Conductive polyether sulfone ultrafiltration membrane and preparation method thereof

Abstract

This invention relates to the field of ultrafiltration membrane preparation technology, specifically disclosing a conductive polyethersulfone ultrafiltration membrane and its preparation method. The preparation method of the conductive polyethersulfone ultrafiltration membrane includes the following steps: (1) mixing raw materials for a conductive polyethersulfone ultrafiltration membrane casting solution to prepare a casting solution; (2) coating the casting solution onto the surface of a glass plate, then transferring it to a gel bath for phase inversion to form a membrane. After membrane formation, the membrane is immersed in deionized water to obtain the conductive polyethersulfone ultrafiltration membrane. This invention, by adding a conductive agent to the conductive polyethersulfone ultrafiltration membrane casting solution, enables the prepared polyethersulfone ultrafiltration membrane to possess a certain conductivity; this facilitates improving the separation capacity of the polyethersulfone ultrafiltration membrane by passing an electric current through it.

Description

Technical Field

[0001] This invention relates to the field of ultrafiltration membrane preparation technology, specifically to a conductive polyethersulfone ultrafiltration membrane and its preparation method. Background Technology

[0002] Polyethersulfone (PES) ultrafiltration membranes are widely used in water treatment due to their good chemical stability and mechanical strength. Conductive ultrafiltration membranes are made by adding conductive substances during the preparation process, giving the ultrafiltration membrane a certain degree of conductivity. This allows for the application of electricity to the ultrafiltration membrane during the ultrafiltration process, thereby enhancing the membrane's separation capacity.

[0003] Chinese invention patent CN106621830A discloses a method for modifying polyethersulfone ultrafiltration membranes with hollow Fe3O4 nanoparticles. The specific steps of the method are: (1) mixing polyethersulfone, polyvinylpyrrolidone, hollow Fe3O4 nanoparticles with a solvent to obtain a casting solution; (2) using an immersion precipitation method, the ultrafiltration membrane is obtained by coating, phase separation curing, shaping, and cleaning. The hollow Fe3O4 nanoparticle-modified polyethersulfone ultrafiltration membrane prepared by this method has good hydrophilicity, strong antifouling properties, high flux, high rejection rate, and heavy metal adsorption capacity. However, the polyethersulfone ultrafiltration membrane prepared by this invention does not have electrical conductivity; therefore, it needs further improvement. In addition, it also does not have antibacterial function, which will lead to bacteria multiplying on the surface of the polyethersulfone ultrafiltration membrane after use, which will easily clog the polyethersulfone ultrafiltration membrane; therefore, it also needs to be improved. Summary of the Invention

[0004] In order to overcome at least one of the technical problems existing in the prior art, the present invention first provides a method for preparing a conductive polyethersulfone ultrafiltration membrane.

[0005] The above-mentioned technical problem to be solved by the present invention is achieved through the following technical solution:

[0006] A method for preparing a conductive polyethersulfone ultrafiltration membrane, comprising the following steps:

[0007] (1) Mix the raw materials of the conductive polyethersulfone ultrafiltration membrane casting solution to prepare the casting solution;

[0008] (2) The casting solution is coated on the surface of the glass plate, and then transferred to the gel bath for phase inversion to form a membrane. After the membrane is formed, it is immersed in deionized water to obtain the conductive polyethersulfone ultrafiltration membrane.

[0009] The conductive polyethersulfone ultrafiltration membrane casting solution in step (1) contains the following components in parts by weight:

[0010] 10-20 parts of polyethersulfone; 3-6 parts of polyvinylpyrrolidone; 0.05-0.3 parts of nano-ferric oxide; 0.5-2 parts of conductive agent; 75-85 parts of N,N-dimethylformamide.

[0011] This invention adds a conductive agent to the casting solution of a conductive polyethersulfone ultrafiltration membrane, thereby giving the prepared polyethersulfone ultrafiltration membrane a certain conductivity; this facilitates the improvement of the separation capacity of the polyethersulfone ultrafiltration membrane by passing an electric current through it.

[0012] Preferably, the conductive polyethersulfone ultrafiltration membrane casting solution in step (1) comprises the following components in parts by weight:

[0013] 15 parts polyethersulfone; 5 parts polyvinylpyrrolidone; 0.2 parts nano iron oxide; 1 part conductive agent; 80 parts N,N-dimethylformamide.

[0014] Preferably, the conductive agent in the conductive polyethersulfone ultrafiltration membrane casting solution in step (1) is carbon nanotubes.

[0015] Preferably, the conductive polyethersulfone ultrafiltration membrane casting solution in step (1) also contains an antibacterial agent.

[0016] Furthermore, by adding an antibacterial agent to the casting solution of the conductive polyethersulfone ultrafiltration membrane, the present invention can enable the prepared conductive polyethersulfone ultrafiltration membrane to have a certain antibacterial ability.

[0017] More preferably, the antibacterial agent is present in an amount of 0.05 to 0.3 parts by weight.

[0018] Most preferably, the antibacterial agent is present in a weight fraction of 0.1 parts.

[0019] Preferably, the antibacterial agent comprises nano-silver and nano-titanium dioxide.

[0020] The weight ratio of nano-silver to nano-titanium dioxide is 2 to 4:1.

[0021] Most preferably, the weight ratio of nano-silver to nano-titanium dioxide is 3:1.

[0022] Preferably, the antibacterial agent is a modified antibacterial agent, which is prepared by the following method:

[0023] (1) Take nano silver and nano titanium dioxide, and then soak them in an aqueous solution containing sodium dibenzylaminobenzenesulfonate; after soaking, take out the solid and dry it to obtain a pre-treated antibacterial agent mixture;

[0024] (2) The pre-treated antibacterial agent mixture is mixed evenly with a solution containing cocoa oil-based trimethylammonium chloride to obtain a solid-liquid mixture; the solid-liquid mixture is dried to obtain the modified antibacterial agent.

[0025] The inventors discovered in their research that while nano-silver and nano-titanium dioxide possess antibacterial properties, the antibacterial ability of conductive polyethersulfone (PES) ultrafiltration membranes prepared by directly adding them to the casting solution is not strong. To further improve the antibacterial ability of the prepared PES ultrafiltration membranes, the inventors conducted extensive experiments and found that modifying nano-silver and nano-titanium dioxide using the method described in this invention to prepare a modified antibacterial agent, and then adding this agent to the casting solution of the PES ultrafiltration membrane, results in a conductive PES ultrafiltration membrane with excellent antibacterial effects. The antibacterial effect is significantly improved compared to directly adding nano-silver and nano-titanium dioxide.

[0026] The inventors emphasize that the preparation steps of the modified antibacterial agent are crucial. The modified antibacterial agent prepared by first soaking nano-silver and nano-titanium dioxide in an aqueous solution containing sodium dibenzylaminobenzenesulfonate, and then mixing them with a solution containing cocotrimethylammonium chloride, significantly improves the antibacterial effect of the prepared conductive polyethersulfone ultrafiltration membrane. The inventors surprisingly discovered that modified antibacterial agents prepared solely by soaking nano-silver and nano-titanium dioxide in an aqueous solution containing sodium dibenzylaminobenzenesulfonate, or solely by mixing nano-silver and nano-titanium dioxide with a solution containing cocotrimethylammonium chloride, do not significantly improve the antibacterial effect of the prepared conductive polyethersulfone ultrafiltration membrane. The modified antibacterial agent obtained by sequentially modifying nano-silver and nano-titanium dioxide with both sodium dibenzylaminobenzenesulfonate and cocotrimethylammonium chloride synergistically enhances the antibacterial effect of the prepared conductive polyethersulfone ultrafiltration membrane.

[0027] In addition, the order of the preparation steps of the modified antibacterial agent is also very important. The modified antibacterial agent prepared by first mixing nano-silver and nano-titanium dioxide with a solution containing cocoa-based trimethylammonium chloride and then soaking it in an aqueous solution containing sodium dibenzylamine benzyl sulfonate does not significantly improve the antibacterial effect of the prepared conductive polyethersulfone ultrafiltration membrane.

[0028] Preferably, the weight ratio of nano-silver to nano-titanium dioxide in step (1) is 2 to 4:1.

[0029] Most preferably, the weight ratio of nano-silver to nano-titanium dioxide is 3:1.

[0030] Preferably, in step (1), the ratio of the total weight of nano-silver and nano-titanium dioxide to the amount of aqueous solution containing sodium dibenzylaminobenzenesulfonate is 1g:5-10mL.

[0031] Most preferably, in step (1), the ratio of the total weight of nano-silver and nano-titanium dioxide to the amount of aqueous solution containing sodium dibenzylaminobenzenesulfonate is 1g:8mL.

[0032] Preferably, in step (1), the weight percentage of sodium dibenzylaminobenzenesulfonate in the aqueous solution is 20-30%.

[0033] Most preferably, in step (1), the weight percentage of sodium dibenzylaminobenzenesulfonate in the aqueous solution is 25%.

[0034] Preferably, the ratio of the amount of the antibacterial agent mixture in the preliminary treatment in step (2) to the solution containing cocoa oil-based trimethylammonium chloride is 1g: 2-3mL.

[0035] Preferably, in step (2), the weight percentage of cocotrimethylammonium chloride in the solution containing cocotrimethylammonium chloride is 10-20%.

[0036] Most preferably, the weight percentage of cocotrimethylammonium chloride in the solution containing cocotrimethylammonium chloride in step (2) is 15%.

[0037] The present invention also provides a conductive polyethersulfone ultrafiltration membrane prepared by the above preparation method.

[0038] Beneficial Effects: This invention provides a novel method for preparing a conductive polyethersulfone (PES) ultrafiltration membrane. By adding a conductive agent to the casting solution, the prepared PES ultrafiltration membrane acquires a certain level of conductivity, facilitating the improvement of its separation capacity by passing an electric current through the membrane. Furthermore, this invention adds an antibacterial agent to the casting solution, thereby imparting antibacterial properties to the prepared conductive PES ultrafiltration membrane. In particular, the conductive PES ultrafiltration membrane prepared by adding the modified antibacterial agent obtained by the method described in this invention to the casting solution exhibits significantly improved antibacterial effects compared to directly adding nano-silver and nano-titanium dioxide, demonstrating excellent antibacterial performance. Detailed Implementation

[0039] The present invention will be further explained below with reference to specific embodiments, but the embodiments do not limit the present invention in any way.

[0040] The polyethersulfone used in the following examples is BASF brand polyethersulfone with the grade E6020P; other raw materials whose source is not specified are all conventional raw materials that can be purchased by those skilled in the art.

[0041] Example 1: Preparation method of conductive polyethersulfone ultrafiltration membrane

[0042] (1) Mix the raw materials of the conductive polyethersulfone ultrafiltration membrane casting solution evenly to obtain the casting solution;

[0043] (2) The casting solution is coated on the surface of the glass plate, and then transferred to a gel bath (isopropanol) at 25°C for phase inversion to form a membrane. After the membrane is formed, it is immersed in deionized water for 12 hours to obtain the conductive polyethersulfone ultrafiltration membrane.

[0044] The conductive polyethersulfone ultrafiltration membrane casting solution in step (1) contains the following components in parts by weight: 15 parts polyethersulfone; 5 parts polyvinylpyrrolidone; 0.2 parts nano-iron oxide; 1 part multi-walled carbon nanotubes; 0.1 parts antibacterial agent; 80 parts N,N-dimethylformamide;

[0045] The antibacterial agent is composed of nano-silver and nano-titanium dioxide in a weight ratio of 3:1.

[0046] Example 2: Preparation method of conductive polyethersulfone ultrafiltration membrane

[0047] (1) Mix the raw materials of the conductive polyethersulfone ultrafiltration membrane casting solution evenly to obtain the casting solution;

[0048] (2) The casting solution is coated on the surface of the glass plate, and then transferred to a gel bath (isopropanol) at 25°C for phase inversion to form a membrane. After the membrane is formed, it is immersed in deionized water for 12 hours to obtain the conductive polyethersulfone ultrafiltration membrane.

[0049] The conductive polyethersulfone ultrafiltration membrane casting solution in step (1) contains the following components in parts by weight: 15 parts polyethersulfone; 5 parts polyvinylpyrrolidone; 0.2 parts nano-iron oxide; 1 part multi-walled carbon nanotubes; 0.1 parts modified antibacterial agent; 80 parts N,N-dimethylformamide;

[0050] The modified antibacterial agent is prepared by the following method:

[0051] (1) Take nano silver and nano titanium dioxide in a weight ratio of 3:1, and then add them to an aqueous solution containing 25% sodium dibenzylaminobenzenesulfonate and soak for 1 hour; after soaking, take out the solid and dry it to obtain a pre-treated antibacterial agent mixture; wherein, the total weight of nano silver and nano titanium dioxide to the amount of aqueous solution containing sodium dibenzylaminobenzenesulfonate is 1g:8mL.

[0052] (2) The pre-treated antibacterial agent mixture is mixed evenly with a methanol solution containing 15% by weight of cocoa-trimethylammonium chloride to obtain a solid-liquid mixture; the solid-liquid mixture is dried to obtain the modified antibacterial agent; wherein the ratio of the amount of the pre-treated antibacterial agent mixture to the methanol solution containing cocoa-trimethylammonium chloride is 1g:3mL.

[0053] Example 3: Preparation method of conductive polyethersulfone ultrafiltration membrane

[0054] (1) Mix the raw materials of the conductive polyethersulfone ultrafiltration membrane casting solution evenly to obtain the casting solution;

[0055] (2) The casting solution is coated on the surface of the glass plate, and then transferred to a gel bath (isopropanol) at 25°C for phase inversion to form a membrane. After the membrane is formed, it is immersed in deionized water for 12 hours to obtain the conductive polyethersulfone ultrafiltration membrane.

[0056] The conductive polyethersulfone ultrafiltration membrane casting solution in step (1) contains the following components in parts by weight: 20 parts polyethersulfone; 3 parts polyvinylpyrrolidone; 0.05 parts nano iron oxide; 0.5 parts multi-walled carbon nanotubes; 0.3 parts modified antibacterial agent; 85 parts N,N-dimethylformamide;

[0057] The modified antibacterial agent is prepared by the following method:

[0058] (1) Take nano silver and nano titanium dioxide in a weight ratio of 4:1, and then add them to an aqueous solution containing 20% ​​sodium dibenzylaminobenzenesulfonate and soak for 1 hour; after soaking, take out the solid and dry it to obtain a pre-treated antibacterial agent mixture; wherein, the total weight of nano silver and nano titanium dioxide to the amount of aqueous solution containing sodium dibenzylaminobenzenesulfonate is 1g:10mL.

[0059] (2) The pre-treated antibacterial agent mixture is mixed evenly with a methanol solution containing 10% by weight of cocoa-trimethylammonium chloride to obtain a solid-liquid mixture; the solid-liquid mixture is dried to obtain the modified antibacterial agent; wherein the ratio of the amount of the pre-treated antibacterial agent mixture to the methanol solution containing cocoa-trimethylammonium chloride is 1g:2mL.

[0060] Example 4: Preparation method of conductive polyethersulfone ultrafiltration membrane

[0061] (1) Mix the raw materials of the conductive polyethersulfone ultrafiltration membrane casting solution evenly to obtain the casting solution;

[0062] (2) The casting solution is coated on the surface of the glass plate, and then transferred to a gel bath (isopropanol) at 25°C for phase inversion to form a membrane. After the membrane is formed, it is immersed in deionized water for 12 hours to obtain the conductive polyethersulfone ultrafiltration membrane.

[0063] The conductive polyethersulfone ultrafiltration membrane casting solution in step (1) contains the following components in parts by weight: 10 parts polyethersulfone; 6 parts polyvinylpyrrolidone; 0.3 parts nano-iron oxide; 2 parts multi-walled carbon nanotubes; 0.05 parts modified antibacterial agent; 75 parts N,N-dimethylformamide;

[0064] The modified antibacterial agent is prepared by the following method:

[0065] (1) Take nano silver and nano titanium dioxide in a weight ratio of 2:1, and then add them to an aqueous solution containing 20% ​​sodium dibenzylaminobenzenesulfonate and soak for 1 hour; after soaking, take out the solid and dry it to obtain a pre-treated antibacterial agent mixture; wherein, the total weight of nano silver and nano titanium dioxide to the amount of aqueous solution containing sodium dibenzylaminobenzenesulfonate is 1 g: 5 mL.

[0066] (2) The pre-treated antibacterial agent mixture is mixed evenly with a methanol solution containing 20% ​​by weight of cocoa-based trimethylammonium chloride to obtain a solid-liquid mixture; the solid-liquid mixture is dried to obtain the modified antibacterial agent; wherein the ratio of the amount of the pre-treated antibacterial agent mixture to the methanol solution containing cocoa-based trimethylammonium chloride is 1g:3mL.

[0067] Comparative Example 1: Preparation method of conductive polyethersulfone ultrafiltration membrane

[0068] (1) Mix the raw materials of the conductive polyethersulfone ultrafiltration membrane casting solution evenly to obtain the casting solution;

[0069] (2) The casting solution is coated on the surface of the glass plate, and then transferred to a gel bath (isopropanol) at 25°C for phase inversion to form a membrane. After the membrane is formed, it is immersed in deionized water for 12 hours to obtain the conductive polyethersulfone ultrafiltration membrane.

[0070] The conductive polyethersulfone ultrafiltration membrane casting solution in step (1) contains the following components in parts by weight: 15 parts polyethersulfone; 5 parts polyvinylpyrrolidone; 0.2 parts nano-iron oxide; 1 part multi-walled carbon nanotubes; 0.1 parts modified antibacterial agent; 80 parts N,N-dimethylformamide;

[0071] The modified antibacterial agent is prepared by the following method:

[0072] Take nano-silver and nano-titanium dioxide in a weight ratio of 3:1, and then soak them in an aqueous solution containing 25% by weight of sodium dibenzylaminobenzenesulfonate for 1 hour; after soaking, take out the solid and dry it to obtain the modified antibacterial agent; wherein, the total weight of nano-silver and nano-titanium dioxide to the amount of aqueous solution containing sodium dibenzylaminobenzenesulfonate is 1g:8mL.

[0073] Comparative Example 2: Preparation method of conductive polyethersulfone ultrafiltration membrane

[0074] (1) Mix the raw materials of the conductive polyethersulfone ultrafiltration membrane casting solution evenly to obtain the casting solution;

[0075] (2) The casting solution is coated on the surface of the glass plate, and then transferred to a gel bath (isopropanol) at 25°C for phase inversion to form a membrane. After the membrane is formed, it is immersed in deionized water for 12 hours to obtain the conductive polyethersulfone ultrafiltration membrane.

[0076] The conductive polyethersulfone ultrafiltration membrane casting solution in step (1) contains the following components in parts by weight: 15 parts polyethersulfone; 5 parts polyvinylpyrrolidone; 0.2 parts nano-iron oxide; 1 part multi-walled carbon nanotubes; 0.1 parts modified antibacterial agent; 80 parts N,N-dimethylformamide;

[0077] The modified antibacterial agent is prepared by the following method: nano-silver and nano-titanium dioxide in a weight ratio of 3:1 are mixed evenly with a methanol solution containing 15% by weight of cocoyltrimethylammonium chloride to obtain a solid-liquid mixture; the solid-liquid mixture is dried to obtain the modified antibacterial agent; wherein, the total weight ratio of nano-silver and nano-titanium dioxide to the amount of methanol solution containing cocoyltrimethylammonium chloride is 1g:3mL.

[0078] Comparative Example 3: Preparation method of conductive polyethersulfone ultrafiltration membrane

[0079] (1) Mix the raw materials of the conductive polyethersulfone ultrafiltration membrane casting solution evenly to obtain the casting solution;

[0080] (2) The casting solution is coated on the surface of the glass plate, and then transferred to a gel bath (isopropanol) at 25°C for phase inversion to form a membrane. After the membrane is formed, it is immersed in deionized water for 12 hours to obtain the conductive polyethersulfone ultrafiltration membrane.

[0081] The conductive polyethersulfone ultrafiltration membrane casting solution in step (1) contains the following components in parts by weight: 15 parts polyethersulfone; 5 parts polyvinylpyrrolidone; 0.2 parts nano-iron oxide; 1 part multi-walled carbon nanotubes; 0.1 parts modified antibacterial agent; 80 parts N,N-dimethylformamide;

[0082] The modified antibacterial agent is prepared by the following method:

[0083] (1) Take nano silver and nano titanium dioxide in a weight ratio of 3:1 and mix them evenly with a methanol solution containing 15% by weight of cocoa oil-based trimethyl ammonium chloride to obtain a solid-liquid mixture; after drying the solid-liquid mixture, a pre-treated antibacterial agent mixture is obtained; wherein, the total weight of nano silver and nano titanium dioxide to the amount of solution containing cocoa oil-based trimethyl ammonium chloride is 1g:3mL.

[0084] (2) The pre-treated antibacterial agent mixture is added to an aqueous solution containing 25% by weight of sodium dibenzylaminobenzenesulfonate and soaked for 1 hour; after soaking, the solid is removed and dried to obtain the modified antibacterial agent; wherein, the ratio of the amount of the pre-treated antibacterial agent mixture to the aqueous solution containing sodium dibenzylaminobenzenesulfonate is 1 g: 8 mL.

[0085] The conductive polyethersulfone ultrafiltration membranes prepared in Examples 1-4 and Comparative Examples 1-3 were tested for their antibacterial performance against Staphylococcus aureus and Escherichia coli according to the test method for antibacterial properties of antibacterial plastics in QB / T2591-2003; the specific results are shown in Table 1.

[0086] Table 1.

[0087]

[0088] As can be seen from the experimental data in Table 1, the conductive polyethersulfone ultrafiltration membrane prepared by directly adding nano-silver and nano-titanium dioxide to the casting solution of the conductive polyethersulfone ultrafiltration membrane has a certain antibacterial ability, but its antibacterial ability is not strong.

[0089] As can be seen from the experimental data in Table 1, the conductive polyethersulfone ultrafiltration membranes prepared in Examples 2-4 exhibit significantly improved antibacterial activity compared to Example 1, demonstrating excellent antibacterial performance. This indicates that the conductive polyethersulfone ultrafiltration membranes prepared by modifying nano-silver and nano-titanium dioxide using the method described in this invention and adding the modified antibacterial agent to the casting solution of the conductive polyethersulfone ultrafiltration membrane exhibit excellent antibacterial effects, which are significantly improved compared to directly adding nano-silver and nano-titanium dioxide.

[0090] As can be seen from the experimental data in Table 1, the antibacterial ability of the conductive polyethersulfone ultrafiltration membranes prepared in Comparative Examples 1-3 is not significantly improved compared to Example 1, and is far less than that of Example 2. This indicates that the preparation steps of the modified antibacterial agent are crucial. Modified antibacterial agents prepared by simply soaking nano-silver and nano-titanium dioxide in an aqueous solution containing sodium dibenzylaminobenzenesulfonate, or by simply mixing nano-silver and nano-titanium dioxide with a solution containing cocoyltrimethylammonium chloride, cannot significantly improve the antibacterial effect of the prepared conductive polyethersulfone ultrafiltration membrane. Furthermore, the order of the preparation steps is also very important. Modified antibacterial agents prepared by first mixing nano-silver and nano-titanium dioxide with a solution containing cocoyltrimethylammonium chloride, and then soaking them in an aqueous solution containing sodium dibenzylaminobenzenesulfonate, also cannot significantly improve the antibacterial effect of the prepared conductive polyethersulfone ultrafiltration membrane. To significantly improve the antibacterial effect of the prepared conductive polyethersulfone ultrafiltration membrane, it is necessary to first soak nano-silver and nano-titanium dioxide in an aqueous solution containing sodium dibenzylaminobenzenesulfonate, and then mix them with a solution containing cocotrimethylammonium chloride. The modified antibacterial agent obtained by sequentially modifying nano-silver and nano-titanium dioxide with both sodium dibenzylaminobenzenesulfonate and cocotrimethylammonium chloride can synergistically enhance the antibacterial effect of the prepared conductive polyethersulfone ultrafiltration membrane.

Claims

1. A method for preparing a conductive polyethersulfone ultrafiltration membrane, comprising the following steps: (1) Mix the raw materials of the conductive polyethersulfone ultrafiltration membrane casting solution to prepare the casting solution; (2) The casting solution is coated on the surface of the glass plate, and then transferred to the gel bath for phase inversion to form a membrane. After the membrane is formed, it is immersed in deionized water to obtain the conductive polyethersulfone ultrafiltration membrane. characterized in that The conductive polyethersulfone ultrafiltration membrane casting solution in step (1) contains the following components in parts by weight: Polyethersulfone 10-20 parts; polyvinylpyrrolidone 3-6 parts; nano-ferric oxide 0.05-0.3 parts; conductive agent 0.5-2 parts; N,N-dimethylformamide 75-85 parts; The conductive polyethersulfone ultrafiltration membrane casting solution in step (1) also contains an antibacterial agent; The antibacterial agent is a modified antibacterial agent, which is prepared by the following method: (1) Take nano silver and nano titanium dioxide, and then soak them in an aqueous solution containing sodium dibenzylaminobenzenesulfonate; after soaking, take out the solid and dry it to obtain a pre-treated antibacterial agent mixture; (2) The pre-treated antibacterial agent mixture is mixed evenly with a solution containing cocoa oil-based trimethylammonium chloride to obtain a solid-liquid mixture; the solid-liquid mixture is dried to obtain the modified antibacterial agent.

2. The method for preparing the conductive polyethersulfone ultrafiltration membrane according to claim 1, characterized in that, In step (1), the conductive agent in the conductive polyethersulfone ultrafiltration membrane casting solution is carbon nanotubes.

3. The method for preparing the conductive polyethersulfone ultrafiltration membrane according to claim 1, characterized in that, The antibacterial agent is present in parts by weight of 0.05 to 0.3 parts.

4. The method for preparing the conductive polyethersulfone ultrafiltration membrane according to claim 1, characterized in that, In step (1), the weight ratio of nano-silver to nano-titanium dioxide is 2~4:

1.

5. The method for preparing the conductive polyethersulfone ultrafiltration membrane according to claim 1, characterized in that, In step (1), the ratio of the total weight of nano-silver and nano-titanium dioxide to the amount of aqueous solution containing sodium dibenzylaminobenzenesulfonate is 1g:5~10mL.

6. The method for preparing the conductive polyethersulfone ultrafiltration membrane according to claim 1, characterized in that, In step (2), the ratio of the amount of the antibacterial agent mixture used in the preliminary treatment to the solution containing coconut oil-based trimethylammonium chloride is 1g: 2~3mL.

7. The conductive polyethersulfone ultrafiltration membrane prepared by the preparation method according to any one of claims 1 to 6.

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