Microcapsule encapsulated repair agent, anti-icing coating, and methods of making and using the same

Abstract

The application belongs to the technical field of functional coating materials, and particularly relates to a microcapsule encapsulated repairing agent, an anti-icing coating and a preparation method and application thereof. The microcapsule encapsulated repairing agent is prepared by taking a complex of epoxy resin and microcrystalline wax as a core material, wrapping the core material with an inorganic nanomaterial-graphene composite material to obtain a primary microcapsule, and then performing surface modification on the primary microcapsule with dopamine to form a photo-thermal modification layer. The microcapsule encapsulated repairing agent has a high-density micro-nano protrusion rough structure, which significantly increases the specific surface area of the microcapsule, greatly improves the effective surface area of photo-thermal conversion, and also helps to improve the bonding force between the microcapsule and the coating matrix.

Description

Technical Field

[0001] This invention belongs to the field of functional coating materials technology, specifically relating to a microcapsule encapsulation repair agent, an anti-icing coating, its preparation method, and its application. Background Technology

[0002] In fields such as power grids, wind power, and aerospace, icing in low-temperature environments can lead to decreased equipment efficiency, increased risk of failure, and even safety accidents. Traditional anti-icing coatings primarily achieve icing prevention by reducing surface energy and active heating, such as superhydrophobic coatings for reducing surface energy and electrothermal coatings for active heating. However, these methods have the following drawbacks: (1) Superhydrophobic coating: Relying on the air trapping effect of the surface microstructure, the structure is prone to wear after long-term use and has poor anti-icing durability; (2) Electric heating coating: High energy consumption, and prone to local overheating or circuit failure in extreme environments; (3) Photothermal coating: Existing materials have low photothermal conversion efficiency, long ice melting response time, and lack self-repair function, making it difficult to cope with performance failure caused by coating damage.

[0003] To address these issues, researchers have attempted to combine self-healing technology with photothermal functionality, for example, by encapsulating repair agents in microcapsules while adding photothermal materials such as carbon nanotubes and graphene. However, the shell materials used in traditional microcapsule encapsulation of repair agents are urea-formaldehyde resin, melamine-formaldehyde resin, or polyurea / polyurethane. Their chemical nature means that they do not possess the driving force to generate roughness during the formation process, resulting in smooth surfaces, limited effective photothermal conversion area, and low self-healing ability. Furthermore, the simultaneous addition of self-healing agents and photothermal materials often leads to a decrease in coating adhesion. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a microcapsule encapsulation repair agent, an anti-icing coating, its preparation method, and its application.

[0005] A microcapsule encapsulation repair agent, wherein the microcapsule encapsulation repair agent uses a composite of epoxy resin and microcrystalline wax as the core material, and an inorganic nanomaterial-graphene composite material is coated on the surface to obtain a primary microcapsule. The surface of the primary microcapsule is polymerized with dopamine to form a photothermal modification layer, thereby obtaining the microcapsule encapsulation repair agent.

[0006] The inorganic nanomaterials and graphene in the microcapsule encapsulation repair agent of this invention self-assemble and grow in a controlled manner on the surface of primary microcapsules, forming a high-density micro-nano protrusion rough structure, which significantly increases the specific surface area of ​​the microcapsules. While greatly improving the effective surface area for photothermal conversion, it also helps to improve the bonding force between the microcapsules and the coating substrate.

[0007] Preferably, the core material is obtained by mixing epoxy resin and microcrystalline wax in a mass ratio of 1~7:1~3, and heating to mix the molten microcrystalline wax and epoxy resin evenly.

[0008] Preferably, the inorganic nanomaterial-graphene composite material is obtained by mixing inorganic nanomaterials, graphene, hexadecyltrimethylammonium bromide and formamide in a mass ratio of 1:1~3:1~3:50~100.

[0009] Preferably, the inorganic nanomaterial is any one of SiO2, CeO2, TiO2 and ZnO, and its particle size is 10nm~200nm.

[0010] Preferably, the graphene is hydroxyl-modified graphene or graphene oxide.

[0011] A method for preparing the microcapsule-encapsulated repair agent includes the following steps: The core material and the inorganic nanomaterial-graphene composite material were mixed at a mass ratio of 1:5 to 10. A polyacrylamide solution with a mass percentage concentration of 0.1 wt% to 1.0 wt% was added, and the mixture was emulsified at 5000 r / min to 15000 r / min at 40℃ to 70℃ for 5 min to 15 min to form primary microcapsules. The ratio of the polyacrylamide solution to the core material was 10 g: 5 to 8 mL. Primary microcapsules are dispersed in a dopamine hydrochloride solution and reacted at 30℃~40℃ in the dark for 4~12 hours to allow dopamine to polymerize on the surface of the primary microcapsules to form a photothermal modified layer. After filtration and drying, the microcapsule encapsulation repair agent is obtained. The mass ratio of microcapsules to dopamine hydrochloride in the dopamine hydrochloride solution is 10~20:1.

[0012] An anti-icing coating is composed of 100 parts of a base epoxy resin, 5 to 20 parts of the microcapsule encapsulation repair agent, 25 to 30 parts of a curing agent, and 0.8 to 1.3 parts of a coating additive.

[0013] Preferably, the curing agent is polyamide, and the coating additive is a mixture of defoamer and leveling agent in a mass ratio of 0.5~0.8:0.3~0.5.

[0014] A method for preparing the aforementioned anti-icing coating includes the following steps: The surface micro-nano rough structure microcapsule additive is mixed with the matrix epoxy resin, and then a curing agent and coating additive are added and mixed to obtain a mixed slurry. The mixed slurry is coated on the surface of the substrate and cured at 50℃~100℃ to obtain the photothermal self-healing anti-icing coating.

[0015] The application of the anti-icing coating in preventing icing on the surface of power grid transmission and transformation equipment or wind turbine blades.

[0016] The core innovation of this invention lies in the design of microcapsule additives with surface micro / nano rough structures, which achieves performance breakthroughs through the following three dimensions: 1. Micron-nano multi-level rough structure: Using polyacrylamide as a surfactant regulator to induce the self-assembly and controlled aggregation growth of inorganic nanomaterials and graphene on the surface of microcapsules, a multi-level structure of "1~5μm micron protrusions and 50~200nm nanon protrusions" is formed, which significantly increases the specific surface area of ​​microcapsules. While greatly improving the effective surface area for photothermal conversion, it also helps to improve the adhesion between microcapsules and coating substrate.

[0017] 2. Composite photothermal system: Through the synergistic effect of polydopamine surface modification and graphene, the light absorption range is broadened, covering the ultraviolet region and extending to the infrared region, and the photothermal conversion efficiency is greatly improved. In addition, polydopamine improves the interfacial compatibility between microcapsules and matrix resin through catechol groups, which helps to improve the bonding force between microcapsules and coating matrix.

[0018] 3. Rapid self-healing mechanism: Using epoxy resin and microcrystalline wax composite material as core material, when the coating is damaged, the microcapsules rupture to release the core material, which is then rapidly cross-linked and cured on the substrate surface. The microcrystalline wax can be simultaneously melted under photothermal temperature. The epoxy resin and microcrystalline wax work together to repair and quickly restore the integrity of the coating.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: The photothermal self-healing anti-icing coating of this invention features a micro-nano rough surface structure that increases light capture rate. Graphene and polydopamine synergistically absorb sunlight, converting light energy into heat energy. This allows the coating surface temperature to rise from -20°C to above 0°C within 15-30 seconds and to 50°C within 40-50 seconds under a single solar irradiance, achieving rapid ice melting. After 100 repeated ice melting cycles at -20°C, the photothermal conversion efficiency shows no significant attenuation. When the coating is damaged, the microcapsule wall ruptures, and the epoxy resin in the core material comes into contact with moisture in the air or the curing agent on the substrate surface, undergoing a cross-linking reaction. Scratches ≤50μm can be repaired within 15 minutes, and scratches ≤100μm can be repaired within 30 minutes. After self-healing, the photothermal conversion efficiency shows no significant attenuation, and the coating exhibits excellent durability. Attached Figure Description

[0020] Figure 1 It is the morphology of microcapsule additives with surface micro-nano rough structure.

[0021] Figure 2 The results are EDS energy dispersive spectroscopy characterization results of microcapsule additives with surface micro-nano rough structure.

[0022] Figure 3 This is a comparison chart of the photothermal conversion temperatures of the coatings.

[0023] Figure 4 This is the SEM morphology of the coating after self-healing of scratches. Detailed Implementation

[0024] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods.

[0025] The hydroxyl-modified graphene used in this invention was purchased from Röhn Reagents, model number CAS: 7782-42-5.

[0026] The graphene oxide was purchased from KERI Nano (Guangdong) Co., Ltd., model number CAS: 308068-56-6.

[0027] Example 1: Preparation of a 5% low-addition photothermal self-healing microcapsule coating suitable for light-load protection scenarios.

[0028] 1. Preparation of microcapsule encapsulated repair agent.

[0029] S1. Preparation of core material premix liquid.

[0030] Raw material ratio: 50g epoxy resin E-51, 50g microcrystalline wax, with a mass ratio of 1:1. The epoxy value of epoxy resin E-51 is 0.51eq / 100g, and the microcrystalline wax is industrial grade with a melting point of 58℃.

[0031] Process parameters: Add the above raw materials to a 500mL three-necked flask, stir with a mechanical stirrer at 400r / min, heat the water bath to 70℃, at which point the microcrystalline wax will be completely melted, and continue stirring for 10 minutes to obtain a uniform and transparent core material premix.

[0032] S2. Preparation of wall material premix liquid.

[0033] Raw material ratio: 5g hexadecyltrimethylammonium bromide, 5g nano-silica, 5g graphene oxide, 500g formamide, in a mass ratio of 1:1:1:100. Hexadecyltrimethylammonium bromide (CTAB) is of analytical grade; nano-silica has a particle size of 20nm; graphene has 5-10 layers with a sheet diameter of 1μm-5μm; hexadecyltrimethylammonium bromide is used as a surfactant; and formamide is of analytical grade.

[0034] Process parameters: CTAB, nano silica, and graphene oxide are added to formamide in sequence and stirred at 400 r / min for 10 minutes in a 50℃ water bath to form a black suspension with a solid content of 2%. The suspension is ultrasonically dispersed for 5 minutes to remove air bubbles and obtain the wall material premix.

[0035] S3. Preparation of primary microcapsules.

[0036] Mixing and emulsification: 100g of the core material premix prepared in S1 was slowly added dropwise to 520g of the wall material premix prepared in S2. After stirring at 400 rpm for 20 minutes, 50mL of 0.5wt% polyacrylamide aqueous solution was added. The mixture was then transferred to a homogenizer and emulsifier, set to 10000 rpm and a water bath temperature of 60℃, and emulsified for 10 minutes to form a white emulsion, which is the emulsion of primary microcapsules. Polyacrylamide is a surface-active regulator used to regulate the growth of the wall material. Too much polyacrylamide can lead to severe agglomeration of inorganic materials, while too little can prevent the wall material from forming a rough structure.

[0037] S4. Construction of the dopamine photothermal modified layer.

[0038] Dopamine polymerization: The emulsion of primary microcapsules was centrifuged to separate the precipitate and obtain microcapsules. 150g of microcapsules were dispersed in 2000mL of a 3mg / mL dopamine hydrochloride aqueous solution and reacted in a 35℃ water bath at 200r / min in the dark for 5 hours. The solution changed from white to dark brown. The pH of the dopamine hydrochloride aqueous solution was 8.8. The pH was adjusted using Tris-HCl buffer. The mass ratio of microcapsules to dopamine hydrochloride was 15:1, specifically 150g of microcapsules and 10g of dopamine hydrochloride. Too high or too low pH values ​​will affect the formation of polydopamine.

[0039] Post-processing: Vacuum filtration was performed using a 0.45μm filter membrane, followed by washing with deionized water three times and vacuum drying at 60℃ for 12 hours to obtain a microcapsule additive with a surface micro-nano rough structure, i.e., a microcapsule encapsulation repair agent.

[0040] The prepared surface micro / nano roughened structure microcapsule additive has an average particle size of approximately 100 μm, forming a high-density micro / nano protrusion roughened structure, such as... Figure 1 As shown, silica nanoparticles are uniformly distributed on the surface of the microcapsules, such as... Figure 2 As shown.

[0041] 2. Preparation of photothermal self-healing anti-icing coating.

[0042] S1. Preparation of coating slurry.

[0043] Raw material ratio: 100g of base epoxy resin EP-3310, 5g of surface micro / nano roughened structure microcapsule additive prepared by S4, 25g of type 650 polyamide curing agent, 0.5g of BYK-066N defoamer, and 0.3g of BYK-333 leveling agent. The type 650 polyamide curing agent has an active hydrogen equivalent of 220.

[0044] Mixing process: The matrix epoxy resin and the surface micro-nano rough structure microcapsule additive are mixed and mechanically stirred. After stirring for 10 minutes, the curing agent, defoamer and leveling agent are added, and stirring is continued for 10 minutes to obtain a uniform coating slurry.

[0045] S2, Coating and Curing.

[0046] Substrate pretreatment: Q235 steel sheets with specifications of 100mm×100mm×2mm are successively sanded with 800-grit sandpaper, degreased with acetone, cleaned with ethanol, and dried for later use.

[0047] Coating process: The S1 coating slurry was sprayed onto the pretreated Q235 steel sheet using air spraying. The wet film thickness was 400μm. After leveling at room temperature for 15 minutes, the sheet was placed in a forced-air oven and cured at 80℃ for 3 hours to obtain a photothermal self-healing anti-icing coating. During spraying, the nozzle diameter was 2.5mm and the air pressure was 0.4MPa.

[0048] Example 2: 1. Preparation of microcapsule encapsulated repair agent.

[0049] S1. Preparation of core material premix liquid.

[0050] Raw material ratio: 60g epoxy resin E-44, 40g microcrystalline wax, with a mass ratio of 3:2. The epoxy value of epoxy resin E-44 is 0.44eq / 100g.

[0051] Process parameters: Add the above raw materials to a three-necked flask, stir with a mechanical stirrer at 500 r / min, heat to 75℃ in a water bath, stir for 12 minutes to obtain the core material premix.

[0052] S2. Preparation of wall material premix liquid.

[0053] Raw material ratio: CTAB 8g, nano titanium dioxide 16g, hydroxyl-modified graphene 16g, formamide 800g, with a mass ratio of 1:2:2:100. The nano titanium dioxide is anatase phase with a particle size of 15nm.

[0054] Process parameters: CTAB, nano titanium dioxide, and hydroxyl-modified graphene are added to formamide in sequence, stirred at 500 r / min for 15 minutes in a 50℃ water bath, and ultrasonically dispersed for 8 minutes to obtain the wall material premix.

[0055] S3. Preparation of primary microcapsules.

[0056] Emulsification process: 100g core material premix and 800g wall material premix were stirred at 450r / min for 25 minutes, 60mL of 1.0wt% polyacrylamide aqueous solution was added, and emulsification was carried out in a homogenizer at 12000r / min and 65℃ for 8 minutes to obtain an emulsion of primary microcapsules.

[0057] S4. Construction of the dopamine photothermal modified layer.

[0058] Dopamine polymerization: The emulsion of primary microcapsules was centrifuged and the precipitate was collected to obtain microcapsules. 180g of microcapsules were dispersed in 2000mL of dopamine hydrochloride aqueous solution with a concentration of 4mg / mL and stirred at 38℃ for 6 hours. The mass ratio of microcapsules to dopamine hydrochloride was 12:1, specifically 180g of microcapsules and 15g of dopamine hydrochloride. The pH of the dopamine solution was 8.8.

[0059] A 0.45 μm filter membrane was vacuum filtered, washed three times with deionized water, and vacuum dried at 60 °C for 12 hours to obtain a microcapsule additive with a surface micro-nano rough structure, namely a microcapsule encapsulation repair agent.

[0060] The prepared surface micro-nano rough structure microcapsule additive has an average particle size of about 160 μm, a rough surface, and a high-density micro-nano protrusion structure.

[0061] 2. Coating preparation.

[0062] S1. Coating slurry preparation: 100g of base epoxy resin EP-3310, 15g of surface micro-nano rough structure microcapsule additive, 30g of type 650 polyamide curing agent, 0.6g of BYK-066N defoamer, and 0.4g of BYK-333 leveling agent.

[0063] The matrix epoxy resin and the surface micro-nano rough structure microcapsule additive are mixed and mechanically stirred. After stirring for 10 minutes, the curing agent, defoamer and leveling agent are added, and stirring is continued for 10 minutes to obtain a uniform coating slurry.

[0064] S2. Coating and Curing: The coating slurry of S1 was sprayed onto 6061 aluminum alloy by air spraying. The wet film thickness was 400μm. After leveling at room temperature for 15 minutes, it was placed in a forced-air oven and cured at 100℃ for 2.5 hours to obtain a photothermal self-healing anti-icing coating with a dry film thickness of 300μm and an adhesion grade of 0.

[0065] Example 3: 1. Preparation of microcapsule encapsulated repair agent.

[0066] S1. Preparation of core material premix: 70g of epoxy resin E-51 and 30g of microcrystalline wax in a mass ratio of 7:3 were added to a three-necked flask and stirred at 500r / min for 15 minutes. The water bath temperature was raised to 80℃ and stirred for 10 minutes to obtain a uniform and transparent core material premix.

[0067] S2. Preparation of the wall material premix: 10g CTAB, 30g nano zinc oxide, 30g graphene, and 500g formamide in a mass ratio of 1:3:3:50. CTAB, nano zinc oxide, and graphene are added sequentially to the formamide. The mixture is stirred at 500r / min for 20 minutes in a 50℃ water bath and then ultrasonically dispersed for 10 minutes. The nano zinc oxide has a particle size of 30nm.

[0068] S3. Preparation of primary microcapsules: 100g of core material premix and 1000g of wall material premix were stirred at 500r / min for 30 minutes, 80mL of 0.8wt% polyacrylamide aqueous solution was added, and emulsified in a homogenizer at 15000r / min and 70℃ for 5 minutes to obtain an emulsion of primary microcapsules.

[0069] S4. Construction of the dopamine photothermal modified layer: The primary microcapsule emulsion was centrifuged and the precipitate was collected to obtain microcapsules. 200g of microcapsules were dispersed in 2000mL of dopamine hydrochloride aqueous solution with a concentration of 5mg / mL. The mixture was stirred at 40℃ for 6 hours and then vacuum filtered through a 0.45μm filter membrane. The microcapsules were washed three times with deionized water and then vacuum dried at 60℃ for 12 hours to obtain a microcapsule additive with a surface micro-nano rough structure, i.e., a microcapsule encapsulation repair agent. The mass ratio of microcapsules to dopamine hydrochloride was 10:1, specifically 200g of microcapsules and 20g of dopamine hydrochloride. The pH of the dopamine hydrochloride aqueous solution was 8.5.

[0070] The prepared surface micro-nano rough structure microcapsule additive has an average particle size of about 150 μm, a rough surface, and a high-density micro-nano protrusion structure.

[0071] 2. Coating preparation.

[0072] S1. Coating slurry preparation: 100g of base epoxy resin EP-3310, 20g of surface micro-nano rough structure microcapsule additive, 35g of 650 type polyamide curing agent, 0.8g of BYK-066N defoamer, and 0.5g of BYK-333 leveling agent. Mix the base epoxy resin and surface micro-nano rough structure microcapsule additive and mechanically stir at 500r / min for 30 minutes. Then add the curing agent, defoamer, and leveling agent, and continue stirring for 10 minutes to obtain a uniform coating slurry.

[0073] S2. Coating and curing: The prepared coating slurry was sprayed onto a steel pipe substrate with a specification of φ50mm×200mm using the dip coating method. The wet film thickness was 1000μm. The coating was pre-cured at 50℃ for 1 hour and cured at 100℃ for 3 hours to obtain a photothermal self-healing anti-icing coating with a dry film thickness of 800μm.

[0074] Comparative Example 1: Coating slurry preparation: 100g of epoxy resin EP-3310, 0.5g of BYK-066N defoamer, and 0.3g of BYK-333 leveling agent. The 650 type polyamide curing agent has an active hydrogen equivalent of 220. Mix the epoxy resin, curing agent, defoamer, and leveling agent for 10 minutes to obtain a uniform coating slurry.

[0075] Substrate pretreatment: Q235 steel sheets with specifications of 100mm×100mm×2mm are successively sanded with 800-grit sandpaper, degreased with acetone, cleaned with ethanol, and dried for later use.

[0076] Coating process: The prepared coating slurry was sprayed onto pretreated Q235 steel sheets using air spraying. The wet film thickness was 400 μm. After leveling at room temperature for 15 minutes, the sheets were placed in a forced-air oven and cured at 80°C for 3 hours to obtain a photothermal self-healing anti-icing coating. During spraying, the nozzle diameter was 2.5 mm and the air pressure was 0.4 MPa.

[0077] Comparative Example 2: The difference between Comparative Example 2 and Example 1 is that the dopamine photothermal modification layer was not constructed, as detailed below: S1. Preparation of core material premix: 50g of epoxy resin E-51 and 50g of microcrystalline wax in a mass ratio of 1:1. The epoxy value of epoxy resin E-51 is 0.51eq / 100g, and the microcrystalline wax is industrial grade with a melting point of 58℃. The above raw materials are added to a 500mL three-necked flask and stirred at 400r / min using a mechanical stirrer. The water bath temperature is raised to 70℃, at which point the microcrystalline wax is completely melted. Stirring is continued for 10 minutes to obtain a uniform and transparent core material premix.

[0078] S2. Preparation of wall material premix: 5g of cetyltrimethylammonium bromide, 5g of nano silica, 5g of graphene, and 500g of formamide in a mass ratio of 1:1:1:100. Add CTAB, nano silica, and graphene to formamide in sequence. Stir at 400r / min for 10 minutes in a 50℃ water bath to form a black suspension with a solid content of 2%. Ultrasonically disperse for 5 minutes to remove air bubbles to obtain the wall material premix.

[0079] S3. Preparation of primary microcapsules: Slowly drop 100g of the core material premix prepared in S1 into 520g of the wall material premix prepared in S2. Stir at 400r / min for 20 minutes, then add 50mL of 0.5wt% polyacrylamide aqueous solution. Transfer to a homogenizer and emulsifier, set the speed to 10000r / min and the water bath temperature to 60℃, and emulsify for 10 minutes to form a white emulsion, which is the emulsion of primary microcapsules.

[0080] S4. Coating slurry preparation: 100g of epoxy resin EP-3310 as the base, 5g of the emulsion of the prepared primary microcapsules, 25g of type 650 polyamide curing agent, 0.5g of BYK-066N defoamer, and 0.3g of BYK-333 leveling agent. The type 650 polyamide curing agent has an active hydrogen equivalent of 220. The epoxy resin and the surface micro / nano roughened microcapsule additive are mixed and mechanically stirred for 10 minutes. Then, the curing agent, defoamer, and leveling agent are added, and stirring continues for another 10 minutes to obtain a uniform coating slurry.

[0081] S5. Coating and Curing: Q235 steel sheets with dimensions of 100mm×100mm×2mm were sequentially sanded with 800-grit sandpaper, degreased with acetone, cleaned with ethanol, and dried for later use. The prepared coating slurry was sprayed onto the pretreated Q235 steel sheets using air spraying, with a wet film thickness of 400μm. After leveling at room temperature for 15 minutes, the sheets were placed in a forced-air oven and cured at 80℃ for 3 hours to obtain a photothermal self-healing anti-icing coating. During spraying, the nozzle diameter was 2.5mm and the air pressure was 0.4MPa.

[0082] The coatings of the examples and comparative examples were subjected to performance tests. The test items and methods are as follows: Photothermal conversion efficiency: Xenon lamp simulates sunlight, 1 solar irradiance, infrared temperature measurement and timing.

[0083] De-icing cycle durability: -20℃ freezing / sunlight de-icing, 100 cycles, each cycle lasting 2 hours, the de-icing time for each cycle is recorded, and the de-icing time change rate is calculated. De-icing time change rate = (first de-icing time - last de-icing time) / first de-icing time.

[0084] Self-healing performance: The blade can scratch 50μm and then be left to stand under sunlight of 1 intensity.

[0085] Coating adhesion: Scratch test, see GB / T 30707-2014.

[0086] Note: One solar irradiance is 100 mW / cm². 2 .

[0087] The performance test results are shown in Table 1.

[0088] Table 1: Performance test results.

[0089]

[0090] Photothermal conversion temperature comparison chart as follows Figure 3 The SEM morphology of the scratch after self-healing is as follows: Figure 4 Performance test results demonstrate that the coating of the embodiment exhibits rapid heating under light irradiation, good stability under repeated freeze-thaw cycles, fast self-healing speed, and high coating adhesion. In particular, a comparison was made of the photothermal conversion efficiency of coatings prepared with no SiO2, with SiO2 but without polydopamine modification, and with SiO2 and polydopamine-modified microcapsules. It was found that both the addition of SiO2 and polydopamine modification significantly improved the photothermal conversion efficiency, fully demonstrating the crucial influence of the surface protrusion structure and polydopamine modification proposed in this invention on photothermal conversion performance.

[0091] It should be noted that when numerical ranges are mentioned in the claims of this invention, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. To avoid redundancy, the present invention describes preferred embodiments.

[0092] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0093] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A microcapsule-encapsulated repair agent, characterized in that, The microcapsule encapsulation repair agent uses a composite of epoxy resin and microcrystalline wax as the core material, and then coats the surface with an inorganic nanomaterial-graphene composite material to obtain a primary microcapsule. The surface of the primary microcapsule is polymerized with dopamine to form a photothermal modification layer, thereby obtaining the microcapsule encapsulation repair agent.

2. The microcapsule encapsulation repair agent according to claim 1, characterized in that, The core material is obtained by mixing epoxy resin and microcrystalline wax in a mass ratio of 1~7:1~3, and heating to mix the molten microcrystalline wax and epoxy resin evenly.

3. The microcapsule encapsulation repair agent according to claim 1, characterized in that, The inorganic nanomaterial-graphene composite material is obtained by mixing inorganic nanomaterials, graphene, hexadecyltrimethylammonium bromide and formamide in a mass ratio of 1:1~3:1~3:50~100.

4. The microcapsule encapsulation repair agent according to claim 1, characterized in that, The inorganic nanomaterial is any one of SiO2, CeO2, TiO2 and ZnO, with a particle size of 10nm~200nm.

5. The microcapsule encapsulation repair agent according to claim 1, characterized in that, The graphene is hydroxyl-modified graphene or graphene oxide.

6. A method for preparing the microcapsule-encapsulated repair agent according to claim 1, characterized in that, Includes the following steps: The core material and the inorganic nanomaterial-graphene composite material are mixed at a mass ratio of 1:5 to 10. A polyacrylamide solution with a mass percentage concentration of 0.1 wt% to 1.0 wt% is added, and the mixture is emulsified at 5000 r / min to 15000 r / min at 40℃ to 70℃ for 5 min to 15 min to form primary microcapsules. The ratio of the polyacrylamide solution to the core material is 10g: 5~8mL; Primary microcapsules are dispersed in a dopamine hydrochloride solution and reacted at 30℃~40℃ in the dark for 4~12 hours to allow dopamine to polymerize on the surface of the primary microcapsules to form a photothermal modified layer. After filtration and drying, the microcapsule encapsulation repair agent is obtained. The mass ratio of primary microcapsules to dopamine hydrochloride in the dopamine hydrochloride solution is 10~20:

1.

7. An anti-icing coating, characterized in that, It is composed of 100 parts of base epoxy resin, 5 to 20 parts of the microcapsule encapsulation repair agent as described in claim 1, 25 to 30 parts of curing agent and 0.8 to 1.3 parts of coating additive.

8. The anti-icing coating according to claim 7, characterized in that, The curing agent is polyamide, and the coating additive is a mixture of defoamer and leveling agent in a mass ratio of 0.5~0.8:0.3~0.

5.

9. A method for preparing the anti-icing coating according to claim 7, characterized in that, Includes the following steps: The surface micro-nano rough structure microcapsule additive is mixed with the matrix epoxy resin, and then a curing agent and coating additive are added and mixed to obtain a mixed slurry. The mixed slurry is coated on the surface of the substrate and cured at 50℃~100℃ to obtain the photothermal self-healing anti-icing coating.

10. The application of the anti-icing coating according to claim 7 in preventing icing on the surface of power grid transmission and transformation equipment or wind turbine blades.

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