Photo-thermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating and preparation method thereof

Abstract

The invention relates to the technical field of anti-icing, in particular to a photo-thermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating and a preparation method thereof. Comprising the following steps: S1, preparing a phase change microcapsule of chitosan coated paraffin through a single coacervation method; s2, modifying a carbon nano tube, and adding the modified carbon nano tube into the suspension of the phase change microcapsule to form a composite microcapsule; and S3, uniformly mixing the composite microcapsule with organic silicon. Compared with the prior art, by combining the photo-thermal and super-hydrophobic characteristics and the energy storage effect of the phase change microcapsules, the effect of effectively delaying icing can be achieved, the ice resistance and deicing efficiency is high, the photo-thermal conversion performance is good, the super-hydrophobic performance is good, and surface ice prevention and deicing under the extreme weather condition can be achieved; and the coating can keep effective anti-icing and deicing functions under low-temperature and high-humidity conditions. 2, the nanoparticles are grafted to the surface of the chitosan phase change microcapsule to form an organic-inorganic composite phase change microcapsule, and the flexibility of organic substances and the stability of inorganic materials are combined;

Description

Technical Field

[0001] The present invention relates to the field of anti-icing technology, and in particular to a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating and a preparation method thereof. Background Art

[0002] Icing has irreversible impacts on various sectors, even causing economic losses and safety incidents. For example, ice on aircraft wings can affect engine operation, and ice on cables can cause power grids to malfunction. Traditional de-icing methods, such as mechanical and chemical de-icing, suffer from high costs, high energy consumption, environmental pollution, and low efficiency. In recent years, with the development of new materials technologies, super-hydrophobic coatings based on photothermal conversion technology have emerged as a green, environmentally friendly, and low-energy anti-icing / de-icing solution. These materials combine passive anti-icing and active de-icing, effectively reducing energy consumption and improving the coating's anti-icing / de-icing efficiency. On the one hand, the hydrophobic nanoscale hierarchical structure firmly binds air within the surface texture and minimizes the water-solid contact area, making the material surface impervious to water droplets. On the other hand, the photothermal conversion material absorbs the inexhaustible solar energy to generate heat, which accelerates the melting of ice on the surface and reduces ice accumulation.

[0003] Deng et al. (Deng, Lechun, et al. CNTs-induced superhydrophobic and photothermal coating with long-term durability and self-replenishing properties for anti-icing / de-icing. Composites Science and Technology 245 (2024):110347.) loaded mesoporous silica nanoparticles (mSiO2) with a high dose of polydimethylsiloxane (PDMS) to prepare a hydrophobic PDMS@mSiO2 polymer. They then combined this polymer with carbon nanotubes (CNTs) into a silicone resin matrix to construct a near-infrared-responsive anti-icing / de-icing coating via a one-step spray coating. The PDMS@mSiO2 particles imparted microscale roughness and low surface energy to the coating, while the CNTs complemented it to form a micro-nano hierarchical structure, enhancing the coating's hydrophobicity and photothermal properties. Li et al. (Li, S., et al. (2024). A photothermal superhydrophobic coating with un-fluorinated modified CNTs for anti-icing applications on concrete. Materials Letters 355: 135463.) constructed a superhydrophobic photothermal coating composed of fluorine-free modified carbon nanotubes (M-CNTs) and commercial epoxy resin on the concrete surface through a simple spraying process. The addition of M-CNTs gives the coating excellent superhydrophobic and photothermal properties, endowing the coating surface with outstanding deicing performance under sunlight.

[0004] However, due to the low energy density of solar energy and the day-night cycle, photothermal superhydrophobic materials struggle to achieve all-weather anti-icing and de-icing performance, particularly in low-temperature, high-humidity environments. Organic phase change materials, with their high latent heat and adjustable phase transition temperature range, can store thermal energy when solar energy is abundant. When the ambient temperature drops or solar energy is insufficient, they release the stored thermal energy through a phase change process to maintain or raise the material's surface temperature. They are considered a solution for prolonging anti-icing and de-icing performance.

[0005] Therefore, a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating and its preparation method are designed, combining phase change materials and photothermal hydrophobic materials to solve the problem that the existing materials have low anti-icing efficiency under low temperature, low humidity and no light conditions during the anti-icing process. Summary of the Invention

[0006] In order to overcome the shortcomings of the existing technology, the present invention provides a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating and a preparation method thereof, which solves the problem that the coating has poor all-weather anti-icing / de-icing effect under low temperature and high humidity conditions.

[0007] To achieve the above objectives, a method for preparing a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating is designed, comprising the following steps: S1, preparation of phase-change microcapsules: chitosan-coated paraffin phase-change microcapsules were prepared by single coacervation method; S2, preparation of composite microcapsules: modifying carbon nanotubes, and adding the modified carbon nanotubes to a suspension of phase change microcapsules to form composite microcapsules; S3, composite coating preparation: uniformly mixing the composite microcapsules and the organosilicon to obtain a composite coating.

[0008] The specific method of step S1 is as follows: S11, dissolving chitosan in acetic acid solution to obtain a chitosan solution; S12, adding anionic surfactant to deionized water and ultrasonically forming a stable emulsifier solution, and adding solid paraffin to the emulsifier, and ultrasonically forming the paraffin until the paraffin is completely emulsified; S13, adding the chitosan solution, and reacting to form chitosan phase change microcapsules.

[0009] In the step S11, the mass volume ratio of chitosan to acetic acid solution is 0.5-3g:30-60ml, and the content of acetic acid solution is 0.5-33%; in the step S12, the volume mass ratio of deionized water to anionic surfactant is 40-60ml:0.05-0.2g, the ultrasonic time is 1-3h, the reaction temperature is 50-80°C, and the paraffin is 0.1-0.5g; in the step S13, the reaction temperature is 50-80°C, and the reaction time is 8-12h.

[0010] The anionic surfactant includes one or more of sodium dodecylbenzenesulfonate (SDBS), sodium tetrapropylenebenzenesulfonate (ABS), and sodium dibutylnaphthalenesulfonate.

[0011] The specific method of step S2 is as follows: S21, uniformly dispersing carbon nanotube particles in a mixed solution of ethanol and water, and ultrasonically treating the suspension until the suspension is completely dispersed; S22, simultaneously adding a silane coupling agent for modification; S23, mixing the modified carbon nanotubes with the phase change microcapsules of step S1 to obtain composite microcapsules.

[0012] In the step S21, the amount of carbon nanotubes is 0.3-0.6 g, and the ratio of ethanol to water is 7-9:3-1; in the step S22, the content of silane coupling agent is 3-6%, and the modification time is 1-3 hours; in the step S23, the reaction temperature is 40-60°C, and the reaction time is 8-12 hours.

[0013] The silane coupling agent includes one or more of 3-glycidoxytrimethoxysilane and perfluorooctylethyltrimethoxysilane.

[0014] In step S3, the mass ratio of the composite microcapsules to the silicone resin is 8-12:4-6.

[0015] To achieve the above objectives, a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating was designed, including a mixture of composite microcapsules and silicone. The composite microcapsules are a mixture of modified carbon nanotubes and chitosan-coated paraffin phase change microcapsules.

[0016] To achieve the above objectives, a method for preparing a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating is designed. A substrate is provided, and a composite coating is coated on the surface of the substrate. After curing, the coating is applied in all-weather anti-icing.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Combining the photothermal and superhydrophobic properties and the energy storage function of phase change microcapsules, it can effectively delay the formation of ice. The preparation method is simple, the anti-icing and deicing efficiency is high, the photothermal conversion performance is good, the superhydrophobic property is good, and it can cope with surface anti-icing and deicing under extreme climatic conditions, ensuring that the coating maintains effective anti-icing and deicing functions under low temperature and high humidity conditions.

[0018] 2. Grafting nanoparticles onto the surface of chitosan phase change microcapsules to form organic-inorganic composite phase change microcapsules. Organic-inorganic composite phase change microcapsules are a highly efficient energy storage material that combines the flexibility of organic matter with the stability of inorganic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a performance comparison of the existing polydimethylsiloxane coating, modified carbon nanotube coating and the photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating prepared in Examples 1 to 3 of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described below.

[0021] The present invention provides a method for preparing a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating, which includes a mixture of composite microcapsules and silicone. The composite microcapsules are a mixture of modified carbon nanotubes and chitosan-coated paraffin phase change microcapsules.

[0022] The preparation method thereof comprises the following steps: S1, preparation of phase change microcapsules: chitosan-coated paraffin phase change microcapsules were prepared by single coacervation method.

[0023] The specific method is as follows: S11, dissolving chitosan in an acetic acid solution to obtain a chitosan solution, wherein the mass-to-volume ratio of chitosan to acetic acid solution is 0.5-3g:30-60ml, and the acetic acid content is 0.5-33%. S12, adding anionic surfactant to deionized water and ultrasonically forming a stable emulsifier solution, then adding solid paraffin to the emulsifier and ultrasonically performing the process at 50-80°C for 1-3 hours until the paraffin is completely emulsified, wherein the mass-to-volume ratio of deionized water to anionic surfactant is 40-60ml:0.05-0.2g. S13, adding the chitosan solution and reacting at 50-80°C for 8-12 hours to form chitosan phase change microcapsules.

[0024] The anionic surfactant includes one or more of sodium dodecylbenzenesulfonate (SDBS), sodium tetrapropylenebenzenesulfonate (ABS), and sodium dibutylnaphthalenesulfonate.

[0025] S2, preparation of composite microcapsules: modifying carbon nanotubes, and adding the modified carbon nanotubes into a suspension of phase change microcapsules to form composite microcapsules.

[0026] The specific method is as follows: S21, uniformly dispersing 0.3-0.6g of carbon nanotube particles in a mixed solution of ethanol and water, and ultrasonically treating the suspension until it is completely dispersed. S22, simultaneously adding 3-6% of a silane coupling agent for modification for 1-3 hours. S23, mixing the modified carbon nanotubes with the phase change microcapsules from step S1 at 40-60°C for 8-12 hours to obtain composite microcapsules.

[0027] In the mixed solution of ethanol and water, the ratio of ethanol to water is 7-9:3-1. The silane coupling agent includes one or more of 3-glycidoxytrimethoxysilane and perfluorooctylethyltrimethoxysilane.

[0028] S3, preparation of composite coating: uniformly mixing composite microcapsules and organic silicon in a mass ratio of 8-12:4-6 to obtain a composite coating.

[0029] In specific use, a substrate is provided, and the composite coating obtained in step S3 is coated on the surface of the substrate. After curing, the coating is used in all-weather anti-icing applications, and the curing temperature is 40-80°C.

[0030] When used in all-weather anti-icing applications, paraffin wax, as the core shell material, can absorb or release large amounts of heat energy at specific temperatures, allowing the coating to retain heat during hot and cold weather, reducing heat loss and improving energy efficiency. By regulating the surface temperature, it effectively prolongs the accumulation of ice and frost on the surface in low-temperature, high-humidity environments, achieving all-weather anti-icing and de-icing. The outer shell material, a composite of modified carbon nanotubes and chitosan, provides the coating with superhydrophobic and photothermal properties. The superhydrophobicity also makes the surface less susceptible to the adhesion of some contaminants, imparting self-cleaning properties while also improving the mechanical strength and thermal stability of the microcapsules. Example

[0031] This embodiment prepares a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating, including the following steps: S1. Preparation of phase-change microcapsules: First, dissolve 1g of chitosan in 50ml of 1% acetic acid solution to obtain a chitosan solution. Next, add 0.1g of sodium dodecylbenzenesulfonate to 50ml of deionized water and sonicate for 2h to form a stable emulsifier solution. Subsequently, add 0.3g of solid paraffin wax to the emulsifier solution at 60°C and sonicate until the wax is completely emulsified. Finally, add the chitosan solution and react at 60°C for 10h to form chitosan phase-change microcapsules.

[0032] S2, Preparation of CNT / chitosan Composite Microcapsules: First, 0.5 g of carbon nanotube particles were uniformly dispersed in a 9:1 mixture of ethanol and water and treated under ultrasonication for 30 minutes. Once the suspension was completely dispersed, the temperature was raised to 60°C. Simultaneously, 5% 3-epoxypropyltrimethoxysilane was added to the carbon nanotube suspension and allowed to react in the suspension for 1 hour. In the final step, the modified carbon nanotube particles were mixed with chitosan phase change microcapsules and reacted at 50°C for 10 hours to obtain CNTs / chitosan composite microcapsules.

[0033] S3, composite coating preparation: 10g of CNTs / chitosan composite microcapsules (microcapsule content of 10wt%) and 5g of silicone resin were mixed evenly and coated on a pre-prepared substrate, and dried at 60°C until a consistent constant weight was reached to obtain a photothermal phase change energy storage superhydrophobic composite coating.

[0034] The coating sample was subjected to a contact angle test and placed in a temperature-controlled container maintained at -10°C. A humidifier with a relative humidity of 99% was then used to generate a water spray within the container. When the coating surface became opaque or frosted, the frost formation delay was recorded. After the coating froze, a xenon lamp with a constant intensity of 1000W / m² was used to simulate sunlight and the surface temperature was measured. Example

[0035] S1. Preparation of phase-change microcapsules: First, dissolve 1g of chitosan in 50ml of 1% acetic acid solution to obtain a chitosan solution. Next, add 0.1g of sodium dodecylbenzenesulfonate to 50ml of deionized water and sonicate for 2h to form a stable emulsifier solution. Subsequently, add 0.3g of solid paraffin wax to the emulsifier solution at 60°C and sonicate until the wax is completely emulsified. Finally, add the chitosan solution and react at 60°C for 10h to form chitosan phase-change microcapsules.

[0036] S2, Preparation of CNT / chitosan Composite Microcapsules: First, 0.5 g of carbon nanotube particles were uniformly dispersed in a 9:1 mixture of ethanol and water and treated under ultrasonication for 30 minutes. Once the suspension was fully dispersed, the temperature was raised to 60°C. Simultaneously, 5% 3-epoxypropyltrimethoxysilane was added to the carbon nanotube suspension and allowed to react in the suspension for 1 hour. In the final step, the modified carbon nanotube particles were mixed with chitosan phase change microcapsules and reacted at 50°C for 10 hours to produce CNT / chitosan composite microcapsules.

[0037] S3, composite coating preparation: 8 g of CNTs / chitosan composite microcapsules (microcapsule content of 10 wt%) and 5 g of silicone resin were mixed evenly and coated on a pre-prepared substrate. The coating was then dried at 60°C until a consistent constant weight was reached to obtain a photothermal phase change energy storage superhydrophobic composite coating.

[0038] The coating sample was subjected to a contact angle test and placed in a temperature-controlled container maintained at -10°C. A humidifier with a relative humidity of 99% was then used to generate a water spray within the container. When the coating surface became opaque or frosted, the frost formation delay was recorded. After the coating froze, a xenon lamp with a constant intensity of 1000W / m² was used to simulate sunlight and the surface temperature was measured. Example

[0039] S1, Preparation of Phase Change Microcapsules: "First, 1 g of chitosan was dissolved in 50 ml of 1% acetic acid solution to obtain a chitosan solution. Next, 0.1 g of sodium dodecylbenzenesulfonate was added to 50 ml of deionized water and ultrasonicated for 2 h to form a stable emulsifier solution. Subsequently, 0.3 g of solid paraffin was added to the emulsifier solution at 60 °C and ultrasonicated until the paraffin was completely emulsified. Finally, the chitosan solution was added and reacted at 60 °C for 10 h to obtain chitosan phase change microcapsules.

[0040] S2, Preparation of CNTs / chitosan Composite Microcapsules: First, 0.5 g of carbon nanotube particles were uniformly dispersed in a 9:1 mixture of ethanol and water and treated under ultrasonication for 30 minutes. Once the suspension was completely dispersed, the temperature was raised to 60°C. Simultaneously, 5% 3-epoxypropyltrimethoxysilane was added to the carbon nanotube suspension and allowed to react in the suspension for 1 hour. In the final step, the modified carbon nanotube particles were mixed with chitosan phase change microcapsules and reacted at 50°C for 10 hours to obtain CNTs / chitosan composite microcapsules.

[0041] S3, composite coating preparation: 12 g of CNTs / chitosan composite microcapsules (microcapsule content of 10 wt%) and 5 g of silicone resin were mixed evenly and coated on a pre-prepared substrate. The coating was then dried at 60°C until a consistent constant weight was reached to obtain a photothermal phase change energy storage superhydrophobic composite coating.

[0042] The coating sample was subjected to a contact angle test and placed in a temperature-controlled container maintained at -10°C. A humidifier with a relative humidity of 99% was then used to generate a water spray within the container. When the coating surface became opaque or frosted, the frost formation delay was recorded. After the coating froze, a xenon lamp with a constant intensity of 1000W / m² was used to simulate sunlight and the surface temperature was measured.

[0043] Figure 1 It is a performance comparison of the existing polydimethylsiloxane coating, modified carbon nanotube coating and the photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating prepared in Examples 1 to 3. As can be seen from the figure, the existing polydimethylsiloxane coating has poor hydrophobicity, the delay time of droplet freezing at low temperatures is very short, and it does not have the photothermal deicing function. After being placed in the dark under low temperature and high humidity conditions for 12 hours, the surface is completely covered with ice, and the anti-icing effect is not good. The existing modified carbon nanotube coating has super-hydrophobicity, can delay the formation of ice, and can also perform photothermal deicing, but the photothermal conversion efficiency is low, and it cannot actively de-ice in the dark. Compared with the above-mentioned coatings, the coatings prepared in Examples 1, 2, and 3 have super-hydrophobicity and high-efficiency light conversion efficiency, can significantly delay ice formation, and thanks to the energy storage effect of the phase change material, the coating can maintain a temperature above freezing for a long time under dark conditions, and has an all-weather anti-icing effect.

[0044] This invention uses a single coacervation method to encapsulate paraffin wax with the natural polymer chitosan, enhancing both biodegradability and the stability of the phase change material encapsulation. Modified carbon nanotubes improve their dispersibility and introduce hydrophobic groups to enhance light absorption. Curing creates micro-nano roughness through a silicone resin matrix, synergizing super-hydrophobicity and strengthening adhesion.

[0045] During application, it can be directly applied via spraying technology to surfaces such as power lines, aircraft wings, transmission towers, and roads. The superhydrophobic micro-nanostructure in the coating can reduce the adhesion of droplets, increase the energy barrier for ice nucleation, and prolong the freezing time of droplets, thus serving as the first line of defense for anti-icing and de-icing. Carbon nanotube photothermal materials efficiently convert daytime solar energy into thermal energy through the photothermal effect. Some of this heat heats the coating surface, rapidly melting ice and preventing new ice from forming. The remaining heat is stored in the built-in phase change material for subsequent use, serving as the second line of defense for anti-icing and de-icing. The phase change material releases this stored heat to maintain the coating surface temperature above the supercooling point of water, thereby extending the anti-icing time at night and forming the third line of defense for anti-icing and de-icing. The photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating of the present invention integrates the advantages of super-hydrophobicity, photothermal conversion, and phase change heat storage. It achieves long-term, all-weather anti-icing / de-icing functions through a multi-level anti-icing mechanism, solving the problem of all-weather anti-icing and has important application prospects in anti-icing fields such as power transmission lines, aircraft wings, and roads.

Claims

1. A method for preparing a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating, characterized by: The steps include: S1, preparation of phase-change microcapsules: chitosan-coated paraffin phase-change microcapsules were prepared by single coacervation method; S2, preparation of composite microcapsules: modifying carbon nanotubes, and adding the modified carbon nanotubes to a suspension of phase change microcapsules to form composite microcapsules; S3, composite coating preparation: uniformly mixing the composite microcapsules and the organosilicon to obtain a composite coating.

2. The method for preparing a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating according to claim 1, characterized in that: The specific method of step S1 is as follows: S11, dissolving chitosan in acetic acid solution to obtain a chitosan solution; S12, adding anionic surfactant to deionized water and ultrasonically forming a stable emulsifier solution, and adding solid paraffin to the emulsifier, and ultrasonically forming the paraffin until the paraffin is completely emulsified; S13, adding the chitosan solution, and reacting to form chitosan phase change microcapsules.

3. The method for preparing a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating according to claim 2, characterized in that: In the step S11, the mass volume ratio of chitosan to acetic acid solution is 0.5-3g:30-60ml, and the content of acetic acid solution is 0.5-33%; in the step S12, the volume mass ratio of deionized water to anionic surfactant is 40-60ml:0.05-0.2g, the ultrasonic time is 1-3h, the reaction temperature is 50-80°C, and the paraffin is 0.1-0.5g; in the step S13, the reaction temperature is 50-80°C, and the reaction time is 8-12h.

4. The method for preparing a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating according to claim 2 or 3, characterized in that: The anionic surfactant includes one or more of sodium dodecylbenzenesulfonate (SDBS), sodium tetrapropylenebenzenesulfonate (ABS), and sodium dibutylnaphthalenesulfonate.

5. The method for preparing a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating according to claim 1, characterized in that: The specific method of step S2 is as follows: S21, uniformly dispersing carbon nanotube particles in a mixed solution of ethanol and water, and ultrasonically treating the suspension until the suspension is completely dispersed; S22, simultaneously adding a silane coupling agent for modification; S23, mixing the modified carbon nanotubes with the phase change microcapsules of step S1 to obtain composite microcapsules.

6. The method for preparing a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating according to claim 5, characterized in that: In the step S21, the amount of carbon nanotubes is 0.3-0.6 g, and the ratio of ethanol to water is 7-9:3-1; in the step S22, the content of silane coupling agent is 3-6%, and the modification time is 1-3 hours; in the step S23, the reaction temperature is 40-60°C, and the reaction time is 8-12 hours.

7. The method for preparing a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating according to claim 5 or 6, characterized in that: The silane coupling agent includes one or more of 3-glycidoxytrimethoxysilane and perfluorooctylethyltrimethoxysilane.

8. The method for preparing a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating according to claim 1, characterized in that: In step S3, the mass ratio of the composite microcapsules to the silicone resin is 8-12:4-6.

9. A photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating, characterized by: The invention comprises a mixture of composite microcapsules and organic silicon. The composite microcapsules are a mixture of modified carbon nanotubes and chitosan-coated paraffin phase-change microcapsules. The modified carbon nanotube particles are grafted onto the surface of the phase-change microcapsules.

10. An application of the method for preparing a photothermal phase change energy storage super-hydrophobic all-weather anti-icing composite coating according to any one of claims 1 to 8, characterized in that: A substrate is provided, a composite coating is coated on the surface of the substrate, and after curing, it is used in all-weather anti-icing.

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