Metal-polyphenol-based wear-resistant photo-thermal super-hydrophobic coating and preparation method thereof

Abstract

The invention discloses a wear-resistant photo-thermal super-hydrophobic coating and a preparation method thereof.The preparation method comprises the steps that 1, after bamboo powder is subjected to alkali treatment and drying, high-temperature carbonization treatment is conducted under the hydrothermal condition, and carbonized bamboo powder is obtained; (2) dissolving gallic acid and cerous nitrate in an ethanol-water mixed solvent, carrying out a complexation reaction under a weakly alkaline condition to form a metal-polyphenol network precursor solution, and depositing the metal-polyphenol network precursor solution on the surface of the pretreated substrate under a hydrothermal condition to form a metal-polyphenol network layer; and (3) dispersing the carbonized bamboo powder and a fluorine-containing silane modifier in an organic solvent to prepare a hydrophobic modified dispersion liquid, spraying the hydrophobic modified dispersion liquid on the surface of the metal-polyphenol network layer, and performing drying and thermocuring treatment to obtain the wear-resistant photo-thermal super-hydrophobic coating.

Description

Technical Field

[0001] This invention relates to the field of superhydrophobic materials technology, specifically to a metal-polyphenol-based wear-resistant photothermal superhydrophobic coating and its preparation method. Background Technology

[0002] When wind turbines operate in low-temperature, high-humidity environments, icing easily forms on the blade surfaces. Icing not only increases the blade's weight and disrupts its aerodynamic shape, leading to decreased power generation efficiency, but also exacerbates the mechanical load on the equipment, causing vibration and noise problems, and in severe cases, even threatening the equipment's operational safety. Therefore, developing efficient, stable, and environmentally friendly anti-icing technologies is of great significance for the safe and stable operation of wind power generation equipment. Among these, surface coating anti-icing methods are considered a promising anti-icing technology due to their low energy consumption, simple construction, and wide applicability.

[0003] In recent years, anti-icing strategies based on superhydrophobic surfaces have received widespread attention. Superhydrophobic surfaces are typically achieved by constructing micron / nano-level rough structures and introducing low surface energy materials, which can effectively reduce the contact area between water droplets and solid surfaces, thereby delaying ice nucleation, inhibiting ice growth, and reducing ice adhesion strength. For example, Chinese patent CN202410275599.3 discloses a method for preparing an environmentally friendly and durable ultra-slippery superhydrophobic coating. To further improve anti-icing performance, combining superhydrophobic structures with photothermal functions is considered an effective approach. By introducing functional components with photothermal conversion capabilities, the coating can generate localized heating under illumination, effectively delaying ice nucleation, slowing ice accumulation, and even achieving active de-icing after freezing. Chinese patent CN202511133294.X discloses a carbon nanotube / fluorocarbon resin composite microsphere photothermal superhydrophobic anti-condensation coating and its preparation method. However, existing photothermal superhydrophobic coatings mostly use inorganic nanoparticles or carbon-based materials as functional components, and their adhesion and long-term stability on the substrate surface are still limited. Especially under wind and sand erosion, mechanical wear, or alternating humid and hot environments, the coating is prone to peeling or structural damage.

[0004] Metal-polyphenol networks (MPNs) have gained increasing attention in recent years as a novel surface functionalization strategy. Chinese patent CN202211610012.7 discloses a method for preparing a multifunctional coating of antimicrobial peptides coupled to a metal-polyphenol network. MPN coatings offer advantages such as simple construction and strong adhesion, making them suitable for harsh environments. Jiang et al. combined F-SiO2@Tp / Fe (tea polyphenol-Fe) coatings using a one-step spraying method. 3+A durable photothermal superhydrophobic coating was designed using nanoparticles and silicone resin (Bochen Jiang, et al. Superhydrophobic F-SiO2 / tea polyphenol coating with high efficiency photothermal anti-icing and de-icing properties, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 683(2024)132846), which has good superhydrophobic and photothermal properties, but the coating has insufficient stability and high manufacturing cost.

[0005] Existing strategies for constructing photothermal superhydrophobic coatings using metal-polyphenol networks generally rely on complex nano-inorganic fillers and high-cost fluorination systems. Furthermore, metal-polyphenol networks primarily function as functional binders or auxiliary layers, and their stability in structural construction, photothermal regulation, and complex service environments remains a significant bottleneck. By introducing a gallic acid-cerium ion complex system, this study transforms the metal-polyphenol network from a "functional auxiliary unit" into a "structure-photothermal-interface synergistic regulation unit" for the first time. Combined with carbonized bamboo powder, a sustainable biomass carbon material, this enables the in-situ construction of micro / nano-hierarchical structures and broadband photothermal absorption. Compared to traditional Fe... 3+ –Compared to polyphenol systems, Ce 3+ The GA network exhibits superior complexation stability and hydrolysis resistance in neutral and weakly alkaline environments, enabling the resulting coating to maintain stable hydrophobic and photothermal properties under complex conditions such as low temperature, freeze-thaw cycles, and mechanical wear. This strategy significantly reduces material costs and environmental burden, while providing a new design paradigm for the large-scale application of metal-polyphenol networks in anti-icing engineering. Summary of the Invention

[0006] To address the technical problems commonly found in existing superhydrophobic coatings in practical applications, such as complex preparation processes, insufficient wear resistance, poor mechanical stability, and limited photothermal functions, this invention provides a wear-resistant photothermal superhydrophobic coating and its preparation method.

[0007] The technical solution adopted in this invention is: A method for preparing a wear-resistant, photothermal, and superhydrophobic coating includes the following steps: (1) After alkali treatment and drying, bamboo powder is subjected to high-temperature carbonization under hydrothermal conditions to obtain carbonized bamboo powder; (2) Gallic acid and cerium nitrate are dissolved in an ethanol-water mixed solvent and undergo a complexation reaction under weakly alkaline conditions to form a metal-polyphenol network precursor solution. The solution is then deposited on the surface of the pretreated substrate under hydrothermal conditions to form a metal-polyphenol network layer. (3) The carbonized bamboo powder and the fluorinated silane modifier are dispersed in an organic solvent to prepare a hydrophobic modified dispersion, which is then sprayed onto the surface of the metal-polyphenol network layer. After drying and heat curing, a wear-resistant, photothermal, and superhydrophobic coating is obtained.

[0008] Furthermore, the carbonization process is carried out in a drying oven at a temperature of 180–200 °C, and the temperature is maintained for 10–14 h.

[0009] Furthermore, in the metal-polyphenol network precursor solution, the concentrations of gallic acid and cerium nitrate are 1–5 mg / mL, respectively.

[0010] Furthermore, sodium hydroxide is added dropwise to the metal-polyphenol network precursor solution to maintain the pH at 7-8.

[0011] Furthermore, the metal-polyphenol network deposition is carried out using a hydrothermal reaction method, with a reaction temperature of 140–160 °C and a reaction time of 10–14 h.

[0012] Furthermore, the carbonized bamboo powder has a mass fraction of 0.5–2 wt% in the hydrophobic modified dispersion, and the fluorinated silane modifier has a mass fraction of 1–3 wt% in the hydrophobic modified dispersion.

[0013] Metal-polyphenol-based wear-resistant, photothermal, and superhydrophobic coatings prepared by any of the above methods.

[0014] The beneficial effects of this invention are: (1) The metal-polyphenol network of the present invention makes the coating and the photothermal hydrophobic layer of carbonized bamboo powder not a simple layered superposition, but a synergistic coupling system formed through multiple chemical interactions. The gallic acid-cerium ion network serves as an interfacial transition layer, which forms hydrogen bonds and coordination bridges with oxygen-containing functional groups on the substrate and the surface of carbonized bamboo powder through phenolic hydroxyl groups, providing a chemical basis for the stable anchoring and energy transfer of carbonized bamboo powder.

[0015] (2) This invention prepares carbonized bamboo powder through alkali treatment-carbonization, which simultaneously serves as a photothermal absorption unit and a micro / nano rough structure framework in the network. Further, fluorosilane modification is introduced to regulate only the outermost interfacial energy, achieving a stable superhydrophobic state without damaging the internal chemical and thermal conduction network, thereby constructing an anti-icing coating system with highly coupled structure, photothermal and interfacial properties. Attached Figure Description

[0016] Figure 1Microscopic image of the surface morphology of the coating prepared in Example 1.

[0017] Figure 2 Fourier transform infrared images of the coating surfaces prepared in Example 1 and Comparative Example 2.

[0018] Figure 3 The diagram shows the water contact angles of the superhydrophobic coatings prepared in Examples 1-5 and Comparative Examples 1-3 of this invention.

[0019] Figure 4 The above are the temperature rise curves of the superhydrophobic coatings prepared in Examples 1, 3, 5 and Comparative Example 1 of this invention.

[0020] Figure 5 This is a temperature rise curve diagram of Embodiment 1 of the present invention under solar irradiance intensities of 0.5, 1, and 1.5.

[0021] Figure 6 The graph shows the temperature rise / fall curves for Example 1 over 10 cycles under one solar radiation intensity. Detailed Implementation

[0022] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0023] Unless otherwise specified, the methods used in this invention are conventional methods, and the reagents used in this invention are commercially available products unless otherwise specified. Example 1

[0024] (1) Immerse a fiberglass board substrate with dimensions of 1 cm × 1 cm × 0.2 cm in an ethanol solution and treat it with ultrasound to remove impurities and oil stains from the surface of the substrate. Then, sandblast the fiberglass board and clean it in an ultrasonic cleaner for 10 min. After cleaning, place the fiberglass board in a drying oven at 60 ℃ for 3 h for later use.

[0025] (2) Weigh 10 g of bamboo powder and add it to 100 mL of 2% Na2CO3 aqueous solution. Stir and treat at room temperature for 5 h. After treatment, filter with deionized water and wash repeatedly until the filtrate is neutral. Place the washed wet bamboo powder in a drying oven at 60 ℃ and dry for 12 h. Place the dried bamboo powder in a reaction vessel, push it to the center of the drying oven, heat at 200 ℃ for 12 h, and then cool to room temperature to obtain black carbonized bamboo powder (CBP).

[0026] (3) Weigh 0.15 g gallic acid and 0.15 g cerium nitrate and add them to 50 mL of ethanol-water mixed solvent, where the volume ratio of ethanol to water is 3:17. Dissolve them completely under magnetic stirring. Then add 1 M NaOH solution dropwise to adjust the pH of the system to 7.5 and continue stirring for 30 min. The solution color gradually deepens, indicating that gallic acid and cerium ions undergo a complexation reaction to form a metal-polyphenol network precursor solution.

[0027] The above solution was transferred to a reaction vessel, and the pretreated and dried fiberglass substrate from step (1) was completely immersed in it. The reaction was carried out under hydrothermal conditions at 150 °C for 12 h. After the reaction was completed, the substrate was removed, dried at 60 °C for 1 h, and then heat-cured at 80 °C for 6 h to obtain a substrate with a metal-polyphenol network layer deposited on its surface.

[0028] (4) Weigh 0.5 g of carbonized bamboo powder and 0.75 g of heptadecafluorodecyltrimethoxysilane and add them to 48.75 mL of ethanol. Disperse the mixture using an ultrasonic oscillator for 30 min and then stir it under magnetic stirring for 24 h to obtain a uniform and stable FC hydrophobic modified dispersion.

[0029] The substrate obtained in step (3) was laid flat, and the FC dispersion was sprayed onto its surface using a spray gun at a pressure of 0.6 MPa and a spraying distance of 15 cm. After spraying, the substrate was placed in a 60 ℃ drying oven for pre-curing for 1 h, followed by curing at 80 ℃ for 12 h to obtain a wear-resistant, photothermal, and superhydrophobic coating. Its scanning electron microscope image is shown below. Figure 1 As shown.

[0030] from Figure 1 As can be seen, the surface of Example 1 is relatively smooth, with only a small number of agglomerated particles, while a distinct micron-sized spherical structure appears in the sample. This micron-sized spherical structure not only improves the surface roughness of the coating but also provides a key morphological basis for the formation of hierarchical microstructures and superhydrophobic properties. Example 2

[0031] (1) Immerse a fiberglass board substrate with dimensions of 1 cm × 1 cm × 0.2 cm in an ethanol solution and treat it with ultrasound to remove impurities and oil stains from the surface of the substrate. Then, sandblast the fiberglass board and clean it in an ultrasonic cleaner for 10 min. After cleaning, place the fiberglass board in a drying oven at 60 ℃ for 3 h for later use.

[0032] (2) Weigh 10 g of bamboo powder and add it to 100 mL of 2% Na2CO3 aqueous solution. Stir at room temperature for 5 h. After treatment, filter with deionized water and wash repeatedly until the filtrate is neutral. Place the washed wet bamboo powder in a drying oven at 60 ℃ and dry for 12 h. Place the dried bamboo powder in a reaction vessel, push it into the center of the drying oven, heat it at 200 ℃ for 10 h, and then cool it to room temperature to obtain black carbonized bamboo powder (CBP).

[0033] (3) Weigh 0.05 g gallic acid and 0.05 g cerium nitrate and add them to 50 mL of ethanol-water mixed solvent, where the volume ratio of ethanol to water is 3:17. Dissolve them completely under magnetic stirring. Then add 1 M NaOH solution dropwise to adjust the pH of the system to 7.5 and continue stirring for 30 min. The solution color gradually deepens, indicating that gallic acid and cerium ions undergo a complexation reaction to form a metal-polyphenol network precursor solution.

[0034] The above solution was transferred to a reaction vessel, and the pretreated and dried fiberglass substrate from step (1) was completely immersed in it. The reaction was carried out under hydrothermal conditions at 150 °C for 12 h. After the reaction was completed, the substrate was removed, dried at 60 °C for 1 h, and then heat-cured at 80 °C for 6 h to obtain a substrate with a metal-polyphenol network layer deposited on its surface.

[0035] (4) Weigh 0.5 g of carbonized bamboo powder and 0.75 g of heptadecafluorodecyltrimethoxysilane and add them to 48.75 mL of ethanol. Disperse the mixture using an ultrasonic oscillator for 30 min and then stir it under magnetic stirring for 24 h to obtain a uniform and stable FC hydrophobic modified dispersion.

[0036] The substrate obtained in step (3) is laid flat, and the FC dispersion is sprayed onto its surface using a spray gun at a pressure of 0.6 MPa and a spraying distance of 15 cm. After spraying, the substrate is placed in a 60 ℃ drying oven for pre-curing for 1 h, and then cured at 80 ℃ for 12 h to obtain a wear-resistant, photothermal, and superhydrophobic coating. Example 3

[0037] (1) Immerse a fiberglass board substrate with dimensions of 1 cm × 1 cm × 0.2 cm in an ethanol solution and treat it with ultrasound to remove impurities and oil stains from the surface of the substrate. Then, sandblast the fiberglass board and clean it in an ultrasonic cleaner for 10 min. After cleaning, place the fiberglass board in a drying oven at 60 ℃ for 3 h for later use.

[0038] (2) Weigh 10 g of bamboo powder and add it to 100 mL of 2% Na2CO3 aqueous solution. Stir and treat at room temperature for 5 h. After treatment, filter with deionized water and wash repeatedly until the filtrate is neutral. Place the washed wet bamboo powder in a drying oven at 60 ℃ and dry for 12 h. Place the dried bamboo powder in a reaction vessel, push it to the center of the drying oven, heat at 200 ℃ for 12 h, and then cool to room temperature to obtain black carbonized bamboo powder (CBP).

[0039] (3) Weigh 0.15 g gallic acid and 0.15 g cerium nitrate and add them to 50 mL of ethanol-water mixed solvent, where the volume ratio of ethanol to water is 3:17. Dissolve them completely under magnetic stirring. Then add 1 M NaOH solution dropwise to adjust the pH of the system to 7.5 and continue stirring for 30 min. The solution color gradually deepens, indicating that gallic acid and cerium ions undergo a complexation reaction to form a metal-polyphenol network precursor solution.

[0040] The above solution was transferred to a reaction vessel, and the pretreated and dried fiberglass substrate from step (1) was completely immersed in it. The reaction was carried out at 150 °C for 10 h under hydrothermal conditions. After the reaction was completed, the substrate was removed, dried at 60 °C for 1 h, and then heat-cured at 80 °C for 6 h to obtain a substrate with a metal-polyphenol network layer deposited on its surface.

[0041] (4) Weigh 1 g of carbonized bamboo powder and 1.5 g of heptadecafluorodecyltrimethoxysilane and add them to 48.75 mL of ethanol. Disperse the mixture using an ultrasonic oscillator for 30 min and then stir it under magnetic stirring for 24 h to obtain a uniform and stable FC hydrophobic modified dispersion.

[0042] The substrate obtained in step (3) is laid flat, and the FC dispersion is sprayed onto its surface using a spray gun at a pressure of 0.6 MPa and a spraying distance of 15 cm. After spraying, the substrate is placed in a 60 ℃ drying oven for pre-curing for 1 h, and then cured at 80 ℃ for 12 h to obtain a wear-resistant, photothermal, and superhydrophobic coating. Example 4

[0043] (1) Immerse a fiberglass board substrate with dimensions of 1 cm × 1 cm × 0.2 cm in an ethanol solution and treat it with ultrasound to remove impurities and oil stains from the surface of the substrate. Then, sandblast the fiberglass board and clean it in an ultrasonic cleaner for 10 min. After cleaning, dry the fiberglass board in a drying oven at 60 ℃ for 3 h for later use.

[0044] (2) Weigh 10 g of bamboo powder and add it to 100 mL of 2% Na2CO3 aqueous solution. Stir and treat at room temperature for 5 h. After treatment, filter with deionized water and wash repeatedly until the filtrate is neutral. Place the washed wet bamboo powder in a drying oven at 60 ℃ and dry for 12 h. Place the dried bamboo powder in a reaction vessel, push it to the center of the drying oven, heat at 200 ℃ for 12 h, and then cool to room temperature to obtain black carbonized bamboo powder (CBP).

[0045] (3) Weigh 0.25 g gallic acid and 0.25 g cerium nitrate and add them to 50 mL of ethanol-water mixed solvent, where the volume ratio of ethanol to water is 3:17. Dissolve them completely under magnetic stirring. Then add 1 M NaOH solution dropwise to adjust the pH of the system to 7.5 and continue stirring for 30 min. The solution color gradually deepens, indicating that gallic acid and cerium ions undergo a complexation reaction to form a metal-polyphenol network precursor solution.

[0046] The above solution was transferred to a reaction vessel, and the pretreated and dried fiberglass substrate from step (1) was completely immersed in it. The reaction was carried out at 150 °C for 10 h under hydrothermal conditions. After the reaction was completed, the substrate was removed, dried at 60 °C for 1 h, and then heat-cured at 80 °C for 6 h to obtain a substrate with a metal-polyphenol network layer deposited on its surface.

[0047] (4) Weigh 0.5 g of carbonized bamboo powder and 0.75 g of heptadecafluorodecyltrimethoxysilane and add them to 48.75 mL of ethanol. Disperse the mixture using an ultrasonic oscillator for 30 min and then stir it under magnetic stirring for 24 h to obtain a uniform and stable FC hydrophobic modified dispersion.

[0048] The substrate obtained in step (3) is laid flat, and the FC dispersion is sprayed onto its surface using a spray gun at a pressure of 0.6 MPa and a spraying distance of 15 cm. After spraying, the substrate is placed in a 60 ℃ drying oven for pre-curing for 1 h, and then cured at 80 ℃ for 12 h to obtain a wear-resistant, photothermal, and superhydrophobic coating. Example 5

[0049] (1) Immerse a fiberglass board substrate with dimensions of 1 cm × 1 cm × 0.2 cm in an ethanol solution and treat it with ultrasound to remove impurities and oil stains from the surface of the substrate. Then, sandblast the fiberglass board and clean it in an ultrasonic cleaner for 10 min. After cleaning, place the fiberglass board in a drying oven at 60 ℃ for 3 h for later use.

[0050] (2) Weigh 10 g of bamboo powder and add it to 100 mL of 2% Na2CO3 aqueous solution. Stir at room temperature for 5 h. After treatment, filter with deionized water and wash repeatedly until the filtrate is neutral. Place the washed wet bamboo powder in a drying oven at 60 ℃ and dry for 12 h. Place the dried bamboo powder in a reaction vessel, push it into the center of the drying oven, and keep it at 180 ℃ for 12 h. Then cool it to room temperature to obtain black carbonized bamboo powder (CBP).

[0051] (3) Weigh 0.15 g gallic acid and 0.15 g cerium nitrate and add them to 50 mL of ethanol-water mixed solvent, where the volume ratio of ethanol to water is 3:17. Dissolve them completely under magnetic stirring. Then add 1 M NaOH solution dropwise to adjust the pH of the system to 7.5 and continue stirring for 30 min. The solution color gradually deepens, indicating that gallic acid and cerium ions undergo a complexation reaction to form a metal-polyphenol network precursor solution.

[0052] The above solution was transferred to a reaction vessel, and the pretreated and dried fiberglass substrate from step (1) was completely immersed in it. The reaction was carried out at 150 °C for 10 h under hydrothermal conditions. After the reaction was completed, the substrate was removed, dried at 60 °C for 1 h, and then heat-cured at 70 °C for 12 h to obtain a substrate with a metal-polyphenol network layer deposited on its surface.

[0053] (4) Weigh 0.25 g of carbonized bamboo powder and 0.75 g of heptadecafluorodecyltrimethoxysilane and add them to 48.75 mL of ethanol. Disperse the mixture using an ultrasonic oscillator for 30 min and then stir it under magnetic stirring for 24 h to obtain a uniform and stable FC hydrophobic modified dispersion.

[0054] The substrate obtained in step (3) is laid flat, and the FC dispersion is sprayed onto its surface using a spray gun at a pressure of 0.6 MPa and a spraying distance of 15 cm. After spraying, the substrate is placed in a 60 ℃ drying oven for pre-curing for 1 h, and then cured at 80 ℃ for 12 h to obtain a wear-resistant, photothermal, and superhydrophobic coating. Example 6

[0055] (1) Immerse a fiberglass board substrate with dimensions of 1 cm × 1 cm × 0.2 cm in an ethanol solution and treat it with ultrasound to remove impurities and oil stains from the surface of the substrate. Then, sandblast the fiberglass board and clean it in an ultrasonic cleaner for 10 min. After cleaning, place the fiberglass board in a drying oven at 60 ℃ for 3 h for later use.

[0056] (2) Weigh 10 g of bamboo powder and add it to 100 mL of 2% Na2CO3 aqueous solution. Stir at room temperature for 5 h. After treatment, filter with deionized water and wash repeatedly until the filtrate is neutral. Place the washed wet bamboo powder in a drying oven at 60 ℃ and dry for 12 h. Place the dried bamboo powder in a reaction vessel, push it into the center of the drying oven, and keep it at 180 ℃ for 10 h. Then cool it to room temperature to obtain black carbonized bamboo powder (CBP).

[0057] (3) Weigh 0.15 g gallic acid and 0.15 g cerium nitrate and add them to 50 mL of ethanol-water mixed solvent, where the volume ratio of ethanol to water is 3:17. Dissolve them completely under magnetic stirring. Then add 1 M NaOH solution to adjust the pH of the system to 7 and continue stirring for 30 min. The solution color gradually deepens, indicating that gallic acid and cerium ions undergo a complexation reaction to form a metal-polyphenol network precursor solution.

[0058] The above solution was transferred to a reaction vessel, and the pretreated and dried fiberglass substrate from step (1) was completely immersed in it. The reaction was carried out at 140 °C for 10 h under hydrothermal conditions. After the reaction was completed, the substrate was removed, dried at 60 °C for 1 h, and then heat-cured at 70 °C for 12 h to obtain a substrate with a metal-polyphenol network layer deposited on its surface.

[0059] (4) Weigh 0.625 g of carbonized bamboo powder and 0.5 g of heptadecafluorodecyltrimethoxysilane and add them to 48.75 mL of ethanol. Disperse the mixture using an ultrasonic oscillator for 30 min and then stir it under magnetic stirring for 24 h to obtain a uniform and stable FC hydrophobic modified dispersion.

[0060] The substrate obtained in step (3) is laid flat, and the FC dispersion is sprayed onto its surface using a spray gun at a pressure of 0.6 MPa and a spraying distance of 15 cm. After spraying, the substrate is placed in a 60 ℃ drying oven for pre-curing for 1 h, and then cured at 80 ℃ for 12 h to obtain a wear-resistant, photothermal, and superhydrophobic coating. Example 7

[0061] (1) Immerse a fiberglass board substrate with dimensions of 1 cm × 1 cm × 0.2 cm in an ethanol solution and treat it with ultrasound to remove impurities and oil stains from the surface of the substrate. Then, sandblast the fiberglass board and clean it in an ultrasonic cleaner for 10 min. After cleaning, place the fiberglass board in a drying oven at 60 ℃ for 3 h for later use.

[0062] (2) Weigh 10 g of bamboo powder and add it to 100 mL of 2% Na2CO3 aqueous solution. Stir at room temperature for 5 h. After treatment, filter with deionized water and wash repeatedly until the filtrate is neutral. Place the washed wet bamboo powder in a drying oven at 60 ℃ and dry for 12 h. Place the dried bamboo powder in a reaction vessel, push it into the center of the drying oven, heat at 190 ℃ for 14 h, and then cool to room temperature to obtain black carbonized bamboo powder (CBP).

[0063] (3) Weigh 0.15 g gallic acid and 0.15 g cerium nitrate and add them to 50 mL of ethanol-water mixed solvent, where the volume ratio of ethanol to water is 3:17. Dissolve them completely under magnetic stirring. Then add 1 M NaOH solution to adjust the pH of the system to 8 and continue stirring for 30 min. The solution color gradually deepens, indicating that gallic acid and cerium ions undergo a complexation reaction to form a metal-polyphenol network precursor solution.

[0064] The above solution was transferred to a reaction vessel, and the pretreated and dried fiberglass substrate from step (1) was completely immersed in it. The reaction was carried out at 160 °C for 14 h under hydrothermal conditions. After the reaction was completed, the substrate was removed, dried at 60 °C for 1 h, and then heat-cured at 80 °C for 6 h to obtain a substrate with a metal-polyphenol network layer deposited on its surface.

[0065] (4) Weigh 0.625 g of carbonized bamboo powder and 1.5 g of heptadecafluorodecyltrimethoxysilane and add them to 48.75 mL of ethanol. Disperse the mixture using an ultrasonic oscillator for 30 min and then stir it under magnetic stirring for 24 h to obtain a uniform and stable FC hydrophobic modified dispersion.

[0066] The substrate obtained in step (3) is laid flat, and the FC dispersion is sprayed onto its surface using a spray gun at a pressure of 0.6 MPa and a spraying distance of 15 cm. After spraying, the substrate is placed in a 60 ℃ drying oven for pre-curing for 1 h, and then cured at 80 ℃ for 12 h to obtain a wear-resistant, photothermal, and superhydrophobic coating.

[0067] Comparative Example 1 (1) Immerse a fiberglass board substrate with dimensions of 1 cm × 1 cm × 0.2 cm in an ethanol solution and treat it with ultrasound to remove impurities and oil stains from the surface of the substrate. Then, sandblast the fiberglass board and clean it in an ultrasonic cleaner for 10 min. After cleaning, place the fiberglass board in a drying oven at 60 ℃ for 3 h for later use.

[0068] (2) Weigh 10 g of bamboo powder and add it to 100 mL of 2% Na2CO3 aqueous solution. Stir and treat at room temperature for 5 h. After treatment, filter with deionized water and wash repeatedly until the filtrate is neutral. Place the washed wet bamboo powder in a drying oven at 60 ℃ and dry for 12 h. Place the dried bamboo powder in a reaction vessel, push it to the center of the drying oven, heat at 200 ℃ for 12 h, and then cool to room temperature to obtain black carbonized bamboo powder (CBP).

[0069] (3) Weigh 0.5 g of carbonized bamboo powder and 0.75 g of heptadecafluorodecyltrimethoxysilane and add them to 48.75 mL of ethanol. Disperse the mixture using an ultrasonic oscillator for 30 min and then stir it under magnetic stirring for 24 h to obtain a uniform and stable FC hydrophobic modified dispersion.

[0070] The substrate obtained in step (1) is laid flat, and the FC dispersion is sprayed onto its surface using a spray gun at a pressure of 0.6 MPa and a spraying distance of 15 cm. After spraying, the substrate is placed in a 60 ℃ drying oven for pre-curing for 1 h, and then cured at 80 ℃ for 12 h to obtain a wear-resistant, photothermal, and superhydrophobic coating.

[0071] Comparative Example 2 (1) Immerse a fiberglass board substrate with dimensions of 1 cm × 1 cm × 0.2 cm in an ethanol solution and treat it with ultrasound to remove impurities and oil stains from the surface of the substrate. Then, sandblast the fiberglass board and clean it in an ultrasonic cleaner for 10 min. After cleaning, place the fiberglass board in a drying oven at 60 ℃ for 3 h for later use.

[0072] (2) Weigh 0.05 g gallic acid and 0.05 g cerium nitrate and add them to 50 mL of ethanol-water mixed solvent, where the volume ratio of ethanol to water is 3:17. Dissolve them completely under magnetic stirring. Then add 1 M NaOH solution dropwise to adjust the pH of the system to 7.5 and continue stirring for 30 min. The solution color gradually deepens, indicating that gallic acid and cerium ions undergo a complexation reaction to form a metal-polyphenol network precursor solution.

[0073] The above solution was transferred to a reaction vessel, and the pretreated and dried fiberglass substrate from step (1) was completely immersed in it. The reaction was carried out at 150 °C for 10 h under hydrothermal conditions. After the reaction was completed, the substrate was removed, dried at 60 °C for 1 h, and then heat-cured at 80 °C for 6 h to obtain a substrate with a metal-polyphenol network layer deposited on its surface.

[0074] (4) Weigh 0.75 g of heptadecafluorodecyltrimethoxysilane and add it to 49.25 mL of ethanol. Disperse the mixture using an ultrasonic oscillator for 30 min, and then stir it under magnetic stirring for 24 h to obtain a uniform and stable hydrophobic modified dispersion of FAS-17. Place the substrate obtained in step (3) flat and spray the FAS-17 dispersion onto its surface using a spray gun. The spray gun pressure is 0.6 MPa and the spraying distance is 15 cm. After spraying, place the substrate in a 60 ℃ drying oven for pre-curing for 1 h, and then cure it at 80 ℃ for 12 h to obtain a wear-resistant, photothermal, and superhydrophobic coating.

[0075] Comparative Example 3 (1) Immerse a fiberglass board substrate with dimensions of 1 cm × 1 cm × 0.2 cm in an ethanol solution and treat it with ultrasound to remove impurities and oil stains from the surface of the substrate. Then, sandblast the fiberglass board and clean it in an ultrasonic cleaner for 10 min. After cleaning, place the fiberglass board in a drying oven at 60 ℃ for 3 h for later use.

[0076] (2) Weigh 10 g of bamboo powder and add it to 100 mL of 2% Na2CO3 aqueous solution. Stir and treat at room temperature for 5 h. After treatment, filter with deionized water and wash repeatedly until the filtrate is neutral. Place the washed wet bamboo powder in a drying oven at 60 ℃ and dry for 12 h. Place the dried bamboo powder in a reaction vessel, push it to the center of the drying oven, heat at 200 ℃ for 12 h, and then cool to room temperature to obtain black carbonized bamboo powder (CBP).

[0077] (3) Weigh 0.15 g gallic acid and 0.15 g cerium nitrate and add them to 50 mL of ethanol-water mixed solvent, where the volume ratio of ethanol to water is 3:17. Dissolve them completely under magnetic stirring. Then add 1 M NaOH solution dropwise to adjust the pH of the system to 7.5 and continue stirring for 30 min. The solution color gradually deepens, indicating that gallic acid and cerium ions undergo a complexation reaction to form a metal-polyphenol network precursor solution.

[0078] The above solution was transferred to a reaction vessel, and the pretreated and dried fiberglass substrate from step (1) was completely immersed in it. The reaction was carried out at 150 °C for 10 h under hydrothermal conditions. After the reaction was completed, the substrate was removed, dried at 60 °C for 1 h, and then heat-cured at 80 °C for 6 h to obtain a substrate with a metal-polyphenol network layer deposited on its surface.

[0079] (4) Weigh 0.5 g of carbonized bamboo powder and add it to 49.5 mL of ethanol. Disperse it using an ultrasonic oscillator for 30 min, and then stir it under magnetic stirring for 24 h to obtain a uniform and stable FC hydrophobic modified dispersion.

[0080] The substrate obtained in step (3) is laid flat, and the FC dispersion is sprayed onto its surface using a spray gun at a pressure of 0.6 MPa and a spraying distance of 15 cm. After spraying, the substrate is placed in a 60 ℃ drying oven for pre-curing for 1 h, and then cured at 80 ℃ for 12 h to obtain a wear-resistant, photothermal, and superhydrophobic coating.

[0081] The wear resistance test involves placing the test sample flat on sandpaper, applying a 50 g weight to the sample, and sliding it for 5 m. The water contact angle of the sample surface after wear is then measured. The photothermal performance results are shown in Table 1.

[0082] As shown in Table 1, the wear-resistant, photothermal, and superhydrophobic coatings prepared by this invention exhibit excellent comprehensive performance under different formulation conditions. The initial water contact angles of the coatings prepared in Examples 1-7 are all between 150.3° and 154.4°, all exceeding 150°, indicating that the prepared coatings have stable superhydrophobic properties. Among them, Example 3 has the highest water contact angle after wear, at 154.2°, indicating that the fluorinated silane coupling agent has a certain influence on the water contact angle, but the influence is small after reaching a certain proportion. In contrast, the water contact angle of the coating in Comparative Example 2 (without carbonized bamboo powder) is only 81°, and the water contact angle of Comparative Example 3 (without fluorinated silane coupling agent) is 74°, neither of which formed a superhydrophobic surface, indicating that the micro-nano structure constructed by carbonized bamboo powder and the fluorinated silane have irreplaceable roles in reducing surface energy. Regarding photothermal performance, under 10 minutes of sunlight irradiation, the surface temperatures of Examples 1 to 5 all reached 64.6–68.0°C. Example 3, due to its higher carbonized bamboo powder content and enhanced light absorption, achieved the highest surface temperature of 68.0°C. Comparative Example 1 (without the metal-polyphenol network layer) had a surface temperature of only 63.4°C under the same conditions, indicating that the metal-polyphenol network structure helps enhance the photothermal conversion efficiency of the coating. Regarding abrasion resistance, after 5 minutes of wear, the water contact angles of Examples 1–7 remained within the range of 121.7°–132.6°. Example 3 exhibited the highest water contact angle after wear at 132.6°, indicating that the coating maintained strong anti-wetting ability even after mechanical wear. In contrast, the water contact angle of Comparative Example 2 after wear was only 72°, and that of Comparative Example 3 was only 71°, with almost complete loss of hydrophobicity. This demonstrates that in the absence of carbonized bamboo powder or fluorinated silanes, the coating structure is easily damaged under abrasion. In terms of photothermal performance, Examples 1-7 all exhibited the best photothermal retention rate after wear, indicating that the metal-polyphenol network layer and the appropriate CBP content have a better synergistic effect. In contrast, the photothermal performance of the coating without the metal-polyphenol network layer (Comparative Example 1) decreased sharply after wear, demonstrating the core role of the metal-polyphenol network layer in anchoring functional particles and maintaining structural integrity. Compared with Comparative Examples 1-3, the coating prepared by this invention can still maintain a high water contact angle and photothermal heating capacity after mechanical wear, indicating that this composite structure has significant advantages in anti-icing, anti-frost, and long-term service environments.

[0083] from Figure 2 In the FTIR spectrum, it can be observed that in Example 1 at 1200-1300 cm⁻¹ -1 Significant CF stretching vibration peaks appeared nearby, particularly at 2800-3000 cm⁻¹. -1 A strong -CH2 / -CH3 stretching vibration peak appears at this location. These low-polarity fluorocarbon and alkyl structures can significantly reduce the surface free energy of the material, thereby improving its hydrophobic properties. In contrast, the -OH (~3400 cm⁻¹) peak in the GA-Ce sample...-1 ) and C=O (~1700cm) -1 The strong peak indicates the presence of hydrophilic polar groups on the surface, resulting in poor hydrophobic properties. Furthermore, the aromatic ring C=C (~1600 cm⁻¹) retained in the sample... -1 The absorption peak is beneficial for enhancing the absorption of visible light, providing a molecular structural basis for efficient photothermal conversion. In contrast, the -OH (~3400 cm⁻¹) in Comparative Example 2... -1 ) and C=O (~1700cm) -1 The strong peaks indicate the presence of hydrophilic polar groups on the surface, resulting in poor hydrophobicity. However, it exhibits strong infrared absorption peaks for hydroxyl and carbonyl groups, demonstrating good photothermal properties. Furthermore, the abundant -OH and -COOH groups can form strong hydrogen bonds or chemical bonds with the hydroxyl groups on the surface of inorganic substrates such as fiberglass boards, allowing the metal-polyphenol layer to adhere tightly and firmly to the substrate. Simultaneously, these polar functional groups on the surface can firmly hold carbonized bamboo powder particles through physical adsorption, hydrogen bonding, and even coordination, thereby achieving better wear resistance.

[0084] Figure 4 The figures show the surface temperature rise curves of the superhydrophobic coatings of Examples 1, 3, 5, and Comparative Example 1 under one solar irradiation condition. As can be seen from the figures, the surface temperature of each sample increases rapidly with the extension of irradiation time, and then gradually stabilizes. The surface temperature of Comparative Example 1 only rises from about 27°C to about 41°C within 10 minutes, indicating a slow heating rate and limited photothermal performance. In contrast, the coatings of the present invention exhibit a higher heating rate and higher final temperature under the same conditions, indicating a significantly enhanced photothermal conversion capability. With the increase of the carbon-based photothermal component content in the coating, the absorption capacity of the samples for sunlight is further improved, with Example 3 exhibiting the highest final surface temperature, reaching over 65°C.

[0085] Figure 5 The figures show the temperature rise curves for Example 1 under solar irradiance intensities of 0.5, 1, and 1.5. From... Figure 5 As can be seen, Example 1 can still reach 54.5°C even with only 0.5 times the intensity of sunlight, and can still reach a certain temperature even in low-temperature environments. At the intensity of 1.5 times the intensity of sunlight, it can reach a high temperature of 75°C.

[0086] Figure 6 The image shows the temperature rise / fall curves for Example 1 after 10 cycles under one solar irradiance. After 10 switching cycles, the temperature rise-fall curves remain almost identical, with minimal fluctuations in the maximum temperature. This indicates that the coating exhibits good photothermal stability and structural durability. Its superhydrophobic surface prevents moisture or impurities from intruding, avoiding material performance degradation, making it suitable for long-term photothermal applications.

[0087] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, all technical solutions obtained through equivalent substitution or transformation fall within the protection scope of the present invention.

Claims

1. A method for preparing a wear-resistant, photothermal, and superhydrophobic coating, characterized in that, Includes the following steps: (1) After alkali treatment and drying, bamboo powder is carbonized at high temperature under hydrothermal conditions to obtain carbonized bamboo powder. (2) Gallic acid and cerium nitrate are dissolved in an ethanol-water mixed solvent and undergo a complexation reaction under weakly alkaline conditions to form a metal-polyphenol network precursor solution. The solution is then deposited on the surface of the pretreated substrate under hydrothermal conditions to obtain a metal-polyphenol network layer. (3) The carbonized bamboo powder and the fluorinated silane modifier are dispersed in an organic solvent, ultrasonically dispersed, stirred to obtain a hydrophobic modified dispersion, and sprayed onto the surface of the metal-polyphenol network layer. After drying and heat curing, a wear-resistant, photothermal, and superhydrophobic coating is obtained.

2. The method for preparing a wear-resistant, photothermal, and superhydrophobic coating according to claim 1, characterized in that, The carbonization process is carried out in a drying oven at a temperature of 180–200°C for 10–14 hours.

3. The method for preparing a wear-resistant, photothermal, and superhydrophobic coating according to claim 1, characterized in that, In the metal-polyphenol network precursor solution, the concentrations of gallic acid and cerium nitrate are 1–5 mg / mL, respectively.

4. The method for preparing a wear-resistant, photothermal, and superhydrophobic coating according to claim 1, characterized in that, In the metal-polyphenol network precursor solution, sodium hydroxide is added dropwise to maintain the pH at 7-8.

5. The method for preparing a wear-resistant, photothermal, and superhydrophobic coating according to claim 1, characterized in that, The metal-polyphenol network deposition is carried out by a hydrothermal reaction, with a reaction temperature of 140-160℃ and a reaction time of 10-14h.

6. The method for preparing a wear-resistant, photothermal, and superhydrophobic coating according to claim 1, characterized in that, The carbonized bamboo powder has a mass fraction of 0.5–2 wt% in the hydrophobic modified dispersion, and the fluorinated silane modifier has a mass fraction of 1–3 wt% in the hydrophobic modified dispersion.

7. A metal-polyphenol-based wear-resistant, photothermal, and superhydrophobic coating prepared by the preparation method according to any one of claims 1 to 6.

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