Thermochromic photothermal superhydrophobic coating and preparation method and application thereof

Abstract

The present application belongs to the technical field of super-hydrophobic coating, and particularly relates to a thermochromic photo-thermal super-hydrophobic coating, a preparation method and application thereof. The thermochromic photo-thermal super-hydrophobic coating comprises, from bottom to top along the thickness direction, a photo-thermal epoxy bottom layer, a thermochromic epoxy intermediate layer and a super-hydrophobic surface layer. The photo-thermal epoxy bottom layer is distributed with phase change microcapsules encapsulating phase change materials, and the surface of the phase change microcapsules is sequentially self-assembled with a polydopamine layer and a MXene layer. The thermochromic epoxy intermediate layer is distributed with thermochromic microcapsules. The super-hydrophobic surface layer is a micro / nano structure formed by a silane derivative. The present application realizes all-weather anti-icing / de-icing through the multifunctional design of integrating photo-thermal conversion, phase change and thermochromic mechanisms, optimizes the energy utilization efficiency through the intelligent temperature control mechanism, and provides a sustainable solution for surface anti-icing in extreme environments.

Description

Technical Field

[0001] This invention belongs to the field of superhydrophobic coating technology, specifically relating to a thermochromic photothermal superhydrophobic coating, its preparation method, and its application. Background Technology

[0002] Icing poses a serious threat to critical infrastructure such as power grids, aerospace, and transportation, potentially leading to major accidents such as power line breaks and reduced aircraft lift. Traditional active de-icing technologies, such as mechanical and chemical de-icing, while mitigating icing problems, generally suffer from high energy consumption, low efficiency, and environmental pollution. In contrast, passive anti-icing strategies have gained widespread attention due to their energy-saving and environmentally friendly characteristics. Among these, superhydrophobic surfaces (SHS) exhibit excellent hydrophobicity and low ice adhesion through the synergistic effect of micro / nano structures and low surface energy materials. However, the performance of SHS is prone to degradation in low-temperature and high-humidity environments, and it cannot actively remove ice. To address this, researchers have combined photothermal materials with SHS to develop a solar-assisted superhydrophobic surface that combines passive anti-icing and active de-icing functions. This surface utilizes photothermal materials such as carbon-based materials, MXene, and metal oxides to convert solar energy into thermal energy, achieving efficient melting of the ice layer.

[0003] However, the efficiency of photothermal materials is limited by the intermittent nature of solar energy, especially under weak or no light conditions where performance deteriorates significantly. To address this issue, phase change materials (PCMs) have been introduced as thermal energy storage media. Microencapsulated PCMs (MPCMs) solve the leakage problem by encapsulating organic PCMs, but their low thermal conductivity and poor heat transfer efficiency limit practical applications. Current researchers have combined organic shell materials modified with highly thermally conductive materials to significantly improve the thermal conductivity and photothermal conversion efficiency of photothermal phase change microcapsules. However, photothermal performance cannot be controlled, and excessive temperature rise caused by strong sunlight in summer accelerates material aging. Summary of the Invention

[0004] The purpose of this invention is to provide a thermochromic photothermal superhydrophobic coating, its preparation method, and its application, in order to solve the problem that existing photothermal superhydrophobic coatings are highly dependent on sunlight intensity and have uncontrollable photothermal performance. Through a multifunctional design that integrates photothermal conversion, phase change, and thermochromic mechanisms, it not only achieves all-weather anti-icing / de-icing, but also optimizes energy utilization efficiency through an intelligent temperature control mechanism, providing a sustainable solution for surface anti-icing in extreme environments.

[0005] To achieve the above objectives, the specific technical solution provided by the present invention is as follows:

[0006] The first objective of this invention is to provide a thermochromic photothermal superhydrophobic coating, wherein the thermochromic photothermal superhydrophobic coating comprises, from bottom to top, a photothermal epoxy underlayer, a thermochromic epoxy intermediate layer, and a superhydrophobic surface layer along the thickness direction; wherein, the photothermal epoxy underlayer contains phase change microcapsules encapsulating phase change materials, and the surface of the phase change microcapsules is modified layer by layer with a polydopamine layer and an MXene layer for absorbing light and converting it into heat energy; the thermochromic epoxy intermediate layer contains thermochromic microcapsules for regulating light absorption; and the superhydrophobic surface layer is a micro / nano structure formed by silane derivatives.

[0007] In this invention, phase change microcapsules are modified layer by layer by using polydopamine and MXene through a layer-by-layer self-assembly process. The surface-modified phase change microcapsules have a rough and thickened surface morphology. Polydopamine and MXene have broad-spectrum light absorption properties, which can endow the phase change microcapsules with photothermal properties, absorb sunlight and convert it into heat energy, thereby achieving the active de-icing performance of the coating. When the temperature is higher than the melting point of the solvent, the thermochromic microcapsules can change from dark to white, thereby reflecting excess sunlight and achieving intelligent thermal management of the coating, avoiding heat-induced coating degradation and aging. The silane mixture solution formed by silane derivatives and water can create a superhydrophobic surface on the coating surface. The rough micro / nano structure can capture air to form cavitation, reduce the solid-liquid contact area, thereby delaying heat conduction and enhancing the anti-icing performance of the coating. Based on this, the thermochromic photothermal superhydrophobic coating has a dual-mode conversion function. It can automatically change the coating color at high temperatures and reflect excess sunlight to reduce the temperature, thereby achieving intelligent thermal management. It integrates photothermal conversion, phase change and thermochromic mechanisms, which not only achieves all-weather anti-icing / de-icing, but also optimizes energy utilization efficiency through intelligent temperature control mechanism, providing a sustainable solution for surface anti-icing in extreme environments.

[0008] Furthermore, the thickness of the thermochromic photothermal superhydrophobic coating is 205μm to 405μm, the thickness of the photothermal epoxy underlayer is 100μm to 200μm, the thickness of the thermochromic epoxy intermediate layer is 100μm to 200μm, and the thickness of the superhydrophobic surface layer is 5μm to 10μm.

[0009] A second objective of this invention is to provide a method for preparing a thermochromic photothermal superhydrophobic coating, comprising the following steps:

[0010] S1. Disperse thermochromic microcapsules in epoxy resin containing curing agent to obtain thermochromic coating. Spray the thermochromic coating onto the surface of the uncured photothermal epoxy underlayer to obtain thermochromic epoxy intermediate layer.

[0011] In this process, thermochromic microcapsules are added to epoxy resin, and the mixture is dispersed evenly in the epoxy resin using ultrasonication and stirring. Then, a curing agent is added, and the mixture is stirred until homogeneous to obtain a thermochromic coating. Preferably, the ultrasonication time is 3-5 minutes, the stirring rate is 300-500 rpm, and the stirring time is 5-10 minutes to obtain a uniformly dispersed thermochromic coating. It should be noted that the spraying method is not specifically limited, as long as the thickness of the thermochromic epoxy intermediate layer is 100 μm-200 μm.

[0012] Furthermore, the mass ratio of thermochromic microcapsules to epoxy resin is 5:25 to 100, the mass ratio of epoxy resin to curing agent is 100:60 to 100, the epoxy resin is one of E51, E44 and 6101, and the curing agent is one of amine curing agent, polyamide curing agent and modified amine curing agent.

[0013] S2. Spray the silane derivative solution onto the surface of the incompletely cured thermochromic epoxy intermediate layer, and cure to obtain a thermochromic photothermal superhydrophobic coating.

[0014] The silane derivative solution is prepared by mixing the silane derivative and water using a mixer. During the mixing process, the stirring speed is 2000 rpm to 3000 rpm and the stirring time is 10 s to 30 s. Then, the mixture is ultrasonically treated for 10 s to 30 s to obtain a uniformly dispersed silane derivative solution. It should be noted that the spraying method is not specifically limited, as long as the thickness of the superhydrophobic surface layer is 5 μm to 10 μm.

[0015] Furthermore, the silane derivative solution is prepared by mixing silane derivative and water at a volume ratio of 0.02:2 to 4, and the silane derivative is one of octadecyltrichlorosilane, perfluorodecyltrichlorosilane, and perfluorooctyltrichlorosilane; the curing temperature is 25℃ to 60℃, and the time is 12h to 24h.

[0016] Furthermore, the preparation method of the photothermal epoxy underlayer includes the following steps:

[0017] Step 1: Using phase change material as the core material, disperse the core material in a surfactant, then add a capsule wall precursor to form a mixture. Use hydrochloric acid as a catalyst to carry out a sol-gel reaction to encapsulate the phase change material and obtain phase change microcapsules encapsulating the phase change material.

[0018] In this process, phase change material, surfactant, and solvent are mixed and stirred and sheared at 55℃~65℃ for 4h~6h to form a uniform and stable oil-in-water emulsion. This allows the tiny phase change material droplets to be encapsulated by the surfactant and dispersed in the solvent. The stirring and shearing speed is 300rpm~500rpm. Then, capsule wall precursor is added, and stirring is continued at 55℃~65℃ for 4h~6h to form a mixture, dispersing the capsule wall precursor in the solution system. Hydrochloric acid is then added dropwise to the mixture by peristalsis to carry out the sol-gel reaction.

[0019] Furthermore, the mass ratio of phase change material to surfactant is 2:0.45–0.9, the mass ratio of capsule wall precursor to phase change material is 2:3.2–6.4, the mass ratio of phase change material to hydrochloric acid is 1:15–30, and the concentration of hydrochloric acid is 1 mol / mL–2 mol / mL. The sol-gel reaction involves adding hydrochloric acid to the mixture via peristalsis and reacting at 55℃–65℃ for 4–6 hours. After the reaction, the mixture is aged for 12–24 hours. The phase change material is one of n-tetradecane, n-eicosane, n-tetracosane, and paraffin; the surfactant is one of polyvinyl alcohol, sodium dodecyl sulfate, and hexadecyltrimethylammonium bromide; and the capsule wall precursor is one of tetraethoxysilane, methyl methacrylate, and styrene.

[0020] Step 2: Using phase change microcapsules, dopamine hydrochloride and tris(hydroxymethyl)aminomethane as raw materials, the first self-assembly modification is carried out at room temperature, so that dopamine hydrochloride polymerizes to form a polydopamine layer and self-assembles on the surface of the phase change microcapsules to obtain a polydopamine layer / phase change microcapsule.

[0021] In this process, dopamine hydrochloride and tris(hydroxymethyl)aminomethane are first dissolved in water and stirred continuously at 300 rpm to 500 rpm at room temperature to form a modification solution. Phase change microcapsules are then added to the modification solution and sonicated for 5 min to 10 min until completely dispersed. The mixture is then stirred continuously at 300 rpm to 500 rpm at room temperature to polymerize dopamine hydrochloride to form a polydopamine layer, which then self-assembles on the surface of the phase change microcapsules.

[0022] Furthermore, the ratio of dopamine hydrochloride to tris(hydroxymethyl)aminomethane was 0.45–0.9:0.48, the ratio of phase change microcapsules to tris(hydroxymethyl)aminomethane was 1–2:0.48, and the time for the first self-assembly modification reaction was 20–28 h.

[0023] Step 3: Using polydopamine layer / phase change microcapsules and MXene solution as raw materials, a second self-assembly modification is performed to allow MXene to self-assemble on the surface of the polydopamine layer, thus obtaining MXene layer / polydopamine layer / phase change microcapsules.

[0024] In this process, polydopamine layer / phase change microcapsules are first dispersed in water and sonicated for 5 to 10 minutes until completely dispersed. Then, MXene solution is added, and the mixture is heated in an oil bath under stirring at 300 to 500 rpm to carry out a second self-assembly modification reaction.

[0025] Furthermore, the ratio of MXene to polydopamine layer / phase change microcapsule in the MXene solution was 0.2:1 to 2, the temperature of the second self-assembly modification reaction was 45℃ to 55℃, and the reaction time was 4h to 8h.

[0026] Furthermore, the method for preparing the MXene solution includes the following steps:

[0027] LiF and hydrochloric acid were mixed and stirred to form an etching solution. Ti3AlC2 powder was then gradually added and stirred and kept at 35℃~45℃ for 1.5h~2.5h to carry out the etching reaction. After the reaction was completed, the solution was centrifuged and washed until the pH was close to 6. The solution was then ultrasonically peeled off in an ice-water bath under a protective atmosphere and centrifuged to obtain a monolayer MXene solution.

[0028] Furthermore, the ratio of Ti3AlC2 powder, LiF and hydrochloric acid is 1g:0.5g~4.8g:6.5mL~60mL, the centrifugation speed is 5000rpm~8000rpm, the centrifugation time is 3min~5min, and the washing is performed with deionized water 5~8 times.

[0029] Step 4: Disperse the MXene layer / polydopamine layer / phase change microcapsules in an epoxy resin containing a curing agent to obtain a photothermal coating. After spraying, a photothermal epoxy underlayer is obtained.

[0030] In this process, MXene layer / polydopamine layer / phase change microcapsules are added to epoxy resin and ultrasonicated for 3 to 5 minutes, and stirred at 300 to 500 rpm to disperse them evenly in the epoxy resin. Then, a curing agent is added and stirred evenly to obtain a photothermal coating. The photothermal coating is then sprayed onto the surface of a substrate, which is plexiglass, to obtain a photothermal epoxy underlayer.

[0031] Furthermore, the ratio of MXene layer / polydopamine layer / phase change microcapsule to epoxy resin is 5:25-100, the ratio of epoxy resin to curing agent is 100:60-100, the epoxy resin is one of E51, E44 and 6101, and the curing agent is one of amine curing agent, polyamide curing agent and modified amine curing agent.

[0032] The thermochromic photothermal superhydrophobic coating prepared by this invention exhibits excellent superhydrophobicity, durability, and mechanical stability. Simultaneously, the thermochromic photothermal superhydrophobic coating demonstrates outstanding photothermal conversion performance, exhibiting excellent passive anti-icing and active de-icing properties on various substrate surfaces. The coating possesses a dual-mode conversion function, automatically changing its color at high temperatures to reflect excess sunlight and lower the temperature, thereby achieving intelligent thermal management.

[0033] A third objective of this invention is to provide the application of the aforementioned thermochromic photothermal superhydrophobic coating in anti-icing or de-icing materials. The thermochromic photothermal superhydrophobic coating has a strength of 1 W / cm². 2 Under illumination, its surface temperature rose from room temperature (23℃) to 49.1℃ within 10 minutes, achieving a cooling effect of 12.1℃. The water contact angle was 174°~175°. On a -20℃ cold stage, the delayed freezing time of a 100μL water droplet on the surface was 3400s~3500s. Under the same conditions, the delayed freezing time of a water droplet on the blank coating surface was 180s. This is only at 1W / cm². 2 Under light, the coating surface is completely frozen at 1cm. 3 The ice melts in just 223 seconds, while under the same conditions, it takes 626 seconds for ice on a blank coating surface to completely melt.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] This invention provides a thermochromic photothermal superhydrophobic coating. Through layer-by-layer self-assembly, polydopamine and MXene are used to modify phase change microcapsules. Polydopamine and MXene possess broad-spectrum light absorption properties, endowing the phase change microcapsules with photothermal properties, absorbing sunlight and converting it into heat energy, thus achieving active de-icing performance of the coating. When the temperature is higher than the melting point of the solvent, the thermochromic microcapsules change from dark to white, reflecting excess sunlight and achieving intelligent thermal management of the coating, avoiding heat-induced coating degradation and aging. A silane mixture solution formed by silane derivatives and water can create a superhydrophobic surface on the coating surface. The rough micro / nano structure can trap air to form cavitation, reducing the solid-liquid contact area, thereby delaying heat conduction and enhancing the coating's anti-icing performance. Based on this, the thermochromic photothermal superhydrophobic coating has a dual-mode conversion function. It can automatically change the coating color at high temperatures and reflect excess sunlight to reduce the temperature, thereby achieving intelligent thermal management. It integrates photothermal conversion, phase change and thermochromic mechanisms, which not only achieves all-weather anti-icing / de-icing, but also optimizes energy utilization efficiency through intelligent temperature control mechanism, providing a sustainable solution for surface anti-icing in extreme environments.

[0036] The thermochromic photothermal superhydrophobic coating provided by this invention has a conductivity of 1 W / cm². 2Under illumination, its surface temperature rose from room temperature (23℃) to 49.1℃ within 10 minutes, achieving a cooling effect of 12.1℃. The water contact angle was 174°~175°. On a -20℃ cold stage, the delayed freezing time of a 100μL water droplet on the surface was 3400s~3500s. Under the same conditions, the delayed freezing time of a water droplet on the blank coating surface was 180s. This is only at 1W / cm². 2 Under light, the coating surface is completely frozen at 1cm. 3 The ice melts in just 223 seconds, while under the same conditions, it takes 626 seconds for ice on a blank coating surface to completely melt. Attached Figure Description

[0037] Figure 1 This is a morphological structure diagram of MXene prepared in Example 1 of the present invention.

[0038] Figure 2 These are morphological and structural diagrams of various phase change microcapsules in Example 1 of the present invention. Figure 2 In the figure, (a) is a morphological structure diagram of phase change microcapsule MPCM, (b) is a morphological structure diagram of phase change microcapsule PDA-MPCM, and (c) is a morphological structure diagram of phase change microcapsule MXene-MPCM.

[0039] Figure 3 These are morphological diagrams of the thermochromic photothermal superhydrophobic coatings prepared in Examples 1 to 3 of the present invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3. Figure 3 In the figures, (a) is a morphological structure diagram of the blank coating of Comparative Example 1, (b) is a morphological structure diagram of the photothermal coating of Comparative Example 2 without a thermochromic layer and without a superhydrophobic surface, (c) is a morphological structure diagram of the photothermal coating of Comparative Example 3 without a thermochromic layer, (d) is a morphological structure diagram of the thermochromic photothermal superhydrophobic coating of Example 1, (e) is a morphological structure diagram of the thermochromic photothermal superhydrophobic coating of Example 2, and (f) is a morphological structure diagram of the thermochromic photothermal superhydrophobic coating of Example 3.

[0040] Figure 4 Laser confocal images of the thermochromic photothermal superhydrophobic coating prepared in Example 1 of the present invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3. Figure 4 In the figure, (a) is a laser confocal image of the thermochromic photothermal superhydrophobic coating of Example 1, (b) is a laser confocal image of the blank coating of Comparative Example 1 without phase change microcapsules and without a thermochromic layer or superhydrophobic surface, (c) is a laser confocal image of the photothermal coating of Comparative Example 2 without a thermochromic layer or superhydrophobic surface, and (d) is a laser confocal image of the photothermal coating of Comparative Example 3 without a thermochromic layer.

[0041] Figure 5 Comparison of water contact angles of the thermochromic photothermal superhydrophobic coating prepared in Example 1 of the present invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3.

[0042] Figure 6 The figures show a comparison of the photothermal properties at room temperature of the thermochromic photothermal superhydrophobic coatings prepared in Examples 1 to 3 of the present invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3.

[0043] Figure 7 Comparison of photothermal performance at -20℃ for the thermochromic photothermal superhydrophobic coatings prepared in Examples 1 to 3 of the present invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3.

[0044] Figure 8 The diagram shows the freezing / melting process of water droplets in the thermochromic photothermal superhydrophobic coating prepared in Example 1 of the present invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3.

[0045] Figure 9 The diagram shows the photothermal de-icing process of the thermochromic photothermal superhydrophobic coating prepared in Example 1 of the present invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3. Detailed Implementation

[0046] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings. However, the embodiments described are not intended to limit the present invention.

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0048] Example 1

[0049] A method for preparing a thermochromic photothermal superhydrophobic coating includes the following steps:

[0050] Step 1: Add 3.2g of LiF and 40mL of 9mol / L hydrochloric acid to a polytetrafluoroethylene (PTFE) container and stir until homogeneous to form an etching solution. Then, slowly add 2g of Ti3AlC2 powder. After the addition is complete, place the PTFE container in a constant temperature water bath at 40℃ for 24h and stir continuously at 300rpm using a magnetic stirrer until complete etching. After the etching reaction is complete, centrifuge at 5000rpm for 3min and wash repeatedly with deionized water and centrifuge 5 times until the pH of the supernatant is close to 6. Then, under argon atmosphere protection, ultrasonically peel off in an ice-water bath for 2h and centrifuge at 5000rpm for 30min to obtain a monolayer MXene solution.

[0051] Step 2: Add 2g of n-tetradecane, 0.45g of hexadecyltrimethylammonium bromide and 30mL of formamide to a three-necked flask, heat in an oil bath at 55°C, and stir mechanically at 300rpm for 4 hours to form a stable oil-in-water emulsion.

[0052] Step 3: Add 3.2 mL of tetraethoxysilane to the oil-in-water emulsion, and then continue heating and stirring for 5 hours to form a mixture.

[0053] Step 4: 30 mL of 1 mol / L hydrochloric acid solution was slowly added dropwise to the mixture using a peristaltic pump. The addition was completed within 4 hours. The mixture was then heated and stirred for another 4 hours. After the reaction was completed, the temperature was maintained for aging for 12 hours to obtain phase change microcapsules, which were named MPCM.

[0054] Step 5: Add 0.9g of dopamine hydrochloride and 0.48g of tris(hydroxymethyl)aminomethane to 200mL of deionized water and stir continuously at room temperature to form a modified solution.

[0055] Step 6: Add 2g of MPCM to the modification solution, sonicate for 10min until completely dispersed, and then stir continuously at 300rpm for 24h at room temperature to obtain polydopamine-modified phase change microcapsules, named PDA-MPCM.

[0056] Step 7: Add 2g of PDA-MPCM to the dispersion in deionized water, sonicate for 10min until completely dispersed, then add 10mL of MXene solution with a concentration of 10mg / mL, heat to 45℃ using an oil bath, and stir at 300rpm for 4h using a mechanical stirrer to obtain MXene-modified phase change microcapsules, named MXene-MPCM.

[0057] Step 8: Add 2g of MXene-MPCM to 10g of epoxy resin E51, then sonicate for 5min and stir at 300rpm for 5min to disperse MXene-MPCM evenly in the epoxy resin. Then add 6g of amine curing agent and stir for 5min to obtain photothermal coating. Spray the photothermal coating onto the surface of the glass substrate using a spray gun to a thickness of 100μm and cure for 10min to obtain a semi-cured photothermal epoxy underlayer.

[0058] Step 9: Add 2g of thermochromic microcapsules to 10g of epoxy resin E51, then sonicate for 5min and stir at 300rpm for 5min to disperse the microcapsules evenly in the epoxy resin. Then add 6g of amine curing agent and stir for 5min to obtain thermochromic coating. Spray the thermochromic coating onto the surface of the semi-cured photothermal epoxy substrate using a spray gun to a thickness of 100μm to obtain the thermochromic epoxy intermediate layer.

[0059] Step 10: Add 2 mL of octadecyltrichlorosilane and 40 μL of deionized water to the sample vial. Mix at 3000 rpm for 30 s using a mixer, followed by sonication for 30 s, and then mix for another 30 s to obtain a silane mixture solution. Spray the silane mixture solution onto the surface of the semi-cured thermochromic epoxy intermediate layer using a spray gun to a thickness of 5 μm. After spraying, place the substrate in an oven and cure at 60 °C for 24 h to obtain a thermochromic photothermal superhydrophobic coating.

[0060] Example 2

[0061] A method for preparing a thermochromic photothermal superhydrophobic coating includes the following steps:

[0062] Step 1: Add 2.4g of LiF and 20mL of 9mol / L hydrochloric acid to a polytetrafluoroethylene (PTFE) container and stir until homogeneous to form an etching solution. Then, slowly add 1.5g of Ti3AlC2 powder. After the addition is complete, place the PTFE container in a constant temperature water bath at 40℃ and keep it warm for 24h. Use a magnetic stirrer to continuously stir at 300rpm until complete etching. After the etching reaction is complete, centrifuge at 6000rpm for 3min and wash repeatedly with deionized water and centrifuge 6 times until the pH of the supernatant is close to 6. Then, under argon atmosphere protection, ultrasonically peel off in an ice-water bath for 2h and centrifuge at 6000rpm for 30min to obtain a monolayer MXene solution.

[0063] Step 2: Add 2g of n-eicosane, 0.6g of polyvinyl alcohol and 30mL of formamide to a three-necked flask, heat in an oil bath at 60°C, and stir mechanically at 300rpm for 4 hours to form a stable oil-in-water emulsion.

[0064] Step 3: Add 4.8 mL of methyl methacrylate to the oil-in-water emulsion, and then continue heating and stirring for 4 hours to form a mixture.

[0065] Step 4: 45 mL of 1.5 mol / L hydrochloric acid solution was slowly added dropwise to the mixture using a peristaltic pump. The addition was completed within 4 hours. The mixture was then heated and stirred for another 5 hours. After the reaction was completed, the temperature was maintained for aging for 18 hours to obtain phase change microcapsules, which were named MPCM.

[0066] Step 5: Add 0.6g of dopamine hydrochloride and 0.48g of tris(hydroxymethyl)aminomethane to 200mL of deionized water and stir continuously at room temperature to form a modified solution.

[0067] Step 6: Add 1.5g of MPCM to the modification solution, sonicate for 10min until completely dispersed, and then stir continuously at 300rpm for 24h at room temperature to obtain polydopamine-modified phase change microcapsules, named PDA-MPCM.

[0068] Step 7: Add 1.5g of PDA-MPCM to the dispersion in deionized water, sonicate for 10min until completely dispersed, then add 15mL of MXene solution with a concentration of 10mg / mL, heat to 50℃ using an oil bath, and stir at 300rpm for 6h using a mechanical stirrer to obtain MXene-modified phase change microcapsules, named MXene-MPCM.

[0069] Step 8: Add 1g of MXene-MPCM to 10g of epoxy resin E44, then sonicate for 4min and stir at 400rpm for 4min to disperse MXene-MPCM evenly in the epoxy resin. Then add 8g of polyamide curing agent and stir for 4min to obtain photothermal coating. Spray the photothermal coating onto the surface of the glass substrate using a spray gun to a thickness of 150μm and cure for 10min to obtain a semi-cured photothermal epoxy underlayer.

[0070] Step 9: Add 1g of thermochromic microcapsules to 10g of epoxy resin E44, then sonicate for 4 minutes, and stir at 400rpm for 4 minutes to ensure uniform dispersion of the microcapsules in the epoxy resin. Then add 8g of polyamide curing agent and stir for 4 minutes to obtain a thermochromic coating. Spray the thermochromic coating onto the surface of the semi-cured photothermal epoxy substrate using a spray gun to a thickness of 150μm. This yields a thermochromic epoxy intermediate layer.

[0071] Step 10: Add 2 mL of perfluorodecyltrichlorosilane and 30 μL of deionized water to the sample vial. Mix at 3000 rpm for 30 s using a mixer, followed by sonication for 30 s, and then mix for another 30 s to obtain a silane mixture solution. Spray the silane mixture solution onto the surface of the semi-cured thermochromic epoxy intermediate layer using a spray gun to a thickness of 7.5 μm. After spraying, place the substrate in an oven and cure at 25 °C for 12 h to obtain a thermochromic photothermal superhydrophobic coating.

[0072] Example 3

[0073] A method for preparing a thermochromic photothermal superhydrophobic coating includes the following steps:

[0074] Step 1: Add 3.2g of LiF and 40mL of 9mol / L hydrochloric acid to a polytetrafluoroethylene (PTFE) container and stir until homogeneous to form an etching solution. Then, slowly add 2g of Ti3AlC2 powder. After the addition is complete, place the PTFE container in a constant temperature water bath at 40℃ and keep it warm for 24h. Use a magnetic stirrer to continuously stir at 300rpm until complete etching. After the etching reaction is complete, centrifuge at 5000rpm for 3min and wash and centrifuge repeatedly with deionized water until the pH of the supernatant is close to 6. Then, under argon atmosphere protection, ultrasonically peel off in an ice-water bath for 2h and centrifuge at 5000rpm for 30min to obtain a monolayer MXene solution.

[0075] Step 2: Add 2g of n-tetracosane, 0.9g of sodium dodecyl sulfate and 30mL of formamide to a three-necked flask, heat in an oil bath at 65°C, and stir mechanically at 300rpm for 4 hours to form a stable oil-in-water emulsion.

[0076] Step 3: Add 6.4 mL of styrene to the oil-in-water emulsion, and then continue heating and stirring for 4 hours to form a mixture.

[0077] Step 4: 60 mL of 2 mol / L hydrochloric acid solution was slowly added dropwise to the mixture using a peristaltic pump. The addition was completed within 4 hours. The mixture was then heated and stirred for another 6 hours. After the reaction was completed, the temperature was maintained for aging for 24 hours to obtain phase change microcapsules, which were named MPCM.

[0078] Step 5: Add 0.45g of dopamine hydrochloride and 0.48g of tris(hydroxymethyl)aminomethane to 200mL of deionized water and stir continuously at room temperature to form a modified solution.

[0079] Step 6: Add 1g of MPCM to the modification solution, sonicate for 10min until completely dispersed, and then stir continuously at 300rpm for 24h at room temperature to obtain polydopamine-modified phase change microcapsules, named PDA-MPCM.

[0080] Step 7: Add 1g of PDA-MPCM to the dispersion in deionized water, sonicate for 10min until completely dispersed, then add 20mL of MXene solution with a concentration of 10mg / mL, heat to 45℃ using an oil bath, and stir with a mechanical stirrer at 300rpm to obtain MXene-modified phase change microcapsules, named MXene-MPCM.

[0081] Step 8: Add 0.5g of MXene-MPCM to 10g of epoxy resin 6101, then sonicate for 3min and stir at 500rpm for 3min to disperse MXene-MPCM evenly in the epoxy resin. Then add 10g of modified amine curing agent and stir for 3min to obtain photothermal coating. Spray the photothermal coating onto the surface of the glass substrate using a spray gun to a thickness of 200μm and cure for 10min to obtain a semi-cured photothermal epoxy underlayer.

[0082] Step 9: Add 0.5g of thermochromic microcapsules to 10g of epoxy resin 6101, then sonicate for 3min and stir at 500rpm for 3min to disperse the microcapsules evenly in the epoxy resin. Then add 10g of modified amine curing agent and stir for 3min to obtain thermochromic coating. Spray the thermochromic coating onto the surface of the semi-cured photothermal epoxy substrate using a spray gun to a thickness of 200μm to obtain the thermochromic epoxy intermediate layer.

[0083] Step 10: Add 2 mL of perfluorooctyltrichlorosilane and 20 μL of deionized water to the sample vial, mix at 3000 rpm for 30 s using a mixer, then sonicate for 30 s, and mix again for 30 s to obtain a silane mixture solution. Spray the silane mixture solution onto the surface of the semi-cured thermochromic epoxy intermediate layer using a spray gun to a thickness of 10 μm. After spraying, place the substrate in an oven and cure at 45°C for 18 h to obtain a thermochromic photothermal superhydrophobic coating.

[0084] Comparative Example 1

[0085] A method for preparing an epoxy resin blank coating includes the following steps:

[0086] Mix 10g of epoxy resin E51 and 6g of amine curing agent, and stir at 300rpm for 5min until uniformly dispersed to obtain epoxy coating. Spray the epoxy coating onto the surface of glass substrate using a spray gun to a thickness of 100μm, and place it in an oven to cure at 60℃ for 24h to obtain epoxy resin blank coating.

[0087] Comparative Example 2

[0088] A method for preparing a photothermal coating without a thermochromic layer and without a superhydrophobic surface includes the following steps:

[0089] Step 1: Add 3.2g of LiF and 40mL of 9mol / L hydrochloric acid to a polytetrafluoroethylene (PTFE) container and stir until homogeneous to form an etching solution. Then, slowly add 2g of Ti3AlC2 powder. After the addition is complete, place the PTFE container in a constant temperature water bath at 40℃ and keep it warm for 24h. Use a magnetic stirrer to continuously stir at 300rpm until complete etching. After the etching reaction is complete, centrifuge at 5000rpm for 3min and wash and centrifuge repeatedly with deionized water until the pH of the supernatant is close to 6. Then, under argon atmosphere protection, ultrasonically peel off in an ice-water bath for 2h and centrifuge at 5000rpm for 30min to obtain a monolayer MXene solution.

[0090] Step 2: Add 2g of n-tetradecane, 0.48g of hexadecyltrimethylammonium bromide and 30mL of formamide to a three-necked flask, heat in an oil bath at 55°C, and stir mechanically at 300rpm for 4 hours to form a stable oil-in-water emulsion.

[0091] Step 3: Add 3.2 mL of tetraethoxysilane to the oil-in-water emulsion, and then continue heating and stirring for 5 hours to form a mixture.

[0092] Step 4: 30 mL of 1 mol / L hydrochloric acid solution was slowly added dropwise to the mixture using a peristaltic pump. The addition was completed within 4 hours. The mixture was then heated and stirred for another 4 hours. After the reaction was completed, the temperature was maintained for aging for 12 hours to obtain phase change microcapsules, which were named MPCM.

[0093] Step 5: Add 0.9g of dopamine hydrochloride and 0.48g of tris(hydroxymethyl)aminomethane to 200mL of deionized water and stir continuously at room temperature to form a modified solution.

[0094] Step 6: Add 2g of MPCM to the modification solution, sonicate for 10min until completely dispersed, and then stir continuously at 300rpm for 24h at room temperature to obtain polydopamine-modified phase change microcapsules, named PDA-MPCM.

[0095] Step 7: Add 2g of PDA-MPCM to the dispersion in deionized water, sonicate for 10min until completely dispersed, then add 10mL of MXene solution with a concentration of 10mg / mL, heat to 45℃ using an oil bath, and stir with a mechanical stirrer at 300rpm to obtain MXene-modified phase change microcapsules, named MXene-MPCM.

[0096] Step 8: Add 2g of MXene-MPCM to 10g of epoxy resin E51, then sonicate for 5min and stir at 300rpm for 5min to disperse MXene-MPCM evenly in the epoxy resin. Then add 6g of amine curing agent and stir for 5min to obtain photothermal coating. Spray the photothermal coating onto the surface of the glass substrate using a spray gun to a thickness of 100μm. After spraying, place the substrate in an oven and cure at 60℃ for 24h to obtain the photothermal coating.

[0097] Comparative Example 3

[0098] A method for preparing a photothermal coating without a thermochromic layer includes the following steps:

[0099] Step 1: Add 3.2g of LiF and 40mL of 9mol / L hydrochloric acid to a polytetrafluoroethylene (PTFE) container and stir until homogeneous to form an etching solution. Then, slowly add 2g of Ti3AlC2 powder. After the addition is complete, place the PTFE container in a constant temperature water bath at 40℃ and keep it warm for 24h. Use a magnetic stirrer to continuously stir at 300rpm until complete etching. After the etching reaction is complete, centrifuge at 5000rpm for 3min and wash and centrifuge repeatedly with deionized water until the pH of the supernatant is close to 6. Then, under argon atmosphere protection, ultrasonically peel off in an ice-water bath for 2h and centrifuge at 5000rpm for 30min to obtain a monolayer MXene solution.

[0100] Step 2: Add 2g of n-tetradecane, 0.48g of hexadecyltrimethylammonium bromide and 30mL of formamide to a three-necked flask, heat in an oil bath at 55°C, and stir mechanically at 300rpm for 4 hours to form a stable oil-in-water emulsion.

[0101] Step 3: Add 3.2 mL of tetraethoxysilane to the oil-in-water emulsion, and then continue heating and stirring for 5 hours to form a mixture.

[0102] Step 4: 30 mL of 1 mol / L hydrochloric acid solution was slowly added dropwise to the mixture using a peristaltic pump. The addition was completed within 4 hours. The mixture was then heated and stirred for another 4 hours. After the reaction was completed, the temperature was maintained for aging for 12 hours to obtain phase change microcapsules, which were named MPCM.

[0103] Step 5: Add 0.9g of dopamine hydrochloride and 0.48g of tris(hydroxymethyl)aminomethane to 200mL of deionized water and stir continuously at room temperature to form a modified solution.

[0104] Step 6: Add 2g of MPCM to the modification solution, sonicate for 10min until completely dispersed, and then stir continuously at 300rpm for 24h at room temperature to obtain polydopamine-modified phase change microcapsules, named PDA-MPCM.

[0105] Step 7: Add 2g of PDA-MPCM to the dispersion in deionized water, sonicate for 10min until completely dispersed, then add 10mL of MXene solution with a concentration of 10mg / mL, heat to 45℃ using an oil bath, and stir with a mechanical stirrer at 300rpm to obtain MXene-modified phase change microcapsules, named MXene-MPCM.

[0106] Step 8: Add 2g of MXene-MPCM to 10g of epoxy resin E51, then sonicate for 5min and stir at 300rpm for 5min to disperse MXene-MPCM evenly in the epoxy resin. Then add 6g of amine curing agent and stir for 5min to obtain photothermal coating. Spray the photothermal coating onto the surface of the glass substrate using a spray gun to a thickness of 100μm and cure for 10min to obtain a semi-cured photothermal epoxy underlayer.

[0107] Step 9: Add 2 mL of octadecyltrichlorosilane and 40 μL of deionized water to the sample vial, mix at 3000 rpm for 30 s using a mixer, then sonicate for 30 s, and mix again for 30 s to obtain a silane mixture solution. Spray the silane mixture solution onto the surface of the semi-cured photothermal epoxy substrate using a spray gun to a thickness of 5 μm. After spraying, place the substrate in an oven and cure at 60 °C for 24 h to obtain a photothermal coating.

[0108] To investigate the microstructure of phase change microcapsules at different synthesis stages, scanning electron microscopy was used to characterize the morphology of the prepared MXene phase change microcapsules at different synthesis stages and the surface morphology of the coating. Figures 1-3 As shown.

[0109] Figure 1 This is a morphological structure diagram of the MXene prepared in Example 1 of the present invention. Figure 1 As shown, MXene prepared by ultrasonic exfoliation exhibits a single-layer nanosheet morphology.

[0110] Figure 2 These are morphological and structural diagrams of various phase change microcapsules in Example 1 of the present invention. Figure 2In the figure, (a) shows the morphological structure of the phase change microcapsule MPCM, (b) shows the morphological structure of the phase change microcapsule PDA-MPCM, and (c) shows the morphological structure of the phase change microcapsule MXene-MPCM. Figure 2 As shown in Figure (a), the unmodified MPCM has a smooth and dense surface, exhibits a regular spherical morphology, and shows good monodispersity; Figure 2 As shown in Figure (b), after dopamine undergoes oxidative self-polymerization on the MPCM surface to form a PDA layer, the surface morphology of the PDA-MPCM changes from smooth to rough; as shown in Figure (b), the surface morphology of the PDA-MPCM changes from smooth to rough. Figure 2 As shown in Figure (c), the MXene-MPCM modified with MXene exhibits a rougher surface morphology, and MXene nanosheets are clearly visible on the PDA layer. The hydrogen bonds and electrostatic interactions between PDA and MXene enable the nanosheets to adhere tightly.

[0111] Figure 3 These are morphological diagrams of the thermochromic photothermal superhydrophobic coatings prepared in Examples 1 to 3 of the present invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3. Figure 3 In the figures, (a) shows the morphological structure of the blank coating of Comparative Example 1, (b) shows the morphological structure of the photothermal coating of Comparative Example 2 without a thermochromic layer and without a superhydrophobic surface, (c) shows the morphological structure of the photothermal coating of Comparative Example 3 without a thermochromic layer, (d) shows the morphological structure of the thermochromic photothermal superhydrophobic coating of Example 1, (e) shows the morphological structure of the thermochromic photothermal superhydrophobic coating of Example 2, and (f) shows the morphological structure of the thermochromic photothermal superhydrophobic coating of Example 3. Figure 3 As shown, the blank coating and the photothermal coating exhibit a relatively smooth surface morphology; after the surface is sprayed with a silane mixture solution composed of octadecyltrichlorosilane and water, the surface morphology of the photothermal superhydrophobic coating and the thermochromic photothermal superhydrophobic coating changes from smooth to rough, which is attributed to the solution-induced formation of multi-level micro-nano structures.

[0112] The surface roughness of the thermochromic photothermal superhydrophobic coating prepared in Example 1, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3 were tested using a laser scanning confocal microscope. Figure 4 Laser confocal images of the thermochromic photothermal superhydrophobic coating prepared in Example 1 of the present invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3. Figure 4In the figures, (a) is a laser confocal image of the thermochromic photothermal superhydrophobic coating of Example 1, (b) is a laser confocal image of the blank coating of Comparative Example 1 without phase change microcapsules and without a thermochromic layer or superhydrophobic surface, (c) is a laser confocal image of the photothermal coating of Comparative Example 2 without a thermochromic layer or superhydrophobic surface, and (d) is a laser confocal image of the photothermal coating of Comparative Example 3 without a thermochromic layer. Figure 4 As shown, the surface roughness Ra of the blank coating and the photothermal coating are 2.33 μm and 4.778 μm, respectively. After spraying a silane mixture solution composed of octadecyltrichlorosilane and water onto the surface, the surface roughness Ra of the superhydrophobic photothermal coating and the thermochromic photothermal superhydrophobic coating are increased to 19.3 μm and 22.42 μm, respectively.

[0113] The static water contact angles of the surfaces of the thermochromic photothermal superhydrophobic coating prepared in Example 1, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3 were tested using a contact angle measuring instrument. Figure 5 Comparison of water contact angles for the thermochromic photothermal superhydrophobic coating prepared in Example 1 of this invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3. Figure 5 As shown, the blank coating and the photothermal coating exhibit poor superhydrophobicity, with water contact angles of only 55.1° and 77.5°, respectively. However, after spraying a silane mixture solution composed of octadecyltrichlorosilane and water onto the surface, the surface superhydrophobicity of both the photothermal and thermochromic photothermal superhydrophobic coatings is improved, with contact angles increasing to 163° and 172.6°, demonstrating excellent static superhydrophobic properties.

[0114] The photothermal performance of the thermochromic photothermal superhydrophobic coating prepared in Example 1, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3 were tested using a xenon lamp source at a constant light intensity of 1000 W / m². 2 Irradiation was conducted under specific conditions using a PLX-SXE300 xenon lamp equipped with an AM1.5 filter. The photothermal conversion performance of the thermochromic photothermal superhydrophobic coating prepared in Example 1, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3 was evaluated by monitoring and analyzing the surface temperature changes. During the experiment, a portable infrared thermal imager was used to record temperature data in real time and simultaneously acquire infrared thermal images.

[0115] Figure 6 The figures show a comparison of the photothermal properties at room temperature of the thermochromic photothermal superhydrophobic coatings prepared in Examples 1-3 of this invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2-3. Figure 6As shown, under room temperature conditions, the surface temperature of the blank coating increased from 23°C to 30.5°C after 10 minutes of illumination, a negligible temperature rise. However, the photothermal coating and the superhydrophobic photothermal coating exceeded 50°C within 100 seconds, reaching equilibrium temperatures of 57.3°C and 61.2°C respectively after 10 minutes. This is mainly attributed to the excellent light absorption and photothermal conversion performance of MXene-MPCM. Notably, when the temperature of the thermochromic photothermal superhydrophobic coating reached 40°C, the molecular structure of its thermochromic material changed, triggering adaptive spectral characteristics, and the coating color changed from blue to white. Due to the reflection of solar radiation by the white surface, the temperature stabilized at 49.1°C after 10 minutes. Compared to the photothermal coating, a cooling effect of 12.1°C was achieved under 1 solar intensity, fully demonstrating the significant temperature regulation capability of the thermochromic layer. The thermochromic photothermal superhydrophobic coatings prepared in Examples 2 and 3 reached equilibrium temperatures of 52.9°C and 52°C respectively after 10 minutes of illumination.

[0116] Figure 7 The graph shows a comparison of the photothermal performance of the thermochromic photothermal superhydrophobic coatings prepared in Examples 1-3 of this invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2-3 at a low temperature of -20℃. Figure 7 As shown, in an environment of -20℃, the temperature of the blank coating remained below 0℃ after 10 minutes of illumination, and the temperature dropped sharply to the ambient temperature within 100 seconds after the light source was turned off. The photothermal coating, the superhydrophobic photothermal coating, and the thermochromic photothermal superhydrophobic coating, as in Examples 1 to 3, all showed a rapid temperature rise from -20℃ to above 15℃ within 100 seconds, and reached equilibrium temperatures of 20.2℃, 29.3℃, 22.7℃, 24.1℃, and 23.1℃ respectively after 10 minutes. This indicates that the thermochromic layer has little effect on the photothermal performance of the coating in a low-temperature environment. When the illumination was stopped, the coating temperature first dropped rapidly to about -10℃ and remained there for 200 seconds, corresponding to the latent heat release stage of the phase change material crystallization phase change, and finally gradually returned to the ambient temperature.

[0117] Anti-icing measures were taken for the thermochromic photothermal superhydrophobic coating prepared in Example 1, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3: 100 μL of methylene blue-stained deionized water droplets were dropped onto the surface of the thermochromic photothermal superhydrophobic coating prepared in Example 1, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3 at -20°C. The freezing process and time were monitored using a digital camera. After the droplets were completely frozen, the melting behavior was observed by light.

[0118] Figure 8The diagram shows the water droplet freezing / thawing process of the thermochromic photothermal superhydrophobic coating prepared in Example 1 of this invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3. Figure 8 As shown, water droplets on the blank coating surface freeze completely in 180s, while the freezing time of water droplets on the photothermal coating surface is extended to 312s. The freezing time of water droplets on the photothermal superhydrophobic coating surface is delayed by about 12.8 times compared to the blank coating, reaching 2316s. This is attributed to the synergistic effect of its surface roughness structure and low surface energy. Under the same conditions, water droplets on the thermochromic photothermal superhydrophobic coating surface can remain unfrozen for 1980s, with a complete freezing time of 3840s. Its delayed freezing effect is 21 times that of the blank coating. This is attributed to the low surface energy superhydrophobic rough surface and multilayer structure: on the one hand, the air cushion layer formed at the solid-liquid interface and the three-layer composite structure can significantly block heat conduction and reduce the solid-liquid contact area; on the other hand, this unique structure greatly increases the energy barrier for ice nucleus formation, thereby effectively extending the freezing time.

[0119] De-icing tests were conducted on the thermochromic photothermal superhydrophobic coating prepared in Example 1, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3, using a xenon lamp source at a constant light intensity of 1000 W / m². 2 Irradiation was performed under certain conditions, and the melting process of a 1cm×1cm×1cm ice block in the thermochromic photothermal superhydrophobic coating prepared in Example 1, the blank coating prepared in Comparative Example 1, and the photothermal coating samples prepared in Comparative Examples 2 to 3 was monitored using a digital camera.

[0120] Figure 9 The diagram shows the photothermal de-icing process of the thermochromic photothermal superhydrophobic coating prepared in Example 1 of this invention, the blank coating prepared in Comparative Example 1, and the photothermal coatings prepared in Comparative Examples 2 to 3. Figure 9 As shown, the blank coating takes 626 seconds to melt, while the photothermal coating, superhydrophobic photothermal coating, and thermochromic photothermal coating take only 219 seconds, 184 seconds, and 223 seconds to melt, respectively, demonstrating significant photothermal de-icing efficiency.

[0121] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, it is intended to include any modifications and variations that fall within the scope of the claims and their equivalents.

Claims

1. A thermochromic photothermal superhydrophobic coating, characterized in that, The thermochromic photothermal superhydrophobic coating comprises, from bottom to top, a photothermal epoxy underlayer, a thermochromic epoxy intermediate layer, and a superhydrophobic surface layer along the thickness direction. Among them, phase change microcapsules encapsulating phase change materials are distributed in the photothermal epoxy bottom layer. The surface of the phase change microcapsules is modified with polydopamine layer and MXene layer layer by layer for absorbing light and converting it into heat energy. Thermochromic epoxy intermediate layer contains thermochromic microcapsules, which are used to regulate light absorption; Thermochromic microcapsules can change from dark to white when the temperature is higher than the melting point of the solvent, thereby reflecting excess sunlight and realizing intelligent thermal management of thermochromic photothermal superhydrophobic coatings. The superhydrophobic surface layer is a micro / nano structure formed from silane derivatives; A method for preparing a thermochromic photothermal superhydrophobic coating includes the following steps: Thermochromic microcapsules are dispersed in epoxy resin containing curing agent to obtain thermochromic coating. The thermochromic coating is sprayed onto the surface of an incompletely cured photothermal epoxy underlayer to obtain thermochromic epoxy intermediate layer. A silane derivative solution was sprayed onto the surface of an incompletely cured thermochromic epoxy intermediate layer, and cured to obtain a thermochromic photothermal superhydrophobic coating. The mass ratio of thermochromic microcapsules to epoxy resin is 5:25-100, the mass ratio of epoxy resin to curing agent is 100:60-100, the epoxy resin is one of E51, E44 and 6101, and the curing agent is one of amine curing agent and modified amine curing agent. The silane derivative solution is prepared by mixing silane derivative and water in a volume ratio of 0.02:2 to 4. The silane derivative is one of octadecyltrichlorosilane, perfluorodecyltrichlorosilane, and perfluorooctyltrichlorosilane. The curing temperature is 25℃ to 60℃ and the curing time is 12h to 24h.

2. The thermochromic photothermal superhydrophobic coating according to claim 1, characterized in that, The thickness of the photothermal epoxy underlayer is 100μm to 200μm, the thickness of the thermochromic epoxy intermediate layer is 100μm to 200μm, and the thickness of the superhydrophobic surface layer is 5μm to 10μm.

3. The thermochromic photothermal superhydrophobic coating according to claim 1, characterized in that, The preparation method of the photothermal epoxy substrate includes the following steps: Using phase change material as the core material, the core material is dispersed in a surfactant, and then a capsule wall precursor is added to form a mixture. Hydrochloric acid is used as a catalyst to carry out a sol-gel reaction to encapsulate the phase change material, thereby obtaining phase change microcapsules encapsulating the phase change material. Using phase change microcapsules, dopamine hydrochloride and tris(hydroxymethyl)aminomethane as raw materials, the first self-assembly modification was carried out at room temperature, so that dopamine hydrochloride was polymerized to form a polydopamine layer and self-assembled on the surface of phase change microcapsules, thus obtaining polydopamine layer / phase change microcapsules. Using polydopamine layer / phase change microcapsules and MXene solution as raw materials, a second self-assembly modification was performed to allow MXene to self-assemble on the surface of the polydopamine layer, thus obtaining MXene layer / polydopamine layer / phase change microcapsules. MXene layer / polydopamine layer / phase change microcapsules are dispersed in epoxy resin containing curing agent to obtain photothermal coating, and then sprayed to obtain photothermal epoxy underlayer.

4. The thermochromic photothermal superhydrophobic coating according to claim 3, characterized in that, The mass ratio of phase change material to surfactant is 2:0.45–0.9, the mass ratio of capsule wall precursor to phase change material is 2:3.2–6.4, the mass ratio of phase change material to hydrochloric acid is 1:15–30, and the concentration of hydrochloric acid is 1 mol / mL–2 mol / mL. The sol-gel reaction involves adding hydrochloric acid to the mixture via peristalsis and reacting at 55℃–65℃ for 4–6 hours. After the reaction, the mixture is aged for 12–24 hours. The phase change material is one of n-tetradecane, n-eicosane, n-tetracosane, or paraffin. The surfactant is one of polyvinyl alcohol, sodium dodecyl sulfate, or hexadecyltrimethylammonium bromide. The capsule wall precursor is one of tetraethoxysilane, methyl methacrylate, or styrene.

5. The thermochromic photothermal superhydrophobic coating according to claim 3, characterized in that, The ratio of dopamine hydrochloride to tris(hydroxymethyl)aminomethane was 0.45–0.9:0.48, the ratio of phase change microcapsules to tris(hydroxymethyl)aminomethane was 1–2:0.48, and the time for the first self-assembly modification reaction was 20–28 h. The ratio of MXene to polydopamine layer / phase change microcapsules in the MXene solution was 0.2:1–2, the temperature for the second self-assembly modification reaction was 45–55 °C, and the reaction time was 4–8 h.

6. The thermochromic photothermal superhydrophobic coating according to claim 3, characterized in that, The ratio of MXene layer / polydopamine layer / phase change microcapsule to epoxy resin is 5:25-100, the ratio of epoxy resin to curing agent is 100:60-100, the epoxy resin is one of E51, E44 and 6101, and the curing agent is one of amine curing agent and modified amine curing agent.

7. The application of the thermochromic photothermal superhydrophobic coating of claim 1 in anti-icing or de-icing materials.

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