A high-temperature resistant superhydrophobic micro / nano structure coating and its preparation method

Abstract

This invention provides a high-temperature resistant superhydrophobic micro / nanostructure coating and its preparation method. The coating is constructed on a substrate surface and includes an adhesive underlayer and a functional surface layer located on the surface of the adhesive underlayer. The adhesive underlayer contains phenyl silicone resin, and the functional surface layer contains superhydrophobic particles, phenyl silicone resin, and carbon fiber shear tubes. The carbon fiber shear tubes form a micron-scale framework structure, and the superhydrophobic particles form a nano-scale rough structure; together, they constitute a hierarchical micro / nanostructure. This invention forms an inorganic-organic hybrid high-temperature resistant superhydrophobic micro / nanostructure coating by synergistically constructing superhydrophobic particles, phenyl silicone resin, and carbon fiber shear tubes on the substrate surface. The superhydrophobic particles provide a high-temperature resistant hydrophobic base, the phenyl silicone resin provides a high-temperature resistant bonding effect, and the carbon fiber shear tubes provide structural reinforcement. Therefore, the resulting coating possesses both good thermal stability and structural stability, and can mitigate performance degradation under high temperatures.

Description

Technical Field

[0001] This invention relates to the fields of micro-nano manufacturing and surface functionalization technology, and in particular to a high-temperature resistant superhydrophobic micro-nano structure coating and its preparation method. Background Technology

[0002] In engineering applications such as high-temperature molten salt power generation, high-temperature industrial wastewater treatment, high-temperature metal smelting, and high-temperature liquid transportation, the substrate surface is typically exposed to a high-temperature environment of 300–500°C for extended periods, simultaneously subjected to corrosive media, deposition media, and thermal stress. Particularly in molten salt power generation and high-temperature evaporation, the liquid medium readily wets and spreads on the solid surface. The larger solid-liquid contact area enhances the adhesion of the liquid to the wall, prolonging the residence time of the corrosive medium on the surface and thus exacerbating the corrosion of the substrate material. Simultaneously, continuous wetting promotes the precipitation, nucleation, and deposition of solutes on the surface, gradually forming a scale layer, which in turn affects the operational stability and transmission efficiency of the equipment.

[0003] To reduce the wetting behavior of liquids on solid surfaces, the surface wetting state is typically controlled by constructing micron- and nano-composite hierarchical structures on the substrate surface and introducing low surface energy materials. Under normal conditions, such surfaces can provide macroscopic roughness support through micron-structures, and further increase surface roughness and reduce the solid-liquid contact area through nanostructures, thereby achieving certain hydrophobic properties.

[0004] However, traditional hydrophobic or superhydrophobic surfaces still have significant shortcomings under high-temperature service conditions: On the one hand, commonly used low surface energy modified components have limited heat resistance and are prone to thermal decomposition in high-temperature environments, leading to a rapid decay of their liquid-repellent properties. On the other hand, the existing micro-nano rough structures have insufficient bonding force with the substrate, and are prone to cracking, peeling or structural collapse under spraying, rinsing, thermal cycling or long-term high temperature action, making it difficult to simultaneously ensure liquid repellency retention, adhesion reliability and structural stability. To address this, a high-temperature resistant superhydrophobic micro / nano structure coating and its preparation method are proposed. Summary of the Invention

[0005] In view of this, the present invention provides a high-temperature resistant superhydrophobic micro / nano structure coating and its preparation method to solve or alleviate the technical problems existing in the prior art, and at least provide a beneficial option.

[0006] The technical solution of the present invention is implemented as follows: a high-temperature resistant superhydrophobic micro / nano structure coating is constructed on the surface of a substrate, including an adhesive underlayer and a functional surface layer located on the surface of the adhesive underlayer; the adhesive underlayer contains phenyl silicone resin; the functional surface layer contains superhydrophobic particles, phenyl silicone resin and carbon fiber shear tubes; the carbon fiber shear tubes form a micron-scale skeleton structure in the functional surface layer, and the superhydrophobic particles are distributed between the micron-scale skeleton structure and form a nano-scale rough structure, so that the functional surface layer forms a hierarchical micro / nano structure.

[0007] Furthermore, the superhydrophobic particles are inorganic and organic hybrid particles formed by the high-temperature reaction of cyclic siloxanes under alkaline conditions, and the superhydrophobic particles contain a network structure composed of silicon-oxygen-silicon bonds.

[0008] Furthermore, the superhydrophobic particles have a particle size of 10–500 nm, which can provide nanoscale roughness features in the functional surface layer and cooperate with the micron-scale framework to form a layered rough surface.

[0009] Furthermore, the carbon fiber shear tube has a length of 5–70 μm and a diameter of 4–30 μm, and the carbon fiber shear tube is randomly oriented in the functional surface layer.

[0010] Furthermore, the thickness of the high-temperature resistant superhydrophobic micro / nano structure coating is 10–500 μm, and the functional surface layer forms a hierarchical pore structure composed of micron-level and nano-level pores. This hierarchical pore structure helps to reduce the actual contact area between the liquid and the surface and improve the hydrophobic stability of the surface.

[0011] Furthermore, the matrix is ​​a metal matrix, alloy matrix, ceramic matrix, glass matrix, or high-temperature resistant polymer matrix.

[0012] Furthermore, the bonding underlayer is pre-cured, and the functional surface layer is integrated with the bonding underlayer after curing, so as to stably fix the superhydrophobic particles and the carbon fiber shear tube to the substrate surface.

[0013] A second aspect of the present invention provides a method for preparing a high-temperature resistant superhydrophobic micro / nano structure coating, comprising the following steps: Preparation of superhydrophobic particles: Cyclic siloxane monomers, alcohol solvents and alkaline aqueous solutions are added to a high-pressure reactor for high-temperature reaction. After the reaction is completed, the particles are cooled, washed and dried to obtain superhydrophobic particles. Substrate pretreatment: The substrate surface is degreased, cleaned, and dried; Constructing the bonding underlayer: Mix phenyl silicone resin with an organic solvent to form a spraying solution, spray it onto the pretreated substrate surface, and then perform a pre-curing treatment to form the bonding underlayer; Constructing a functional surface layer: The superhydrophobic particles, phenyl silicone resin, carbon fiber shear tube and organic solvent are mixed and dispersed to form a dispersion, and the dispersion is sprayed onto the surface of the bonding substrate to form a functional surface layer containing a hierarchical micro-nano structure. Curing and film formation: The sprayed coating is cured to obtain a high-temperature resistant superhydrophobic micro / nano structure coating.

[0014] Furthermore, in the preparation process of the superhydrophobic particles, the temperature of the high-temperature reaction is 240-280°C, the reaction time is 6-12 hours, and the total volume of the alcohol solvent and water accounts for 40%-50% of the volume of the high-pressure reactor.

[0015] Furthermore, during the construction of the bonding underlayer, the spraying solution is pre-cured by heating or being placed at room temperature after spraying; during the construction of the functional surface layer, the dispersion is sprayed after stirring and ultrasonic dispersion; during the curing and film formation process, the curing treatment is heat curing or room temperature curing.

[0016] The embodiments of the present invention have the following advantages due to the adoption of the above technical solutions: I. This invention forms an inorganic and organic hybrid high-temperature resistant superhydrophobic micro / nano structure coating by synergistically constructing superhydrophobic particles, phenyl silicone resin, and carbon fiber shear tubes on the substrate surface. The superhydrophobic particles provide a high-temperature resistant hydrophobic base, the phenyl silicone resin provides a high-temperature resistant bonding effect, and the carbon fiber shear tubes provide a structural reinforcement effect. As a result, the coating has both good thermal stability and structural stability, and can slow down the performance degradation under high temperature.

[0017] II. This invention constructs a micron-scale skeleton structure formed by carbon fiber shear tubes and a nano-scale rough structure formed by superhydrophobic particles in the coating, thereby forming a hierarchical micro-nano structure on the surface. This effectively reduces the actual contact area between the liquid and the solid surface, weakens the wetting, adhesion and spreading behavior of high-temperature liquids on the surface, and thus helps to inhibit corrosion, deposit scaling and increase flow resistance.

[0018] Third, in this invention, the phenyl silicone resin and carbon fiber shear tube work together to not only stably fix the superhydrophobic particles to the substrate surface and improve the coating adhesion reliability, but also to disperse high-temperature thermal stress through the support skeleton formed by the carbon fiber shear tube, suppressing coating cracking, peeling or structural instability, thereby improving the service stability and service life of the coating under high-temperature conditions.

[0019] Fourth, the present invention adopts a process route that combines hydrothermal preparation of superhydrophobic particles with secondary spraying and curing. The overall steps are clear and the process is controllable, without the need for complex surface etching or multi-step chemical modification. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of the preparation method of the high-temperature resistant superhydrophobic micro / nano structure coating in this invention; Figure 2 These are contact angle photographs of the high-temperature resistant superhydrophobic micro / nano structure coating of the present invention after 30 minutes in different high-temperature environments; Figure 3 This is a graph showing the changes in contact angle and roll-off angle of the high-temperature resistant superhydrophobic micro / nano structure coating and the commercially available high-temperature resistant hydrophobic coating at an ambient temperature of 405 °C. Detailed Implementation

[0022] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0023] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0024] Figure 2 In the figures, (a) is the water droplet contact angle of a high-temperature resistant surface at 453 ℃, (b) is the water droplet contact angle of a high-temperature resistant surface at 508 ℃, (c) is the water droplet contact angle of a high-temperature resistant surface at 551 ℃, and (d) is the water droplet contact angle of a commercially available high-temperature resistant surface at 405 ℃.

[0025] This invention provides a high-temperature resistant superhydrophobic micro / nanostructure coating and its preparation method. The high-temperature resistant superhydrophobic micro / nanostructure coating is constructed on a substrate surface and comprises an adhesive underlayer and a functional surface layer located on the surface of the adhesive underlayer. The adhesive underlayer contains phenyl silicone resin to improve the interfacial bonding between the coating and the substrate. The functional surface layer contains superhydrophobic particles, phenyl silicone resin, and carbon fiber shear tubes. The carbon fiber shear tubes form a micrometer-scale framework structure in the functional surface layer, and the superhydrophobic particles are distributed between the micrometer-scale framework structure, forming a nanometer-scale rough structure. Together, they constitute the hierarchical micro / nanostructure of the functional surface layer.

[0026] Example 1 In this embodiment, a high-temperature resistant superhydrophobic micro / nano structure coating was prepared using a stainless steel substrate. The selected stainless steel substrate had dimensions of 20mm × 20mm and a thickness of 1mm to 3mm. First, the substrate was pretreated by sequentially ultrasonically cleaning it in acetone and anhydrous ethanol for 10 minutes each to remove surface oil and impurities. Subsequently, the substrate was thoroughly rinsed with deionized water and dried using nitrogen gas to obtain a clean substrate.

[0027] Superhydrophobic particles were prepared using a high-temperature hydrothermal method. Specifically, a cyclic siloxane monomer, an alcohol solvent, and an alkaline aqueous solution were sequentially added to the polytetrafluoroethylene liner of a high-pressure reactor, wherein the total volume of the alcohol solvent and water accounted for 40%–50% of the reactor's volume. In this embodiment, the cyclic siloxane monomer was octamethylcyclotetrasiloxane, the alcohol solvent was isopropanol, and the alkaline aqueous solution was sodium carbonate aqueous solution. After the feeding was completed, the high-pressure reactor was sealed and placed in a heating device, reacting at 240℃–280℃ for 6–12 hours. After the reaction, the mixture was naturally cooled to room temperature, and the resulting solid product was removed. It was then repeatedly washed with an alcohol solvent and deionized water, and finally dried at 100℃–150℃ to obtain superhydrophobic particles. The obtained superhydrophobic particles had a particle size of 10 nm–500 nm and contained a network structure composed of silicon-oxygen-silicon bonds.

[0028] After particle preparation, the bonding underlayer was first constructed. Phenyl silicone resin was weighed and added to n-hexane. The mixture was continuously treated for at least 30 minutes using a combination of magnetic stirring and ultrasonic dispersion to ensure thorough dispersion of the phenyl silicone resin in the organic solvent, forming a uniform spraying solution. The pretreated stainless steel substrate was fixed on a spraying platform, and the spraying solution was uniformly sprayed onto the substrate surface using a spray gun, with the spraying distance controlled between 10cm and 25cm. After spraying, the sample was placed at 80℃ to 120℃ for pre-curing treatment, allowing a continuous and adhesive bonding underlayer to form on the substrate surface.

[0029] Subsequently, a functional surface layer was constructed. The superhydrophobic particles prepared above were weighed and added to n-hexane, followed by carbon fiber shear tubes and phenyl silicone resin. The carbon fiber shear tubes had a length of 5μm–70μm and a diameter of 4μm–30μm. The above materials were subjected to alternating magnetic stirring and ultrasonic dispersion for at least 40 minutes to form a uniform and stable dispersion of the superhydrophobic particles, phenyl silicone resin, and carbon fiber shear tubes in the solvent. This dispersion was then sprayed onto the substrate surface where a bonding underlayer had already formed. By controlling the spraying rate, spraying path, and number of sprays, the functional surface layer was gradually deposited and formed. After spraying, the sample was placed at room temperature for at least 30 minutes to allow the organic solvent in the system to fully evaporate. Subsequently, it was thermosetting at 150℃–200℃ to obtain a high-temperature resistant superhydrophobic micro / nano structure coating. The total thickness of the resulting coating was controlled within the range of 10μm–500μm.

[0030] The coating prepared by the above method forms a continuous overlay on the substrate surface. From the substrate outwards, there are sequentially an adhesive underlayer and a functional surface layer. In the functional surface layer, the micron-sized pore structure formed by carbon fiber shear tubes and the nano-sized pore structure formed by superposition of superhydrophobic particles superimpose to form a micro / nano structure with obvious hierarchical characteristics. Because this structure can effectively reduce the actual contact area between the liquid and the solid, it can still maintain a good hydrophobic state under high temperature conditions.

[0031] Example 2 In this embodiment, a high-temperature resistant superhydrophobic micro / nano structure coating is prepared using a ceramic substrate. The material system, particle preparation route, and surface construction idea are the same as in Example 1. The difference lies in the substrate type and some curing conditions. The ceramic substrate is degreased, cleaned, and dried in the same way as in Example 1. Then, superhydrophobic particles are prepared according to the method in Example 1, and a phenyl silicone resin spraying solution is prepared. After uniformly spraying the coating solution onto the ceramic substrate surface, it is pre-cured at room temperature to allow the phenyl silicone resin to form a continuous bonding underlayer on the substrate surface. Subsequently, a functional layer dispersion consisting of superhydrophobic particles, phenyl silicone resin, carbon fiber shear tubes, and organic solvents is sprayed onto the bonding underlayer surface and then allowed to stand at room temperature followed by subsequent heat curing to obtain a high-temperature resistant superhydrophobic micro / nano structure coating.

[0032] Similar to Example 1, the functional surface layer obtained in this example also forms a micron-scale support framework composed of carbon fiber shear tubes and a nano-scale rough structure composed of superhydrophobic particles. Because the phenyl silicone resin forms a good interfacial bonding layer on the substrate surface, and the functional surface layer is integrally bonded to the bonding underlayer after curing, the resulting coating not only has good adhesion properties but also meets the application requirements of ceramic substrates under high-temperature conditions.

[0033] Example 3 This embodiment uses a glass substrate to prepare a high-temperature resistant superhydrophobic micro / nano structure coating to verify the adaptability of the invention to different substrates. The specific preparation steps are as follows: First, the glass substrate is degreased, cleaned, and dried; second, superhydrophobic particles are prepared according to the method in Example 1, and the bonding underlayer spraying solution and functional surface dispersion are prepared according to the method in Example 1; then, the bonding underlayer spraying solution is uniformly sprayed onto the surface of the glass substrate and pre-cured to form the bonding underlayer; finally, the functional surface dispersion is sprayed onto the surface of the bonding underlayer and cured to obtain the high-temperature resistant superhydrophobic micro / nano structure coating on the glass substrate.

[0034] In this embodiment, the formed functional surface layer still exhibits a layered micro / nano structure with superimposed micron-scale framework and nano-scale rough structure. Because the glass substrate itself has a relatively smooth surface, the continuous film-forming effect of the bonding layer on the substrate surface is more pronounced, which is beneficial for the uniform spreading and stable adhesion of the functional surface layer.

[0035] Comparative Example 1 The only difference between this comparative example and Example 1 is that carbon fiber shear tubes are not added to the functional surface layer; the remaining steps are the same as in Example 1. The same method was used to prepare the superhydrophobic particles, the same pretreatment was performed on the stainless steel substrate, and a bonding underlayer formed of phenyl silicone resin was first constructed on the substrate surface. Then, a dispersion consisting only of superhydrophobic particles, phenyl silicone resin, and an organic solvent was sprayed onto the bonding underlayer surface, and the comparative sample was obtained after standing and heat curing.

[0036] Since this comparative example lacks carbon fiber shear tubes, the functional surface layer lacks a micron-scale skeletal support structure, and the surface mainly relies on the accumulation of superhydrophobic particles to form a rough surface. This sample can be used to investigate the influence of carbon fiber shear tubes on the coating structure stability, high-temperature retention, and thermal stress resistance.

[0037] Comparative Example 2 The only difference between this comparative example and Example 1 is that no adhesive underlayer is provided. Specifically, after degreasing, cleaning, and drying the stainless steel substrate, phenyl silicone resin is not sprayed separately to form an adhesive underlayer. Instead, a functional layer dispersion consisting of superhydrophobic particles, phenyl silicone resin, carbon fiber shear tubes, and organic solvent is directly sprayed onto the substrate surface in one go, and the comparative example sample is obtained after static and heat curing treatment.

[0038] Since no pre-formed adhesive underlayer was set in this comparative example, there is no dedicated interfacial adhesive transition layer between the functional layer and the substrate. This sample can be used to investigate the impact of the "adhesive underlayer + functional surface layer" two-layer construction method on adhesion reliability, structural integrity and high-temperature service stability.

[0039] Comparative Example 3 The difference between this comparative example and Example 1 is that, although a double-layer spraying method is used, the superhydrophobic particles prepared in this invention are not added to the functional surface layer. Instead, a dispersion is prepared using phenyl silicone resin, carbon fiber shear tube and organic solvent, and sprayed onto the surface of the already formed adhesive underlayer. After static and heat curing treatment, the comparative example sample is obtained.

[0040] Since this comparative example lacks superhydrophobic particles formed by the high-temperature reaction of cyclic siloxanes, although the functional surface layer has a certain fiber skeleton rough structure, it lacks the fine-scale rough structure formed by nanoscale functional particles and the corresponding high-temperature resistant hydrophobic chemical basis. Therefore, it can be used to investigate the effect of superhydrophobic particles on surface hydrophobic properties and high-temperature stability.

[0041] Comparative Example 4 The difference between this comparative example and Example 1 is that a single-layer structure is used. That is, instead of forming a separate adhesive underlayer and functional surface layer, the superhydrophobic particles, phenyl silicone resin, carbon fiber shear tube and organic solvent are mixed at one time, stirred and ultrasonically dispersed, and then directly sprayed onto the pretreated substrate surface. After static and thermosetting treatment, a single-layer composite coating is obtained.

[0042] Although this comparative example still contains three components: superhydrophobic particles, phenyl silicone resin, and carbon fiber shear tube, it does not adopt the "bonding substrate + functional surface" two-layer construction relationship of the present invention. Therefore, it can be used to examine the influence of the layered construction method on interface stability, component distribution order, and high-temperature service performance.

[0043] Comparative Example 5 This comparative example uses a commercially available high-temperature resistant hydrophobic surface as a control sample. This sample does not employ the superhydrophobic particles, phenyl silicone resin, and carbon fiber shear tube composite system of this invention, nor does it use the secondary spraying construction route of this invention. Instead, it uses a commercially available high-temperature resistant hydrophobic treated surface as a prior art control.

[0044] This comparative example can be used to compare the contact angle retention, roll-off angle change, and hydrophobic property decay of the samples in the embodiments of the present invention with those of the present invention, thereby demonstrating the advantages of the coating system of the present invention in terms of high temperature retention.

[0045] Test Example 1: Surface Wetting Performance Test After High Temperature Treatment The high-temperature resistant superhydrophobic micro / nano structure coating sample prepared in Example 1, as well as the samples obtained in Comparative Examples 1 to 5, were placed in high-temperature environments for treatment. The surface wetting state of the sample from Example 1 was observed after treatment at 453°C, 508°C, and 551°C for 30 minutes; the surface wetting state of the commercially available high-temperature resistant hydrophobic surface from Comparative Example 5 was observed after treatment at approximately 405°C for the same period.

[0046] Test results show that the coating obtained in Example 1 of the present invention still maintains a large apparent contact angle and exhibits a stable superhydrophobic state after being treated in a high-temperature environment of around 450°C to 550°C; while the commercial high-temperature resistant hydrophobic surface Comparative Example 5 showed a significant deterioration in its hydrophobic state after being treated at around 405°C. Therefore, the three-phase composite system of superhydrophobic particles, phenyl silicone resin and carbon fiber shear tube used in this invention, as well as the layered construction method of "bonding underlayer + functional surface layer", can improve the wettability retention of the coating under high temperature conditions.

[0047] For Comparative Examples 1 to 4, under the same high-temperature treatment conditions, their surface hydrophobic state was lower than that of Example 1. Among them, Comparative Example 1, which does not contain carbon fiber shear tubes, is more prone to surface instability due to the lack of micron-level skeleton support; Comparative Example 2, which does not have a bonding underlayer, is more prone to local instability after treatment due to insufficient interfacial bonding ability; Comparative Example 3, which does not contain superhydrophobic particles, lacks a stable high-temperature resistant hydrophobic functional phase; and Comparative Example 4, with its single-layer structure, has weaker performance retention at high temperatures than Example 1 due to insufficient uniformity of structural distribution and interfacial hierarchy. The above comparisons further illustrate that the multi-component, multi-level composite structure of the present invention plays a crucial role in maintaining hydrophobicity at high temperatures.

[0048] Test Example 2: Test on changes in contact angle and roll-off angle under continuous high temperature Samples from Example 1 and Comparative Example 5 were subjected to continuous heating treatment at approximately 400°C, and the static contact angle and dynamic roll-off angle were tested periodically. The test results are as follows: Figure 3 As shown. The static contact angle of the sample in this embodiment of the invention remained above approximately 155° throughout the entire heating process, with a small variation range, while the dynamic roll-off angle remained at a low level, less than 10°. In contrast, the static contact angle of the commercial high-temperature resistant hydrophobic surface comparative example 5 decreased significantly during the heating process, while the dynamic roll-off angle increased rapidly and transformed from a hydrophobic state to a low hydrophobic state or even a hydrophilic state in a short period of time.

[0049] Under the same test conditions, Comparative Examples 1 to 4, although no new quantitative data were introduced, showed that their roll-off angle increase and contact angle decrease trends were greater than those of Example 1. In particular, Comparative Examples 1 and 3, due to the lack of micron-scale framework reinforcing phase and nano-scale high-temperature resistant hydrophobic functional phase, respectively, had surface roughness and surface chemical stability that were difficult to match those of Example 1. Comparative Examples 2 and 4 mainly exhibited insufficient adhesion stability under high temperature and rapid interface structure degradation. This demonstrates that the hierarchical micro / nano structure and double-layer construction method of the present invention have a significant promoting effect on maintaining a low roll-off angle and a high contact angle under continuous high-temperature conditions.

[0050] Test Example 3: Droplet bounce and high-temperature retention test The sample obtained in Example 1 was subjected to high-temperature heating at 450°C for 2 hours, followed by a droplet bounce test on the sample surface. Under these conditions, the coating still maintained its superhydrophobic properties. When a droplet was released from a height of 1 cm, it could still bounce back to a height of 1.9 mm, indicating that the droplet adhesion on the sample surface was weak and the droplets had good desorption ability.

[0051] Furthermore, the coating can withstand baking at 500°C for 1 hour or at 400°C for 6 hours, and still maintains its superhydrophobic properties after high-temperature baking.

[0052] In comparison, after undergoing the same high-temperature treatment, Comparative Examples 1 to 4 showed weaker droplet desorption performance and high-temperature retention capacity than Example 1. Among them, Comparative Example 1, lacking the micron-scale skeleton formed by carbon fiber shear tubes, is more prone to structural shrinkage and insufficient support at high temperatures. Comparative Example 2, due to the lack of an adhesive underlayer, exhibits poor interfacial stability of its functional layer after high temperature. Comparative Example 3, lacking the superhydrophobic particles of this invention, struggled to establish a stable high-temperature resistant hydrophobic interface. Comparative Example 4, due to the lack of a double-layer construction method, has a weaker overall structural integration and high-temperature stress dispersion capability.

[0053] The above test results demonstrate that the hierarchical micro-nano structure constructed by the present invention through the synergistic construction of superhydrophobic particles, phenyl silicone resin, and carbon fiber shear tubes can maintain good surface morphology stability and hydrophobic properties under high temperature conditions.

[0054] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in the present invention, and these should all be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-temperature resistant superhydrophobic micro / nano structure coating, characterized in that: Constructed on the surface of a substrate, comprising an adhesive underlayer and a functional surface layer located on the surface of the adhesive underlayer; the adhesive underlayer contains phenyl silicone resin; The functional surface layer contains superhydrophobic particles, phenyl silicone resin, and carbon fiber shear tubes. The carbon fiber shear tube forms a micron-scale skeleton structure in the functional surface layer, and the superhydrophobic particles are distributed between the micron-scale skeleton structure to form a nano-scale rough structure, so that the functional surface layer forms a hierarchical micro-nano structure.

2. The high-temperature resistant superhydrophobic micro / nano structure coating according to claim 1, characterized in that: The superhydrophobic particles are inorganic and organic hybrid particles formed by the high-temperature reaction of cyclic siloxanes under alkaline conditions, and the superhydrophobic particles contain a network structure composed of silicon-oxygen-silicon bonds.

3. The high-temperature resistant superhydrophobic micro / nano structure coating according to claim 1, characterized in that: The particle size of the superhydrophobic particles is 10–500 nm.

4. The high-temperature resistant superhydrophobic micro / nano structure coating according to claim 1, characterized in that: The carbon fiber shear tube has a length of 5–70 μm and a diameter of 4–30 μm, and the carbon fiber shear tube is randomly oriented in the functional surface layer.

5. The high-temperature resistant superhydrophobic micro / nano structure coating according to claim 1, characterized in that: The thickness of the high-temperature resistant superhydrophobic micro / nano structure coating is 10–500 μm, and the functional surface layer forms a hierarchical pore structure composed of micron-level and nano-level pores.

6. The high-temperature resistant superhydrophobic micro / nano structure coating according to claim 1, characterized in that: The matrix is ​​a metal matrix, alloy matrix, ceramic matrix, glass matrix, or high-temperature resistant polymer matrix.

7. The high-temperature resistant superhydrophobic micro / nano structure coating according to claim 1, characterized in that: The bonding underlayer is formed by pre-curing, and the functional surface layer is integrated with the bonding underlayer after curing to stably fix the superhydrophobic particles and the carbon fiber shear tube to the substrate surface.

8. A method for preparing a high-temperature resistant superhydrophobic micro / nano structure coating, characterized in that, Includes the following steps: S1. Preparation of superhydrophobic particles: Cyclic siloxane monomers, alcohol solvents and alkaline aqueous solutions are added to a high-pressure reactor for high-temperature reaction. After the reaction is completed, the particles are cooled, washed and dried to obtain superhydrophobic particles. S2. Substrate pretreatment: Degrease and clean the substrate surface and dry it; S3. Constructing the bonding underlayer: Mix phenyl silicone resin with an organic solvent to form a spraying solution, spray it onto the pretreated substrate surface, and then perform a pre-curing treatment to form the bonding underlayer; S4. Constructing a functional surface layer: The superhydrophobic particles, phenyl silicone resin, carbon fiber shear tube and organic solvent are mixed and dispersed to form a dispersion liquid. The dispersion liquid is sprayed onto the surface of the bonding substrate to form a functional surface layer containing a hierarchical micro-nano structure. S5. Curing and film formation: The sprayed coating is cured to obtain a high-temperature resistant superhydrophobic micro / nano structure coating.

9. The preparation method according to claim 8, characterized in that: In step S1, the temperature of the high-temperature reaction is 240-280°C, the reaction time is 6-12 hours, and the total volume of the alcohol solvent and water accounts for 40%-50% of the volume of the high-pressure reactor.

10. The preparation method according to claim 8, characterized in that: In step S3, the spraying solution is pre-cured by heating or leaving it at room temperature after spraying; In step S4, the dispersion is sprayed after being stirred and ultrasonically dispersed. In step S5, the curing process is either heat curing or room temperature curing.

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