Reverse osmosis membrane with a polyethylene glycol-branched cyclodextrin-resveratrol antifouling coating

Abstract

The present invention discloses a reverse osmosis membrane with a polyethylene glycol-branched cyclodextrin-resveratrol anti-fouling coating. The surface of the reverse osmosis membrane is coated with an anti-fouling coating. The preparation method of the anti-fouling coating is as follows: Preparation of cyclodextrin-resveratrol inclusion complex: Resveratrol is dissolved in ethanol, and cyclodextrin is dissolved in ultrapure water. A quantitative resveratrol solution is added dropwise to the cyclodextrin solution. After mixing evenly, the solvent is removed to obtain a cyclodextrin-resveratrol inclusion complex; The cyclodextrin-resveratrol inclusion complex and activated polyethylene glycol are dispersed in acetonitrile, heated under reflux, reacted, and the solvent is evaporated to obtain a polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex; The polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex is dissolved in water, epichlorohydrin is added, and the pH value is adjusted using a pH regulator. After mixing evenly, a coating solution is prepared. The present invention has excellent stability, and after the existing reverse osmosis membrane is coated with this anti-fouling coating, the flux decay of the membrane sheet is small.

Description

Technical Field

[0001] The present invention relates to the technical field of reverse osmosis membranes, and particularly to a reverse osmosis membrane with a polyethylene glycol-branched cyclodextrin-resveratrol anti-fouling coating. Background Art

[0002] Due to its functions of separation, concentration, purification, and refinement, and its characteristics of high efficiency, energy conservation, environmental protection, and easy control, membrane separation technology has been widely applied in the fields of food, medicine, etc., generating huge economic and social benefits, and has become one of the most important means in separation science today.

[0003] Reverse osmosis technology is a technology that separates substances through a pressure-driven membrane. According to the selective permeability of the reverse osmosis membrane that only allows water molecules to pass through while retaining ionic substances or small molecule substances, with the pressure difference across the membrane as the driving force, the separation of the mixture is achieved. During the actual operation of the reverse osmosis membrane, due to the complexity of water quality and the variability of the environment, a layer of contaminants is easily attached to its surface, thereby greatly reducing the separation effect of the reverse osmosis membrane.

[0004] Defects and deficiencies of the prior art:

[0005] In order to reduce membrane fouling, hydrophilic modification is generally carried out on the surface of the polyamide desalination layer during the production of reverse osmosis membranes to reduce the hydrophobicity of the membrane surface and reduce the fouling of some substances. The existing production process usually selects water-soluble polymers, such as directly performing hydrophilic modification on the surface of the reverse osmosis membrane using polyvinyl alcohol (PVA). Due to the good water solubility of polyvinyl alcohol, it is unstable on the surface of reverse osmosis polyamide and is easily detached; in order to fix the polyvinyl alcohol molecules, a cross-linking agent is used to cross-link them to form a dense network structure, but after the reverse osmosis membrane is coated with the cross-linked polyvinyl alcohol coating, its water flux will be greatly reduced, affecting the performance of the reverse osmosis membrane. Summary of the Invention

[0006] The present invention provides a reverse osmosis membrane with a polyethylene glycol-branched resveratrol-cyclodextrin anti-fouling coating. This anti-fouling reverse osmosis membrane is realized by preparing a layer of polyethylene glycol-branched resveratrol-cyclodextrin coating on the surface of a commercial reverse osmosis membrane sheet; compared with the traditional polyvinyl alcohol coating, this coating has excellent stability, and after the existing reverse osmosis membrane is coated with this anti-fouling coating, the flux decay of the membrane sheet is small.

[0007] To solve the above technical problems, one technical solution adopted by the present invention is: The present invention provides a reverse osmosis membrane with a polyethylene glycol-branched cyclodextrin-resveratrol anti-fouling coating, and the surface of the reverse osmosis membrane is coated with a polyethylene glycol-branched cyclodextrin-resveratrol anti-fouling coating. The preparation method of the anti-fouling coating is as follows:

[0008] S1. Preparation of cyclodextrin-resveratrol inclusion complex: Resveratrol is dissolved in ethanol, and cyclodextrin is dissolved in ultrapure water. A quantitative resveratrol solution is added dropwise to the cyclodextrin solution. After mixing evenly, the solvent is removed (using a vacuum rotary evaporator) to obtain the cyclodextrin-resveratrol inclusion complex;

[0009] S2. The cyclodextrin-resveratrol inclusion complex and activated polyethylene glycol are dispersed in acetonitrile (CH3CN), heated under reflux (reflux), reacted, and the solvent is evaporated to obtain a polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex;

[0010] S3. The polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex is dissolved in water, epichlorohydrin is added, and the pH value is adjusted to 9.0 - 12.50 using a pH regulator. After mixing evenly, a coating solution is prepared for standby.

[0011] Furthermore, the step S4 of coating the membrane solution prepared in step S3 onto the reverse osmosis membrane is as follows:

[0012] S4. The coating solution in step S3 is coated on the surface of a commercial reverse osmosis membrane. After drying, a reverse osmosis membrane with a polyethylene glycol-branched resveratrol-cyclodextrin anti-fouling coating is obtained.

[0013] Furthermore, the cyclodextrin is selected from at least one of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, methyl-β-cyclodextrin, sulfobutyl-β-cyclodextrin, hydroxyethyl-β-cyclodextrin, and hydroxypropyl-β-cyclodextrin, but is not limited thereto.

[0014] Furthermore, in step S1: 2.0 - 10.0 g of resveratrol is dissolved in 50 mL of ethanol, and 4.0 - 10.0 g of cyclodextrin is dissolved in 50 mL of ultrapure water.

[0015] Furthermore, the method for activating polyethylene glycol in step S2 is: Polyethylene glycol (PEG) is dissolved in tetrahydrofuran (THF), p-toluenesulfonyl chloride (TsCl) is added, the pH value is adjusted to 9.0 - 13.0 using a pH regulator, and the reaction is carried out (for example, reacting for 24 h in an environment of 0 °C). After removing the solvent, activated polyethylene glycol molecules (PEG-OTs) are obtained.

[0016] Preferably, the method for activating polyethylene glycol in step S2 is: 0.5 - 5.0 g of polyethylene glycol with a molecular weight of 200 (PEG200 - 6000) is dissolved in 100 mL of tetrahydrofuran (THF), 0.1 - 0.8 g of p-toluenesulfonyl chloride (TsCl) is added, the pH value is adjusted to 9.0 - 13.0, and after reacting for 24 h in an environment of 0 °C, the solvent is evaporated using a vacuum rotary evaporator to obtain activated polyethylene glycol molecules (PEG-OTs).

[0017] Furthermore, the pH regulator is an alkaline substance, which is selected from at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, sodium carbonate, sodium ethoxide, and sodium phenoxide, but is not limited thereto.

[0018] Furthermore, the molecular weight of the polyethylene glycol molecule is between 200 and 6000.

[0019] Furthermore, step S2 is as follows: 4.0 - 10.0 g of cyclodextrin-resveratrol inclusion complex and 0.4 g - 1.0 g of activated polyethylene glycol are dispersed in 100 mL of acetonitrile (CH3CN), heated under reflux, and after reacting for 24 h, the solvent is removed by a vacuum rotary evaporator to obtain a polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex.

[0020] Furthermore, step S3 is specifically as follows: 2.0 - 5.0 g of the polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex is dissolved in 100 mL of water, 1.0 g - 2.5 g of epichlorohydrin is added, the pH value is adjusted to 9.0 - 12.50 using sodium hydroxide, and after mixing evenly, a coating solution is prepared for standby.

[0021] Furthermore, the thickness of the coating solution in step S4 is 10 - 50 μm.

[0022] Preferably, the thickness of the coating solution is 20 μm.

[0023] Furthermore, in step S4, drying is performed by drying in an oven, and the drying temperature is 70 °C, but is not limited thereto.

[0024] The beneficial effects of the present invention are as follows:

[0025] For the traditional polyvinyl alcohol anti-fouling coating, the anti-fouling coating involved in the present invention has excellent stability; after the traditional polyvinyl alcohol anti-fouling coating is impacted by water flow, the coating will fall off, and thus lose the anti-pollution function, because the cyclodextrin structure provides a large number of hydroxyl groups, which is beneficial to improving the hydrophilicity of the coating;

[0026] For the traditional cross-linked polyvinyl alcohol anti-fouling coating, the anti-fouling coating prepared by the present invention has a small impact on the water flux of the reverse osmosis membrane; although the traditional cross-linked polyvinyl alcohol coating has excellent stability, the water flux of the reverse osmosis membrane will be greatly attenuated after coating this coating, which has a negative impact on the use of the reverse osmosis membrane, while the polyethylene glycol-branched resveratrol-cyclodextrin anti-fouling coating has a small impact on the water flux of the reverse osmosis membrane, because the cyclodextrin molecule has a hollow frustum-shaped three-dimensional structure with an inner hydrophobic cavity and an outer hydrophilic edge, and this unique structure has extremely small resistance to water molecules during the separation process, thereby reducing the negative impact on the water flux of the reverse osmosis membrane.

[0027] In addition, after the resveratrol molecule is branched by polyethylene glycol, a chain molecular brush is introduced on the surface of the coating. This unique molecular brush structure can effectively reduce the attachment of pollutants such as microorganisms and colloidal particles on the surface of the reverse osmosis membrane, producing an effect similar to that of aquatic plants, thereby enhancing the anti-fouling ability of the surface of the reverse osmosis membrane.

[0028] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly and to be implemented in accordance with the content of the specification, the following will be described in detail with reference to the preferred embodiments of the present invention and the accompanying drawings. Brief Description of the Drawings

[0029] Figure 1 is the design schematic diagram of the reverse osmosis membrane of the present invention;

[0030] Figure 2 is the SEM image of the reverse osmosis membrane with a polyethylene glycol-branched resveratrol-cyclodextrin anti-fouling coating before alkali treatment of the present invention;

[0031] Figure 3 is the SEM image of the reverse osmosis membrane with a polyethylene glycol-branched resveratrol-cyclodextrin anti-fouling coating after alkali treatment of the present invention. Detailed Description of the Invention

[0032] The following specific embodiments illustrate the specific implementation manners of the present invention. Those skilled in the art can easily understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented in other different ways, that is, without departing from the scope disclosed by the present invention, different modifications and changes can be made.

[0033] Example: A reverse osmosis membrane with a polyethylene glycol-branched cyclodextrin-resveratrol anti-fouling coating, the surface of the reverse osmosis membrane is coated with a polyethylene glycol-branched cyclodextrin-resveratrol anti-fouling coating, as Figure 1 shown, the preparation method of the anti-fouling coating is as follows:

[0034] S1. Preparation of cyclodextrin-resveratrol inclusion complex: Resveratrol is dissolved in ethanol, and cyclodextrin is dissolved in ultrapure water. A quantitative resveratrol solution is added dropwise to the cyclodextrin solution. After mixing evenly, the solvent is removed (the vacuum rotary evaporator can be used) to obtain a cyclodextrin-resveratrol inclusion complex;

[0035] S2. The cyclodextrin-resveratrol inclusion complex and activated polyethylene glycol are dispersed in acetonitrile (CH3CN), heated under reflux, reacted, and the solvent is evaporated to obtain a polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex;

[0036] S3. Dissolve the polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex in water, add epichlorohydrin, use a pH regulator to adjust the pH value to 9.0 - 12.50. After mixing evenly, prepare a coating solution for standby.

[0037] Step S4 of coating the membrane solution prepared in step S3 onto the reverse osmosis membrane is as follows:

[0038] S4. Coat the coating solution in step S3 onto the surface of a commercial reverse osmosis membrane. After drying, obtain a reverse osmosis membrane with a polyethylene glycol-branched resveratrol-cyclodextrin anti-fouling coating. Specific Example 1:

[0040] S1. Dissolve 5.0 g of resveratrol in 50 mL of ethanol, dissolve 8.0 g of cyclodextrin in 50 mL of ultrapure water. Slowly drop the resveratrol solution into the cyclodextrin solution, mix evenly, and use a vacuum rotary evaporator to evaporate the solvent to obtain a cyclodextrin-resveratrol inclusion complex;

[0041] Dissolve 2.0 g of polyethylene glycol (PEG200) with a molecular weight of 200 in 100 mL of tetrahydrofuran (THF), add 0.5 g of p-toluenesulfonyl chloride (TsCl), use sodium hydroxide (NaOH) to adjust the pH value to 10.0, react for 24 h in a 0 °C environment, and then use a vacuum rotary evaporator to evaporate the solvent to obtain an activated polyethylene glycol molecule (PEG-OTs);

[0042] S2. Disperse 10.0 g of the cyclodextrin-resveratrol inclusion complex and 1.0 g of the activated polyethylene glycol in 100 mL of acetonitrile (CH3CN), heat under reflux, react for 24 h, and then use a vacuum rotary evaporator to evaporate the solvent to obtain a polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex;

[0043] S3. Dissolve 5.0 g of the polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex in 100 mL of water, add 2.5 g of epichlorohydrin, use sodium hydroxide (NaOH) to adjust the pH value to 10.0, mix evenly, and prepare a coating solution for standby;

[0044] S4. Uniformly coat the coating solution in step S3 onto the surface of a commercial reverse osmosis membrane. The thickness of the coating solution is about 20 μm. After drying in an oven at 70 °C, obtain a reverse osmosis membrane with a polyethylene glycol-branched resveratrol-cyclodextrin anti-fouling coating.

[0045] Example 2:

[0046] Change the amount of resveratrol in step S1 of Example 1 from 5.0 g to 2.5 g, keep other steps unchanged and the raw materials unchanged, and obtain a reverse osmosis membrane with a polyethylene glycol-branched resveratrol-cyclodextrin anti-fouling coating.

[0047] Example 3:

[0048] Replace the polyethylene glycol (PEG200) with a molecular weight of 200 in step S1 of Example 1 with polyethylene glycol (PEG1000) with a molecular weight of 1000, keep other steps unchanged and the raw materials unchanged, and obtain a reverse osmosis membrane with a polyethylene glycol-branched resveratrol-cyclodextrin anti-fouling coating.

[0049] Example 4:

[0050] Change the coating solution thickness of 20 μm in step S4 of Example 1 to a coating solution thickness of 40 μm, keep other steps unchanged and the raw materials unchanged, and obtain a reverse osmosis membrane with a polyethylene glycol-branched resveratrol-cyclodextrin anti-fouling coating.

[0051] Comparative Example 1:

[0052] 1. Dissolve 5.0 g of polyvinyl alcohol in 100 mL of water, mix well, and prepare a coating solution for standby;

[0053] 2. Uniformly coat the coating solution in step 1 on the surface of a commercial reverse osmosis membrane, with a coating solution thickness of about 20 μm. After drying in an oven at 70 °C, obtain a reverse osmosis membrane with a polyvinyl alcohol anti-fouling coating, which is Comparative Sample 1.

[0054] Comparative Example 2:

[0055] 1. Dissolve 5.0 g of polyvinyl alcohol in 100 mL of water, add 1.0 g of glutaraldehyde, adjust the pH value to 3.0 with sulfuric acid, mix well, and prepare a coating solution for standby;

[0056] 2. Uniformly coat the coating solution in step S1 on the surface of a commercial reverse osmosis membrane, with a coating solution thickness of about 20 μm. After drying in an oven at 70 °C, obtain a reverse osmosis membrane with a cross-linked polyvinyl alcohol anti-fouling coating, which is Comparative Sample 2.

[0057] Performance Test

[0058] Perform performance tests on the reverse osmosis membranes modified in the above examples and comparative examples, including surface performance, water treatment performance, and stability.

[0059] a. Conduct surface static water contact angle tests and surface Zeta potential tests on the membrane before and after rinsing, and the results are shown in Table 1.

[0060] Table 1 Surface Performance of Reverse Osmosis Membranes Modified in Examples and Comparative Examples

[0061]

[0062] As can be seen from Table 1, the static water contact angle of the reverse osmosis membrane sheet coated with the anti-fouling coating is about 30.0°, and the Zeta potential value is between -10 mV and -15 mV, which conforms to the hydrophilicity and charge properties of the surface of a conventional anti-fouling reverse osmosis membrane; after being rinsed with pure water, the contact angle and Zeta potential value of the polyvinyl alcohol anti-fouling coating increase, indicating that the polyvinyl alcohol anti-fouling coating on the surface of the reverse osmosis membrane has been washed off, and the anti-fouling performance will decrease during operation; the contact angle and Zeta potential value of the cross-linked polyvinyl alcohol anti-fouling coating and the polyethylene glycol-branched resveratrol-cyclodextrin anti-fouling coating do not change significantly, indicating that the coating still exists and the coating stability is good.

[0063] b. Water treatment performance test conditions: On a cross-flow test bench, using an aqueous solution of 2000 ppm NaCl and 50 ppm cetyltrimethylammonium bromide as the test solution, at an operating pressure of 225 psi, a temperature of 25 °C, and a pH value of 6.5 - 7.5, the water production (m0) and salt rejection rate of the membrane sheet are tested. After continuous operation for 12 hours, the water production (m1) of the membrane sheet is tested; then, after rinsing the membrane sheet with hydrochloric acid solution (pH = 2) and sodium hydroxide solution (pH = 12) in sequence, the water production (m2) of the membrane sheet is tested. The anti-fouling performance of the membrane sheet is investigated by calculating the flux loss rate and flux recovery rate. The less the flux decays after operation, the better the anti-fouling performance. Flux loss rate = (1 - m1 / m0) × 100%, Flux recovery rate = m2 / m0 × 100%. The results are shown in Table 2.

[0064] Table 2 Water treatment performance of the reverse osmosis membranes obtained by modification in the examples and comparative examples

[0065]

[0066] According to the data in Table 2, comparing the initial performance among various cases, except for the reverse osmosis membrane with a cross-linked polyvinyl alcohol coating (Comparative Example 2), the water flux of the reverse osmosis membranes with other coatings is between 42 - 46 GFD, and the salt rejection rate is higher than 99.5%. In contrast, the water flux and salt rejection rate of the reverse osmosis membrane with a cross-linked polyvinyl alcohol coating are lower. This is because the network structure of cross-linked polyvinyl alcohol is dense, resulting in a large resistance to water molecules, thus reducing the water flux of the membrane sheet. Moreover, during the preparation process of the cross-linked polyvinyl alcohol coating, sulfuric acid solution is used to adjust the pH value. Sulfuric acid is a non-volatile acid, and after the subsequent drying of the membrane sheet, it will cause the local acid concentration of the membrane sheet to be too high, damaging the separation layer and thus reducing the salt rejection rate of the membrane sheet.

[0067] Deeply compare the flux decline rate after the diaphragm operates for 12 h and the flux recovery rate after cleaning; except for the polyvinyl alcohol-coated reverse osmosis membrane (Comparative Example 1), the flux decline rate of the reverse osmosis membranes with other coatings after operating for 12 h is lower than 13.5%, and the flux recovery rate after cleaning is higher than 95%; the polyvinyl alcohol coating will be washed off during operation, so its anti-pollution performance is poor. In addition, the flux decline rate and the flux recovery rate after cleaning of the anti-pollution coating involved in this patent are higher than those of the traditional anti-pollution coating (polyvinyl alcohol-based coating), which also proves that the reverse osmosis membrane with the anti-pollution coating of polyethylene glycol-branched resveratrol-cyclodextrin of the present invention has excellent anti-pollution effect.

[0068] C. Observation of the stability of the anti-pollution coating

[0069] Immerse the reverse osmosis membrane with the anti-pollution coating of polyethylene glycol-branched resveratrol-cyclodextrin in a 4% sodium hydroxide solution for 150 h, and observe the microscopic structure of the coating on the surface of the membrane before and after the alkali treatment (as Figure 2 and Figure 3 shown); by comparison, it is found that before and after the alkali treatment, the anti-pollution coating of polyethylene glycol-branched resveratrol-cyclodextrin exists on the surface of the membrane, and there is no obvious change in the surface morphology of the membrane, which proves that: the anti-pollution coating of polyethylene glycol-branched resveratrol-cyclodextrin has excellent stability.

[0070] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure made by using the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A reverse osmosis membrane with a polyethylene glycol-branched cyclodextrin-resveratrol anti-fouling coating, characterized in that: The surface of the reverse osmosis membrane is coated with a polyethylene glycol-branched cyclodextrin-resveratrol anti-fouling coating, and the preparation method of the anti-fouling coating is as follows: S1. Preparation of cyclodextrin-resveratrol inclusion complex: Resveratrol is dissolved in ethanol, and cyclodextrin is dissolved in ultrapure water. A quantitative resveratrol solution is added dropwise to the cyclodextrin solution. After mixing evenly, the solvent is removed to obtain a cyclodextrin-resveratrol inclusion complex; S2. The cyclodextrin-resveratrol inclusion complex and activated polyethylene glycol are dispersed in acetonitrile, heated under reflux, reacted, and the solvent is evaporated to obtain a polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex; S3. The polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex is dissolved in water, epichlorohydrin is added, and the pH value is adjusted to 9.0 - 12.50 with a pH regulator. After mixing evenly, a coating solution is prepared for standby; The step of coating the membrane solution prepared in step S3 onto the reverse osmosis membrane is as follows: S4. The coating solution in step S3 is coated on the surface of a commercial reverse osmosis membrane. After drying, a reverse osmosis membrane with a polyethylene glycol-branched resveratrol-cyclodextrin anti-fouling coating is obtained; Among them, the method for activating polyethylene glycol in step S2 is: Polyethylene glycol is dissolved in tetrahydrofuran, p-toluenesulfonyl chloride is added, the pH value is adjusted to 9.0 - 13.0 with a pH regulator, and after reaction, the solvent is removed to obtain activated polyethylene glycol molecules.

2. The reverse osmosis membrane with a polyethylene glycol-branched cyclodextrin-resveratrol antifouling coating according to claim 1, wherein: The cyclodextrin is selected from at least one of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, methyl-β-cyclodextrin, sulfobutyl-β-cyclodextrin, hydroxyethyl-β-cyclodextrin, and hydroxypropyl-β-cyclodextrin.

3. The reverse osmosis membrane with a polyethylene glycol-branched cyclodextrin-resveratrol antifouling coating according to claim 1, characterized in that: In step S1: 2.0 - 10.0 g of resveratrol is dissolved in 50 mL of ethanol, and 4.0 - 10.0 g of cyclodextrin is dissolved in 50 mL of ultrapure water.

4. The reverse osmosis membrane with a polyethylene glycol-branched cyclodextrin-resveratrol anti-fouling coating according to claim 1, characterized in that: The pH regulator is an alkaline substance, and the alkaline substance is selected from at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, sodium carbonate, sodium ethoxide, and sodium phenoxide.

5. The reverse osmosis membrane with a polyethylene glycol-branched cyclodextrin-resveratrol anti-fouling coating according to claim 1, characterized in that: The molecular weight of the polyethylene glycol molecule is between 200 and 6000.

6. The reverse osmosis membrane with a polyethylene glycol-branched cyclodextrin-resveratrol anti-fouling coating according to claim 1, characterized in that: Step S2: 4.0 g - 10.0 g of the cyclodextrin-resveratrol inclusion complex and 0.4 g - 1.0 g of activated polyethylene glycol are dispersed in 100 mL of acetonitrile, heated under reflux, reacted for 24 h, and then the solvent is evaporated using a vacuum rotary evaporator to obtain a polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex.

7. The reverse osmosis membrane with a polyethylene glycol-branched cyclodextrin-resveratrol antifouling coating according to claim 1, characterized in that: Step S3 specifically: 2.0 g - 5.0 g of the polyethylene glycol-branched resveratrol-cyclodextrin inclusion complex is dissolved in 100 mL of water, 1.0 g - 2.5 g of epichlorohydrin is added, and the pH value is adjusted to 9.0 - 12.50 with sodium hydroxide. After mixing evenly, a coating solution is prepared for standby.

8. The reverse osmosis membrane with a polyethylene glycol-branched cyclodextrin-resveratrol antifouling coating according to claim 1, characterized in that: The thickness of the coating solution in step S4 is 10 - 50 μm.

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