Efficient light-heat conversion and wear-resistant super-hydrophobic coating, preparation method thereof and application in ice prevention and removal

Abstract

The present application relates to the technical field of micro-nano functional materials, and particularly relates to a high-efficiency light-heat conversion and wear-resistant super-hydrophobic coating, a preparation method thereof and an application thereof in ice prevention and removal, the preparation method adopts ammonium persulfate as an oxidant to initiate polymerization of pyrrole on the surface of halloysite nanotubes to generate polypyrrole, so as to obtain a halloysite nanotube composite material wrapped by polypyrrole. The super-hydrophobic coating is obtained by mixing the composite material with low-surface-energy polydimethylsiloxane, and the coating layer formed by the super-hydrophobic coating has the characteristics of high roughness and low surface energy, and thus has excellent hydrophobic performance. The coating layer also has good light-heat effect, flexibility, elasticity, mechanical performance, high-temperature resistance and durability. In addition, by adding hydrophobic nano-SiO2, the super-hydrophobic performance of the coating layer is further improved, and the hardness and wear resistance of the coating layer are also enhanced. Finally, the coating layer has excellent light absorption capacity and light-heat conversion efficiency, and realizes the performance of efficient protection and ice layer removal in the application of ice prevention and removal.

Description

Technical Field

[0001] This invention relates to the field of micro-nano functional materials technology, specifically to a highly efficient photothermal conversion and wear-resistant superhydrophobic coating, its preparation method, and its application in anti-icing and de-icing. Background Technology

[0002] In cold natural environments, icing can cause irreversible damage to infrastructure such as aviation systems, transportation systems, and power transmission networks, posing a serious threat to human safety and social property. For example, icing on the wings of aircraft or drones can impair their aerodynamic performance; icing in engine air intakes can lead to the ingestion of ice fragments and damage to blades; icing on bridges and railway tracks can cause serious safety accidents; and icing on high-voltage power lines can cause transmission towers to collapse, resulting in large-scale power outages. Currently, traditional de-icing methods include chemical de-icing, mechanical de-icing, and thermal de-icing. These traditional technologies are mostly labor-intensive and resource-intensive, costly, and energy-intensive.

[0003] As an important direction in the research of anti-icing and de-icing materials, the rough structure of superhydrophobic surfaces can trap numerous air pockets, forming Cassie-Baxter states with extremely high contact angles and extremely low roll-off angles, making it almost impossible for water droplets to remain on such surfaces. However, current superhydrophobic surfaces typically only possess passive anti-icing capabilities and cannot prevent water vapor from directly freezing within the coating microstructure. Moreover, the anti-icing and de-icing effects of existing superhydrophobic materials need further improvement.

[0004] In addition, the coatings formed by superhydrophobic materials in the existing technology still have problems with mechanical and chemical stability that need to be improved, making it difficult to adapt to different outdoor working scenarios, and the scope of application and service life need to be improved. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the first objective of this invention is to provide a method for preparing a superhydrophobic coating with high efficiency photothermal conversion and wear resistance. This preparation method is characterized by simple process and mild reaction conditions. The superhydrophobic coating with high efficiency photothermal conversion and wear resistance obtained has both passive and active anti-icing capabilities. It can achieve superhydrophobic anti-icing under light-free conditions and de-icing and melting under light conditions with excellent photothermal conversion performance.

[0006] To overcome the shortcomings of the prior art, the second objective of this invention is to provide a superhydrophobic coating that is both highly efficient in photothermal conversion and wear-resistant. This superhydrophobic coating is characterized by low preparation cost, and the resulting coating surface has the advantages of excellent superhydrophobic properties, high anti-icing and de-icing efficiency, good photothermal stability, and high mechanical and chemical stability.

[0007] To overcome the shortcomings of the prior art, the third objective of this invention is to provide a method for preparing a superhydrophobic coating that is both highly efficient in photothermal conversion and wear-resistant.

[0008] The fourth objective of this invention is to provide an application of a highly efficient photothermal conversion and wear-resistant superhydrophobic coating in anti-icing and de-icing processes.

[0009] To achieve the first objective of the invention, the technical solution adopted by the present invention is as follows:

[0010] This invention provides a method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating, comprising the following steps:

[0011] S1. Halloysite powder was added to an acid solution for dispersion, then pyrrole and ammonium persulfate were added, and after stirring and reaction, the mixture was filtered, washed and dried to obtain a polypyrrole-encapsulated halloysite nanotube composite material.

[0012] S2. Add polydimethylsiloxane and curing agent to an organic solvent, stir and mix to obtain a polydimethylsiloxane dispersion;

[0013] S3. The polypyrrole-encapsulated halloysite nanotube composite material and hydrophobic nano-SiO2 are added to the polydimethylsiloxane dispersion and ultrasonically dispersed to obtain the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating.

[0014] In this invention, halloysite powder appears as hollow nanotubes under an electron microscope, hence it is also called halloysite nanotubes. The particle size of the halloysite powder is 300 nm to 2.5 μm.

[0015] This invention discloses a method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating. Pyrrole is added to a dispersion of halloysite powder in an acidic solution. The pyrrole adsorbs onto the surface of halloysite nanotubes. Ammonium persulfate is added as an oxidant, initiating a polymerization reaction of pyrrole on the surface of the halloysite nanotubes to generate polypyrrole. This results in the in-situ growth of oriented conductive polymer chains on the micro-nano structured halloysite nanotubes, producing a polypyrrole-encapsulated halloysite nanotube composite material. The polypyrrole encapsulates the halloysite nanotubes, forming a rough outer surface structure. Then, the polypyrrole-encapsulated halloysite nanotube composite material is added to a polydimethylsiloxane dispersion. Because polydimethylsiloxane has low surface energy, the resulting superhydrophobic coating possesses both high roughness and low surface energy, thus exhibiting excellent hydrophobic properties and good photothermal effects, flexibility, elasticity, mechanical properties, high-temperature resistance, and durability. Furthermore, the addition of hydrophobic nano-SiO2 enriches the micro-nano structure of the coating surface, making the composite micro-nano structure finer and more stable. This results in an ultra-low roll-off angle for the superhydrophobic coating, making it virtually impossible for water droplets to remain on the surface. This gives the coating a stable Cassie-Baxter state, effectively waterproofing the surface and reducing ice adhesion. Additionally, as rigid nanoparticles, nano-SiO2 acts as a reinforcing and toughening agent in the polymer system, improving the coating's hardness, wear resistance, and scratch resistance.

[0016] In this invention, polypyrrole, formed through polymerization, is an excellent photothermal material with superior hydrophobicity, chemical resistance, mechanical strength, and environmental stability. Encapsulating halloysite nanotubes with polypyrrole provides excellent photothermal properties and superhydrophobicity to the resulting coatings and coatings. Compared to existing technologies that use water-based resins (polyurethane or epoxy resins) mixed with halloysite nanotubes, this invention offers superior superhydrophobicity. This is because existing water-based resins not only weaken the hydrophobicity of the coatings but also lack conductivity and chemical resistance, and have lower mechanical strength and poorer environmental stability. Furthermore, the polydimethylsiloxane (PDMS) used in this invention has better anti-aging properties than epoxy resins, especially in resisting ultraviolet radiation, high temperatures, and humidity.

[0017] In this invention, polydimethylsiloxane and polypyrrole-coated halloysite nanotube composite material are dispersed and mixed. Compared with the prior art, which uses small molecule silane coupling agents (such as octadecyltrimethoxysilane) to modify the coating surface, this method has the following advantages: Since polydimethylsiloxane is a high molecular weight polymer, it can form a larger cross-linked network structure during the curing process, giving it better flexibility, elasticity, mechanical properties and high temperature resistance. It can also bond more firmly with polypyrrole-coated halloysite nanotube composite material and hydrophobic nano-SiO2, making the coating more firmly bonded to the substrate surface. This improves the defects of poor brittleness and durability of coatings in the prior art. Furthermore, the role of PDMS in the coating differs from that of existing small-molecule silane coupling agents: PDMS in the present invention serves as the matrix of the coating, forming the continuous phase of the coating film, responsible for binding the functional fillers (PPy@HNTs, SiO2) together and attaching them to the substrate; while existing small-molecule silane coupling agents are usually used as surface modifiers to pre-modify the surface of nanoparticles (such as SiO2 or HNTs) to make them hydrophobic, and then dispersed into other resin matrices, without constituting the main body of the coating film itself.

[0018] In this invention, halloysite powder is dispersed by an acid solution. On the one hand, this provides an acidic polymerization environment, allowing the oxidative polymerization of pyrrole monomers to form polypyrrole to proceed efficiently and smoothly in an acidic environment. On the other hand, the acid solution causes halloysite nanotubes (HNTs) to carry a positive charge on their surface due to protonation, resulting in strong repulsive forces between HNT particles, preventing HNT particle agglomeration and improving HNT dispersion. This provides a better adhesion point for the polymerization reaction of pyrrole, enabling microstructure control and the growth of nanowires and nanosheets of polypyrrole on the surface of the microstructure. Thirdly, the acid solution slightly etches the HNTs, increasing their roughness and active sites, which is beneficial for pyrrole adsorption. That is, this etching creates more surface defects, steps, and unsaturated bonds on the smooth walls of the HNTs. These sites have high energy and strong activity, making them highly adsorbent of pyrrole monomers and becoming "anchor points" for the polymerization reaction.

[0019] In this invention, the flexibility of polydimethylsiloxane (PDMS) and the rigidity of halloysite nanotubes and nano-SiO2 are synergistically combined, which greatly enhances the flexibility and mechanical wear resistance of the superhydrophobic coating. Specifically, the silicon-oxygen structure of PDMS and the silicon-oxygen structure of halloysite nanotubes can form a good bonding effect, further improving the structural stability of the superhydrophobic coating. Furthermore, both PDMS and polypyrrole are high molecular weight polymers, giving the superhydrophobic coating the advantage of good chemical stability; it is resistant to acids, alkalis, and salts. After immersion in solutions with a pH of 1-12 or in sodium chloride for 24 hours, the superhydrophobic coating remains in a superhydrophobic state.

[0020] Further, in step S1, halloysite powder is added to an acid solution and ultrasonically dispersed for 20-40 minutes to obtain a halloysite suspension; ammonium persulfate is dissolved in water to obtain an ammonium persulfate solution; pyrrole is added to water and ultrasonically treated to obtain a pyrrole dispersion; under stirring conditions, the ammonium persulfate solution and the pyrrole dispersion are added dropwise to the halloysite suspension, and the mixture is stirred at 200-400 rpm for 3-7 minutes. After filtration, washing, and drying, a polypyrrole-encapsulated halloysite nanotube composite material is obtained.

[0021] And / or, the mass-to-volume ratio of the ammonium persulfate to water is (0.2~0.5) g : (8~12) mL; and / or

[0022] The volume ratio of pyrrole to water is (0.1~0.3):(8~12); and / or

[0023] The halloysite suspension has a dispersion concentration of 5 g / L to 7 g / L; and / or

[0024] The washing method involves washing twice with deionized water, followed by washing once with anhydrous ethanol; and / or

[0025] The drying process involves drying at 55℃~65℃ for 6h~8h.

[0026] Further, in step S1, the mass-to-volume ratio of halloysite powder, pyrrole, and ammonium persulfate is (0.3~0.4) g : (0.3~0.4) g : (0.1~0.2) mL; and / or

[0027] The acid solution is a hydrochloric acid solution; and / or the concentration of the hydrochloric acid solution is 1.0M to 1.5M.

[0028] Further, in step S2, the mass-to-volume ratio of the polydimethylsiloxane, curing agent, and organic solvent is (0.1~0.2) g : (0.01~0.02) g : (10~20) mL; and / or

[0029] The curing agent is Dow Corning 184 Component B; wherein, Dow Corning 184 Component B uses a platinum complex as a catalyst and hydrogen-containing silicone oil as a crosslinking agent; and / or

[0030] The organic solvent is ethyl acetate.

[0031] Furthermore, in step S2, the mixing method is to stir at 200 rpm to 400 rpm for 0.5 h to 1 h at room temperature.

[0032] Further, in step S3, the mass-to-volume ratio of the polypyrrole-encapsulated halloysite nanotube composite material, the hydrophobic nano-SiO2, and the polydimethylsiloxane dispersion is (0.1~0.2) g : (0.05~0.2) g : (10~20) mL; and / or

[0033] The ultrasonic dispersion time is 1h to 2h.

[0034] To achieve the second objective of the invention, the technical solution adopted by the present invention is as follows:

[0035] This invention provides a highly efficient photothermal conversion and wear-resistant superhydrophobic coating, which is prepared by the above-described method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating.

[0036] To achieve the third objective of the invention, the technical solution adopted by the present invention is as follows:

[0037] This invention provides a method for preparing a superhydrophobic coating with high efficiency photothermal conversion and wear resistance. The method involves spraying the aforementioned superhydrophobic coating with high efficiency photothermal conversion and wear resistance onto the surface of a substrate, and then drying it to obtain the superhydrophobic coating with high efficiency photothermal conversion and wear resistance.

[0038] Furthermore, the spraying is performed using a spray gun with a pressure of 0.4 MPa to 0.7 MPa and a distance of 10 cm to 15 cm from the substrate; and / or

[0039] The drying temperature is 60℃~80℃, and the drying time is 1h~2h.

[0040] To achieve the fourth objective of the invention, the technical solution adopted by the present invention is as follows:

[0041] This invention provides a highly efficient photothermal conversion and wear-resistant superhydrophobic coating, or the application of a highly efficient photothermal conversion and wear-resistant superhydrophobic coating prepared by the above-mentioned method in anti-icing and de-icing.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0043] (1) A method for preparing a superhydrophobic coating with high efficiency photothermal conversion and wear resistance according to the present invention involves adsorbing pyrrole onto the surface of halloysite nanotubes in an acid solution and using ammonium persulfate as an oxidant to initiate a polymerization reaction of pyrrole on the surface of halloysite nanotubes to generate polypyrrole. That is, conductive polymer chains with directional arrangement are grown in situ on halloysite nanotubes with micro-nano structures to obtain a polypyrrole-encapsulated halloysite nanotube composite material. Subsequently, by mixing with polydimethylsiloxane with low surface energy, the coating formed by the obtained superhydrophobic coating can simultaneously possess the characteristics of high roughness and low surface energy. Therefore, the coating formed has excellent hydrophobic properties and also has good photothermal effect, flexibility, elasticity, mechanical properties, high temperature resistance and durability. In addition, the addition of hydrophobic nano-SiO2 can enrich the micro-nano structure of the coating surface, making the composite micro-nano structure more refined and stable. This results in the coating formed by the superhydrophobic coating having an ultra-low roll-off angle, making it almost impossible for water droplets to stay on such a coating surface. This gives the coating a stable Cassie-Baxter state, which can not only effectively waterproof the coating, but also reduce the ice adhesion strength of the coating surface.

[0044] (2) The present invention provides a method for preparing a superhydrophobic coating with high efficiency photothermal conversion and wear resistance. By encapsulating halloysite nanotubes with polypyrrole, which has excellent hydrophobicity, conductivity, chemical resistance, mechanical strength and environmental stability, the prepared superhydrophobic coating with high efficiency photothermal conversion and wear resistance has excellent photothermal performance and superhydrophobicity at the same time.

[0045] (3) The preparation method of the superhydrophobic coating with high efficiency photothermal conversion and wear resistance of the present invention combines the flexibility of polydimethylsiloxane (PDMS) with the rigidity of halloysite nanotubes and nano SiO2, which can greatly improve the flexibility and mechanical wear resistance of the coating formed by the superhydrophobic coating. At the same time, it has the advantage of good chemical stability and can resist acids, alkalis and salts.

[0046] (4) The present invention provides a highly efficient photothermal conversion and wear-resistant superhydrophobic coating with excellent photothermal properties, superhydrophobicity, flexibility, mechanical wear resistance and chemical stability.

[0047] (5) A method for preparing a superhydrophobic coating with high efficiency photothermal conversion and wear resistance according to the present invention. The coating obtained has excellent light absorption capacity and photothermal conversion efficiency, which can accelerate the photothermal melting and de-icing process.

[0048] (6) The application of a high-efficiency photothermal conversion and wear-resistant superhydrophobic coating in anti-icing and de-icing of the present invention. This high-efficiency photothermal conversion and wear-resistant superhydrophobic coating has both passive and active anti-icing capabilities. It exhibits unique advantages in inhibiting ice crystal formation and achieving interface de-icing. By utilizing the synergistic effect of surface wettability control and photothermal conversion, it achieves high-efficiency anti-icing and de-icing performance under conditions of no pollution and no external energy input. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a SEM image of halloysite powder from Example 1 of the present invention.

[0051] Figure 2 This is a SEM image of PPy@HNTs obtained in step S1 of embodiment 1 of the present invention.

[0052] Figure 3 This is a SEM image of the highly efficient photothermal conversion and wear-resistant superhydrophobic coating of Embodiment 6 of the present invention.

[0053] Figure 4 This is a graph showing the water contact angle test results of the superhydrophobic coating with high efficiency photothermal conversion and wear resistance in Embodiment 6 of the present invention.

[0054] Figure 5 This is a graph showing the water contact angle test results of the highly efficient photothermal conversion and wear-resistant superhydrophobic coating of Embodiment 7 of the present invention.

[0055] Figure 6 This is a graph showing the water contact angle test results of the superhydrophobic coating with high efficiency photothermal conversion and wear resistance in Embodiment 8 of the present invention.

[0056] Figure 7 This is a graph showing the water contact angle test results of the coating in Comparative Example 2 of the present invention.

[0057] Figure 8 The graph shows the test results of the anti-icing performance of the superhydrophobic coating with high efficiency photothermal conversion and wear resistance of the present invention embodiment 6 and the blank aluminum sheet.

[0058] Figure 9 This is a photothermal temperature rise curve of the superhydrophobic coating with high efficiency photothermal conversion and wear resistance of Embodiment 6 of the present invention and a blank aluminum sheet for photothermal conversion performance testing.

[0059] Figure 10This is a photothermal heating curve of the highly efficient photothermal conversion and wear-resistant superhydrophobic coating of Embodiment 6 of the present invention under different light intensities.

[0060] Figure 11 This is a graph showing the temperature rise / fall curves of the highly efficient photothermal conversion and wear-resistant superhydrophobic coating of Embodiment 6 of the present invention under 1 solar radiation intensity for 5 photothermal cycles. Detailed Implementation

[0061] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0062] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. In this invention, the singular forms “a,” “the,” and “the” as used in the embodiments and appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0063] In this embodiment of the invention, a method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating includes the following steps:

[0064] S1. Halloysite powder was added to an acid solution for dispersion, then pyrrole and ammonium persulfate were added, and after stirring and reaction, the mixture was filtered, washed and dried to obtain a polypyrrole-encapsulated halloysite nanotube composite material.

[0065] S2. Add polydimethylsiloxane and curing agent to an organic solvent, stir and mix to obtain a polydimethylsiloxane dispersion;

[0066] S3. The polypyrrole-encapsulated halloysite nanotube composite material and hydrophobic nano-SiO2 are added to the polydimethylsiloxane dispersion and ultrasonically dispersed to obtain the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating.

[0067] In some embodiments, in step S1, halloysite powder is added to an acid solution and ultrasonically dispersed for 20 min to 40 min to obtain a halloysite suspension; ammonium persulfate is dissolved in water to obtain an ammonium persulfate solution; pyrrole is added to water and ultrasonically treated to obtain a pyrrole dispersion; under stirring conditions, the ammonium persulfate solution and the pyrrole dispersion are added dropwise to the halloysite suspension, and the mixture is stirred at 200 rpm to 400 rpm for 3 min to 7 min. After filtration, washing, and drying, a polypyrrole-encapsulated halloysite nanotube composite material is obtained.

[0068] And / or, the mass-to-volume ratio of the ammonium persulfate to water is (0.2~0.5) g : (8~12) mL; and / or

[0069] The volume ratio of pyrrole to water is (0.1~0.3):(8~12); and / or

[0070] The halloysite suspension has a dispersion concentration of 5 g / L to 7 g / L; and / or

[0071] The washing method involves washing twice with deionized water, followed by washing once with anhydrous ethanol; and / or

[0072] The drying process involves drying at 55℃~65℃ for 6h~8h.

[0073] In some embodiments, in step S1, the mass-to-volume ratio of halloysite powder, pyrrole, and ammonium persulfate is (0.3~0.4) g : (0.3~0.4) g : (0.1~0.2) mL; and / or

[0074] The acid solution is a hydrochloric acid solution; and / or the concentration of the hydrochloric acid solution is 1.0M to 1.5M.

[0075] In some embodiments, in step S2, the mass-to-volume ratio of the polydimethylsiloxane, curing agent, and organic solvent is (0.1~0.2) g : (0.01~0.02) g : (10~20) mL; and / or

[0076] The curing agent is Dow Corning 184 Type B component; and / or

[0077] The organic solvent is ethyl acetate.

[0078] In some embodiments, in step S2, the stirring and mixing method is to stir at 200 rpm to 400 rpm for 0.5 h to 1 h at room temperature.

[0079] In some embodiments, in step S3, the mass-to-volume ratio of the polypyrrole-encapsulated halloysite nanotube composite material, hydrophobic nano-SiO2, and polydimethylsiloxane dispersion is (0.1~0.2) g : (0.05~0.2) g : (10~20) mL; and / or

[0080] The ultrasonic dispersion time is 1h to 2h.

[0081] In this invention, a highly efficient photothermal conversion and wear-resistant superhydrophobic coating is prepared using the above-described method for preparing such a coating.

[0082] In this embodiment of the invention, a method for preparing a superhydrophobic coating with high efficiency photothermal conversion and wear resistance is described above. The high efficiency photothermal conversion and wear resistance superhydrophobic coating is sprayed onto the surface of a substrate and dried to obtain the superhydrophobic coating with high efficiency photothermal conversion and wear resistance.

[0083] In some embodiments, the spraying is performed using a spray gun, with a pressure of 0.4 MPa to 0.7 MPa and a distance of 10 cm to 15 cm from the substrate; and / or

[0084] The drying temperature is 60℃~80℃, and the drying time is 1h~2h.

[0085] In this embodiment of the invention, the application of the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating or the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating prepared by the above-described preparation method in anti-icing and de-icing.

[0086] The following description is based on specific embodiments.

[0087] Example 1

[0088] A method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating, characterized by comprising the following steps:

[0089] S1. Halloysite powder was added to a 1.2M hydrochloric acid solution and ultrasonically dispersed for 30 min to obtain a 6 g / L halloysite suspension. 0.33 g of ammonium persulfate was dissolved in 10 mL of deionized water to obtain an ammonium persulfate solution. 0.15 mL of pyrrole was added to 10 mL of deionized water and ultrasonically treated to obtain a pyrrole dispersion. Under stirring conditions, the ammonium persulfate solution and pyrrole dispersion were added dropwise to the halloysite suspension. After stirring at 300 rpm for 5 min, the mixture was filtered, washed twice with deionized water, and then washed once with anhydrous ethanol. The mixture was dried at 60 °C for 7 h to obtain a polypyrrole-encapsulated halloysite nanotube composite material (denoted as PPy@HNTs). In this embodiment, the mass-to-volume ratio of halloysite powder, pyrrole, and ammonium persulfate was 0.35 g: 0.35 g: 0.15 mL.

[0090] S2. Polydimethylsiloxane and curing agent are added to the organic solvent ethyl acetate and stirred at 300 rpm for 0.8 h to obtain a polydimethylsiloxane dispersion. In this embodiment, the mass-volume ratio of polydimethylsiloxane, curing agent and organic solvent is 0.2 g: 0.02 g: 10 mL. In this embodiment, the curing agent is Dow Corning 184 type B component.

[0091] S3. The polypyrrole-coated halloysite nanotube composite material and hydrophobic nano-SiO2 are added to the polydimethylsiloxane dispersion and ultrasonically dispersed for 1.5 h to obtain the highly efficient photothermal conversion and wear-resistant superhydrophobic coating. In this embodiment, the mass-to-volume ratio of the polypyrrole-coated halloysite nanotube composite material, hydrophobic nano-SiO2, and polydimethylsiloxane dispersion is 0.15 g: 0.1 g: 15 mL.

[0092] Example 2

[0093] A method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating, characterized by comprising the following steps:

[0094] S1. Halloysite powder was added to a 1.0M hydrochloric acid solution and ultrasonically dispersed for 20 min to obtain a 5 g / L halloysite suspension; 0.2 g ammonium persulfate was dissolved in 8 mL deionized water to obtain an ammonium persulfate solution; 0.1 mL pyrrole was added to 8 mL water and ultrasonically treated to obtain a pyrrole dispersion; under stirring conditions, the ammonium persulfate solution and pyrrole dispersion were added dropwise to the halloysite suspension, and the mixture was stirred at 200 rpm for 7 min. After filtration, the mixture was washed twice with deionized water and once with anhydrous ethanol, and dried at 55℃ for 8 h to obtain a polypyrrole-encapsulated halloysite nanotube composite material (denoted as PPy@HNTs); In this embodiment, the mass-volume ratio of halloysite powder, pyrrole, and ammonium persulfate was 0.3 g: 0.3 g: 0.1 mL;

[0095] S2. Polydimethylsiloxane and curing agent are added to the organic solvent ethyl acetate and stirred at 200 rpm for 1 h to obtain a polydimethylsiloxane dispersion. In this embodiment, the mass-volume ratio of polydimethylsiloxane, curing agent and organic solvent is 0.1 g: 0.01 g: 10 mL. In this embodiment, the curing agent is Dow Corning 184 type B component.

[0096] S3. The polypyrrole-coated halloysite nanotube composite material and hydrophobic nano-SiO2 are added to the polydimethylsiloxane dispersion and ultrasonically dispersed for 1 hour to obtain the highly efficient photothermal conversion and wear-resistant superhydrophobic coating. In this embodiment, the mass-to-volume ratio of the polypyrrole-coated halloysite nanotube composite material, hydrophobic nano-SiO2, and polydimethylsiloxane dispersion is 0.1g:0.1g:10mL.

[0097] Example 3

[0098] A method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating, characterized by comprising the following steps:

[0099] S1. Halloysite powder was added to a 1.5M hydrochloric acid solution and ultrasonically dispersed for 40 min to obtain a 7 g / L halloysite suspension; 0.5 g ammonium persulfate was dissolved in 12 mL deionized water to obtain an ammonium persulfate solution; 0.3 mL pyrrole was added to 12 mL water and ultrasonically treated to obtain a pyrrole dispersion; under stirring conditions, the ammonium persulfate solution and pyrrole dispersion were added dropwise to the halloysite suspension, and the mixture was stirred at 400 rpm for 3 min. After filtration, the mixture was washed twice with deionized water and once with anhydrous ethanol, and dried at 65℃ for 6 h to obtain a polypyrrole-encapsulated halloysite nanotube composite material (denoted as PPy@HNTs); In this embodiment, the mass-volume ratio of halloysite powder, pyrrole, and ammonium persulfate was 0.4 g: 0.4 g: 0.2 mL;

[0100] S2. Polydimethylsiloxane and curing agent are added to the organic solvent ethyl acetate and stirred at 400 rpm for 0.5 h to obtain a polydimethylsiloxane dispersion. In this embodiment, the mass-volume ratio of polydimethylsiloxane, curing agent and organic solvent is 0.2 g: 0.02 g: 20 mL. In this embodiment, the curing agent is Dow Corning 184 type B component.

[0101] S3. The polypyrrole-coated halloysite nanotube composite material and hydrophobic nano-SiO2 are added to the polydimethylsiloxane dispersion and ultrasonically dispersed for 2 hours to obtain the highly efficient photothermal conversion and wear-resistant superhydrophobic coating. In this embodiment, the mass-to-volume ratio of the polypyrrole-coated halloysite nanotube composite material, hydrophobic nano-SiO2, and polydimethylsiloxane dispersion is 0.1 g: 0.05 g: 10 mL.

[0102] Example 4

[0103] A method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating, characterized by comprising the following steps:

[0104] S1. Halloysite powder was added to a 1.1M hydrochloric acid solution and ultrasonically dispersed for 25 min to obtain a 5.5 g / L halloysite suspension. 0.25 g of ammonium persulfate was dissolved in 9 mL of deionized water to obtain an ammonium persulfate solution. 0.15 mL of pyrrole was added to 9 mL of water and ultrasonically treated to obtain a pyrrole dispersion. Under stirring conditions, the ammonium persulfate solution and pyrrole dispersion were added dropwise to the halloysite suspension. After stirring at 250 rpm for 6 min, the mixture was filtered, washed twice with deionized water, and then washed once with anhydrous ethanol. The mixture was dried at 58 °C for 7.5 h to obtain a polypyrrole-encapsulated halloysite nanotube composite material (denoted as PPy@HNTs). In this embodiment, the mass-to-volume ratio of halloysite powder, pyrrole, and ammonium persulfate was 0.33 g: 0.38 g: 0.14 mL.

[0105] S2. Polydimethylsiloxane and curing agent are added to the organic solvent ethyl acetate and stirred at 250 rpm for 0.6 h to obtain a polydimethylsiloxane dispersion. In this embodiment, the mass-volume ratio of polydimethylsiloxane, curing agent and organic solvent is 0.13 g: 0.015 g: 12 mL. In this embodiment, the curing agent is Dow Corning 184 type B component.

[0106] S3. The polypyrrole-coated halloysite nanotube composite material and hydrophobic nano-SiO2 are added to the polydimethylsiloxane dispersion and ultrasonically dispersed for 18 hours to obtain the highly efficient photothermal conversion and wear-resistant superhydrophobic coating. In this embodiment, the mass-to-volume ratio of the polypyrrole-coated halloysite nanotube composite material, hydrophobic nano-SiO2, and polydimethylsiloxane dispersion is 0.2g:0.2g:20mL.

[0107] Example 5

[0108] A method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating, characterized by comprising the following steps:

[0109] S1. Halloysite powder was added to a 1.4M hydrochloric acid solution and ultrasonically dispersed for 35 min to obtain a 6.5 g / L halloysite suspension. 0.4 g of ammonium persulfate was dissolved in 11 mL of deionized water to obtain an ammonium persulfate solution. 0.25 mL of pyrrole was added to 11 mL of water and ultrasonically treated to obtain a pyrrole dispersion. Under stirring conditions, the ammonium persulfate solution and pyrrole dispersion were added dropwise to the halloysite suspension. After stirring at 350 rpm for 4 min, the mixture was filtered, washed twice with deionized water, and then washed once with anhydrous ethanol. The mixture was dried at 62℃ for 6.5 h to obtain a polypyrrole-encapsulated halloysite nanotube composite material (denoted as PPy@HNTs). In this embodiment, the mass-to-volume ratio of halloysite powder, pyrrole, and ammonium persulfate was 0.36 g: 0.32 g: 0.17 mL.

[0110] S2. Polydimethylsiloxane and curing agent are added to the organic solvent ethyl acetate and stirred at 280 rpm for 0.6 h to obtain a polydimethylsiloxane dispersion. In this embodiment, the mass-volume ratio of polydimethylsiloxane, curing agent and organic solvent is 0.1 g: 0.02 g: 12 mL. In this embodiment, the curing agent is Dow Corning 184 type B component.

[0111] S3. The polypyrrole-coated halloysite nanotube composite material and hydrophobic nano-SiO2 are added to the polydimethylsiloxane dispersion and ultrasonically dispersed for 1.3 h to obtain the highly efficient photothermal conversion and wear-resistant superhydrophobic coating. In this embodiment, the mass-to-volume ratio of the polypyrrole-coated halloysite nanotube composite material, hydrophobic nano-SiO2, and polydimethylsiloxane dispersion is 0.2 g: 0.1 g: 13 mL.

[0112] Example 6

[0113] A method for preparing a superhydrophobic coating with high efficiency photothermal conversion and wear resistance is described. The superhydrophobic coating with high efficiency photothermal conversion and wear resistance of Example 1 is sprayed onto the surface of an aluminum sheet using a spray gun. The pressure of the spray gun is 0.5 MPa, the distance between the spray gun and the aluminum sheet is 12 cm, and then it is pre-cured at 60°C for 1 hour and then cured at 80°C for 1 hour to obtain the superhydrophobic coating with high efficiency photothermal conversion and wear resistance.

[0114] Example 7

[0115] A method for preparing a superhydrophobic coating with high efficiency photothermal conversion and wear resistance is described. The superhydrophobic coating with high efficiency photothermal conversion and wear resistance of Example 2 is sprayed onto the surface of an aluminum sheet using a spray gun. The pressure of the spray gun is 0.4 MPa, the distance between the spray gun and the aluminum sheet is 10 cm, and then it is pre-cured at 65°C for 0.5 h and then cured at 80°C for 1 h to obtain the superhydrophobic coating with high efficiency photothermal conversion and wear resistance.

[0116] Example 8

[0117] A method for preparing a high-efficiency photothermal conversion and wear-resistant superhydrophobic coating involves spraying a high-efficiency photothermal conversion and wear-resistant superhydrophobic coating of Example 3 onto the surface of an aluminum sheet using a spray gun. The pressure of the spray gun is 0.7 MPa, the distance between the spray gun and the aluminum sheet is 15 cm, and then the coating is pre-cured at 70°C for 0.5 h and then cured at 80°C for 0.5 h to obtain the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating.

[0118] Example 9

[0119] The high-efficiency photothermal conversion and wear-resistant superhydrophobic coating prepared by any one of the preparation methods in Examples 1 to 5 above can be applied in anti-icing and de-icing. Applied to various outdoor working scenarios, especially to the surface of outdoor equipment, it increases the surface temperature of the equipment through efficient photothermal conversion, exhibiting unique advantages in inhibiting ice crystal formation and achieving interface de-icing. It achieves highly efficient anti-icing and de-icing performance under conditions of no pollution and no external energy input.

[0120] Comparative Example 1

[0121] A method for preparing a coating is described. The difference between this comparative example and Example 1 is that in step S3, the addition of hydrophobic nano-SiO2 is omitted to obtain a coating. The rest of the preparation methods are the same as in Example 1.

[0122] Comparative Example 2

[0123] A method for preparing a coating. The difference between this comparative example and Example 6 is that a coating prepared in Comparative Example 1 is used to replace the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating prepared in Example 1, and a coating is prepared in this way. The rest of the preparation methods are the same as those in Example 6.

[0124] Structural morphology characterization

[0125] (I) Morphological characterization by scanning electron microscopy

[0126] The halloysite powder (HNTs) from Example 1, the polypyrrole-encapsulated halloysite nanotube composite material (PPy@HNTs), and the highly efficient photothermal conversion and wear-resistant superhydrophobic coating prepared in Example 6 were characterized by scanning electron microscopy (SEM). The SEM images of HNTs are shown below. Figure 1 As shown, the SEM image of PPy@HNTs is as follows: Figure 2 As shown in the figure, the SEM image of the superhydrophobic coating with high efficiency photothermal conversion and wear resistance is as follows. Figure 3 As shown.

[0127] Depend on Figure 1 As can be seen, the halloysite powder (HNTs) used in this invention, also known as halloysite nanotubes, appears as a tubular structure in the SEM image. Figure 2 It is evident that the surface of halloysite nanotubes is coated with polypyrrole, and the coating uniformity is relatively good. Figure 3 It is evident that the surface of the highly efficient photothermal conversion and wear-resistant superhydrophobic coating possesses abundant micro-nano structures and a large number of cavities, enabling the coating to have good and stable air-trapping capabilities. This leads to a stable Cassie-Baxter state (i.e., water droplets cannot directly contact the coating surface but are separated by numerous tiny air bubbles). Consequently, this highly efficient photothermal conversion and wear-resistant superhydrophobic coating exhibits excellent hydrophobicity and stability, resulting in superior anti-icing and de-icing performance.

[0128] Performance testing

[0129] (a) Water contact angle test of coating

[0130] The water contact angles of the high-efficiency photothermal conversion and wear-resistant superhydrophobic coatings prepared in Examples 6 to 8, and a coating prepared in Comparative Example 2, were tested. The water contact angle test results for Example 6 are as follows: Figure 4 As shown, the water contact angle detection results of Example 7 are as follows: Figure 5 As shown, the water contact angle detection results of Example 8 are as follows: Figure 6 As shown, the water contact angle test results for Comparative Example 2 are as follows: Figure 7 As shown.

[0131] Depend on Figure 4As can be seen, the water contact angle of the highly efficient photothermal conversion and wear-resistant superhydrophobic coating in Example 6 is 155.9 degrees. Figure 5 As can be seen, the water contact angle of the highly efficient photothermal conversion and wear-resistant superhydrophobic coating in Example 7 is 151.6 degrees. Figure 6 As can be seen, the water contact angle of the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating of Example 8 is 151.7 degrees. Compared with the water contact angle of polydimethylsiloxane (PDMS) of 102.8 degrees, the coating formed by the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating of the present invention has excellent hydrophobic properties.

[0132] Depend on Figure 7 As can be seen, the water contact angle of the coating in Comparative Example 2 is 118.1 degrees. It is evident that the coating obtained in Comparative Example 2, due to the absence of hydrophobic nano-SiO2, has a water contact angle of only 118.1 degrees, thus exhibiting relatively poor hydrophobic properties.

[0133] (ii) Testing the roll-off angle of the coating

[0134] The high-efficiency photothermal conversion and wear-resistant superhydrophobic coatings prepared in Examples 6 to 8, and a coating prepared in Comparative Example 2, were tested for their rolling angles. The test results are shown in Table 1.

[0135] Table 1. Roll-off angle test results of coatings from Examples 6 to 8 and Comparative Example 2.

[0136]

[0137] As shown in Table 1, in the preparation of the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating used to form the coating in Example 8, the amount of hydrophobic nano-SiO2 was less than that in Examples 6 and 7. This resulted in a larger roll-off angle in Example 8 and slightly worse hydrophobicity compared to Examples 6 and 7. This indicates that the addition of hydrophobic nano-SiO2 can improve the hydrophobic performance of the coating. In addition, the coating obtained in Comparative Example 2, due to the absence of hydrophobic nano-SiO2, had a water contact angle of only 118.1 degrees, which is much less than 150 degrees. Consequently, its roll-off angle was much greater than 10 degrees, indicating poor hydrophobic performance.

[0138] (iii) Anti-icing performance test of the coating

[0139] Anti-icing performance test method: The anti-icing performance is measured by the delayed freezing time of water droplets on the sample surface. First, the coated sample is placed in a -15℃ freezer for 10 minutes. Then, a 10μL water droplet is placed on the coating surface, and the phase transition process of the water droplet is captured using a macro camera, and the freezing time of the water droplet is recorded. The freezing time of the water droplet on the coating surface is compared with the freezing time of the water droplet on the surface of a blank aluminum sheet.

[0140] The high-efficiency photothermal conversion and wear-resistant superhydrophobic coating prepared in Example 6, and a blank aluminum sheet were respectively tested for anti-icing performance. The test results are as follows: Figure 8 As shown.

[0141] Depend on Figure 8 As can be seen, the water droplet solidification time on the surface of the blank aluminum sheet is 322s, while the water droplet solidification time on the surface of the coating prepared in Example 6 is as long as 5211s. This indicates that the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating prepared by the present invention has a significant improvement in anti-icing performance compared to the blank aluminum sheet. This is because the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating prepared by the present invention has an ultra-high contact angle, which increases the nucleation energy barrier for water droplets to freeze and significantly reduces the contact area between the water droplets and the coating surface, making it more difficult for water droplets to freeze on the surface of the superhydrophobic coating.

[0142] (iv) Photothermal conversion performance test of coating

[0143] The high-efficiency photothermal conversion and wear-resistant superhydrophobic coating prepared in Example 6, and a blank aluminum sheet were tested for photothermal conversion performance. The test results are as follows: Figure 9 The graph shows the photothermal heating curve.

[0144] Depend on Figure 9 As can be seen, the superhydrophobic coating with high efficiency photothermal conversion and wear resistance prepared by the present invention rises from room temperature to 70°C after 2 minutes of light irradiation, and then reaches the equilibrium temperature of 82°C in about 5 minutes. This shows that the superhydrophobic coating prepared by the present invention has good photothermal conversion capability.

[0145] (v) Temperature rise test of coating

[0146] The high-efficiency photothermal conversion and wear-resistant superhydrophobic coating prepared in Example 6 was tested for its temperature rise capability under different light intensities. The test results are as follows: Figure 10 As shown. Figure 10 In the study, four different light intensities (0.6 sun, 0.8 sun, 1.0 sun and 1.5 sun) were tested, where 1 sun = 1000 W / m².

[0147] Depend on Figure 10 As can be seen, under different light intensities, the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating prepared by this invention can still maintain a certain temperature rise capability to cope with the complex and variable outdoor lighting environment. The higher the light intensity, the better the temperature rise capability. Specifically, when the light intensity is 1.5 sun, the coating reaches approximately 95°C from room temperature in 5 minutes. This indicates that the coating formed by the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating prepared by this invention has excellent temperature rise capability, thereby achieving efficient anti-icing and de-icing.

[0148] (vi) Photothermal stability and durability test of coating

[0149] The high-efficiency photothermal conversion and wear-resistant superhydrophobic coating prepared in Example 6 was subjected to 5 photothermal cycles (heating / cooling) at one solar intensity (1000 W / m²) to test the photothermal stability and durability of the coating. The test results are as follows: Figure 11 As shown.

[0150] Depend on Figure 11 As can be seen, the superhydrophobic coating of the present invention, which is highly efficient in photothermal conversion and wear-resistant, did not show a significant weakening of its photothermal conversion capability after five photothermal cycles, demonstrating that the superhydrophobic coating has excellent photothermal stability and durability.

[0151] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A highly efficient photothermal conversion and wear-resistant superhydrophobic coating, characterized in that, The preparation method of the highly efficient photothermal conversion and wear-resistant superhydrophobic coating includes the following steps: S1. Halloysite powder is dispersed in an acid solution, then pyrrole and ammonium persulfate are added, and the mixture is stirred and reacted. After stirring, the mixture is filtered, washed, and dried to obtain a polypyrrole-encapsulated halloysite nanotube composite material. The mass-volume ratio of halloysite powder, pyrrole, and ammonium persulfate is (0.3~0.4) g: (0.3~0.4) g: (0.1~0.2) mL. S2. Add polydimethylsiloxane and curing agent to an organic solvent and stir to mix to obtain a polydimethylsiloxane dispersion; the mass-volume ratio of polydimethylsiloxane, curing agent and organic solvent is (0.1~0.2) g : (0.01~0.02) g : (10~20) mL; S3. The polypyrrole-coated halloysite nanotube composite material and hydrophobic nano-SiO2 are added to the polydimethylsiloxane dispersion and ultrasonically dispersed to obtain the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating. The mass-volume ratio of the polypyrrole-coated halloysite nanotube composite material, hydrophobic nano-SiO2 and polydimethylsiloxane dispersion is (0.1~0.2) g: (0.05~0.2) g: (10~20) mL.

2. The method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating as described in claim 1, characterized in that, In step S1, halloysite powder is added to an acid solution and ultrasonically dispersed for 20-40 minutes to obtain a halloysite suspension; ammonium persulfate is dissolved in water to obtain an ammonium persulfate solution; pyrrole is added to water and ultrasonically treated to obtain a pyrrole dispersion; under stirring conditions, the ammonium persulfate solution and pyrrole dispersion are added dropwise to the halloysite suspension, and the mixture is stirred at 200-400 rpm for 3-7 minutes. After filtration, washing, and drying, a polypyrrole-encapsulated halloysite nanotube composite material is obtained. And / or, the mass-to-volume ratio of the ammonium persulfate to water is (0.2~0.5) g : (8~12) mL; and / or The volume ratio of pyrrole to water is (0.1~0.3):(8~12); and / or The halloysite suspension has a dispersion concentration of 5 g / L to 7 g / L; and / or The washing method involves washing twice with deionized water, followed by washing once with anhydrous ethanol; and / or The drying process involves drying at 55℃~65℃ for 6h~8h.

3. The method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating as described in claim 2, characterized in that, In step S1, the acid solution is a hydrochloric acid solution; and / or, the concentration of the hydrochloric acid solution is 1.0M to 1.5M.

4. The method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating as described in claim 2, characterized in that, In step S2, The curing agent is Dow Corning 184 Type B component; and / or The organic solvent is ethyl acetate.

5. The method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating as described in claim 2, characterized in that, In step S2, the mixing method is to stir at 200 rpm to 400 rpm for 0.5 h to 1 h at room temperature.

6. The method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating as described in claim 2, characterized in that, In step S3, The ultrasonic dispersion time is 1h to 2h.

7. A method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating, characterized in that, The high-efficiency photothermal conversion and wear-resistant superhydrophobic coating of claim 1 is sprayed onto the surface of a substrate and dried to obtain the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating.

8. The method for preparing a highly efficient photothermal conversion and wear-resistant superhydrophobic coating as described in claim 7, characterized in that, The spraying is performed using a spray gun with a pressure of 0.4 MPa to 0.7 MPa and a distance of 10 cm to 15 cm from the substrate; and / or The drying temperature is 60℃~80℃, and the drying time is 1h~2h.

9. The application of the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating prepared by the preparation method of the high-efficiency photothermal conversion and wear-resistant superhydrophobic coating according to claim 1 or any one of claims 2 to 6 in anti-icing and de-icing.

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