An aqueous emulsion self-laminating coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles and a method of preparation

Abstract

The present application relates to a kind of water-based latex self-lamination coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles and preparation method, including following preparation steps: S1, sodium styrene sulfonate, potassium persulfate is dissolved in methanol water, organic polymer monomer, crosslinking agent is added, heated under inert atmosphere, obtain organic microsphere;S2, silane acrylate monomer, silane coupling agent monomer, initiator and water are mixed to obtain monomer emulsion, organic microsphere dispersion liquid is mixed with monomer emulsion, stirred under inert atmosphere, adjust pH to alkaline, heated, obtain amphiphilic asymmetric organic-inorganic hybrid nanoparticles;S3, amphiphilic asymmetric organic-inorganic hybrid nanoparticles are dispersed in water, mixed with water-based latex primer diluent, drop on silicon chip, after drying, obtain water-based latex self-lamination coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles.The self-lamination coating prepared by the present application has mechanical robustness and low adhesion.

Description

Technical Field

[0001] This invention relates to the field of chemical technology, and in particular to an aqueous latex self-layering coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles and its preparation method. Background Technology

[0002] Coatings are ubiquitous in daily life, ranging from common interior and exterior wall coatings to food packaging, kitchen and household appliances, electronic products, sports equipment, entertainment facilities, and transportation vehicles—the list goes on. The primary functions of coatings are color enhancement and surface protection. Traditional coating preparation methods involve multiple layers. First, a primer is applied to increase adhesion to the substrate. The second layer is an intermediate coat, which sometimes requires a special functional substance. The outermost layer, also called the topcoat, not only gives the coating an aesthetically pleasing appearance (smoothness and gloss) but also provides anti-fouling, scratch-resistant, chemical-resistant, and weather-resistant properties. Although multi-layer coating systems can combine the individual properties of each layer, each layer still requires complex formulations, lengthy processing and curing procedures. The high labor and processing time requirements, excessive energy consumption, and environmental waste generated severely limit its industrial application. Therefore, to overcome these shortcomings of ordinary multilayer coatings, a one-step method for constructing self-layered coatings with continuous multilayer structures has been proposed. The formulation of self-layered coatings consists of two or more components with different surface energies, which spontaneously undergo phase separation during the coating curing process, further forming multilayer or gradient coatings. The one-step method for preparing self-layered coatings not only saves time and effort and reduces energy consumption, but also largely eliminates interface failures, thus maintaining the function of each layer.

[0003] Waterborne self-stratifying coatings comprise three main types: binary soft polymers, binary hard colloidal particles, and mixtures of soft polymers and hard colloidal particles. Binary soft polymer self-stratifying coatings exhibit low mechanical strength, hardness, and abrasion resistance. Binary hard colloidal particle self-stratifying coatings demonstrate poor film-forming properties. Mixtures of soft polymers and hard colloidal particles can achieve a layered structure by adjusting nanoparticle / polymer interactions, such as hydrodynamic interactions, polymer radius of gyration, polymer molecular weight, evaporation rate, and the settling of aggregated particles or the floating of lightweight particles. However, implementing these strategies places high demands on polymer-particle matching, processing conditions, and nanoparticle properties, indicating an urgent need for a simple method to construct hard colloidal-soft polymer composite self-stratifying coatings that combine mechanical robustness and film-forming properties before achieving widespread industrial application of high-performance waterborne composite self-stratifying coatings. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art by providing an organic-inorganic hybrid amphiphilic asymmetric nano-layered coating and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] One of the technical solutions of the present invention is to provide a method for preparing an aqueous latex self-layering coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles, comprising the following steps:

[0007] S1. Sodium styrene sulfonate and potassium persulfate are dissolved in a mixed solution of methanol and water. Then, organic polymer monomers and crosslinking agents are added, and the mixture is emulsified to obtain Pickering emulsion. The emulsion is heated under an inert atmosphere to obtain organic microspheres.

[0008] S2. Disperse the organic microspheres obtained in step S1 in water to obtain an organic microsphere dispersion. Mix silane acrylate monomer, silane coupling agent monomer, initiator and water to obtain a monomer emulsion. Mix the organic microsphere dispersion and monomer emulsion, emulsify and stir for a period of time under an inert atmosphere. Adjust the pH to alkaline and heat to react to obtain amphiphilic asymmetric organic-inorganic hybrid nanoparticles.

[0009] S3. Disperse the amphiphilic asymmetric organic-inorganic hybrid nanoparticles obtained in step S2 in water to obtain a nanoparticle dispersion. Mix the water-based latex primer with water to obtain a water-based latex primer diluent. Mix the nanoparticle dispersion with the water-based latex primer diluent and drop it onto a silicon wafer. After drying, obtain a water-based latex self-layering coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles.

[0010] In some specific embodiments, in step S1, the organic polymerizable monomer is selected from methyl acrylate, butyl acrylate, methyl methacrylate, styrene, and p-methylstyrene;

[0011] The crosslinking agent is selected from m-divinylbenzene, p-divinylbenzene, 1,3,5-trivinylbenzene, 1,3-pentadiene, and isoprene.

[0012] Preferably, the organic polymeric monomer is selected from methyl methacrylate, butyl acrylate, or styrene;

[0013] Preferably, the crosslinking agent is selected from divinylbenzene and isoprene.

[0014] In some specific embodiments, in step S1, the ratio of sodium styrene sulfonate, potassium persulfate, methanol-water mixed solution, organic polymer monomer, and crosslinking agent is (80-85) mg: (140-160) mg: 200 mL: 27 mL: (0.27-2.7) mL;

[0015] The volume ratio of methanol to water in the methanol-water mixture is 90:10 to 50:50.

[0016] Preferably, the ratio of sodium styrene sulfonate, potassium persulfate, methanol-water, organic polymer monomer, and crosslinking agent is (80-85) mg: (140-160) mg: 200 mL: 27 mL: (0.81-2.7) mL;

[0017] Preferably, the volume ratio of methanol to water in the methanol-water mixture is 90:10-70:30;

[0018] In some specific embodiments, in step S1, the process parameters for heating the reaction under an inert atmosphere are: the inert atmosphere is nitrogen, the heating temperature is 70°C, and the heating time is at least 24 hours.

[0019] In some specific embodiments, in step S1, a fluorine-containing or long-carbon-chain vinyl monomer is added to the mixed emulsion reaction to perform hydrophobic surface modification on the organic microspheres, thereby increasing the hydrophobicity of the organic-inorganic hybrid amphiphilic asymmetric nanoparticles.

[0020] In some specific embodiments, in step S1, the fluorine-containing or long-chain vinyl monomer is selected from trifluoroethyl acrylate, hexafluorobutyl acrylate, trifluoroethyl methacrylate, decyltriethoxysilane, dodecyltrimethoxysilane, and octadecyltriethoxysilane.

[0021] The amount of the fluorinated or long-chain vinyl monomer added is 10-20% of the amount of the organic polymer monomer added.

[0022] In some specific embodiments, in step S2, the silane acrylate monomer is selected from 3-(trimethoxysilyl)propyl methacrylate, 3-(trimethoxysilyl)propyl acrylate, 3-(trimethoxysilyl)butyl acrylate, and 3-(triethoxysilyl)propyl methacrylate.

[0023] The silane coupling agent monomer is selected from 2-cyanoethyltriethoxysilane, 2-cyanoethyltrimethoxysilane, 3-glycidylpropoxytrimethoxysilane, 3-aminopropyltrimethoxysilane, dodecyltrimethoxysilane, octadecyltrimethoxysilane, triethoxyoctylsilane, perfluorodecyltrimethoxysilane, and 3-aminopropyltriethoxysilane.

[0024] The initiator is azobisisobutyronitrile.

[0025] Preferably, the silane acrylate monomer is selected from propyl 3-(trimethoxysilyl)methacrylate or propyl 3-(triethoxysilyl)methacrylate;

[0026] Preferably, the silane coupling agent monomer is selected from 2-cyanoethyltriethoxysilane, 2-cyanoethyltrimethoxysilane, dodecyltrimethoxysilane, perfluorodecyltrimethoxysilane, or 3-aminopropyltriethoxysilane.

[0027] In some specific embodiments, in step S2, the volume ratio of silane acrylate monomer to silane coupling agent monomer in the emulsion is 50:50-90:10.

[0028] The mass of the initiator added is five times the sum of the volumes of the silane acrylate monomer and the silane coupling agent monomer.

[0029] Preferably, the volume ratio of the silane acrylate monomer to the silane coupling agent monomer is 70:30-90:10.

[0030] Preferably, the ratio of the organic microspheres, silane acrylate monomer, and silane coupling agent monomer is 6g:9mL:3mL.

[0031] In some specific embodiments, in step S2, the inert atmosphere is nitrogen, the pH of the solution is adjusted to 9.0, the temperature of the heating reaction is 70°C, and the heating reaction time is at least 36 hours.

[0032] In some specific embodiments, when the silane coupling agent monomer in step S2 is selected from 2-cyanoethyltriethoxysilane or 2-cyanoethyltrimethoxysilane, in step S3, concentrated sulfuric acid is slowly added to the aqueous solution of nanoparticles, and the mixture is heated and reacted for a period of time to obtain a dispersion of surface-carboxylated organic-inorganic hybrid amphiphilic asymmetric nanoparticles, thereby increasing the hydrophilicity of the organic-inorganic hybrid amphiphilic asymmetric nanoparticles.

[0033] In some specific embodiments, concentrated sulfuric acid is slowly added to make the acidic environment in the reaction system pH 1.8-2.5, the reaction temperature is 90°C, and the reaction time is 12-24 hours.

[0034] In some specific embodiments, in step S3, the concentration of nanoparticles in the nanoparticle dispersion is 0.01-0.5 g / mL; the concentration of the aqueous latex primer in the aqueous latex primer diluent is 40%-95% of the original concentration; the pH of the aqueous latex primer diluent is 5.01-12.05; and the volume ratio of the aqueous latex primer diluent to the nanoparticle dispersion is 95:5-50:50.

[0035] Preferably, the concentration of nanoparticles in the nanoparticle dispersion is 0.05-0.2 g / mL; the concentration of the aqueous latex primer in the aqueous latex primer diluent is 55%-90% of the original concentration; the pH of the aqueous latex primer diluent is 7.51-11.21; and the volume ratio of the aqueous latex primer diluent to the nanoparticle dispersion is 95:5-70:30.

[0036] In some specific embodiments, in step S3, the thickness of the mixture of aqueous latex primer diluent and nanoparticle dispersion dropped onto the silicon wafer is 100-3000 μm.

[0037] Preferably, the thickness of the mixture of aqueous latex primer diluent and nanoparticle dispersion dropped onto the silicon wafer is 300-2000 μm.

[0038] The second technical solution of the present invention is to provide an amphiphilic asymmetric organic-inorganic hybrid nano-layered coating, which is prepared based on the preparation method described in one of the above technical solutions.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) The amphiphilic asymmetric organic-inorganic hybrid nanoparticles prepared by the present invention will migrate to the water-air interface to form a self-layered structure and be fixed during the drying process. Therefore, the water-based latex self-layered coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles obtained by mixing with primer and coating on silicon wafer and drying has excellent film-forming performance, and its hardness and elastic modulus are significantly improved compared with primer, and it has both mechanical strength and low adhesion.

[0041] (2) The method for preparing aqueous latex based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles is simple, time-saving, labor-saving, energy-saving and environmentally friendly, and suitable for large-scale production. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the modified synthesis route for preparing amphiphilic asymmetric organic-inorganic hybrid nanoparticles and a structural diagram of the self-layered coating in some embodiments.

[0043] Figure 2 TEM (left) and SEM (right) images of the cyano-modified amphiphilic asymmetric organic-inorganic hybrid nanoparticles prepared in Example 1.

[0044] Figure 3 The image shown is a SEM image of the amphiphilic nature of the cyano-modified asymmetric organic-inorganic hybrid nanoparticles used in Example 1, with the left image being a magnified view of a portion of the right image.

[0045] Figure 4The images show SEM images (left) of the self-layered coating based on carboxylated amphiphilic asymmetric organic-inorganic hybrid nanoparticles prepared in Example 2 and (right) of the commercial primer coating of the control group.

[0046] Figure 5 The images show the micromechanical properties of the self-layered coatings based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles prepared in Examples 1-4 and the control group commercial primer coating. Detailed Implementation

[0047] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0048] In the following embodiments, unless otherwise specified, the raw materials or processing techniques are conventional commercially available raw materials or conventional processing techniques in the art.

[0049] The commercial primer used was Peel Stop primer from Zinsser.

[0050] Example 1:

[0051] This embodiment 1 provides a method for preparing a self-layering coating based on cyano-modified amphiphilic asymmetric organic-inorganic hybrid nanoparticles, comprising the following steps:

[0052] (1) Dissolve 85 mg of sodium styrene sulfonate and 160 mg of potassium persulfate in 200 mL of methanol-water mixture (methanol to water volume ratio of 8:2), then add 27 mL of styrene and 0.81 mL of divinylbenzene. Sonicate the mixture for 10 min to form a milky white Pickering emulsion. Purge with nitrogen gas for 30 min, then heat to 70 °C and react for 24 h. After the reaction is complete, wash the mixture with ethanol and water three or more times to obtain polystyrene microspheres.

[0053] (2) The 6g polystyrene microspheres obtained in step (1) were ultrasonically dispersed in 270mL of ultrapure water, and 9mL of 3-(triethoxysilyl)methacrylate and 3mL of 2-cyanoethyltriethoxysilane were added. Then, 60mg of azobisisobutyronitrile and 90mL of ultrapure water were added, and the mixture was ultrasonically emulsified for 10min. Under nitrogen atmosphere, the mixture was stirred at 500rpm at room temperature for 4h to obtain a monomer-swollen polystyrene microsphere reaction system. The pH of the reaction system was adjusted to about 9.0 with ammonia, and the temperature was raised to 70℃ for 36h. After the reaction was completed, the mixture was washed with ethanol and ultrapure water and centrifuged, respectively. After drying, cyano-modified amphiphilic asymmetric organic-inorganic hybrid nanoparticles, abbreviated as JCN, were obtained, which is a Janus material.

[0054] (3) The cyano-modified amphiphilic asymmetric organic-inorganic hybrid nanoparticles obtained in step (2) were dispersed in water to prepare a nanoparticle dispersion of 0.1 g / mL. A commercial primer was mixed with water to obtain a primer diluent with a concentration of 85% of the original concentration. The nanoparticle dispersion and primer diluent were mixed at a volume ratio of 1.5:8.5, and 120 μL of the above mixture was coated on a 1 cm × 1 cm silicon wafer (with a thickness of approximately 1200 μm). The mixture was then dried in a ventilated environment to finally obtain a self-layering coating based on cyano-modified amphiphilic asymmetric organic-inorganic hybrid nanoparticles.

[0055] The prepared JCN was then subjected to amphiphilic verification:

[0056] Water-paraffin system: First, 4 mL of ultrapure water and 15 mg of JCN were placed in a 10 mL glass bottle and sonicated for 2 min to uniformly disperse the particles, resulting in a milky white aqueous particle dispersion. Then, 200 mg of paraffin wax with a melting point of 55-60℃ was weighed and added to the particle dispersion. The temperature was raised to 85℃, and the mixture was rapidly stirred at 1000 rpm for 10 min to form a water-paraffin emulsion. The emulsion was then rapidly cooled with liquid nitrogen, during which the molten paraffin wax morphology was fixed. The water was then evaporated during drying, resulting in a paraffin wax sample containing asymmetric particles. The surface structure of the paraffin wax was observed under a scanning electron microscope. The results are as follows: Figure 3 The image shown is a SEM image verifying the amphiphilicity of JCN. The left image is a magnified view of a portion of the right image. As can be seen from the image, JCN is observed adsorbed on the surface of the paraffin microspheres, with its hydrophilic end facing outward and its hydrophobic end facing inward, indicating that JCN is amphiphilic.

[0057] like Figure 1 The diagram shown in B illustrates the structure of the self-layering coating. Part of JCN will settle towards the substrate due to gravity, while another part will migrate towards the water-air interface due to the amphiphilicity of the particles, and its morphology will be fixed during the drying process.

[0058] like Figure 2 As shown, the TEM image (left) and SEM image (right) of the prepared JCN are shown. The diameter of the organic part (polystyrene) of the nanoparticle is about 360 nm, and the diameter of the inorganic part (silicon dioxide) is about 290 nm.

[0059] Example 2:

[0060] This embodiment 2 provides a method for preparing a self-layering coating based on carboxylated amphiphilic asymmetric organic-inorganic hybrid nanoparticles, comprising the following steps:

[0061] (1) Take 5g of the cyano-modified amphiphilic asymmetric organic-inorganic hybrid nanoparticles obtained in Example 1, disperse them in 400mL of ultrapure water, and slowly add 100mL of concentrated sulfuric acid to the system under stirring to make the pH of the system 2.1. Heat to 90℃ and stir for 12h. Centrifuge and disperse using anhydrous ethanol and deionized water respectively, repeating 4-6 times. After freeze-drying, obtain surface carboxylated amphiphilic asymmetric organic-inorganic hybrid nanoparticles, abbreviated as JCOOH, which is a Janus material, such as... Figure 1 The modified schematic diagram is shown in Figure A.

[0062] (2) Disperse the JCOOH obtained in step (1) in water to prepare a nanoparticle dispersion of 0.15 g / mL. Mix the commercial primer with water to obtain a primer dilution with a commercial primer concentration of 85% of the original concentration. Mix the nanoparticle dispersion and the primer dilution at a volume ratio of 1.5:8.5, and take 120 μL of the above mixture to coat a 1 cm × 1 cm silicon wafer (thickness of about 1200 μm). Then dry it in a ventilated environment to finally obtain a self-layering coating based on carboxylated amphiphilic asymmetric organic-inorganic hybrid nanoparticles.

[0063] like Figure 4 As shown, the SEM images of the JCOOH self-layering coating (left) and the control group commercial primer coating (right) show that the primer coating has a smooth surface and a low contact angle, indicating that the coating has strong hydrophilicity. In contrast, the self-layering coating after mixing the primer and JCOOH shows hybrid particles and a larger contact angle, indicating that the addition of JCOOH increases the hydrophobicity of the coating.

[0064] Example 3:

[0065] This embodiment 3 provides a method for preparing a self-layering coating based on fluorinated cyano-based amphiphilic asymmetric organic-inorganic hybrid nanoparticles, comprising the following steps:

[0066] (1) Dissolve 85 mg of sodium styrene sulfonate and 160 mg of potassium persulfate in 200 mL of methanol-water mixture (methanol to water volume ratio of 9:1), then add 27 mL of styrene, 3 mL of trifluoroethyl acrylate, and 0.9 mL of divinylbenzene. Sonicate the mixture for 10 min to form a milky white Pickering emulsion. Purge with nitrogen gas for 30 min, then heat to 70 °C and react for 24 h. After the reaction is complete, wash with ethanol and water three or more times to obtain polystyrene microspheres.

[0067] (2) The 6g polystyrene microspheres obtained in step (1) were ultrasonically dispersed in 250mL of ultrapure water, and 9mL of 3-(triethoxysilyl)methacrylate and 3mL of 2-cyanoethyltriethoxysilane were added. Then, 60mg of azobisisobutyronitrile and 90mL of ultrapure water were added, and the mixture was ultrasonically emulsified for 10min. Under nitrogen atmosphere, the mixture was stirred at 500rpm at room temperature for 4h to obtain a monomer-swollen polystyrene microsphere reaction system. The pH of the reaction system was adjusted to about 9.0 with ammonia, and the temperature was raised to 70℃ for 24h. After the reaction was completed, the mixture was washed and centrifuged with ethanol and ultrapure water respectively, and dried to obtain fluorinated cyano-modified amphiphilic asymmetric organic-inorganic hybrid nanoparticles, abbreviated as FJCN, which is a Janus material, such as... Figure 1 The modified schematic diagram is shown in Figure A.

[0068] (3) The fluorinated cyano-modified amphiphilic asymmetric organic-inorganic hybrid nanoparticles obtained in step (2) were dispersed in water to prepare a nanoparticle dispersion of 0.1 g / mL. A commercial primer was mixed with water to obtain a primer dilution with a concentration of 85% of the original concentration. The nanoparticle dispersion and primer dilution were mixed at a volume ratio of 1.5:8.5, and 100 μL of the above mixture was coated on a 1 cm × 1 cm silicon wafer (with a thickness of approximately 1000 μm). The mixture was then dried in a ventilated environment to finally obtain a self-layering coating based on fluorinated cyano-modified amphiphilic asymmetric organic-inorganic hybrid nanoparticles.

[0069] Example 4:

[0070] This embodiment 4 provides a method for preparing a self-layering coating based on fluorinated carboxylated amphiphilic asymmetric organic-inorganic hybrid nanoparticles, comprising the following steps:

[0071] (1) Take 5g of the fluorinated cyano-modified amphiphilic asymmetric organic-inorganic hybrid nanoparticles obtained in Example 3, disperse them in 400mL of ultrapure water, and slowly add 100mL of concentrated sulfuric acid to the system under stirring to make the pH of the system 2.1. Heat to 90℃ and stir for 12h. Centrifuge and disperse using anhydrous ethanol and deionized water respectively, repeating 4-6 times. After freeze-drying, fluorinated carboxyl-modified amphiphilic asymmetric organic-inorganic hybrid nanoparticles, abbreviated as FJCOOH, are a Janus material, such as... Figure 1 The modified schematic diagram is shown in Figure A.

[0072] (2) The fluorinated carboxylated amphiphilic asymmetric organic-inorganic hybrid nanoparticles obtained in step (1) were dispersed in water to prepare a nanoparticle dispersion of 0.1 g / mL. A commercial primer was mixed with water to obtain a primer dilution with a concentration of 85% of the original concentration. The nanoparticle dispersion and primer dilution were mixed at a volume ratio of 1.5:8.5, and 100 μL of the above mixture was coated on a 1 cm × 1 cm silicon wafer (with a thickness of about 1000 μm). The mixture was then dried in a ventilated environment to finally obtain a self-layering coating based on fluorinated carboxylated amphiphilic asymmetric organic-inorganic hybrid nanoparticles.

[0073] Figure 5 The figures show the micromechanical properties of the self-stratifying coatings based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles obtained in Examples 1-4 and the control group commercial primer coating. The testing instrument used was a nano-indentation tester (model UNHT / NST03050702, manufactured by CSM GmbH, Switzerland), used to characterize the mechanical properties of the coating materials. JCN, JCOOH, FJCN, and FJCOOH correspond to the self-stratifying coatings based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles obtained in Examples 1-4, respectively, while Prime corresponds to the control group commercial primer coating. As can be seen from the figures, compared with the control group commercial primer coating, the self-stratifying coating showed a significant increase in hardness (HIT) and elastic modulus (EIT), indicating that the migration of amphiphilic asymmetric organic-inorganic hybrid nanoparticles to the coating surface can increase the micromechanical properties of the coating.

[0074] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for preparing an aqueous latex self-layering coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles, characterized in that, Includes the following steps: S1. Sodium styrene sulfonate and potassium persulfate are dissolved in a mixed solution of methanol and water. Then, organic polymer monomers and crosslinking agents are added, and the mixture is emulsified to obtain Pickering emulsion. The emulsion is heated under an inert atmosphere to obtain organic microspheres. S2. Disperse the organic microspheres obtained in step S1 in water to obtain an organic microsphere dispersion. Mix silane acrylate monomer, silane coupling agent monomer, initiator and water to obtain a monomer emulsion. Mix the organic microsphere dispersion and monomer emulsion, emulsify and stir for a period of time under an inert atmosphere. Adjust the pH to alkaline and heat to react to obtain amphiphilic asymmetric organic-inorganic hybrid nanoparticles. S3. Disperse the amphiphilic asymmetric organic-inorganic hybrid nanoparticles obtained in step S2 in water to obtain a nanoparticle dispersion. Mix the water-based latex primer with water to obtain a water-based latex primer diluent. Mix the nanoparticle dispersion with the water-based latex primer diluent and drop it onto a silicon wafer. After drying, obtain a water-based latex self-layering coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles. In step S1, the organic polymerizable monomer is selected from methyl acrylate, butyl acrylate, methyl methacrylate, styrene, and p-methylstyrene; The crosslinking agent is selected from m-divinylbenzene, p-divinylbenzene, 1,3,5-trivinylbenzene, 1,3-pentadiene, and isoprene; Fluorine-containing or long-chain vinyl monomers are also added to the mixed emulsion reaction to hydrophobically modify the surface of the organic microspheres. In step S2, the silane coupling agent monomer is selected from 2-cyanoethyltriethoxysilane and 2-cyanoethyltrimethoxysilane.

2. The method for preparing an aqueous latex self-layering coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles according to claim 1, characterized in that, In step S1, the ratio of sodium styrene sulfonate, potassium persulfate, methanol-water mixed solution, organic polymer monomer, and crosslinking agent is (80-85) mg: (140-160) mg: 200 mL: 27 mL: (0.27-2.7) mL; The volume ratio of methanol to water in the methanol-water mixture is 90:10 to 50:

50.

3. The method for preparing an aqueous latex self-layering coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles according to claim 1, characterized in that, The fluorinated or long-chain vinyl monomers are selected from trifluoroethyl acrylate, hexafluorobutyl acrylate, trifluoroethyl methacrylate, decyltriethoxysilane, dodecyltrimethoxysilane, and octadecyltriethoxysilane. The amount of the fluorinated or long-chain vinyl monomer added is 10-20% of the amount of the organic polymer monomer added.

4. The method for preparing an aqueous latex self-layering coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles according to claim 1, characterized in that, In step S2, the silane acrylate monomer is selected from 3-(trimethoxysilyl)propyl methacrylate, 3-(trimethoxysilyl)propyl acrylate, 3-(trimethoxysilyl)butyl acrylate, and 3-(triethoxysilyl)propyl methacrylate. The initiator is azobisisobutyronitrile.

5. The method for preparing an aqueous latex self-layering coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles according to claim 1, characterized in that, In step S2, the volume ratio of silane acrylate monomer to silane coupling agent monomer in the emulsion is 50:50-90:

10. The mass of the initiator added is five times the sum of the volumes of the silane acrylate monomer and the silane coupling agent monomer.

6. The method for preparing an aqueous latex self-layering coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles according to claim 1, characterized in that, In steps S1 and S2, the inert atmosphere is nitrogen, the pH of the solution is adjusted to 9.0, the temperature of the heating reaction is 70°C, and the heating reaction time is at least 24 h.

7. The method for preparing an aqueous latex self-layering coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles according to claim 1, characterized in that, When the silane coupling agent monomer in step S2 is selected from 2-cyanoethyltriethoxysilane or 2-cyanoethyltrimethoxysilane, in step S3, concentrated sulfuric acid is slowly added to the nanoparticle aqueous solution, and the reaction is heated for a period of time to obtain a surface carboxylated organic-inorganic hybrid amphiphilic asymmetric nanoparticle dispersion. Slowly add concentrated sulfuric acid to maintain an acidic environment in the reaction system at pH 1.8-2.5, heat the reaction at 90℃, and heat the reaction for 12-24 hours.

8. The method for preparing an aqueous latex self-layering coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles according to claim 1, characterized in that, In step S3, the concentration of nanoparticles in the nanoparticle dispersion is 0.01-0.5 g / mL; the concentration of the aqueous latex primer in the aqueous latex primer diluent is 40%-95% of the original concentration; the pH of the aqueous latex primer diluent is 5.01-12.05; and the volume ratio of the aqueous latex primer diluent to the nanoparticle dispersion is 95:5-50:

50. The thickness of the mixture of aqueous latex primer diluent and nanoparticle dispersion dropped onto the silicon wafer is 100-3000 μm.

9. A waterborne latex self-stratifying coating based on amphiphilic asymmetric organic-inorganic hybrid nanoparticles, characterized in that, Prepared according to the preparation method described in any one of claims 1-8.

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