Preparation method of Janus microcapsule and hydrophobic wear-resistant coating

Abstract

The application discloses a kind of Janus microcapsules and the preparation method of hydrophobic wear-resistant coating.Microcapsules include shell material and core material;Shell material two ends are high surface energy photocuring resin prepolymer, low surface energy photocuring prepolymer, and core material is hydrophobic agent;The surface energy of high surface energy photocuring prepolymer is higher than 20mN / m;The surface energy of low surface energy photocuring prepolymer is lower than 20mN / m.Janus microcapsules are dispersed in organic solvent to prepare Janus microcapsule dispersion;The prepared dispersion is sprayed on the surface of substrate to prepare coating, and hydrophobic wear-resistant coating is formed after solvent volatilization.The application can realize the independent control of microcapsule in structure, morphology and size, greatly widen the control window of microcapsule;Based on the hydrophobic wear-resistant coating of Janus microcapsule, the hydrophobicity and wear resistance of composite coating are improved.

Description

Technical Field

[0001] This invention relates to the field of microcapsule and functional coating preparation technology, and in particular to a method for preparing Janus microcapsules and a hydrophobic and wear-resistant coating. Background Technology

[0002] In the field of materials science, microcapsules with asymmetric shell structures, especially Janus microcapsules exhibiting anisotropic characteristics, show great promise for applications in several cutting-edge areas, including precise drug delivery, functionalized surface construction, and the development of high-performance catalytic systems. The asymmetry of Janus microcapsules is reflected in their structural dimensions (such as unique configurations like snowman and dumbbell shapes) and chemical composition. This characteristic can fully meet the practical needs of selective design and multifunctional integration, which is difficult to achieve with traditional homogeneous microcapsules. However, methods for efficiently constructing Janus microcapsules are currently relatively limited. How to prepare anisotropic Janus microcapsules using traditional emulsion templates remains an important topic that urgently needs further research.

[0003] The construction of hydrophobic and wear-resistant coatings is crucial for improving the water resistance, reducing wear rate, and extending the service life of materials. Constructing low surface energy surfaces, increasing surface roughness, and introducing lubricating materials are the main strategies for achieving hydrophobic and wear-resistant coatings. By spraying functional particles onto the substrate coating surface, surface systems with specific functions can be efficiently constructed. Hydrophobic particles with low surface energy properties, such as polytetrafluoroethylene particles and superhydrophobic SiO2, have been widely used to improve the hydrophobicity and lubrication / wear resistance of coatings. However, the bonding force between low surface energy particles and the substrate surface is usually weak, and the surface roughness is easily affected by wear in practical applications, leading to significant damage to the hydrophobicity and lubricity of the coating.

[0004] Janus microcapsules are a class of particles with two or more surface regions and cavities to support functional core materials. Compared to single-component particles and microcapsules, they exhibit anisotropy in physical and chemical properties and have attracted attention in coatings, drug delivery, and other fields. In constructing hydrophobic and wear-resistant coatings, the low surface energy side of Janus microcapsules can provide hydrophobicity, while the high surface energy side can adhere to the substrate, and the core material component can provide water-transporting lubrication properties. However, current research on hydrophobic coatings constructed with Janus microcapsules is relatively limited, and how the composition and morphology of Janus microcapsules affect the hydrophobic and wear-resistant properties of the coating remains unclear. Therefore, developing an efficient and convenient method for constructing Janus microcapsules and using them as fillers to prepare hydrophobic and wear-resistant coatings has significant practical implications. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this invention provides a method for preparing Janus microcapsules and a hydrophobic wear-resistant coating. This invention enables independent control of the structure, morphology, and size of the microcapsules, significantly broadening the control window for microcapsules; the hydrophobic wear-resistant coating based on Janus microcapsules enhances the hydrophobicity and wear resistance of the composite coating.

[0006] The technical solution of the present invention is as follows: The first objective of this invention is to provide a Janus microcapsule comprising a shell material and a core material; the two ends of the shell material are respectively a high surface energy photocurable resin prepolymer and a low surface energy photocurable prepolymer, and the core material is a hydrophobic agent; The surface energy of the high surface energy photocurable prepolymer is higher than 20 mN / m; The surface energy of the low surface energy photocurable prepolymer is less than 20 mN / m.

[0007] Janus microcapsules have anisotropic structures.

[0008] In one embodiment of the present invention, the high surface energy photocurable resin prepolymer is one or more of liquid polyurethane acrylate, liquid polyester acrylate, and liquid epoxy acrylate; the low surface energy photocurable resin prepolymer is one or more of liquid epoxy soybean oil acrylate, liquid photocurable silicone rubber, fluorine / silicone modified liquid polyurethane acrylate, fluorine / silicone modified liquid polyester acrylate, and fluorine / silicone modified liquid epoxy acrylate.

[0009] A second objective of this invention is to provide a method for preparing the above-mentioned Janus microcapsules, the method comprising the following steps: (1) The incompatible high surface energy photocurable prepolymer and low surface energy photocurable prepolymer, hydrophobic agent and photoinitiator are dissolved in an organic solvent and used as the oil phase; the emulsifier aqueous solution is used as the aqueous phase; (2) An emulsion is prepared by mixing the aqueous phase and the oil phase; (3) Stir the emulsion at 20-60℃ for 2-10 h to remove the organic solvent in the emulsion and obtain Janus droplets. Place them under an ultraviolet light source for irradiation and curing to obtain Janus microcapsules.

[0010] In one embodiment of the present invention, in step (1), the weight parts of each raw material in the oil phase are: 10-20 parts of high surface energy photocurable prepolymer; 10-20 parts of low surface energy photocurable prepolymer; 20-40 parts of hydrophobic agent; 1-2 parts of photoinitiator; 18-59 parts organic solvent.

[0011] In one embodiment of the present invention, the hydrophobic agent is one or more of liquid aliphatic hydrocarbons, aliphatic hydrocarbon derivatives, silicone oil, modified silicone oil, and fluorocarbon compounds.

[0012] Preferably, the hydrophobic agent is one or more of n-hexadecane, linseed oil, dimethylsiloxane, hydroxyl silicone oil, and perfluorohexane.

[0013] In one embodiment of the present invention, the photoinitiator is one or more of the following: 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-hydroxy-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, benzoin dimethyl ether, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, isopropylthioxanthraphenone, 4-chlorobenzophenone, 4,4'-dimethyldiphenyliodonium hexafluorophosphate, isooctyl p-dimethylaminobenzoate, 4-methylbenzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, ethyl 2,4,6-trimethylbenzoyl phenylphosphonate, and 2-isopropylthioxanthraphenone.

[0014] In one embodiment of the present invention, the organic solvent is one or more of aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, ethers, and esters.

[0015] Preferably, the organic solvent is one or more of diethyl ether, dichloromethane, ethyl acetate, and methyl acetate.

[0016] In one embodiment of the present invention, in step (1), the concentration of the emulsifier aqueous solution is 0.5-4 wt%; the emulsifier is one or more of polyoxyethylene ether, polysorbate, fatty acid sorbitan, polyvinyl alcohol, polyvinylpyrrolidone, alkyl sulfate, alkylbenzene sulfonate, and quaternary ammonium salt.

[0017] In one embodiment of the present invention, in step (2), the mass ratio of the oil phase to the water phase is 1:3-1:10.

[0018] In one embodiment of the present invention, in step (3), the method for removing organic solvents from the emulsion is to heat while stirring, with an evaporation temperature of 20-60°C and an evaporation time of 1-24 h.

[0019] Removing the organic solvent from the emulsion can induce phase separation in the system, thereby obtaining Janus droplets.

[0020] In one embodiment of the present invention, the wavelength of the ultraviolet light source for irradiation curing is 230-420 nm, and the curing time is 1-10 min.

[0021] A third objective of this invention is to provide a hydrophobic and wear-resistant coating containing the aforementioned Janus microcapsules, the preparation method of which includes the following steps: Janus microcapsules are dispersed in an organic solvent to prepare a Janus microcapsule dispersion; the prepared dispersion is sprayed onto the surface of a substrate to form a coating, and a hydrophobic and wear-resistant coating is formed after the solvent evaporates.

[0022] In one embodiment of the present invention, the organic solvent is one or more of the following organic solvents: alcohols, ketones, esters, ethers, aromatic hydrocarbons, alicyclic hydrocarbons, and halogenated hydrocarbons.

[0023] Preferably, the organic solvent is one or more of ethanol, acetone, diethyl ether, dichloromethane, and ethyl acetate.

[0024] In one embodiment of the present invention, the concentration of the Janus microcapsule dispersion is 10-200 mg / mL.

[0025] In one embodiment of the present invention, the substrate is one of epoxy resin, polyurethane resin, alkyd resin, and acrylic resin.

[0026] The hydrophobic and wear-resistant coating has a static water contact angle of over 90°, and after 1000 cycles of grinding wheel friction, the mass loss is less than 20 mg while the static water contact angle remains above 90°.

[0027] The beneficial technical effects of this invention are as follows: In this invention, the preparation of Janus microcapsules is achieved in one step using photopolymerization technology. Compared with traditional thermal initiator polymerization, photopolymerization technology has advantages such as high efficiency and speed, making it more suitable for the industrial production of microcapsules. In addition, the hydrophobic and wear-resistant coating is achieved by directly spraying Janus particle dispersion onto the surface of the substrate, which can be applied to different types of substrates and has wider versatility and applicability.

[0028] The hydrophobic and wear-resistant coating of this invention has a static water contact angle higher than 90°, and after 1000 cycles of grinding wheel friction, the mass loss is less than 20 mg while the static water contact angle remains higher than 90°. By controlling the shell material and core material at both ends of the prepared Janus microcapsules, Janus microcapsules with different structures and compositions can be constructed, and based on this, hydrophobic and wear-resistant coatings applicable to different scenarios can be constructed.

[0029] The preparation method of this invention is characterized by its simple process, wide applicability, and ease of industrialization. Janus microcapsules with different structures and functions can be selected according to different coatings, thus promoting the industrial application of high-performance microcapsules. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the preparation process of Janus microcapsules in this invention.

[0031] Figure 2 This is a schematic diagram of the preparation process of the hydrophobic and wear-resistant coating in this invention.

[0032] Figure 3 This is a schematic diagram of the structure of the Janus microcapsule in this invention.

[0033] Figure 4 This is a scanning electron microscope image of the Janus microcapsules prepared in Example 1 of this invention.

[0034] Figure 5 This is a scanning electron microscope image of the hydrophobic and wear-resistant coating prepared in Example 1 of this invention.

[0035] Figure 6 The water contact angle of the hydrophobic and wear-resistant coating prepared in Example 1 of this invention before and after 1000 cycles of grinding wheel friction.

[0036] Figure 7 The image shows the surface morphology of the hydrophobic and wear-resistant coating prepared in Example 1 of this invention after 1000 cycles of grinding wheel friction.

[0037] Figure 8 The images show scanning electron microscope (SEM) images of the composite coating surface prepared in Comparative Example 1 of this invention, as well as the water contact angles of the pure coating and the composite coating.

[0038] Figure 9 This is a scanning electron microscope image of the surface of the composite coating prepared in Comparative Example 2 of this invention. Detailed Implementation

[0039] Figure 1 This is a schematic diagram of the preparation process of Janus microcapsules in this invention. Two prepolymers with different surface energies and a core material can be mixed into a homogeneous phase in an organic solvent. As the solvent evaporates, the prepolymers precipitate from the oil phase and encapsulate around the core material. Due to the poor compatibility of the two prepolymers, phase separation occurs, eventually accumulating at both ends of the droplet to form an anisotropic structure. After UV irradiation, the photocurable prepolymers undergo a curing reaction, thereby preparing Janus microcapsules.

[0040] Figure 2 This is a flowchart illustrating the preparation process of a composite coating using Janus microcapsules sprayed onto the surface. Janus microcapsules are dispersed in a solvent and sprayed onto the coating surface. After drying, the composite coating is obtained. The high surface energy end of the Janus microcapsules is bonded to the resin matrix, while the low surface energy end is distributed on the coating surface, reducing the overall surface energy of the coating.

[0041] Figure 3 This is a schematic diagram of the Janus microcapsule structure. The Janus microcapsule has high surface energy and low surface energy sides, exhibiting an anisotropic structure, and also encapsulates a hydrophobic core material.

[0042] Source of raw materials Changxing Special Materials (Zhuhai) Co., Ltd.: Photocurable silicone resin E4629H; Sinopharm Chemical Reagent Co., Ltd.: Cetyltrimethylammonium bromide, hydroxyl silicone oil, 2-isopropylthioxanthanone, ethyl acetate, acetone, dichloromethane, n-hexadecane, 2-hydroxy-methylphenylacetone, polyvinyl alcohol, ethanol, 2-isopropylthioxanthanone; Jiangsu Kailin Ruiyang Chemical Co., Ltd.: Epoxy soybean oil acrylate RY1202; Zicai Chemical Co., Ltd.: Polyurethane acrylate ZC6203; Tianjin Zhonglian Chemical Reagent Co., Ltd.: Epoxy resin; Hunan Xintian Chemical Coating Co., Ltd.: Alkyd resin; Zhengzhou Senta Chemical Co., Ltd.: Polyurethane resin.

[0043] Test methods (1) Surface Energy Calculation: The interfacial energy between the polymer and the aqueous phase and between polymers was calculated using the Young equation and the harmonic averaging method, respectively. The interfacial energy between the polymer and the aqueous phase (γ) sl Based on the Young equation, Formula 1 is derived as follows: (1) The surface energy γ of aqueous phases containing different emulsifiers at 40℃ was measured using a surface tension meter (DCAT25). lg The contact angle (θ) of an emulsifier aqueous solution at a constant temperature of 40°C on a polymer film was measured using an optical contact angle meter (Theta Flow, Biolin, Sweden). sl The volume of the aqueous solution was 5 μL, and all contact angles were the average of three tests. The surface energy (γ) of the polymer... sg The surface energy components of the polymer were obtained by calculating them using the Owens-Wendt method. Specifically, the surface energy components of the polymer were calculated using Equation 2. , The surface energy can then be calculated by substituting the surface energy component into Formula 3. The contact angles (θ) of two standard liquids, glycerol and water, on polymer films were measured using optical contact angle measurement. The θ and γ values ​​of the two standard liquids are known. lg , and The polymer can be calculated by establishing a two-variable linear equation using Equation 2. and Then, γ can be obtained through Formula 3. sg Finally, according to Formula 1, γ is known. sg γ lg and θ sl γ can then be obtained sl .

[0044] (2) (3) In this context, the subscripts s, l, and g represent solid, liquid, and gas, respectively; and the superscripts d and p represent the dispersive component and the polar component, respectively. For the dispersion force of solid-gas surface, For the dispersion force of liquid-gas surface, For solid-gas surface polar forces, For the polar force on the liquid-gas surface, γ sg For solid surface energy, γ lg θ represents the surface energy of the liquid, and all units are (mN / m); θ is the solid-liquid contact angle (°).

[0045] (2) Wetting performance test: Static contact angle was measured using a contact angle goniometer employing the seated drop method (Theta Flow, Sweden), with 5 μL of distilled water as the test liquid. During the water contact angle (WCA) test, 5 μL of water was dropped onto the sample, and the average WCA value was obtained by measuring the sample at five different locations.

[0046] (3) Friction resistance test: The coating was applied to a circular glass plate and cured. It was fixed on a paint film abrasion tester and worn for 1000 times under a load of 500 g. The mass change before and after wear was weighed to evaluate the friction resistance of the coating. The surface morphology of the coating after wear was observed by scanning electron microscopy.

[0047] Example 1 A method for preparing anisotropic Janus microcapsules and a hydrophobic wear-resistant coating includes the following steps: (1) Preparation of emulsion template: Weigh 0.5 g of photocurable silicone resin (E4629H, surface energy 10.97 mN / m), 0.5 g of polyurethane acrylate (ZC6203, surface energy 26.28 mN / m), 1 g of n-hexadecane, 3 g of dichloromethane, and 0.02 g of 2-hydroxy-methylphenylacetone. After ultrasonic homogenization, use it as the oil phase. Add it to 50 g of 2 wt% hexadecyltrimethylammonium bromide aqueous solution at a mass ratio of oil phase:water phase = 1:10. Emulsify at 5000 rpm for 2 min to obtain a stable emulsion template. (2) Preparation of Janus microcapsules: The emulsion template was stirred at 40°C for 4 h. The two photosensitive prepolymers and n-hexadecane were phase separated by the volatilization of the solvent dichloromethane. The resulting emulsion was irradiated under 365 nm ultraviolet light for 5 min to obtain Janus microcapsules. The scanning electron microscope image of the prepared Janus microcapsules is shown below. Figure 4 As shown in the figure, the microcapsule has an anisotropic structure and is shaped like a snowman. The fracture point of the Janus microcapsule in the figure is the connection point between the two ends, which shows that the microcapsule has a large cavity inside, which can realize the load of the core material.

[0048] (3) Preparation of hydrophobic and wear-resistant coating: Janus microcapsules were dispersed in ethanol to prepare a microcapsule dispersion with a concentration of 40 mg / mL, and sprayed onto the surface of an epoxy resin coating. After drying, the hydrophobic and wear-resistant coating was obtained. The scanning electron microscope image of the hydrophobic and wear-resistant coating is shown below. Figure 5 As shown, the microcapsules are uniformly dispersed on the coating surface and can be embedded in the coating.

[0049] Example 2 A method for preparing anisotropic Janus microcapsules and a hydrophobic wear-resistant coating includes the following steps: (1) Preparation of emulsion template: Weigh 0.33 g of photocurable silicone resin (E4629H, surface energy of 10.97 mN / m), 0.67 g of polyurethane acrylate (ZC6203, surface energy of 26.28 mN / m), 1 g of n-hexadecane, 3 g of dichloromethane, and 0.02 g of 2-hydroxy-methylphenylacetone. After ultrasonic homogenization, use it as the oil phase. Add it to 50 g of 2 wt% polyvinyl alcohol aqueous solution at a mass ratio of oil phase:water phase = 1:10. Emulsify at 10000 rpm for 2 min to obtain a stable emulsion template. (2) Preparation of Janus microcapsules: The emulsion template was stirred at 40°C for 5 h. The two photosensitive prepolymers and n-hexadecane were phase separated by the volatilization of the solvent dichloromethane. The resulting emulsion was irradiated under 365 nm ultraviolet light for 5 min to obtain Janus microcapsules. (3) Preparation of hydrophobic and wear-resistant coating: Janus microcapsules were dispersed in acetone to prepare a microcapsule dispersion with a concentration of 20 mg / mL, and then sprayed onto the surface of alkyd resin coating. After drying, the hydrophobic and wear-resistant coating was obtained.

[0050] Comparative Example 1 A method for preparing high surface energy microcapsules and their coatings includes the following steps: (1) Preparation of emulsion template: Weigh 1 g of polyurethane acrylate (surface energy of 26.28 mN / m), 1 g of n-hexadecane, 3 g of dichloromethane, and 0.02 g of 2-hydroxy-methylphenylacetone. After ultrasonic homogenization, use it as the oil phase. Add it to 50 g of 2 wt% hexadecyltrimethylammonium bromide aqueous solution at a mass ratio of oil phase:water phase = 1:10. Emulsify at 5000 rpm for 2 min to obtain a stable emulsion template. (2) Preparation of microcapsules: The emulsion template was stirred at 40°C for 4 h. The photosensitive prepolymer and n-hexadecane were phase separated by the volatilization of the solvent dichloromethane. The resulting emulsion was irradiated under 365 nm ultraviolet light for 5 min to obtain high surface energy microcapsules. (3) Coating preparation: Microcapsules were dispersed in ethanol to prepare a microcapsule dispersion with a concentration of 40 mg / mL, and sprayed onto the surface of the epoxy resin coating. After drying, a hydrophobic and wear-resistant coating was obtained. The scanning electron microscope image of the hydrophobic and wear-resistant coating is shown below. Figure 8 As shown in Figure a, the microcapsules are uniformly dispersed on the coating surface and can be embedded within the coating. However, due to the high surface energy of the polyurethane acrylate, which is relatively hydrophilic, the water contact angle of the prepared composite coating is only 60.8°, which is basically the same as that of the pure epoxy coating, and thus cannot achieve hydrophobic properties. Figure 8 b).

[0051] Comparative Example 2 A method for preparing low surface energy microcapsules and their coatings includes the following steps: (1) Preparation of emulsion template: Weigh 1 g of photocurable silicone resin (E4629H, surface energy of 10.97 mN / m), 1 g of n-hexadecane, 3 g of dichloromethane, and 0.02 g of 2-hydroxy-methylphenylacetone. After ultrasonic homogenization, use it as the oil phase. Add it to 50 g of 2 wt% hexadecyltrimethylammonium bromide aqueous solution at a mass ratio of oil phase:water phase = 1:10. Emulsify at 5000 rpm for 2 min to obtain a stable emulsion template. (2) Preparation of microcapsules: The emulsion template was stirred at 40°C for 4 h. The photosensitive prepolymer and n-hexadecane were phase separated by the volatilization of the solvent dichloromethane. The resulting emulsion was irradiated under 365 nm ultraviolet light for 5 min to obtain low surface energy microcapsules. (3) Preparation of coating: The microcapsules were dispersed in ethanol to prepare a microcapsule dispersion with a concentration of 40 mg / mL, and sprayed onto the surface of the epoxy resin coating. After drying, a hydrophobic and wear-resistant coating was obtained. Figure 9 The image shows a scanning electron microscope (SEM) image of the hydrophobic and wear-resistant coating. It can be seen that the microcapsules are uniformly dispersed on the coating surface. However, since there is no interaction between the low surface energy photocurable silicone resin and the epoxy material surface, a large number of microcapsules detach from the coating surface.

[0052] Test example: The hydrophobic and wear-resistant coating prepared in Example 1 was rubbed with a grinding wheel 1000 times. The water contact angle before and after rubbing is as follows: Figure 6 As shown, the surface morphology of the coating after friction is as follows: Figure 7 As shown.

[0053] Depend on Figure 6 It can be seen that the water contact angles of the coating before and after friction are 125° and 129°, respectively, with little change.

[0054] Depend on Figure 7 As can be seen, the coating surface is smooth after friction, and no obvious wear marks were observed.

[0055] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A Janus microcapsule, characterized in that, It includes a shell material and a core material; the two ends of the shell material are high surface energy photocurable resin prepolymer and low surface energy photocurable resin prepolymer, respectively, and the core material is a hydrophobic agent; The surface energy of the high surface energy photocurable resin prepolymer is higher than 20 mN / m; The surface energy of the low surface energy photocurable resin prepolymer is less than 20 mN / m; The high surface energy photocurable resin prepolymer is one or more of liquid polyurethane acrylate, liquid polyester acrylate, and liquid epoxy acrylate; the low surface energy photocurable resin prepolymer is one or more of liquid photocurable silicone rubber, fluoro / silicone modified liquid polyurethane acrylate, fluoro / silicone modified liquid polyester acrylate, and fluoro / silicone modified liquid epoxy acrylate.

2. A method for preparing the Janus microcapsules according to claim 1, characterized in that, The preparation method includes the following steps: (1) The incompatible high surface energy photocurable resin prepolymer and low surface energy photocurable resin prepolymer, hydrophobic agent and photoinitiator are dissolved in an organic solvent and used as the oil phase; the emulsifier aqueous solution is used as the aqueous phase; (2) An emulsion is prepared by mixing the aqueous phase and the oil phase; (3) Stir the emulsion at 20-60℃ for 2-10 h to remove the organic solvent in the emulsion and obtain Janus droplets. Place them under an ultraviolet light source for irradiation and curing to obtain Janus microcapsules.

3. The preparation method according to claim 2, characterized in that, In step (1), the weight parts of each raw material in the oil phase are: 10-20 parts of high surface energy photocurable resin prepolymer; 10-20 parts of low surface energy photocurable resin prepolymer; 20-40 parts of hydrophobic agent; 1-2 parts of photoinitiator; 18-59 parts organic solvent.

4. The preparation method according to claim 3, characterized in that, The hydrophobic agent is one or more of liquid aliphatic hydrocarbons, aliphatic hydrocarbon derivatives, silicone oil, modified silicone oil, and fluorocarbon compounds; the photoinitiator is one or more of 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-hydroxy-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, benzoin dimethyl ether, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, isopropylthioxanthone, 4-chlorobenzophenone, 4,4'-dimethyldiphenyliodonium hexafluorophosphate, isooctyl p-dimethylaminobenzoate, 4-methylbenzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, and ethyl 2,4,6-trimethylbenzoyl phenylphosphonate; the organic solvent is one or more of aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, ethers, and ester organic solvents.

5. The preparation method according to claim 2, characterized in that, In step (1), the concentration of the emulsifier aqueous solution is 0.5-5 wt%; the emulsifier is one or more of polyoxyethylene ether, polysorbate, fatty acid sorbitan, polyvinyl alcohol, polyvinylpyrrolidone, alkyl sulfate, alkylbenzene sulfonate, and quaternary ammonium salt.

6. The preparation method according to claim 2, characterized in that, In step (2), the mass ratio of oil phase to water phase is 1:3-10; the photocuring system is UV photocuring, the UV light source wavelength is 230-420 nm, and the irradiation curing time is 1-10 min.

7. The preparation method according to claim 2, characterized in that, In step (3), the method for removing organic solvents from the emulsion is to heat while stirring, with an evaporation temperature of 20-60℃ and an evaporation time of 1-24 h.

8. A hydrophobic and wear-resistant coating containing the Janus microcapsules of claim 1, characterized in that, Its preparation method includes the following steps: Janus microcapsules are dispersed in an organic solvent to prepare a Janus microcapsule dispersion; the prepared dispersion is sprayed onto the surface of a substrate to form a coating, and a hydrophobic and wear-resistant coating is formed after the solvent evaporates.

9. The hydrophobic and wear-resistant coating according to claim 8, characterized in that, The organic solvent is one or more of alcohols, ketones, esters, ethers, aromatic hydrocarbons, alicyclic hydrocarbons, and halogenated hydrocarbons; the concentration of the Janus microcapsule dispersion is 10-200 mg / mL; the substrate is one of epoxy resin, polyurethane resin, alkyd resin, and acrylic resin.

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