A method for preparing a chlorine-resistant reverse osmosis membrane for a temperature-sensitive nanocontainer

Abstract

This invention innovatively designs a temperature-sensitive nanocontainer. Its core comprises silica nanoclusters (SiO2) with a large specific surface area and rich in hydroxyl groups, onto which sericin molecules with characteristic groups such as carboxyl and amino groups are loaded. Finally, it is encapsulated with 1799-PVA. Sericin is a water-soluble spherical protein composed of various amino acids, possessing biocompatibility. Due to its high amino and carboxyl group content, it is often used for coating or deposition on polyamide layers for antifouling and enhanced chlorine resistance. By introducing a temperature-responsive nanocontainer within the polyamide layer of a reverse osmosis membrane, we successfully prepared a self-healing polyamide layer with precise temperature control. After the shell material dissolves under specific response conditions, the released sericin molecules can effectively bind to broken amide bonds through their surface amino and carboxyl groups, filling the structural damage areas of the polyamide layer caused by chlorination, thereby significantly improving the membrane's chlorine resistance and extending its service life.

Description

Technical fields:

[0001] This invention relates to the field of composite materials and reverse osmosis membrane preparation technology, specifically to a method for preparing a chlorine-resistant reverse osmosis membrane with a temperature-sensitive nanocontainer filled with an aromatic polyamide layer. Background technology:

[0002] Reverse osmosis (RO) technology plays a crucial role in seawater desalination and water recycling. Currently, the most common RO membrane is a thin-layer composite membrane prepared by the interfacial polymerization of m-phenylenediamine and trimesoyl chloride. However, the poor chlorine resistance of the polyamide layer on the membrane surface significantly reduces membrane lifespan, increases energy consumption and operating costs in the desalination process, and becomes a fatal weakness of RO membranes in practical applications. Based on these reasons, researchers have conducted various experimental studies to address the problem of poor chlorine resistance. The underlying approach is to change the monomer selection during the interfacial polymerization process, or to coat and graft modified materials onto the membrane surface to reduce the contact sites between the polyamide layer and active chlorine. Physical coating fixes the protective layer to the membrane surface through electrostatic interactions or hydrogen bonds, while chemical grafting reduces the contact between the polyamide layer and active chlorine by covalently attaching the repair material to the membrane surface. However, both methods increase the density or thickness of the polyamide layer on the membrane surface, reducing the water molecule permeation rate. In particular, physical coating methods, due to the lack of stable bonding forces, often lead to weakened effects between the modified material and the polyamide layer, and may even cause delamination, forming larger structural defects and greatly reducing separation performance.

[0003] In recent years, polymer nanovesicles (or polymer vesicles) have attracted considerable interest due to their diverse polymer selection, structural advantages, and sensitivity to environmental changes. These nanovesicles possess hollow structures, large surface areas, and large internal volumes, enabling them to trap small molecules (such as mesoporous silica, polymers, and proteins) and exhibiting excellent molecular trapping and chemical surface functionalization capabilities. Nanovesicles can also consist of a spherical center with carrier properties and a shell coated with polymer material. The shell protects against external chemical and mechanical erosion, allowing for controlled release of the internal material. By designing nanovesicles that respond to specific stimuli, particularly external conditions such as pH, light, and ions, the delivery efficiency of nanoscale polymer materials can be improved. These stimulus-responsive nanovesicles have found wide applications in drug delivery and corrosion resistance. However, research on the use of temperature-responsive systems for post-chlorination repair of reverse osmosis membranes is relatively limited. Summary of the Invention:

[0004] In view of the above technical background, the present invention aims to provide a method for preparing a chlorine-resistant reverse osmosis membrane for a temperature-sensitive nanocontainer. Specifically, it includes the following steps:

[0005] Remove the polysulfone membrane and fix it on a flat plate. Remove the moisture with an air knife. Pour the aqueous solution of the temperature-sensitive nanocontainer onto the surface of the polysulfone membrane. After a period of time, pour off the excess aqueous solution and dry it with an air knife. Then pour the oil solution onto the membrane surface. After a period of time, pour off the excess oil solution.

[0006] The membrane obtained above is placed in an oven and heat-treated for a period of time. After that, it is taken out and cleaned to obtain a chlorine-resistant reverse osmosis membrane for a temperature-sensitive nano-container.

[0007] The method for preparing the aqueous solution of the temperature-sensitive nanocontainer is as follows: prepare an aqueous solution of m-phenylenediamine with a mass fraction of 1.0-3.0%, add a certain mass of the temperature-sensitive nanocontainer to the above solution, and sonicate for a period of time to obtain the aqueous solution of the temperature-sensitive nanocontainer.

[0008] The oil phase solution is a 0.1-0.5% (w / w) solution of pyromellitic chlorohexane.

[0009] The heat treatment temperature is 60–80°C, and the heat treatment time is 1–10 min.

[0010] The method for preparing the temperature-sensitive nanocontainer includes the following steps:

[0011] (1) Place 90-100 mg of L-lysine into a three-necked flask containing 90-100 mL of deionized water and stir at 500-800 rpm for 8-15 minutes in a reflux reflux apparatus at 60°C. Then, quickly add 5-10 mL of tetraethyl orthosilicate and stir for 12 hours until the solution becomes clear. Next, add 10-15 mL of tetraethyl orthosilicate and stir for 12 hours. The solution will gradually turn into a milky white turbid solution. Then, centrifuge at 6000-8000 rpm for 5-10 minutes and wash 3-5 times. Vacuum dry the resulting lower solid layer and grind it into powder to obtain SiO2 nanoparticles.

[0012] (2) Take a certain amount of SiO2 nanoparticles obtained in step (1), add them to 30-50 mL of deionized water, and sonicate them for 20-30 minutes to uniformly disperse the nanoparticles. Add 0.3-0.5 g of sericin to 50 mL of water and stir at 50-80 °C for 30-60 minutes until completely dissolved. Mix the two solutions and stir at 35-40 °C for 1-2 hours to ensure that the sericin is uniformly distributed on the surface of the SiO2 nanoparticles. Then wash with deionized water 3-5 times and centrifuge at 6000-9000 r / min for 5-10 minutes. Finally, dry at 50-70 °C to obtain the powder, which is SiO2@SS.

[0013] (3) Take a certain amount of SiO2@SS powder obtained in step (2), add it to 50-70 ml of water, and sonicate it for 30-40 minutes using a cell disruptor. Then, pour 0.5 g of polyvinyl alcohol into 50-70 ml of water, soak it for 30 minutes, and then heat it at 70-90℃ for 30 minutes to disperse it with SiO2@SS and stir for 1-2 hours. Centrifuge the mixed solution three times at 6000-9000 r / min for 5-10 min, and then freeze-dry it to obtain white SiO2@SS@PVA, i.e., temperature-sensitive nanocontainer powder.

[0014] The temperature-sensitive nanocontainer's chlorine-resistant reverse osmosis membrane has chlorine self-healing properties.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] This invention innovatively prepares a temperature-sensitive nanocontainer. The core consists of high-specific-surface-area hydroxyl-rich silica nanoclusters (SiO2), with sericin molecules bearing characteristic groups such as carboxyl and amino groups on their surface, and encapsulated with 1799-PVA. Sericin is a water-soluble spherical protein rich in various amino acids and possesses biocompatibility. Its amino and carboxyl groups make it commonly used for coating or depositing on polyamide layers for antifouling and resistance to chlorine damage. This method introduces temperature-responsive nanocontainers into the polyamide layer of an RO membrane to prepare a polyamide layer with precise temperature control and self-healing properties. When the shell material undergoes a specific response dissolution, the released sericin molecules effectively bind to broken amide bonds through their surface amino and carboxyl groups, filling structural defects in the polyamide layer caused by chlorination, significantly improving the membrane's chlorination resistance and thus extending its service life. Attached image description:

[0017] Figure 1 This is a scanning electron microscope (SEM) image of the surface structure of the chlorine-resistant reverse osmosis membrane of the temperature-sensitive nanocontainer prepared in Example 1.

[0018] Figure 2 The image shows a scanning electron microscope (SEM) image of the surface structure of the blank control reverse osmosis membrane prepared in Comparative Example 1. Detailed implementation method:

[0019] The present invention will be described in detail below through specific embodiments, but the embodiments do not limit the scope of the present invention.

[0020] Example 1:

[0021] (1) Clean the polysulfone ultrafiltration membrane (molecular weight cutoff 30,000) with pure water and use it as a support layer for later use;

[0022] (2) Prepare a 2.0% m-phenylenediamine aqueous solution; disperse 0.0025 g / L of temperature-sensitive nanocontainer in the above m-phenylenediamine solution by ultrasonication for one hour to obtain an aqueous solution of temperature-sensitive nanocontainer;

[0023] (3) Preparation of oil phase solution: Prepare a 0.1% (w / w) solution of pyromellitic methyl chloride and hexane;

[0024] (4) Preparation of chlorine-resistant reverse osmosis membrane for temperature-sensitive nanocontainers: Take out the polysulfone-based membrane and fix it on a glass plate. Use an air knife to blow dry the water. Pour the aqueous phase solution of the temperature-sensitive nanocontainer onto the surface of the polysulfone-based membrane. After 5 minutes, pour off the excess aqueous phase solution and blow dry with an air knife. Then pour the oil phase solution onto the membrane surface and react for 1 minute. Pour off the excess oil phase solution.

[0025] (5) Place the membrane obtained above in an oven at 80°C and heat treat for 5 minutes; remove the membrane and rinse with pure water for later use.

[0026] Figure 1 The image shows a scanning electron microscope (SEM) image of the surface structure of the chlorine-resistant reverse osmosis membrane of the temperature-sensitive nanocontainer prepared in Example 1.

[0027] Membrane flux and rejection rate testing: The modified reverse osmosis membrane was filtered for 1 hour at 2 MPa and 25°C using a 2000 ppm sodium chloride aqueous solution, and its initial permeate flux and rejection rate were then tested. The membrane flux and sodium chloride rejection rate were calculated using the following formulas.

[0028] Flux = Permeate volume / (Time × Membrane area)

[0029] Retention rate = (Feed solution conductivity - Permeate conductivity) / Feed solution conductivity

[0030] The initial permeation flux and salt rejection rate of the modified membrane were obtained by filtering a 2000ppm sodium chloride aqueous solution at 2MPa and 25℃, as shown in Table 1.

[0031] Chlorine resistance test: Prepare a sodium hypochlorite solution with a concentration of 1500 ppm, adjust the pH to 7 with HCl, immerse the membrane after the initial performance test in the sodium hypochlorite solution, and conduct a chlorine resistance test. Test the membrane flux and rejection rate after immersion for 1 hour (under the same conditions as above).

[0032] Temperature-sensitive experiment: The reverse osmosis membrane was soaked in deionized water at 70°C for 1 hour.

[0033] The results of the chlorine resistance test and temperature sensitivity test of the reverse osmosis membrane prepared in Example 1 are shown in Table 2.

[0034] Example 2:

[0035] (1) Clean the polysulfone ultrafiltration membrane (molecular weight cutoff 30,000) with pure water and use it as a support layer for later use;

[0036] (2) Prepare a 2.0% m-phenylenediamine aqueous solution; disperse 0.005 g / L of temperature-sensitive nanocontainer in the above m-phenylenediamine solution by ultrasonication for one hour to obtain an aqueous solution of temperature-sensitive nanocontainer;

[0037] (3) Preparation of oil phase solution: Prepare a 0.1% (w / w) solution of pyromellitic methyl chloride and hexane;

[0038] (4) Preparation of chlorine-resistant reverse osmosis membrane for temperature-sensitive nanocontainers: Take out the polysulfone-based membrane and fix it on a glass plate. Use an air knife to blow dry the water. Pour the aqueous phase solution of the temperature-sensitive nanocontainer onto the surface of the polysulfone-based membrane. After 5 minutes, pour off the excess aqueous phase solution and blow dry with an air knife. Then pour the oil phase solution onto the membrane surface and react for 1 minute. Pour off the excess oil phase solution.

[0039] (5) Place the membrane obtained above in an oven at 80°C and heat treat for 5 minutes; remove the membrane and rinse with pure water for later use.

[0040] Membrane flux and rejection rate testing: The modified reverse osmosis membrane was filtered for 1 hour at 2 MPa and 25°C using a 2000 ppm sodium chloride aqueous solution, and its initial permeate flux and rejection rate were then tested. The membrane flux and sodium chloride rejection rate were calculated using the following formulas.

[0041] Flux = Permeate volume / (Time × Membrane area)

[0042] Retention rate = (Feed solution conductivity - Permeate conductivity) / Feed solution conductivity

[0043] The initial permeation flux and salt rejection rate of the modified membrane were obtained by filtering a 2000ppm sodium chloride aqueous solution at 2MPa and 25℃, as shown in Table 1.

[0044] Chlorine resistance test: Prepare a sodium hypochlorite solution with a concentration of 1500 ppm, adjust the pH to 7 with HCl, immerse the membrane after the initial performance test in the sodium hypochlorite solution, and conduct a chlorine resistance test. Test the membrane flux and rejection rate after immersion for 1 hour (under the same conditions as above).

[0045] Temperature-sensitive experiment: The reverse osmosis membrane was soaked in deionized water at 70°C for 1 hour.

[0046] The results of the chlorine resistance test and temperature sensitivity test of the reverse osmosis membrane prepared in Example 1 are shown in Table 2.

[0047] Example 3:

[0048] (1) Clean the polysulfone ultrafiltration membrane (molecular weight cutoff 30,000) with pure water and use it as a support layer for later use;

[0049] (2) Prepare a 2.0% m-phenylenediamine aqueous solution; disperse 0.0075 g / L of temperature-sensitive nanocontainer in the above m-phenylenediamine solution by ultrasonication for one hour to obtain an aqueous solution of temperature-sensitive nanocontainer;

[0050] (3) Preparation of oil phase solution: Prepare a 0.1% (w / w) solution of pyromellitic methyl chloride and hexane;

[0051] (4) Preparation of chlorine-resistant reverse osmosis membrane for temperature-sensitive nanocontainers: Take out the polysulfone-based membrane and fix it on a glass plate. Use an air knife to blow dry the water. Pour the aqueous phase solution of the temperature-sensitive nanocontainer onto the surface of the polysulfone-based membrane. After 5 minutes, pour off the excess aqueous phase solution and blow dry with an air knife. Then pour the oil phase solution onto the membrane surface and react for 1 minute. Pour off the excess oil phase solution.

[0052] (5) Place the membrane obtained above in an oven at 80°C and heat treat for 5 minutes; remove the membrane and rinse with pure water for later use.

[0053] Membrane flux and rejection rate testing: The modified reverse osmosis membrane was filtered for 1 hour at 2 MPa and 25°C using a 2000 ppm sodium chloride aqueous solution, and its initial permeate flux and rejection rate were then tested. The membrane flux and sodium chloride rejection rate were calculated using the following formulas.

[0054] Flux = Permeate volume / (Time × Membrane area)

[0055] Retention rate = (Feed solution conductivity - Permeate conductivity) / Feed solution conductivity

[0056] The initial permeation flux and salt rejection rate of the modified membrane were obtained by filtering a 2000ppm sodium chloride aqueous solution at 2MPa and 25℃, as shown in Table 1.

[0057] Chlorine resistance test: Prepare a sodium hypochlorite solution with a concentration of 1500 ppm, adjust the pH to 7 with HCl, immerse the membrane after the initial performance test in the sodium hypochlorite solution, and conduct a chlorine resistance test. Test the membrane flux and rejection rate after immersion for 1 hour (under the same conditions as above).

[0058] Temperature-sensitive experiment: The reverse osmosis membrane was soaked in deionized water at 70°C for 1 hour.

[0059] The results of the chlorine resistance test and temperature sensitivity test of the reverse osmosis membrane prepared in Example 1 are shown in Table 2.

[0060] Comparative Example 1

[0061] (1) Clean the polysulfone ultrafiltration membrane (molecular weight cutoff 30,000) with pure water and use it as a support layer for later use;

[0062] (2) Prepare an aqueous solution of m-phenylenediamine with a mass fraction of 2.0% to obtain an aqueous phase solution;

[0063] (3) Preparation of oil phase solution: Prepare a 0.1% (w / w) solution of pyromellitic methyl chloride and hexane;

[0064] (4) Preparation of blank control reverse osmosis membrane: Take out the polysulfone-based membrane and fix it on the glass plate. Use an air knife to blow away the moisture. Pour the aqueous phase solution onto the surface of the polysulfone-based membrane. After 5 minutes, pour off the excess aqueous phase solution and blow it dry with an air knife. Then pour the oil phase solution onto the membrane surface and react for 1 minute. Pour off the excess oil phase solution.

[0065] (5) Place the membrane obtained above in an oven at 80°C and heat treat for 5 minutes; remove the membrane and rinse with pure water for later use.

[0066] Figure 2 Scanning electron microscope image of the surface structure of the blank control reverse osmosis membrane prepared for Comparative Example 1.

[0067] Membrane flux and rejection rate testing: The modified reverse osmosis membrane was filtered for 1 hour at 2 MPa and 25°C using a 2000 ppm sodium chloride aqueous solution, and its initial permeate flux and rejection rate were then tested. The membrane flux and sodium chloride rejection rate were calculated using the following formulas.

[0068] Flux = Permeate volume / (Time × Membrane area)

[0069] Retention rate = (Feed solution conductivity - Permeate conductivity) / Feed solution conductivity

[0070] The initial permeation flux and salt rejection rate of the modified membrane were obtained by filtering a 2000ppm sodium chloride aqueous solution at 2MPa and 25℃, as shown in Table 1.

[0071] Chlorine resistance test: Prepare a sodium hypochlorite solution with a concentration of 1500 ppm, adjust the pH to 7 with HCl, immerse the membrane after the initial performance test in the sodium hypochlorite solution, and conduct a chlorine resistance test. Test the membrane flux and rejection rate after immersion for 1 hour (under the same conditions as above).

[0072] Temperature-sensitive experiment: The reverse osmosis membrane was soaked in deionized water at 70°C for 1 hour.

[0073] The results of the chlorine resistance test and temperature sensitivity test of the reverse osmosis membrane prepared in Comparative Example 1 are shown in Table 2.

[0074] Comparative Example 2

[0075] (1) Clean the polysulfone ultrafiltration membrane (molecular weight cutoff 30,000) with pure water and use it as a support layer for later use;

[0076] (2) Prepare a 2.0% m-phenylenediamine aqueous solution; disperse 0.005 g / L of temperature-sensitive nanocontainer in the above m-phenylenediamine solution by ultrasonication for one hour to obtain an aqueous solution of temperature-sensitive nanocontainer;

[0077] (3) Preparation of oil phase solution: Prepare a 0.1% (w / w) solution of pyromellitic methyl chloride and hexane;

[0078] (4) Preparation of chlorine-resistant reverse osmosis membrane for temperature-sensitive nanocontainers: Take out the polysulfone-based membrane and fix it on a glass plate. Use an air knife to blow dry the water. Pour the aqueous phase solution of the temperature-sensitive nanocontainer onto the surface of the polysulfone-based membrane. After 5 minutes, pour off the excess aqueous phase solution and blow dry with an air knife. Then pour the oil phase solution onto the membrane surface and react for 1 minute. Pour off the excess oil phase solution.

[0079] (5) Place the membrane obtained above in an oven at 80°C and heat treat for 5 minutes; remove the membrane and rinse with pure water for later use.

[0080] Membrane flux and rejection rate testing: The modified reverse osmosis membrane was filtered for 1 hour at 2 MPa and 25°C using a 2000 ppm sodium chloride aqueous solution, and its initial permeate flux and rejection rate were then tested. The membrane flux and sodium chloride rejection rate were calculated using the following formulas.

[0081] Flux = Permeate volume / (Time × Membrane area)

[0082] Retention rate = (Feed solution conductivity - Permeate conductivity) / Feed solution conductivity

[0083] Chlorine resistance test: Prepare a sodium hypochlorite solution with a concentration of 1500 ppm, adjust the pH to 7 with HCl, immerse the membrane after the initial performance test in the sodium hypochlorite solution, and conduct a chlorine resistance test. Test the membrane flux and rejection rate after immersion for 1 hour (under the same conditions as above).

[0084] The results of the chlorine resistance test of the reverse osmosis membrane prepared in Comparative Example 1 are shown in Table 2.

[0085] Table 1. Membrane flux and rejection rate tests:

[0086]

[0087] Table 2 Chlorine resistance test:

[0088]

[0089] Test results show that, compared with the blank control reverse osmosis membrane (Comparative Example 1) and the temperature-sensitive nano-container chlorine-resistant reverse osmosis membrane without temperature-sensitive experiment (Comparative Example 2), the temperature-sensitive nano-container chlorine-resistant reverse osmosis membrane prepared by the method of the present invention exhibits a significantly reduced rejection rate after immersion in sodium hypochlorite and activation by temperature-sensitive experiment, demonstrating good self-healing properties after chlorination.

Claims

1. A method for preparing a chlorine-resistant reverse osmosis membrane for a temperature-sensitive nanocontainer, characterized in that, Includes the following steps: Remove the polysulfone membrane and fix it on a flat plate. Use an air knife to dry the surface moisture. Pour a certain mass fraction of the temperature-sensitive nanocontainer aqueous solution onto the surface of the polysulfone membrane. After a period of time, pour off the excess aqueous solution and dry the surface with an air knife. Then pour the oil solution onto the membrane surface. After a period of time, pour off the excess oil solution. The membrane prepared above is placed in an oven for heat treatment. After a period of time, it is removed and cleaned to obtain a chlorine-resistant reverse osmosis membrane for a temperature-sensitive nanocontainer. The preparation method of the temperature-sensitive nanocontainer includes the following steps: (1) A certain mass of L-lysine was added to a three-necked flask containing a certain volume of deionized water. The mixture was stirred in a reflux reflux device at 60°C. A certain volume of tetraethyl orthosilicate was immediately added to the flask and the mixture was stirred for 12 hours until the solution became clear. Then, a certain volume of tetraethyl orthosilicate was added to the three-necked flask and the mixture was stirred for another 12 hours. The solution gradually became a milky white turbid solution. The solution was then centrifuged and washed multiple times. The lower solid was vacuum dried and then ground into powder to obtain SiO2 nanoparticles. (2) Take out a certain amount of SiO2 nanoparticles obtained in step (1), add a certain amount of deionized water, and sonicate for a period of time to make the nanoparticles uniformly dispersed. Add a certain amount of sericin to 50 mL of water and stir to dissolve it completely. Mix the two solutions and stir at a certain temperature for several hours. The sericin is uniformly distributed on the surface of SiO2 nanoparticles. Then wash with deionized water and centrifuge and dry to obtain SiO2@SS powder. (3) Take out a certain amount of SiO2@SS powder obtained in step (2), add it to a certain amount of water, and use a cell disruptor to perform ultrasonic treatment. Then, pour 0.5g of polyvinyl alcohol into a certain amount of water, soak for 30 minutes, and then heat it at a certain temperature for 30 minutes. Mix it with SiO2@SS and stir for several hours. Then centrifuge it three times. Finally, freeze dry it to obtain white SiO2@SS@PVA, i.e., temperature-sensitive nanocontainer powder. The preparation method of the temperature-sensitive nanocontainer aqueous solution is as follows: prepare a 1.0-3.0% m-phenylenediamine aqueous solution, add a certain mass of temperature-sensitive nanocontainer to the above solution, and sonicate it for a period of time to obtain the temperature-sensitive nanocontainer aqueous solution.

2. The method for preparing the chlorine-resistant reverse osmosis membrane of the temperature-sensitive nanocontainer according to claim 1, characterized in that, The method for preparing the temperature-sensitive nanocontainer aqueous solution is as follows: prepare a temperature-sensitive nanocontainer aqueous solution with a mass fraction of 0.0025 to 0.010 wt%, and then perform ultrasonic treatment for a period of time to obtain the temperature-sensitive nanocontainer aqueous solution.

3. The method for preparing the chlorine-resistant reverse osmosis membrane of the temperature-sensitive nanocontainer according to claim 1, characterized in that, In step (1), the mass of L-lysine is 90-100 mg; the amount of deionized water is 90-100 mL; the amount of tetraethyl orthosilicate added for the first time is 5-10 mL; the amount of tetraethyl orthosilicate added for the second time is 10-15 mL; the stirring speed is 500-800 rpm; the stirring time is 8-15 minutes; the centrifugation speed is 6000-8000 r / min; the centrifugation time is 5-10 minutes; and the washing is performed 3-5 times.

4. The method for preparing the chlorine-resistant reverse osmosis membrane of the temperature-sensitive nanocontainer according to claim 1, characterized in that, In step (2), 30-50 mL of deionized water is added, and the mixture is sonicated for 20-30 minutes. The amount of sericin is 0.3-0.5 g. The mixture is stirred at 50-80 °C for 30-60 minutes. The two solutions are mixed and stirred at 35-40 °C for 1-2 hours. The mixture is centrifuged at 6000-9000 r / min for 5-10 minutes, followed by 3-5 washes with deionized water and centrifugation at 6000-9000 r / min for 5-10 minutes. Finally, the mixture is dried at 50-70 °C.

5. The method for preparing the chlorine-resistant reverse osmosis membrane of the temperature-sensitive nanocontainer according to claim 1, characterized in that, In step (3), a certain amount of SiO2@SS powder obtained in step (2) is taken out and added to 50-70 ml of water. It is then sonicated in a cell disruptor for 30-40 minutes. Next, 0.5 g of polyvinyl alcohol is added to 50-70 ml of water and soaked for 30 minutes. Then, it is heated at 70-90 °C for 30 minutes and mixed with SiO2@SS. The mixture is dispersed and stirred for 1-2 hours, and then centrifuged three times at 6000-9000 r / min for 5-10 min.

6. A chlorine-resistant reverse osmosis membrane for a temperature-sensitive nanocontainer prepared according to the method of claim 1, characterized in that, The temperature-sensitive nanocontainer's chlorine-resistant reverse osmosis membrane has self-healing properties after chlorination.

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