the ion exchange membrane.
7. The detection method for the antifouling anion exchange membrane according to claim 5, characterized in that, The detection method includes the following steps: P1. The obtained antifouling anion exchange membrane was immersed in a 0.5 mol / L Na2SO4 aqueous solution for ≥2 h and then washed with water. P2, an anion exchange membrane is sandwiched between two chamber units with silver and silver chloride electrodes, and a 0.1 mol / L Na2SO4 aqueous solution is introduced into the anode chamber; P3, a mixed solution containing sodium dodecylbenzenesulfonate, a high molecular weight organic compound, and Na2SO4, a low molecular weight electrolyte, is added to the cathode chamber; wherein the mass concentration of sodium dodecylbenzenesulfonate in the mixed solution is 5%, and the molar concentration of Na2SO4 is 0.5 mol / L. P4, stir the anode and cathode chambers at 10 mA / cm 2 Electrodialysis is performed using current density; P5. Fix the platinum wire to both sides of the anion exchange membrane and measure the voltage E1 across the anion exchange membrane when the current is first applied. P6, after energizing for 3 hours, measure the voltage value E2 across the anion exchange membrane again; P7, calculate the voltage difference ΔE=E2-E1, and use the voltage difference ΔE as a parameter to measure the antifouling strength of the ion exchange membrane.