A superhydrophobic anti-icing coating combination for synergistic thermal management of photothermal-phase change-thermal insulation, its preparation method, and its application.

Abstract

This invention belongs to the field of hydrophobic coating technology, and provides a superhydrophobic anti-icing coating combination with photothermal-phase change-thermal insulation synergistic thermal management, its preparation method, and application. This coating combination consists of a photothermal-phase change hydrophobic topcoat with a micro-nano hierarchical structure and a thermal insulation primer containing micron-sized particles. The thermal insulation primer forms a functional thermal insulation base layer with micron-level roughness and thermal resistance barrier. The "strawberry"-shaped photothermal-phase change microcapsule hybrid forms a photothermal-phase change superhydrophobic topcoat with photothermal capture, phase change heat storage / release, and micro-nano roughness structure. These components synergistically achieve superhydrophobicity, anti-icing, and inhibition of substrate overheating, forming a long-lasting and stable anti-icing thermal management system compatible with both thermal insulation and anti-icing conditions. This invention can be applied to the surface of wind turbine blades to construct a synergistic coating combination with superhydrophobicity, anti-icing, and inhibition of solar radiation overheating functions.

Description

Technical Field

[0001] This invention belongs to the field of hydrophobic coating technology, specifically relating to a superhydrophobic anti-icing coating combination with photothermal-phase change-thermal insulation synergistic thermal management, its preparation method, and its application. The coating combination consists of a photothermal-phase change hydrophobic topcoat and a thermal insulation primer, and can be applied to the surface of wind turbine blades to construct a synergistic coating combination with superhydrophobicity, anti-icing, and suppression of solar radiation overheating functions. Background Technology

[0002] As the installed capacity of wind power continues to expand, wind farms are gradually being deployed in high-altitude, cold, and humid regions. The complex meteorological conditions in these areas easily trigger extreme weather events such as freezing rain, frost, fog, and snowfall, which can easily cause icing on wind turbine blades and lead to a series of serious hazards. In existing technologies, conventional photothermal superhydrophobic coatings have significant advantages in preventing icing due to their superhydrophobic anti-icing and photothermal de-icing properties. However, they generally suffer from insufficient thermal management: short delayed icing time, insufficient photothermal energy supply in the absence of light or weak light, and poor de-icing effect; and they are prone to overheating under strong solar radiation, damaging the coating and the blade substrate.

[0003] Phase change materials (PCMs) can improve the thermal response lag caused by insufficient sunlight and large diurnal temperature differences in winter through heat storage and thermal buffering. Existing PCM microcapsule photothermal superhydrophobic coatings (such as Chinese invention patent 202511540234.X) can regulate blade surface temperature and reduce icing, but they only focus on thermal buffering and do not effectively design the heat transfer path and heat retention time, making it difficult to achieve synergy between photothermal, phase change, and superhydrophobic functions. In actual operation, focusing only on thermal buffering can easily lead to heat loss to the substrate and environment, limited surface temperature rise and heat retention time, and the anti-icing effect is heavily dependent on sunlight. At the same time, excessive heat conduction can also lead to blade aging and coating failure, failing to achieve efficient thermal management between insulation and anti-icing.

[0004] Therefore, a functional coating for wind turbine blades that can delay heat loss, extend the duration of heat generation, and prevent blade overheating, while also possessing superhydrophobic properties and achieving synergistic effects of photothermal, phase change, and superhydrophobic functions, will effectively improve the long-term operational stability of wind turbine blades. Summary of the Invention

[0005] To address the problems in the prior art, this invention provides a superhydrophobic anti-icing coating combination for photothermal-phase change-thermal insulation synergistic thermal management, its preparation method, and its application. This coating combination consists of a photothermal-phase change hydrophobic topcoat with a micro-nano hierarchical structure and a thermal insulation primer containing micron-sized particles. The thermal insulation primer constructs a functional thermal insulation base layer to block heat loss, extend the duration of heat exposure, and prevent blade overheating. Furthermore, a superhydrophobic anti-icing coating combination is constructed on top using a "strawberry"-shaped photothermal-phase change microcapsule hybrid with a micro-nano hierarchical structure. This synergistic effect of low surface energy, photothermal capture, phase change energy storage, and thermal insulation achieves compatible and long-lasting stable anti-icing thermal management.

[0006] To achieve the above objectives, the present invention employs a technical solution consisting of the following technical measures.

[0007] In one aspect, the present invention provides a method for preparing a superhydrophobic anti-icing coating combination with photothermal-phase change-thermal insulation synergistic thermal management, comprising the following steps:

[0008] (I) Preparation of heat-insulating primer containing micron-sized particles:

[0009] (Ⅰ-1) A 5-15 wt% aerogel dispersion slurry was prepared by using micron-sized aerogel powder;

[0010] (Ⅰ-2) Add aqueous acrylic emulsion, aqueous silica sol, p-toluenesulfonic acid and nanocellulose to the aerogel dispersion slurry, mix evenly, adjust the pH to neutral, and let stand to mature to obtain a heat-insulating primer containing micron particles.

[0011] (II) Preparation of photothermal-phase change hydrophobic topcoat with micro-nano hierarchical structure:

[0012] (II-1) The surfactant, core material alkane, and tetraethyl orthosilicate are mixed in a solvent to obtain the oil phase;

[0013] The core material alkane is composed of at least one of dodecane, tridecane, tetradecane, pentadecane and hexadecane, and the phase transition temperature of the core material alkane is in the range of -10 ~ 5 ℃.

[0014] (II-2) The oil phase obtained in step (II-1) is mixed with deionized water to obtain an oil-in-water emulsion. An alkaline catalyst is added to catalyze the hydrolysis and polycondensation reaction of tetraethyl orthosilicate. After separation and drying, phase change microcapsules are obtained.

[0015] (II-3) The phase change microcapsules, titanium nitride nanoparticles and dopamine hydrochloride obtained in step (II-2) were reacted in a buffer solution to prepare a "strawberry"-shaped photothermal-phase change microcapsule hybrid with micro-nano hierarchical structure;

[0016] The mass ratio of phase change microcapsules to titanium nitride nanoparticles is (1~10):(0.1~5).

[0017] (II-4) Dissolve fluorocarbon resin in an organic solvent, add orthosilicate and fluorinated silane coupling agent, add the "strawberry"-shaped photothermal-phase change microcapsule hybrid obtained in step (II-3) to the precursor mixture after reaction and disperse it to prepare a photothermal-phase change hydrophobic topcoat with micro-nano hierarchical structure.

[0018] The mass ratio of the precursor mixture to the "strawberry"-shaped photothermal-phase change microcapsule hybrid is (65~90):(10~35).

[0019] In one technical solution, in order to improve the dispersion efficiency and defoaming of the aerogel dispersion slurry during the dispersion process, step (Ⅰ-1) is preferably based on the total mass, according to the ratio of 0.5~3 wt% dispersant, 5~15 wt% aerogel micro powder and 0.1~0.5 wt% defoamer, with the balance being deionized water, to mix and disperse evenly to obtain the aerogel dispersion slurry.

[0020] The dispersant mentioned is a dispersant commonly used in the field of water-based coatings. Those skilled in the art can directly refer to the commonly used dispersants in the prior art for selection, such as Tween-80 dispersant.

[0021] The defoamer mentioned is a defoamer commonly used in the field of water-based coatings. Those skilled in the art can directly refer to the defoamers commonly used in the prior art for selection, such as BYK-1707 defoamer.

[0022] Furthermore, in order to improve the dispersion effect, the above-mentioned uniform dispersion is preferably achieved by using 0.8~2.0 mm zirconia beads as the dispersion medium in a sand mill, and dispersing for 30~60 min at 1500~2500 r / min and temperature ≤40 ℃ to obtain an aerogel dispersion slurry.

[0023] In this document, the micron-sized aerogel powder mentioned in step (Ⅰ-1) is a filler selection commonly used in thermal insulation coatings in the prior art that has thermal insulation function. Those skilled in the art can directly refer to commercially available thermal insulation coatings or aerogel powders known in the prior art that have thermal insulation function, such as at least one of the following: silicon-based aerogel powder (such as silica aerogel, etc.), polymer aerogel powder (such as polyimide aerogel, polyurea aerogel, etc.), carbon-based aerogel powder (such as carbon aerogel, reduced graphene oxide aerogel, etc.), and metal oxide aerogel powder (such as Al2O3 aerogel, TiO2 aerogel and ZrO2 aerogel, etc.); the average particle size (D50) of the aerogel powder is preferably 7~100 μm.

[0024] Typically, adjusting the pH to neutral as described in step (Ⅰ-2) is done by adding NaOH solution (or KOH solution) to adjust the pH to 7-8.

[0025] In one technical solution, step (Ⅰ-2) preferably involves adding 10-30 wt% of waterborne acrylic emulsion with a solid content of 35%, 1-5 wt% of waterborne silica sol, 0.2-0.5 wt% of p-toluenesulfonic acid, and 3-5 wt% of nanocellulose to the aerogel dispersion slurry obtained in step (Ⅰ-1) by weight. After mixing evenly, the pH is adjusted to neutral, and then 0.05-0.2 wt% of defoamer is added. After mixing evenly again, the mixture is allowed to stand and mature to obtain a heat-insulating primer containing micron-sized particles.

[0026] In one of the technical solutions, the static curing described in step (Ⅰ-2) is preferably carried out at a temperature of 20~25 ℃ for 12~24 h.

[0027] In this paper, the core material alkane mentioned in step (II-1) is composed of at least one of dodecane, tridecane, tetradecane, pentadecane, and hexadecane, and the phase transition temperature of the core material alkane is in the range of -10 to 5 ℃. That is, the phase transition temperature is in the range of -10 to 5 ℃ by selecting the core material alkane or a compound core material alkane. However, since the core material alkane is only one of the raw material components of the phase change microcapsule, the phase transition temperature of the phase change microcapsule cannot be directly obtained by the specific selection of the core material alkane. Based on the anti-icing functional purpose of this invention, it is preferable to make the obtained phase change microcapsule undergo a solid-liquid phase transition near the freezing point of 0 ℃.

[0028] To explore a more preferred technical solution, in the following verification example, DSC test results show that when the core alkane is selected as dodecane, the solidification initiation temperature (T) of the prepared phase change microcapsules is... onset,f The solidification end temperature (T) is -5.2 ℃. end,f The freezing point is -15.0 ℃, and the solidification peak temperature (T) is... peak,f The solidification initiation temperature (T0) of the prepared phase change microcapsules is -8.0 °C; when the core alkane is tetradecane, the solidification initiation temperature (T0) is -8.0 °C. onset,f The solidification end temperature (T) is 10.2 ℃. end,f The freezing peak temperature is 1.1 ℃, and the solidification peak temperature (T) is 1.1 ℃. peak,f The enthalpy of phase transition (ΔH) for the two types of phase change microcapsules can be obtained by integrating the DSC curves, with a temperature of 7.4 °C. f The concentrations of dodecane and tetradecane are 222.5 J / g and 217.6 J / g, respectively. Therefore, composite alkanes can be obtained by compounding dodecane and tetradecane in different ratios, and then used as core materials to prepare phase change microcapsules. This allows for the modification of the solidification characteristics (Tg) of the phase change microcapsules. onset,f Tend,f T peak,f ΔH f The temperature is adjusted, and through comparison and optimization, the solidification start and end temperatures of the phase change microcapsules are made to fall as close as possible to the temperature range of -10~5℃.

[0029] Based on the above findings, in one preferred technical solution, the core material alkane in step (Ⅱ-1) is preferably composed of a compound of dodecane and tetradecane, and the mass ratio of dodecane to tetradecane is (10~20):(80~90).

[0030] In one of the technical solutions, step (Ⅱ-1) is preferably to dissolve 1 to 5 parts of surfactant in 25 parts of formamide by weight, and then add 2 to 8 parts of core material alkane and tetraethyl orthosilicate, mix evenly, and obtain an oil phase;

[0031] The core material alkane is composed of at least one of dodecane, tridecane, tetradecane, pentadecane, and hexadecane, and the phase transition temperature of the core material alkane is in the range of -10 ~ 5 ℃; the mass ratio of tetraethyl orthosilicate to core material alkane in the oil phase is (0.5~4):1;

[0032] The surfactant is a commonly used surfactant in the field of water-based coatings. Those skilled in the art can directly refer to the commonly used surfactants in the prior art for selection, such as cetyltrimethylammonium bromide.

[0033] Further, step (Ⅱ-2) is preferably to add the oil phase obtained above to 50 parts of deionized water, mix to obtain an oil-in-water emulsion, then add 1 to 5 parts of ammonia water to the oil-in-water emulsion, stir and react for 5 to 24 hours, after which the reaction is carried out, age for at least 12 hours, and then separate, wash and dry in sequence to obtain phase change microcapsules.

[0034] The ammonia water is used as an alkaline catalyst, and its concentration (mass percentage) is preferably 2-3%.

[0035] Furthermore, the stirring reaction is carried out for 5-24 hours. In order to promote the hydrolysis and polycondensation reaction of tetraethyl orthosilicate and improve the reaction efficiency of forming microcapsule shells, the stirring rate is preferably 800-1500 r / min.

[0036] In one of the technical solutions, the water-in-oil emulsion obtained by mixing in step (Ⅱ-2) is preferably treated with ultrasound at 40 kHz and 200 W for 30 min to improve emulsification efficiency.

[0037] In one of the technical solutions, step (Ⅱ-3) is preferably to add the phase change microcapsules obtained in step (Ⅱ-2) to a solvent to prepare a phase change microcapsule dispersion with a solid content of 1~10%, and to add titanium nitride nanoparticles (TiN) to a solvent to prepare a titanium nitride nanoparticle dispersion with a mass concentration of 0.1~1 mg / mL.

[0038] At a temperature of 24–26 °C, a 10 mM Tris buffer solution was added to a titanium nitride nanoparticle dispersion until the pH was adjusted to 8–9. Then, a phase change microcapsule dispersion was added and stirred continuously for at least 6 h. Next, a 0.5–10 mg / mL dopamine hydrochloride aqueous solution was added, and the mixture was stirred at a temperature of 20–30 °C for 12–24 h. The mixture was then separated, washed, and dried sequentially to prepare a "strawberry"-shaped photothermal-phase change microcapsule hybrid with a micro-nano hierarchical structure.

[0039] The mass ratio of phase change microcapsules to titanium nitride nanoparticles is (1~10):(0.1~5), and the mass ratio of titanium nitride nanoparticles to dopamine hydrochloride is (0.1~1):(0.5~10).

[0040] The solvent is a selection of solvents commonly used in chemical coating products, such as any one or more of deionized water, methanol, ethanol, isopropanol, acetone, and acetonitrile.

[0041] The Tris buffer (tris(hydroxymethyl)aminomethane) buffer is a conventional buffer solution in the art and can be obtained commercially.

[0042] Furthermore, the above-mentioned titanium nitride nanoparticles (TiN) are added to a solvent to prepare a titanium nitride nanoparticle dispersion with a mass concentration of 0.1~1 mg / mL. The solvent used is preferably a mixed solvent of water and ethanol with a volume ratio of (70~90):(10~30).

[0043] Further, the phase change microcapsules obtained in step (Ⅱ-2) are added to a solvent to prepare a phase change microcapsule dispersion with a solid content of 1~10%. In order to further improve the dispersion efficiency and dispersion stability, it is preferable to add 0.1~2 wt% polyvinylpyrrolidone (PVP) or polyethylene glycol (PEG).

[0044] Furthermore, the phase change microcapsules obtained in step (Ⅱ-2) are added to a solvent to prepare a phase change microcapsule dispersion with a solid content of 1~10%, and titanium nitride nanoparticles (TiN) are added to a solvent to prepare a titanium nitride nanoparticle dispersion with a mass concentration of 0.1~1 mg / mL. Both are preferably dispersed by ultrasonic treatment, specifically by ultrasonic treatment at 40 kHz and 200 W for 10~30 min.

[0045] In this paper, the titanium nitride nanoparticles mentioned in step (II-3) are commercially available chemical raw materials, preferably titanium nitride nanoparticles with an average particle size of 10~200 nm.

[0046] In one of the technical solutions, step (II-4) is preferably to dissolve fluorocarbon resin in an organic solvent to prepare a fluorocarbon resin solution, and then add tetraethyl orthosilicate and heptadecafluorotrimethylethoxysilane in sequence, stir and react for 30-120 min. After the time is up, the "strawberry"-shaped photothermal-phase change microcapsule hybrid obtained in step (II-3) is added to the precursor mixture obtained after the reaction and dispersed to prepare a photothermal-phase change hydrophobic topcoat with micro-nano hierarchical structure.

[0047] The mass ratio of the precursor mixture to the "strawberry"-shaped photothermal-phase change microcapsule hybrid is (65~90):(10~35); the mass ratio of the fluorocarbon resin, tetraethyl orthosilicate, and heptadecafluorotrimethylethoxysilane is (1~5):(0.1~2):(0.05~1), and the solid content of the photothermal-phase change hydrophobic topcoat is not higher than 35%.

[0048] The organic solvent is selected from organic solvents commonly used in chemical coating products, such as ethyl acetate, butyl acetate, isopropyl acetate, n-propyl acetate, propylene glycol methyl ether acetate, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, toluene, xylene, and aromatic solvent oils, among any one or more of these.

[0049] In one of the technical solutions, the dispersion in step (Ⅱ-4) is preferably carried out by ultrasonic treatment, specifically by treatment under ultrasonic conditions of 40 kHz and 200 W for 10 to 30 minutes.

[0050] In one technical solution, in steps (I-2) and (II-4), other additives commonly used in chemical coating products in the art may also be added; the additives include one or more combinations of ultraviolet absorbers, thickeners, leveling agents, antifreeze agents, light stabilizers, and antioxidants. Typically, the specific selection and dosage of the aforementioned ultraviolet absorbers, thickeners, leveling agents, antifreeze agents, light stabilizers, and antioxidants are well-known and commonly used.

[0051] In this document, the mixing, aging, separation, washing, drying, and stirring processes all follow conventional principles in chemical processes, and those skilled in the art can perform the specific operations based on common knowledge.

[0052] On the other hand, the present invention also provides the application of the above-mentioned superhydrophobic anti-icing coating combination of photothermal-phase change-thermal insulation synergistic thermal management to the surface of wind turbine blades to construct a synergistic coating combination with superhydrophobicity, anti-icing and suppression of solar radiation overheating functions.

[0053] In one technical solution, the heat-insulating primer is applied at a ratio of 40~160 g / m². 2 The amount of product applied to the substrate surface is adjusted to allow the solvent to evaporate, forming a heat-insulating functional base coat; then, the photothermal-phase change hydrophobic topcoat is applied at a ratio of 20~50 g / m². 2 The amount of material used is applied to the thermal insulation functional base layer to form a wet coating and a thin-layer penetration structure attached to the surface of the aerogel skeleton, thereby constructing a photothermal-phase change-superhydrophobic interface with a multi-scale rough structure on the surface. After standing for 4 hours to allow the solvent to evaporate, it is heated and cured in an oven at 60 ℃ for 3 hours to allow the fluorocarbon resin to form a film and promote the further condensation and crosslinking of tetraethyl orthosilicate and heptadecafluorotrimethylethoxysilane, forming a firmly attached photothermal-phase change-superhydrophobic surface coating on the surface of the thermal insulation functional base layer. This enables low surface energy, photothermal capture, phase change energy storage and thermal insulation to work synergistically, thereby achieving thermal insulation and anti-icing conditions compatible and long-term stable anti-icing thermal management.

[0054] It should be noted that the superhydrophobic anti-icing coating combination for photothermal-phase change-thermal insulation synergistic thermal management provided by this invention follows the conventional coating method for hydrophobic coatings in the chemical industry.

[0055] Typically, the coating method is any one of spraying, brushing, or scraping; the substrate is any one of plastic sheets (e.g., polyester, epoxy resin, etc.), glass, wood, stainless steel sheets, sponge, aluminum, iron, cement board, ceramics, or paper products.

[0056] The present invention has the following beneficial effects:

[0057] 1. This invention provides a superhydrophobic anti-icing coating combination for photothermal-phase change-thermal insulation synergistic thermal management, its preparation method, and its application. The coating combination consists of a photothermal-phase change hydrophobic topcoat with a micro-nano multi-level structure and a thermal insulation primer containing micron-sized particles. The thermal insulation primer forms a thermal insulation functional base layer with micron-level roughness and thermal resistance barrier. The "strawberry"-shaped photothermal-phase change microcapsule hybrid forms a photothermal-phase change superhydrophobic topcoat with photothermal capture, phase change heat storage / release, and micro-nano rough structure. This synergistically achieves superhydrophobicity, anti-icing, and inhibition of substrate overheating, forming a long-lasting and stable anti-icing thermal management system that is compatible with both thermal insulation and anti-icing conditions.

[0058] 2. In one technical solution, the present invention optimizes the compound components of the alkane core material through actual comparative experiments, and prepares phase change microcapsules with a phase change temperature regulated to near the freezing point of 0 °C. When the photothermal-phase change hydrophobic topcoat and heat-insulating primer prepared using these phase change microcapsules are coated onto the surface of a wind turbine blade, during the cooling and icing process, the phase change core material undergoes a solidification phase change and releases latent heat, delaying the temperature drop of the coating surface. During the illumination heating process, the phase change core material undergoes a melting phase change and absorbs some heat, buffering surface overheating, thereby improving the coating's tolerance to supercooled environments and delaying ice nucleus formation and ice layer growth, achieving an active thermal buffering anti-icing effect. Compared with passive methods that rely on hydrophobicity or photothermal heating, the present invention still possesses energy storage and anti-icing capabilities under no-light or low-light conditions, making it suitable for anti-icing applications on wind turbine blades in low-light and low-temperature winter environments.

[0059] 3. This invention employs a "strawberry"-shaped photothermal-phase change microcapsule hybrid with a micro-nano hierarchical structure, using phase change microcapsules as the core and polydopamine-coated titanium nitride nanoparticles as the shell. This hybrid structure can construct a close-range thermal contact interface on the substrate surface, significantly improving the efficiency of photothermal energy transfer to the phase change microcapsules and solving the problems of high thermal resistance and low heat transfer efficiency between existing photothermal materials and phase change materials. Furthermore, when the superhydrophobic anti-icing coating combination provided by this invention is applied to the surface of wind turbine blades, this hybrid structure can preferentially store photothermal energy during the phase change process under strong photothermal conditions, preventing the blade surface temperature from becoming too high. During winter icing, the heat is compensated by the synergistic effect of photothermal heating and phase change heat release, thereby improving the photothermal anti-icing capability of wind turbine blades under low-light conditions in winter and achieving a balanced heat distribution for environmental adaptability.

[0060] 4. The dual-layer coating of this invention offers synergistic and complementary functions. The heat-insulating functional base coating provides heat insulation and locks in heat, preventing overheating of the substrate and providing a micron-level rough structure; the photothermal-phase change superhydrophobic surface coating combines photothermal heating, phase change temperature regulation, and superhydrophobic anti-icing properties, delaying icing and reducing ice adhesion strength throughout the entire process, while also providing a multi-level micro-nano structure. The synergistic dual-layer structure forms a superhydrophobic surface that significantly improves the blade's anti-icing performance, extends the icing time, and ensures the safe and stable operation of wind turbine blades under severe cold and icing conditions. Attached Figure Description

[0061] Figure 1 This is a photograph of the heat-insulating primer prepared in Example 1 of the present invention.

[0062] Figure 2 The image shows a comparison of the cooling curves of the phase change microcapsules prepared by differential scanning calorimetry (DSC) in Examples 1-2 of this invention.

[0063] Figure 3The image is a scanning electron microscope (SEM) image of the "strawberry"-shaped photothermal-phase change microcapsule hybrid prepared in Example 1 of this invention.

[0064] Figure 4 The images show optical microscope photographs and physical photographs of the surface of the heat-insulating functional base coating sprayed onto the substrate in Application Example 3 of the present invention.

[0065] Figure 5 This is a photograph taken during a static water contact angle test when the heat-insulating primer and photothermal-phase change hydrophobic topcoat are sprayed onto the substrate in Application Example 3 of the present invention.

[0066] Figure 6 These are comparative photos of the photothermal-phase change hydrophobic topcoats prepared in Examples 1-2 and Comparative Examples 1-2 of the present invention, when sprayed onto substrates and subjected to freezing delay time tests.

[0067] Figure 7 This is a comparison curve showing the change of surface temperature of the coating combination over time when the samples of Example 5, Comparative Example 3, and Comparative Example 4 of the present invention were sprayed onto the substrate and irradiated under a standard sunlight intensity at -15 ℃ and when the light source was turned off. Detailed Implementation

[0068] To further understand the present invention, preferred embodiments are described below with reference to examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims. Those skilled in the art can refer to the content of this document to appropriately improve the process parameters. In particular, it should be noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the scope of the present invention. The methods and applications of the present invention have been described through preferred embodiments, and those skilled in the art can obviously make modifications or appropriate changes and combinations to the methods and applications described herein without departing from the content, spirit and scope of the present invention to realize and apply the technology of the present invention. Although it is believed that those skilled in the art will fully understand the following terms, the following definitions are set forth to help illustrate the subject matter disclosed in the present invention.

[0069] In one aspect, the present invention provides a method for preparing a superhydrophobic anti-icing coating combination with photothermal-phase change-thermal insulation synergistic thermal management, comprising the following steps:

[0070] (I) Preparation of heat-insulating primer containing micron-sized particles:

[0071] (Ⅰ-1) A 5-15 wt% aerogel dispersion slurry was prepared by using micron-sized aerogel powder;

[0072] (Ⅰ-2) Add aqueous acrylic emulsion, aqueous silica sol, p-toluenesulfonic acid and nanocellulose to the aerogel dispersion slurry, mix evenly, adjust the pH to neutral, and let stand to mature to obtain a heat-insulating primer containing micron particles.

[0073] (II) Preparation of photothermal-phase change hydrophobic topcoat with micro-nano hierarchical structure:

[0074] (II-1) The surfactant, core material alkane, and tetraethyl orthosilicate are mixed in a solvent to obtain the oil phase;

[0075] The core material alkane is composed of at least one of dodecane, tridecane, tetradecane, pentadecane and hexadecane, and the phase transition temperature of the core material alkane is in the range of -10 ~ 5 ℃.

[0076] (II-2) The oil phase obtained in step (II-1) is mixed with deionized water to obtain an oil-in-water emulsion. An alkaline catalyst is added to catalyze the hydrolysis and polycondensation reaction of tetraethyl orthosilicate. After separation and drying, phase change microcapsules are obtained.

[0077] (II-3) The phase change microcapsules, titanium nitride nanoparticles and dopamine hydrochloride obtained in step (II-2) were reacted in a buffer solution to prepare a "strawberry"-shaped photothermal-phase change microcapsule hybrid with micro-nano hierarchical structure;

[0078] The mass ratio of phase change microcapsules to titanium nitride nanoparticles is (1~10):(0.1~5).

[0079] (II-4) Dissolve fluorocarbon resin in an organic solvent, add orthosilicate and fluorinated silane coupling agent, add the "strawberry"-shaped photothermal-phase change microcapsule hybrid obtained in step (II-3) to the precursor mixture after reaction and disperse it to prepare a photothermal-phase change hydrophobic topcoat with micro-nano hierarchical structure.

[0080] The mass ratio of the precursor mixture to the "strawberry"-shaped photothermal-phase change microcapsule hybrid is (65~90):(10~35).

[0081] In one embodiment, in order to improve the dispersion efficiency and defoaming of the aerogel dispersion slurry during the dispersion process, step (Ⅰ-1) is preferably based on the total mass, according to the ratio of 0.5~3 wt% dispersant, 5~15 wt% aerogel micro powder and 0.1~0.5 wt% defoamer, with the balance being deionized water, to mix and disperse evenly to obtain the aerogel dispersion slurry.

[0082] The dispersant is a commonly used dispersant in the field of water-based coatings. Those skilled in the art can directly refer to the commonly used dispersants in the prior art for selection, such as Tween-80 dispersant; the dispersant is 0.5~3wt%, for example 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt% or any range or point value between them;

[0083] The defoamer is a commonly used defoamer in the field of water-based coatings. Those skilled in the art can directly refer to the commonly used defoamers in the prior art for selection, such as BYK-1707 defoamer; the defoamer is 0.1~0.5 wt%, for example 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or any range or point value between them;

[0084] The aerogel micro powder is 5~15 wt%, for example 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, or any range or point value between them;

[0085] Furthermore, in order to improve the dispersion effect, the above-mentioned uniform dispersion is preferably achieved by using 0.8~2.0 mm zirconia beads as the dispersion medium in a sand mill, and dispersing for 30~60 min at 1500~2500 r / min and temperature ≤40 ℃ to obtain an aerogel dispersion slurry.

[0086] In this document, the micron-sized aerogel powder mentioned in step (Ⅰ-1) is a filler selection commonly used in thermal insulation coatings in the prior art that has thermal insulation function. Those skilled in the art can directly refer to commercially available thermal insulation coatings or aerogel powders known in the prior art that have thermal insulation function. In one embodiment, for example, it includes at least one of the following: silicon-based aerogel powder (such as silica aerogel, etc.), polymer aerogel powder (such as polyimide aerogel, polyurea aerogel, etc.), carbon-based aerogel powder (such as carbon aerogel, reduced graphene oxide aerogel, etc.), and metal oxide aerogel powder (such as Al2O3 aerogel, TiO2 aerogel and ZrO2 aerogel, etc.); the average particle size (D50) of the aerogel powder is preferably 7~100 μm.

[0087] Typically, adjusting the pH to neutral as described in step (Ⅰ-2) is, in one embodiment, achieved by adding NaOH solution (or KOH solution) to adjust the pH to 7-8.

[0088] In one embodiment, step (Ⅰ-2) preferably involves adding 10-30 wt% of an aqueous acrylic emulsion with a solid content of 35%, 1-5 wt% of an aqueous silica sol, 0.2-0.5 wt% of p-toluenesulfonic acid, and 3-5 wt% of nanocellulose to the aerogel dispersion slurry obtained in step (Ⅰ-1) by weight. After mixing evenly, the pH is adjusted to neutral, and then 0.05-0.2 wt% of an antifoaming agent is added. After mixing evenly again, the mixture is allowed to stand and mature to obtain a heat-insulating primer containing micron-sized particles.

[0089] The aqueous acrylic emulsion with a solid content of 35% is 10-30 wt%, for example, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, or any range or point value between them; the aqueous silica sol is 1-5 wt%, for example, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, or any range or point value between them; the p-toluenesulfonic acid is 0.2-0.5 wt%, for example, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or any range or point value between them; the nanocellulose is 3-5 wt%, for example, 3 wt%, 4 wt%, 5 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, or any range or point value between them; the aqueous silica sol is 1-5 wt%, for example, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, or any range or point value between them; the p-toluenesulfonic acid is 0.2-0.5 wt%, for example wt%, 5 wt%, or any range or point value between them; the defoamer is 0.05~0.2 wt%, for example 0.05 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, or any range or point value between them.

[0090] In one embodiment, the standing curing in step (Ⅰ-2) is preferably performed at a temperature of 20~25 ℃ for 12~24 h.

[0091] In this paper, the core material alkane mentioned in step (II-1) is composed of at least one of dodecane, tridecane, tetradecane, pentadecane, and hexadecane, and the phase transition temperature of the core material alkane is in the range of -10 to 5 ℃. That is, the phase transition temperature is in the range of -10 to 5 ℃ by selecting the core material alkane or a compound core material alkane. However, since the core material alkane is only one of the raw material components of the phase change microcapsule, the phase transition temperature of the phase change microcapsule cannot be directly obtained by the specific selection of the core material alkane. Based on the anti-icing functional purpose of this invention, it is preferable to make the obtained phase change microcapsule undergo a solid-liquid phase transition near the freezing point of 0 ℃.

[0092] To explore a more preferred technical solution, in the following verification example, DSC test results show that when the core alkane is selected as dodecane, the solidification initiation temperature (T) of the prepared phase change microcapsules is... onset,f The solidification end temperature (T) is -5.2 ℃. end,f The freezing point is -15.0 ℃, and the solidification peak temperature (T) is... peak,f The solidification initiation temperature (T0) of the prepared phase change microcapsules is -8.0 °C; when the core alkane is tetradecane, the solidification initiation temperature (T0) is -8.0 °C. onset,f The solidification end temperature (T) is 10.2 ℃. end,f The freezing peak temperature is 1.1 ℃, and the solidification peak temperature (T) is 1.1 ℃. peak,f The enthalpy of phase transition (ΔH) for the two types of phase change microcapsules can be obtained by integrating the DSC curves, with a temperature of 7.4 °C. f The concentrations of dodecane and tetradecane are 222.5 J / g and 217.6 J / g, respectively. Therefore, composite alkanes can be obtained by compounding dodecane and tetradecane in different ratios, and then used as core materials to prepare phase change microcapsules. This allows for the modification of the solidification characteristics (Tg) of the phase change microcapsules. onset,f T end,f T peak,f ΔH f The temperature is adjusted, and through comparison and optimization, the solidification start and end temperatures of the phase change microcapsules are made to fall as close as possible to the temperature range of -10~5℃.

[0093] Based on the above findings, in one preferred embodiment, the core material alkane in step (Ⅱ-1) is preferably composed of a compound of dodecane and tetradecane, and the mass ratio of dodecane to tetradecane is (10~20):(80~90).

[0094] In one embodiment, step (Ⅱ-1) is preferably to dissolve 1 to 5 parts of surfactant in 25 parts of formamide by weight, and then add 2 to 8 parts of core material alkane and tetraethyl orthosilicate, mix evenly, and obtain an oil phase;

[0095] The core material alkane is composed of at least one of dodecane, tridecane, tetradecane, pentadecane, and hexadecane, and the phase transition temperature of the core material alkane is in the range of -10 ~ 5 ℃; the mass ratio of tetraethyl orthosilicate to core material alkane in the oil phase is (0.5~4):1;

[0096] The surfactant is a commonly used surfactant in the field of water-based coatings. Those skilled in the art can directly refer to the commonly used surfactants in the prior art for selection, such as cetyltrimethylammonium bromide.

[0097] The surfactant is 1 to 5 parts, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, or any range or point value therebetween; the core material alkane is 2 to 8 parts, for example, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, or any range or point value therebetween; the mass ratio of tetraethyl orthosilicate to core material alkane in the oil phase is (0.5 to 4):1, for example, 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, or any range or point value therebetween;

[0098] Further, step (Ⅱ-2) is preferably to add the oil phase obtained above to 50 parts of deionized water, mix to obtain an oil-in-water emulsion, then add 1 to 5 parts of ammonia water to the oil-in-water emulsion, stir and react for 5 to 24 hours, after which the reaction is carried out, age for at least 12 hours, and then separate, wash and dry in sequence to obtain phase change microcapsules.

[0099] The ammonia water is used as an alkaline catalyst, and its concentration (mass percentage) is preferably 2-3%.

[0100] Furthermore, the stirring reaction is carried out for 5-24 hours. In order to promote the hydrolysis and polycondensation reaction of tetraethyl orthosilicate and improve the reaction efficiency of forming microcapsule shells, the stirring rate is preferably 800-1500 r / min.

[0101] In one embodiment, the oil-in-water emulsion obtained by mixing in step (Ⅱ-2) is preferably treated with ultrasound at 40 kHz and 200 W for 30 min to improve emulsification efficiency.

[0102] In one embodiment, step (II-3) preferably involves adding the phase change microcapsules obtained in step (II-2) to a solvent to prepare a phase change microcapsule dispersion with a solid content of 1-10%, and adding titanium nitride nanoparticles (TiN) to a solvent to prepare a titanium nitride nanoparticle dispersion with a mass concentration of 0.1-1 mg / mL.

[0103] At a temperature of 24–26 °C, a 10 mM Tris buffer solution was added to a titanium nitride nanoparticle dispersion until the pH was adjusted to 8–9. Then, a phase change microcapsule dispersion was added and stirred continuously for at least 6 h. Next, a 0.5–10 mg / mL dopamine hydrochloride aqueous solution was added, and the mixture was stirred at a temperature of 20–30 °C for 12–24 h. The mixture was then separated, washed, and dried sequentially to prepare a "strawberry"-shaped photothermal-phase change microcapsule hybrid with a micro-nano hierarchical structure.

[0104] The mass ratio of phase change microcapsules to titanium nitride nanoparticles is (1~10):(0.1~5), and the mass ratio of titanium nitride nanoparticles to dopamine hydrochloride is (0.1~1):(0.5~10).

[0105] The solvent is a selection of solvents commonly used in chemical coating products, such as any one or more of deionized water, methanol, ethanol, isopropanol, acetone, and acetonitrile.

[0106] The Tris buffer (tris(hydroxymethyl)aminomethane) buffer is a conventional buffer solution in the art and can be obtained commercially.

[0107] The phase change microcapsule dispersion has a solid content of 1-10%, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or any range or point value between them; the titanium nitride nanoparticle dispersion has a mass concentration of 0.1-1 mg / mL, for example, 0.1 mg / mL, 0.2 mg / mL, 0.3 mg / mL, 0.4 mg / mL, 0.5 mg / mL, 0.6 mg / mL, 0.7 mg / mL, 0.8 mg / mL, 0.9 mg / mL, 1 mg / mL, or any range or point value between them; the dopamine hydrochloride aqueous solution has a mass concentration of 0.5-10 mg / mL, for example, 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, 3 mg / mL, 3.5 mg / mL, 4 mg / mL, 4.5 mg / mL, 5 mg / mL, 5.5 mg / mL, 6 mg / mL, 4 mg / mL, ... mg / mL, 6.5mg / mL, 7 mg / mL, 7.5 mg / mL, 8 mg / mL, 8.5 mg / mL, 9 mg / mL, 9.5 mg / mL, 10 mg / mL or any range or point value therebetween; the mass ratio of the phase change microcapsules to titanium nitride nanoparticles is (1~10):(0.1~5), for example 1:(0.1~5), 2:(0.1~5), 3:(0.1~5), 4:(0.1~5), 5:(0.1~5), 6:(0.1~5), 7:(0.1~5), 8:(0.1~5), 9:(0.1~5), 10:(0.1~5), (1~10):0.1, (1~10):0.5, (1~10):1, (1~10):1.5, (1~10):2, (1~10):2.5, (1~10):3, (1~10):3.5, (1~10):4, (1~10):4.5, (1~10):5 or any range or point value therebetween; the titanium nitride The mass ratio of nanoparticles to dopamine hydrochloride is (0.1~1):(0.5~10), for example 0.1:(0.5~10), 0.2:(0.5~10), 0.3:(0.5~10), 0.4:(0.5~10), 0.5:(0.5~10), 0.6:(0.5~10), 0.7:(0.5~10), 0.8:(0.5~10), 0.9:( 0.5~10), 1: (0.5~10), (0.1~1):0.5, (0.1~1):1, (0.1~1):1.5, (0.1~1):2, (0.1~1):2.5, (0.1~1):3, (0.1~1):3.5, (0.1~1):4, (0.1~1):4.5, (0.1~1):5, (0.1~1):5.5, (0.1~1): 6, (0.1~1): 6.5, (0.1~1): 7, (0.1~1): 7.5, (0.1~1): 8, (0.1~1): 8.5, (0.1~1): 9, (0.1~1): 9.5, (0.1~1): 10 or any range or point value between them;

[0108] Furthermore, the above-mentioned titanium nitride nanoparticles (TiN) are added to a solvent to prepare a titanium nitride nanoparticle dispersion with a mass concentration of 0.1~1 mg / mL. The solvent used is preferably a mixed solvent of water and ethanol with a volume ratio of (70~90):(10~30).

[0109] Further, the phase change microcapsules obtained in step (Ⅱ-2) are added to a solvent to prepare a phase change microcapsule dispersion with a solid content of 1~10%. In order to further improve the dispersion efficiency and dispersion stability, it is preferable to add 0.1~2 wt% polyvinylpyrrolidone (PVP) or polyethylene glycol (PEG).

[0110] Furthermore, the phase change microcapsules obtained in step (Ⅱ-2) are added to a solvent to prepare a phase change microcapsule dispersion with a solid content of 1~10%, and titanium nitride nanoparticles (TiN) are added to a solvent to prepare a titanium nitride nanoparticle dispersion with a mass concentration of 0.1~1 mg / mL. Both are preferably dispersed by ultrasonic treatment, specifically by ultrasonic treatment at 40 kHz and 200 W for 10~30 min.

[0111] In this document, the titanium nitride nanoparticles mentioned in step (Ⅱ-3) are commercially available chemical raw materials. In one embodiment, titanium nitride nanoparticles with an average particle size of 10~200 nm are preferred.

[0112] In one embodiment, step (II-4) preferably involves dissolving fluorocarbon resin in an organic solvent to prepare a fluorocarbon resin solution, then sequentially adding tetraethyl orthosilicate and heptadecafluorotrimethylethoxysilane, stirring the reaction for 30-120 min, and after the reaction time is reached, adding the "strawberry"-shaped photothermal-phase change microcapsule hybrid obtained in step (II-3) to the precursor mixture obtained after the reaction and dispersing it to prepare a photothermal-phase change hydrophobic topcoat with a micro-nano hierarchical structure;

[0113] The mass ratio of the precursor mixture to the "strawberry"-shaped photothermal-phase change microcapsule hybrid is (65~90):(10~35); the mass ratio of the fluorocarbon resin, tetraethyl orthosilicate, and heptadecafluorotrimethylethoxysilane is (1~5):(0.1~2):(0.05~1), and the solid content of the photothermal-phase change hydrophobic topcoat is not higher than 35%.

[0114] The organic solvent is selected from organic solvents commonly used in chemical coating products, such as ethyl acetate, butyl acetate, isopropyl acetate, n-propyl acetate, propylene glycol methyl ether acetate, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, toluene, xylene, and aromatic solvent oils, among any one or more of these.

[0115] The mass ratio of the fluorocarbon resin, tetraethyl orthosilicate, and heptadecafluorotrimethylethoxysilane is (1~5):(0.1~2):(0.05~1), for example, 1:(0.1~2):(0.05~1), 2:(0.1~2):(0.05~1), 3:(0.1~2):(0.05~1), 4:(0.1~2):(0.05~1), 5:(0.1~2):(0.05~1), (1~5):0.1:(0.05~1), (1~5):0.5:(0.05~1), (1~5):1:(0.05~1), (1~5):1.5:(0.05~1). (1~5):2:(0.05~1), (1~5):(0.1~2):0.05, (1~5):(0.1~2):0.1, (1~5):(0.1~2):0.2, (1~5):(0.1~2):0.3, (1~5):(0.1~2):0.4, (1~5):(0.1~2):0.5, (1~5):(0.1~2):0.6, (1~5):(0.1~2):0.7, (1~5):(0.1~2):0.8, (1~5):(0.1~2):0.9, (1~5):(0.1~2):1 or any range or point value between them.

[0116] In one embodiment, the dispersion in step (Ⅱ-4) is preferably performed by ultrasonic treatment, specifically by treatment under ultrasonic conditions of 40 kHz and 200 W for 10 to 30 minutes.

[0117] In one embodiment, in steps (I-2) and (II-4), other additives conventionally used in chemical coating products in the art may also be added; said additives include one or more combinations of ultraviolet absorbers, thickeners, leveling agents, antifreeze agents, light stabilizers, and antioxidants. Typically, the specific selection and dosage of the aforementioned ultraviolet absorbers, thickeners, leveling agents, antifreeze agents, light stabilizers, and antioxidants are well-known and commonly used.

[0118] In this document, the mixing, aging, separation, washing, drying, and stirring processes all follow conventional principles in chemical processes, and those skilled in the art can perform the specific operations based on common knowledge.

[0119] On the other hand, the present invention also provides the application of the above-mentioned superhydrophobic anti-icing coating combination of photothermal-phase change-thermal insulation synergistic thermal management to the surface of wind turbine blades to construct a synergistic coating combination with superhydrophobicity, anti-icing and suppression of solar radiation overheating functions.

[0120] In one embodiment, the heat-insulating primer is applied at a concentration of 40~160 g / m². 2 The amount of product applied to the substrate surface is adjusted to allow the solvent to evaporate, forming an aerogel heat-insulating coating. Then, a photothermal-phase change hydrophobic topcoat is applied at a ratio of 20~50 g / m². 2 The amount of material used is applied to the aerogel thermal insulation coating to form a wet coating and a thin-layer penetration structure attached to the surface of the aerogel skeleton, thereby constructing a photothermal-phase change-superhydrophobic interface with a multi-scale rough structure on the aerogel surface. After standing for 4 hours to allow the solvent to evaporate, it is heated and cured in an oven at 60 ℃ for 3 hours to allow the fluorocarbon resin to form a film and promote the further condensation and crosslinking of tetraethyl orthosilicate and heptadecafluorotrimethylethoxysilane, forming a firmly attached photothermal-phase change-superhydrophobic surface coating on the aerogel thermal insulation coating surface. This enables photothermal capture, phase change energy storage and thermal insulation to work synergistically, thereby achieving thermal insulation and anti-icing conditions compatible and long-term stable anti-icing thermal management.

[0121] It should be noted that the superhydrophobic anti-icing coating combination for photothermal-phase change-thermal insulation synergistic thermal management provided by this invention follows the conventional coating method for hydrophobic coatings in the chemical industry.

[0122] Typically, the coating method is any one of spraying, brushing, or scraping; the substrate is any one of plastic sheets (e.g., polyester, epoxy resin, etc.), glass, wood, stainless steel sheets, sponge, aluminum, iron, cement board, ceramics, or paper products.

[0123] The present application will be further explained in detail below with reference to embodiments. However, those skilled in the art should understand that these embodiments are provided for illustrative purposes only and are not intended to limit the present application.

[0124] Example

[0125] The embodiments of this application will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be construed as limiting the scope of this application. Where specific conditions are not specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Where the manufacturers of reagents or instruments are not specified, they are all commercially available conventional products. This application should not be construed as being limited to the specific embodiments described.

[0126] 1. Raw materials

[0127] Silica aerogel micro powder, Shenzhen Zhongning Technology Co., Ltd.

[0128] Water-based acrylic emulsion (solid content 42~48%), BADF Group Co., Ltd. Dilute with water to a solid content of 35% before use.

[0129] Aqueous silica sol (particle size 10~20 nm), Shandong Baite New Materials Co., Ltd.

[0130] Nanocellulose (fiber diameter 4~20 nm, length 1000~3000 nm), Guilin Qihong Technology Co., Ltd.

[0131] Dodecane, tetradecane, Shanghai Aladdin Biochemical Technology Co., Ltd.

[0132] Titanium nitride nanoparticles (20 nm), Anhui Zhonghang Nanotechnology Development Co., Ltd.

[0133] Fluorocarbon resin (solid content 50±1%), Daikin Fluorochemicals.

[0134] 2. Preparation method

[0135] (I) Preparation of heat-insulating primer containing micron-sized particles:

[0136] (I-1) Based on the total mass, the mixture was premixed at a stirring rate of 3000 r / min with 3 wt% Tween-80 dispersant, 15 wt% silica aerogel micro powder, 0.3 wt% BYK-1707 defoamer, and 100 g deionized water. Then, it was dispersed in a sand mill with 1.5 mm zirconia beads as the dispersion medium at 1500 r / min and a temperature ≤40 ℃ for 30 min to obtain an aerogel dispersion slurry.

[0137] (I-2) Based on the mass of the aerogel dispersion slurry obtained in step (I-1), add 30 wt% of waterborne acrylic emulsion with a solid content of 35%, 5 wt% of waterborne silica sol, 0.5 wt% of p-toluenesulfonic acid and 5 wt% of nanocellulose to the aerogel dispersion slurry. After mixing evenly at a stirring rate of 200 r / min, adjust the pH to neutral, then add 0.2 wt% of BYK-1707 defoamer, stir and mix evenly again, and let stand for 12 h at a temperature of 20~25 ℃ to mature, thus obtaining the heat-insulating primer containing micron particles;

[0138] (II) Preparation of photothermal-phase change hydrophobic topcoat with micro-nano hierarchical structure:

[0139] (II-1) Dissolve 1 g of hexadecyltrimethylammonium bromide in 25 g of formamide, then add 4 g of core material alkane and 2 g of tetraethyl orthosilicate, and mix at a stirring rate of 400 r / min for 20 min to obtain the oil phase;

[0140] (II-2) The oil phase obtained in step (II-1) was added to 50 g of deionized water and mixed at a stirring rate of 600 r / min for 10 min. Then, it was treated under ultrasonic conditions of 40 kHz and 200 W for 30 min to obtain an oil-in-water emulsion. Then, 1 g of 2.5% ammonia water was added to the oil-in-water emulsion and stirred at a stirring rate of 800 r / min for 12 h. After the time was up, it was aged at a temperature of 20~25 ℃ for 12 h. Then, it was washed by vacuum filtration with deionized water and ethanol and freeze-dried under vacuum to obtain phase change microcapsules.

[0141] (II-3) Add 5 g of the phase change microcapsules obtained in step (II-2) to 100 g of 2 wt% polyvinylpyrrolidone aqueous solution and treat under ultrasonic conditions of 40 kHz and 200 W for 30 min to prepare a phase change microcapsule dispersion; add 0.1 g of titanium nitride nanoparticles (TiN) to 100 g of mixed solvent (water and ethanol in a volume ratio of 80:20) and treat under ultrasonic conditions of 40 kHz and 200 W for 30 min to prepare a titanium nitride nanoparticle dispersion;

[0142] At a temperature of 24–26 °C, 10 mM Tris buffer was added to the titanium nitride nanoparticle dispersion until the pH was adjusted to 8.5. Then, phase change microcapsule dispersion was added and stirred for 6 h. Next, 20 mL of 4 mg / mL dopamine hydrochloride aqueous solution was added, and the mixture was stirred for 12 h at a temperature of 20–30 °C. The mixture was then centrifuged, washed 3–5 times with deionized water and ethanol alternately, and vacuum dried for 12 h to prepare a "strawberry"-shaped photothermal-phase change microcapsule hybrid with a micro-nano hierarchical structure.

[0143] (II-4) Dissolve 30 g of fluorocarbon resin in 100 g of ethyl acetate to prepare a fluorocarbon resin solution. Then add 5 g of tetraethyl orthosilicate and 1 g of heptadecafluorotrimethylethoxysilane in sequence. Stir the mixture in a water bath at 60 °C for 2 h. After the reaction time is up, add the "strawberry"-shaped photothermal-phase change microcapsule hybrid obtained in step (II-3) and treat it under ultrasonic conditions of 40 kHz and 200 W for 30 min to prepare a photothermal-phase change hydrophobic topcoat with micro-nano hierarchical structure.

[0144] like Figure 1 As shown, the heat-insulating primer prepared according to step (Ⅰ) of “2. Preparation Method” above is displayed.

[0145] To investigate the effect of the specific choice of core alkane on the phase transition temperature of phase change microcapsules, in the following verification examples 1-5, phase change microcapsules prepared by dodecane and tetradecane under different ratios were subjected to DSC tests to obtain phase change microcapsules with phase transition temperatures regulated to near the freezing point of 0 °C.

[0146] Verification Examples 1-5

[0147] Verification Examples 1-5 are phase change microcapsules prepared according to steps (II-1) and (II-2) of "2. Preparation Method" above, which were used as samples for DSC testing. The alkane composition of the core material and the DSC test results are shown in Table 1 below:

[0148] Table 1. Alkane composition of the core material and DSC test results of the phase change microcapsule samples used in Examples 1-5.

[0149]

[0150] The DSC test was performed using a PE DSC 8000 differential scanning calorimeter, with a cooling rate of 5 °C / min, under nitrogen protection, and a sample mass of approximately 10 mg. Figure 2 The DSC cooling curves are shown for phase change microcapsules with dodecane as the core material (Verification Example 1) and phase change microcapsules with tetradecane as the core material (Verification Example 2). The solidification initiation temperature (T0) of the phase change microcapsules with dodecane as the core material can be obtained from the DSC cooling curves. onset,f The solidification end temperature (T) is -5.2 ℃. end,f The freezing point is -15.0 ℃, and the solidification peak temperature (T) is... peak,f The solidification initiation temperature (T) of the phase change microcapsule with a core material of tetradecane was -8.0 ℃; the solidification initiation temperature (T) of the microcapsule was -8.0 ℃. onset,f The solidification end temperature (T) is 10.2 ℃. end,f The freezing peak temperature is 1.1 ℃, and the solidification peak temperature (T) is 1.1 ℃. peak,f The phase transition enthalpy (ΔH) was calculated at 7.4 °C using DSC curve integration for phase transition microcapsules with dodecane core material (Verification Example 1) and phase transition microcapsules with tetradecane core material (Verification Example 2). f The values ​​are 222.5 J / g and 217.6 J / g, respectively.

[0151] In verification examples 3-5, composite alkanes were obtained by blending dodecane and tetradecane in different mass fractions, and these composite alkanes were used as core material alkanes to evaluate the solidification characteristics (T) of phase change microcapsules. onset,f T end,f T peak,f ΔH fThe temperature was adjusted to ensure that the solidification initiation and termination temperatures fell within the range of -10 to 5 °C. It is evident that the phase change microcapsules prepared in Examples 3 and 4 meet this requirement, with Example 3 being the optimal one. During the cooling process, phase change microcapsules with this solidification characteristic are more conducive to delaying the freezing of liquid water by releasing latent heat (enthalpy of solidification) through solidification phase change, maintaining the interface temperature, inhibiting ice nucleation, and suppressing ice crystal growth, thereby achieving anti-icing.

[0152] As can be seen from the comparison of the above verification examples, when the core material alkane is selected as a compound of 10 wt% dodecane and 90 wt% tetradecane, the resulting phase change microcapsules have a solidification temperature closest to the freezing point and a high solidification enthalpy. Therefore, the phase change microcapsules prepared by verification example 3 are used in the following examples and comparative examples.

[0153] Examples 1-2, Comparative Examples 1-2

[0154] Examples 1-2 and Comparative Examples 1-2 were prepared according to the steps in "2. Preparation Method" above to obtain a photothermal-phase change hydrophobic topcoat with micro-nano hierarchical structure and a heat-insulating primer containing micron particles. In step (II-2), the core material alkane was a mixture of 10 wt% dodecane and 90 wt% tetradecane. In step (II-4), the amount of "strawberry"-shaped photothermal-phase change microcapsule hybrid added was 0 g, 24 g, 58.3 g, and 136 g, respectively, corresponding to Comparative Example 1, Example 1, Example 2, and Comparative Example 2. The amount added was determined according to the mass ratio of the precursor mixture (total mass of 30 g fluorocarbon resin, 100 g ethyl acetate, 5 g tetraethyl orthosilicate, and 1 g heptadecafluorotrimethylethoxysilane) to the "strawberry"-shaped photothermal-phase change microcapsule hybrid in step (II-4) being 100:0, 85:15, 70:30, and 50:50, respectively.

[0155] The "strawberry"-shaped photothermal-phase change microcapsule hybrids prepared in Example 1 were analyzed using scanning electron microscopy (SEM). The surface morphology of all samples was observed using a Hitachi SU8010 scanning electron microscope (Japan). Test conditions: accelerating voltage 20 kV; samples underwent gold sputtering treatment before testing. Figure 3 As shown, its microstructure is "strawberry" shaped and has a micro-nano hierarchical structure. The "strawberry" shaped photothermal-phase change microcapsule hybrid has a size of about 2.6 μm and is loaded with TiN / PDA nanoparticles on its surface, forming a micron-nano hierarchical structure.

[0156] The photothermal-phase change hydrophobic topcoats prepared in Examples 1-2 and Comparative Examples 1-2 were sprayed onto stainless steel substrates for testing. The spraying pressure was 0.2 MPa, the spraying distance was 20 cm, and the spraying amount was 30 g / m. 2The dry film thickness was approximately 40 μm. After spraying, the coating was left at room temperature for 4 hours to allow partial evaporation of the ethyl acetate and achieve surface drying. It was then cured in a 60 °C oven for 3 hours to form a photothermal-phase change superhydrophobic coating from the fluorocarbon resin. The static water contact angle, the surface temperature of the coating at 0 °C, the surface temperature under room temperature light irradiation, ice adhesion strength, freezing delay time, and photothermal de-icing performance were then tested. The specific test methods are as follows:

[0157] (1) Static water contact angle test: The test was conducted in accordance with GB / T 30693-2014 (Measurement of water contact angle between plastic film).

[0158] (2) Temperature test of the coating surface in 0 ℃ environment: Place the coated stainless steel substrate on a cold table surface with a temperature set to 0 ℃ and a relative humidity of 80%. Attach a patch thermocouple to the coating surface and record the coating surface temperature.

[0159] (3) Temperature test of upper surface under room temperature light irradiation: The coated stainless steel substrate was irradiated for 2 minutes under a standard sunlight intensity at room temperature, and a thermocouple was attached to the coating surface to record the coating surface temperature.

[0160] (4) Ice adhesion strength test: Ice adhesion strength was determined using shear mode. The testing apparatus was based on ASTM D4541 (Shear test method for coating adhesion) and the test was conducted at a low temperature of 10 ℃. Specifically, a cube of ice measuring 10×10×50 mm was placed on the surface of the coating to be tested at -10 ℃, with a contact area A between the ice and the coating of 100 mm². 2 Place and fix the coating and ice block horizontally. Use a tension gauge to apply a load along the plane of the coating at a speed of 5 mm / min, and record the maximum load F when the ice block begins to slide. Divide F by the contact area A to obtain the ice adhesion strength τ = F / A, in kPa.

[0161] (5) Freezing delay time test: Place the coated stainless steel substrate on a horizontally placed -10 ℃ cold table, add 20 μL of water, and observe and record the freezing time of the water.

[0162] (6) Photothermal de-icing performance: In an environment of -30 ℃ and 60% humidity, spray 2 mL of water onto the coating surface, wait for a layer of ice to freeze on the coating surface, then place it under a standard solar intensity for irradiation and record the time required for de-icing.

[0163] The test results are shown in Table 2 below:

[0164] Table 2. Test results of Examples 1-2 and Comparative Examples 1-2 under different amounts of "strawberry"-shaped photothermal-phase change microcapsule hybrids.

[0165]

[0166] As can be seen from Table 2 above, when the mass ratio of the current driving mixture to the "strawberry"-shaped photothermal-phase change microcapsule hybrid is 70:30 (Example 2), the static water contact angle of the coating is 161°, indicating that the added "strawberry"-shaped photothermal-phase change microcapsule hybrid constructs a micro-nano hierarchical structure, providing sufficient roughness, while the fluorocarbon resin and heptadecafluorotrimethylethoxysilane used provide sufficiently low surface energy. Furthermore, the surface temperature of the coating of the sample in Example 2 was 4.8 ℃ in a 0 ℃ cold stage environment. Compared with the samples of Comparative Example 1 and Example 1, the increase in surface temperature is attributed to the photothermal effect of the added "strawberry"-shaped photothermal-phase change microcapsule hybrid under weak light and the release of the latent heat of phase change of the phase change microcapsules, which maintained the surface temperature of the coating. The surface temperature of the sample in Example 2 increased to 73 ℃ within 2 minutes under irradiation with 1 standard solar intensity, indicating that the photothermal effect of the "strawberry"-shaped photothermal-phase change microcapsule hybrid was significant, which shortened the de-icing time to 76 s. The icing delay time of the sample in Example 2 was 1134 s, indicating that the coating has a good delayed icing effect. This is the result of the dual effect of the phase change material releasing the latent heat to delay water icing and the "air cushion" provided by the superhydrophobic structure. The ice adhesion strength decreased to 32 kPa, indicating that ice is not easy to form a structural interlock with the superhydrophobic rough structure. By comparison, the optimal ratio of the precursor mixture to the "strawberry"-shaped photothermal-phase change microcapsule hybrid in Example 2, at a mass ratio of 70:30, was found to be the optimal ratio for the photothermal-phase change hydrophobic topcoat of the present invention. Furthermore, although Comparative Example 2 further increased the amount of the "strawberry"-shaped photothermal-phase change microcapsule hybrid added, its test results were still comprehensively inferior to those of Example 2, and the comparative scheme was too costly.

[0167] like Figure 6 The images show comparative photos of the photothermal-phase change hydrophobic topcoats prepared in Examples 1-2 and Comparative Examples 1-2, respectively, sprayed onto stainless steel substrates for freezing delay time testing.

[0168] Examples 3-6

[0169] Examples 3-6 describe the preparation of a photothermal-phase change hydrophobic topcoat with a micro-nano hierarchical structure and a heat-insulating primer containing micron-sized particles, following the steps in "2. Preparation Method" above. In step (II-2), the core material alkane is a mixture of 10 wt% dodecane and 90 wt% tetradecane. In step (II-4), the amount of "strawberry"-shaped photothermal-phase change microcapsule hybrid added is 58.3 g. However, in step (I-1), the average particle size (D50) of the silica aerogel micropowder is 7 μm, 15 μm, 50 μm, and 100 μm, respectively, corresponding to Examples 3, 4, 5, and 6.

[0170] The heat-insulating primers and photothermal-phase change hydrophobic topcoats prepared in Examples 3-6 were sprayed onto stainless steel substrates for testing. The spraying pressure was 0.2 MPa, the spraying distance was 20 cm, and the spraying amount of the heat-insulating primer was 80 g / m². 2 The dry film thickness was approximately 200 μm. The coating amount and dry film thickness of the photothermal-phase change hydrophobic topcoat were as described in Example 1. After spraying, the coating was left at room temperature for 4 hours to allow partial evaporation of the ethyl acetate and achieve surface drying. It was then cured in a 60 °C oven for 3 hours to form a photothermal-phase change superhydrophobic coating from the fluorocarbon resin. Surface roughness, water roll-off angle, surface temperature under room temperature light irradiation, surface temperature under room temperature light irradiation, freezing delay time, and weak photothermal de-icing performance were then tested. Specific test methods are as follows:

[0171] (1) Surface roughness test: The surface roughness Ra of the coating combination was tested using a portable roughness measuring instrument (contact type, diamond tip, tip radius 2~10 μm). The test method was carried out in accordance with GB / T 1031-2009 "Product Geometric Specification (GPS) Surface Structure Profile Method Surface Roughness Parameters and Values".

[0172] (2) Water roll-off angle test: The water roll-off angle of the sample surface is tested by tilting plate method. The sample to be tested is fixed on a tiltable platform and the platform is adjusted to a horizontal state. A 7 μL deionized water droplet is dropped onto the sample surface using a micro-syringe. Then, one end of the platform is raised slowly and uniformly to make the sample plate surface gradually tilt. The state of the droplet is observed and the angle between the sample plate surface and the horizontal plane is recorded when the droplet just starts to roll. This angle is the water roll-off angle.

[0173] (3) Surface temperature under room temperature light irradiation: The stainless steel substrate with coating was irradiated for 2 minutes under a standard sunlight intensity at room temperature, and a thermocouple was attached to the lower surface of the stainless steel substrate to record the surface temperature.

[0174] (4) Temperature of upper surface under room temperature light irradiation: The stainless steel substrate with coating was irradiated for 2 minutes under a standard sunlight intensity at room temperature, and a thermocouple was attached to the surface of the coating to record the surface temperature of the coating.

[0175] (5) Freezing delay time test: Place the stainless steel substrate with coating combination on a horizontally placed -10 ℃ cold table, add 20 μL of water, and observe and record the freezing time of the water.

[0176] (6) De-icing performance under weak light and heat: In an environment of -30 ℃ and 60% humidity, spray 2 mL of water onto the surface of the coating combination, wait for a layer of ice to freeze on the surface of the coating, and then place it under irradiation at 0.5 standard sunlight intensity and record the time required for de-icing.

[0177] The test results are shown in Table 3 below:

[0178] Table 3. Test results of Examples 3-6 under different average particle size (D50) conditions of silica aerogel micropowder.

[0179]

[0180] As shown in Table 3 above, when the average particle size (D50) of silica aerogel powder increases from 7 μm to 50 μm, the surface roughness Ra of the coating combination gradually increases to 12.5 μm, the roll-off angle decreases to 2°, the lower surface temperature and upper surface temperature of the stainless steel plate with the coating combination irradiated under one standard solar intensity decrease to 42 ℃ and 72 ℃ respectively, the delayed icing time increases to 1288 s, and the photothermal de-icing time decreases to 63 s. However, when the average particle size (D50) of silica aerogel powder increases to 100 μm, the surface roughness no longer increases significantly. Correspondingly, the roll-off angle, lower surface temperature, and photothermal de-icing time increase, while the upper surface temperature and delayed icing time decrease. Greater roughness indicates the presence of more "air cushions" on the coating surface. These "air cushions" facilitate droplet sliding off the surface, resulting in a lower water roll-off angle, better thermal insulation, and more heat concentration on the coating surface. This leads to a lower temperature on the lower surface and a higher temperature on the upper surface of the substrate, thus delaying icing and accelerating de-icing under low light conditions. The above comparative results demonstrate that the roughness generated by the silica aerogel micropowder in the thermal insulation functional base coating synergistically with the roughness generated by the "strawberry"-shaped photothermal-phase change microcapsule hybrid in the top coating, resulting in a coating combination with a lower water roll-off angle and superior thermal insulation and de-icing performance. Therefore, the optimal average particle size (D50) of the silica aerogel micropowder used in this invention is 50 μm.

[0181] Application Examples 1-4

[0182] The heat-insulating primer and photothermal-phase change hydrophobic topcoat prepared in Example 5 were sprayed onto a stainless steel substrate for testing. The spraying methods described in Examples 3-6 were followed, but the thickness of the heat-insulating functional base layer was adjusted to approximately 100 μm, 200 μm, 300 μm, and 400 μm, respectively, corresponding to Application Examples 1, 2, 3, and 4. The spraying amount in Application Example 1 was approximately 40 g / m². 2The remaining application examples are increased proportionally. The thickness of the heat-insulating functional base coating is obtained by repeatedly measuring the thickness at 5-6 different coating surface locations using a CM8821 portable coating thickness gauge from Guangzhou Lantai Instrument Co., Ltd., and taking the average value. Then, the photothermal-phase change hydrophobic topcoat is sprayed according to the spraying methods described in Examples 3-6 above. The surface temperature under room temperature light irradiation, the surface temperature under room temperature light irradiation, the freezing delay time, and the weak photothermal de-icing performance are then tested according to the test methods described in Examples 3-6 above. The test results are shown in Table 4 below:

[0183] Table 4. Test results of Application Examples 1-4 under different thermal insulation functional primer coating thicknesses.

[0184]

[0185] As shown in Table 4 above, when the thickness of the heat-insulating functional base coating increases from 100 μm to 300 μm, the lower surface temperature of the stainless steel plate with the coating combination irradiated under one standard solar intensity decreases from 65 ℃ to 35 ℃. This indicates that the base coating has low thermal conductivity, preventing heat transfer to the stainless steel substrate and effectively avoiding overheating of the substrate due to photothermal effect under solar irradiation. Simultaneously, the upper surface temperature of the coating combination gradually increases from 73 ℃ to 82 ℃, indicating that more heat generated by photothermal effect flows to the photothermal-phase change superhydrophobic coating. The photothermal de-icing time under irradiation at 0.5 standard solar intensity is shortened to 45 s, and the photothermal de-icing capability is enhanced. Due to the heat insulation effect of the base coating, the transfer of cold energy from the -10 ℃ cold platform to the droplets is prevented, and the delayed freezing time of the droplets is extended to 2148 s. Therefore, the optimal thickness of the heat-insulating functional base coating in the method of this invention is 300 μm.

[0186] like Figure 4 As shown in Application Example 3, the surface of the heat-insulating functional primer sprayed onto the stainless steel substrate exhibits a distinct groove structure, providing micron-level roughness.

[0187] like Figure 5 As shown, water droplets on the coating surface are approximately spherical, indicating that the coating exhibits superhydrophobicity.

[0188] Comparative Example 3

[0189] In Comparative Example 3, the heat-insulating primer provided in Example 5 was combined with the topcoat described below and sprayed onto a stainless steel substrate in the manner described in Application Example 3 for testing.

[0190] Comparative Example 3: Topcoat without phase change microcapsules, the specific steps are as follows:

[0191] S1: Add 0.1 g of titanium nitride nanoparticles (TiN) to 100 g of mixed solvent (water and ethanol in a volume ratio of 80:20) and treat under ultrasonic conditions of 40 kHz and 200 W for 30 min to prepare a titanium nitride nanoparticle dispersion.

[0192] At a temperature of 24–26 °C, 10 mM Tris buffer solution was added to the titanium nitride nanoparticle dispersion until the pH was adjusted to 8.5. Then, 20 mL of 4 mg / mL dopamine hydrochloride aqueous solution was added, and the mixture was stirred at 20–30 °C for 12 h. The mixture was then centrifuged, washed 3–5 times with deionized water and ethanol alternately, and vacuum dried for 12 h to prepare polydopamine-coated titanium nitride nanoparticles.

[0193] S2: Dissolve 30 g of fluorocarbon resin in 100 g of ethyl acetate to prepare a fluorocarbon resin solution. Then, add 5 g of tetraethyl orthosilicate and 1 g of heptadecafluorotrimethylethoxysilane in sequence. Stir the mixture in a water bath at 60 °C for 2 h. After the reaction time is up, add 58.3 g of polydopamine-coated titanium nitride nanoparticles and treat the mixture with ultrasound at 40 kHz and 200 W for 30 min to prepare the topcoat.

[0194] Comparative Example 4

[0195] In Comparative Example 4, the heat-insulating primer provided in Example 5 was combined with the topcoat described below and sprayed onto a stainless steel substrate in the manner of Application Example 3 for testing.

[0196] Comparative Example 4: MUF phase change microcapsules were prepared by encapsulating alkane core material with melamine-urea-formaldehyde (MUF) resin. The specific steps are as follows:

[0197] S1: Add 1 g of melamine, 3 g of 37 wt% formaldehyde aqueous solution, 0.3 g of urea and 100 mL of deionized water to a round-bottom flask in sequence. Adjust the pH to 8 with sodium hydroxide solution, then heat in a 60 ℃ water bath and stir magnetically for 1 h. When the solution becomes transparent, the MUF prepolymer solution is obtained.

[0198] S2: Prepare a 0.5 wt% sodium dodecyl sulfate aqueous solution, then add 8 g of core material alkane (10 wt% dodecane and 90 wt% tetradecane) to 100 g of sodium dodecyl sulfate aqueous solution, and treat with ultrasound at 40 kHz and 200 W for 30 min to obtain SDS emulsion;

[0199] S3: Transfer the obtained SDS emulsion into a round-bottom flask, stir at a rate of 300 r / min, heat to 60 ℃, then adjust the pH to 4 with dilute hydrochloric acid solution, then add 100 g of MUF prepolymer solution dropwise, heat to 80 ℃, maintain the pH of the reaction system at 5, stir and react for 6 h, after which cool to room temperature, wash with deionized water and anhydrous ethanol alternately more than 3 times, and vacuum dry to obtain MUF phase change microcapsules;

[0200] S4: Dissolve 30 g of fluorocarbon resin in 100 g of ethyl acetate to prepare a fluorocarbon resin solution. Then, add 5 g of tetraethyl orthosilicate and 1 g of heptadecafluorotrimethylethoxysilane in sequence. Stir the mixture in a water bath at 60 °C for 2 h. After the reaction time is up, add 29.15 g of polydopamine-coated titanium nitride nanoparticles and 29.15 g of MUF phase change microcapsule particles. Soak the mixture under ultrasonic conditions of 40 kHz and 200 W for 30 min to prepare the topcoat.

[0201] Examples 5, 3, and 4 were sprayed onto a stainless steel substrate in the manner described in Application Example 3, and the following tests were conducted: the stainless steel substrate with the coating was irradiated under a standard sunlight intensity of -15 °C for about 500 seconds, and then the light source was turned off; thermocouples were attached to the surface of the coating, and the surface temperature of the coating was recorded.

[0202] Test results are as follows Figure 7 As shown, at -15 ℃, the polydopamine-coated titanium nitride nanoparticles in Comparative Example 3 exhibit a significant heating effect during the heating process, reaching a maximum equilibrium temperature of approximately 11 ℃ in about 180 s. In contrast, Comparative Example 4 shows a clear plateau around 5 ℃, primarily attributed to the phase change of the phase change core material delaying the temperature rise of the coating surface. The "strawberry"-shaped photothermal-phase change microcapsule hybrid in Example 5 heats up faster than Comparative Example 4, resulting in a wider plateau region and a higher maximum equilibrium temperature of approximately 16 ℃. Similarly, during the cooling process, Example 5 shows a more pronounced cooling, with a wider cooling plateau region compared to Comparative Example 4. Therefore, the results of the surface temperature changes of each sample over time during the heating and cooling processes show that the "strawberry"-shaped photothermal-phase change microcapsule hybrid with micro-nano hierarchical structure has better light capture and phase change energy storage effects than the MUF phase change microcapsule in Comparative Example 4 and the physical mixing system in Comparative Example 3. This is attributed to the synergy between the heat-insulating primer containing micron-sized particles and the photothermal-phase change hydrophobic topcoat with micro-nano hierarchical structure, which increases the photothermal effect on the coating surface and improves the heat transfer efficiency from photothermal to the phase change core material.

[0203] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a superhydrophobic anti-icing coating combination with photothermal-phase change-thermal insulation synergistic thermal management, characterized in that... Includes the following steps: (I) Preparation of heat-insulating primer containing micron-sized particles: (Ⅰ-1) A 5-15 wt% aerogel dispersion slurry was prepared by using micron-sized aerogel powder; (Ⅰ-2) Add aqueous acrylic emulsion, aqueous silica sol, p-toluenesulfonic acid and nanocellulose to the aerogel dispersion slurry, mix evenly, adjust the pH to neutral, and let stand to mature to obtain a heat-insulating primer containing micron particles. (II) Preparation of photothermal-phase change hydrophobic topcoat with micro-nano hierarchical structure: (II-1) The surfactant, core material alkane, and tetraethyl orthosilicate are mixed in a solvent to obtain the oil phase; The core material alkane is composed of at least one of dodecane, tridecane, tetradecane, pentadecane and hexadecane, and the phase transition temperature of the core material alkane is in the range of -10 ~ 5 ℃. (II-2) The oil phase obtained in step (II-1) is mixed with deionized water to obtain an oil-in-water emulsion. An alkaline catalyst is added to catalyze the hydrolysis and polycondensation reaction of tetraethyl orthosilicate. After separation and drying, phase change microcapsules are obtained. (II-3) The phase change microcapsules obtained in step (II-2), titanium nitride nanoparticles, and dopamine hydrochloride were reacted in a buffer solution to prepare a "strawberry"-shaped photothermal-phase change microcapsule hybrid with a micro-nano hierarchical structure; The mass ratio of phase change microcapsules to titanium nitride nanoparticles is (1~10):(0.1~5). (II-4) Dissolve fluorocarbon resin in an organic solvent, add orthosilicate and fluorinated silane coupling agent, add the "strawberry"-shaped photothermal-phase change microcapsule hybrid obtained in step (II-3) to the precursor mixture after reaction and disperse it to prepare a photothermal-phase change hydrophobic topcoat with micro-nano hierarchical structure; The mass ratio of the precursor mixture to the "strawberry"-shaped photothermal-phase change microcapsule hybrid is (65~90):(10~35).

2. The preparation method according to claim 1, characterized in that: The aerogel powder mentioned in step (Ⅰ-1) includes at least one of silicon-based aerogel powder, polymer aerogel powder, carbon-based aerogel powder, and metal oxide aerogel powder; the average particle size D50 of the aerogel powder is 7~100 μm.

3. The preparation method according to claim 1, characterized in that: Step (Ⅰ-1) involves mixing and dispersing the aerogel dispersion slurry uniformly according to the following proportions based on total mass: 0.5~3wt% dispersant, 5~15wt% aerogel micro powder, 0.1~0.5wt% defoamer, with the balance being deionized water.

4. The preparation method according to claim 1, characterized in that: Step (Ⅰ-2) involves adding 10-30 wt% of waterborne acrylic emulsion with a solid content of 35%, 1-5 wt% of waterborne silica sol, 0.2-0.5 wt% of p-toluenesulfonic acid, and 3-5 wt% of nanocellulose to the aerogel dispersion slurry obtained in step (Ⅰ-1). After mixing evenly, the pH is adjusted to neutral, and then 0.05-0.2 wt% of defoamer is added. After mixing evenly again, the mixture is allowed to stand and mature to obtain a heat-insulating primer containing micron-sized particles.

5. The preparation method according to claim 1, characterized in that: The core material alkane mentioned in step (Ⅱ-1) is composed of dodecane and tetradecane, and the mass ratio of dodecane to tetradecane is (10~20):(80~90).

6. The preparation method according to claim 1, characterized in that: Step (Ⅱ-1) involves dissolving 1-5 parts of surfactant in 25 parts of formamide by weight, then adding 2-8 parts of core material alkane and tetraethyl orthosilicate, mixing thoroughly to obtain the oil phase; The core material alkane is composed of at least one of dodecane, tridecane, tetradecane, pentadecane, and hexadecane, and the phase transition temperature of the core material alkane is in the range of -10 ~ 5 ℃; the mass ratio of tetraethyl orthosilicate to core material alkane in the oil phase is (0.5~4):1; Step (II-2) involves adding the oil phase obtained above to 50 parts of deionized water and mixing to obtain an oil-in-water emulsion. Then, 1-5 parts of ammonia water are added to the oil-in-water emulsion, and the mixture is stirred for 5-24 hours. After the time is reached, the mixture is aged for at least 12 hours. Then, the mixture is separated, washed, and dried sequentially to prepare phase change microcapsules. The concentration of the ammonia water is 2-3%.

7. The preparation method according to claim 1, characterized in that: Step (II-3) involves adding the phase change microcapsules obtained in step (II-2) to a solvent to prepare a phase change microcapsule dispersion with a solid content of 1-10%, and adding titanium nitride nanoparticles to a solvent to prepare a titanium nitride nanoparticle dispersion with a mass concentration of 0.1-1 mg / mL. At a temperature of 24–26 °C, a 10 mM Tris buffer solution was added to a titanium nitride nanoparticle dispersion until the pH was adjusted to 8–9. Then, a phase change microcapsule dispersion was added and stirred continuously for at least 6 h. Next, a 0.5–10 mg / mL dopamine hydrochloride aqueous solution was added, and the mixture was stirred at a temperature of 20–30 °C for 12–24 h. The mixture was then separated, washed, and dried sequentially to prepare a "strawberry"-shaped photothermal-phase change microcapsule hybrid with a micro-nano hierarchical structure. The mass ratio of phase change microcapsules to titanium nitride nanoparticles is (1~10):(0.1~5), and the mass ratio of titanium nitride nanoparticles to dopamine hydrochloride is (0.1~1):(0.5~10).

8. The preparation method according to claim 1, characterized in that: Step (II-4) involves dissolving fluorocarbon resin in an organic solvent to prepare a fluorocarbon resin solution, then sequentially adding tetraethyl orthosilicate and heptadecafluorotrimethylethoxysilane, stirring for 30-120 min, and after the reaction time is reached, adding the "strawberry"-shaped photothermal-phase change microcapsule hybrid obtained in step (II-3) to the precursor mixture obtained after the reaction and dispersing it to prepare a photothermal-phase change hydrophobic topcoat with a micro-nano hierarchical structure. The mass ratio of the precursor mixture to the "strawberry"-shaped photothermal-phase change microcapsule hybrid is (65~90):(10~35); the mass ratio of the fluorocarbon resin, tetraethyl orthosilicate, and heptadecafluorotrimethylethoxysilane is (1~5):(0.1~2):(0.05~1), and the solid content of the photothermal-phase change hydrophobic topcoat is not higher than 35%.

9. The heat-insulating primer containing micron-sized particles and the photothermal-phase change hydrophobic topcoat with micro-nano hierarchical structure obtained by the preparation method of the superhydrophobic anti-icing coating combination of photothermal-phase change-thermal insulation synergistic thermal management as described in claim 1.

10. The application of the heat-insulating primer containing micron particles and the photothermal-phase change hydrophobic topcoat with micro-nano hierarchical structure as described in claim 9 in the preparation of wind turbine blades.

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