A method for preparing a double-layer embedded epoxy resin superhydrophobic coating

Abstract

This invention provides a method for preparing a double-layer embedded epoxy resin superhydrophobic coating, comprising: step 1, inspecting and cleaning the substrate material; step 2, preparing fluorinated multi-walled carbon nanotubes; step 3, preparing a bottom adhesive layer; step 4, adding epoxy resin and curing agent to anhydrous ethanol, adding fluorinated multi-walled carbon nanotubes, stirring thoroughly to obtain solution E; spraying solution E onto the adhesive layer, curing and drying. The adhesive layer involved in this invention uses the same material as the superhydrophobic coating substrate, avoiding chemical reactions between the adhesive layer and the superhydrophobic coating, effectively preventing interactions between different materials. Through this design, the surface roughness of the coating is controlled, resulting in a significantly improved water contact angle, even far exceeding the hydrophobic properties of traditional superhydrophobic coatings, effectively solving the problem of insufficient adhesion between epoxy resin superhydrophobic coatings and the substrate.

Description

Technical Field

[0001] This invention belongs to the field of marine corrosion / fouling prevention; in particular, it relates to a method for preparing a double-layer embedded epoxy resin superhydrophobic coating. Background Technology

[0002] Superhydrophobic coatings are functional coatings developed based on the self-cleaning properties of organisms found in nature. A superhydrophobic coating is defined as a coating on which a water droplet has a contact angle greater than 150° and a roll-off angle less than 5°. With its unique properties such as hydrophobicity, corrosion resistance, abrasion resistance, low adhesion, and anti-icing, superhydrophobic coatings have enormous application prospects in fields such as shipbuilding, aviation, medicine, construction, and automobiles. The preparation methods for superhydrophobic coatings mainly include physical methods and chemical methods. Physical methods involve depositing superhydrophobic materials onto the substrate surface using physical means (spraying, sputtering, etc.); chemical methods involve forming a superhydrophobic coating on the substrate surface through chemical reactions (sol-gel, chemical vapor deposition, electrochemical deposition, etc.).

[0003] Superhydrophobic coatings, developed using biomimetic principles, play a crucial role in corrosion and fouling protection. The synergistic effect of their microscopically rough structure and low surface free energy allows for the trapping of a large amount of air between the solid and liquid surfaces, forming an air layer and resulting in a stable solid-liquid-gas composite interface configuration. Based on this configuration, droplets primarily make point contact at the interface, significantly reducing the actual contact area between the corrosive medium and the substrate material, thus preventing the corrosive medium from eroding the substrate. Simultaneously, the formed air layer effectively reduces the adhesion strength of marine organisms, allowing them to detach from the coating surface under the impact of water flow. However, prolonged immersion in high-salt, high-humidity marine environments, coupled with prolonged seawater erosion and friction, weakens the adhesion between the superhydrophobic coating and the substrate, leading to a decrease in its protective performance. Therefore, the stability of superhydrophobic coating performance remains a significant challenge. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a double-layer embedded epoxy resin superhydrophobic coating. This invention addresses the long-term protective performance of superhydrophobic coatings by proposing a method for preparing embedded epoxy resin superhydrophobic coatings using a double-layer structure, wet chemical surface modification, and organic / inorganic composite methods. This effectively overcomes the problem of reduced adhesion strength between the coating and the substrate under prolonged seawater immersion, improves its stability, and achieves long-term protection with the superhydrophobic coating.

[0005] This invention is achieved through the following technical solution:

[0006] This invention relates to a method for preparing a double-layer embedded epoxy resin superhydrophobic coating, comprising the following steps:

[0007] Step 1: Inspect and clean the base material;

[0008] Step 2, Preparation of fluorinated multi-walled carbon nanotubes:

[0009] First, glacial acetic acid is added to deionized water to prepare a glacial acetic acid solution with a certain pH value. A certain amount of multi-walled carbon nanotube powder is then added to the solution. After thorough stirring, solution A is obtained and set aside for use.

[0010] Next, a solution of perfluorodecyltriethoxysilane was prepared with anhydrous ethanol and stirred thoroughly to obtain solution B;

[0011] Finally, after solutions A and B are prepared, solution B is slowly added to solution A to obtain solution C. After magnetic stirring, centrifugation, washing, and drying, fluorinated modified multi-walled carbon nanotubes are obtained.

[0012] Step 3, Preparation of the bottom adhesive layer: Add epoxy resin and curing agent to anhydrous ethanol, and after magnetic stirring, obtain solution D. Spray solution D onto the substrate surface cleaned in step 1, and cure at room temperature to obtain the adhesive layer.

[0013] Step 4, Preparation of epoxy resin superhydrophobic coating: Add epoxy resin and curing agent to anhydrous ethanol, add fluorinated multi-walled carbon nanotubes, stir thoroughly to obtain solution E; use a spraying device to spray solution E onto the adhesive layer prepared in step 3, cure and dry at room temperature to obtain a double-layer embedded epoxy resin superhydrophobic coating.

[0014] Preferably, in step 1, the inspection and cleaning of the substrate material specifically involves:

[0015] Step 1.1: Observe whether there are defects and oxide layers on the surface of the substrate material. If there are oxide layers, polish the surface of the substrate material. If there are defects, replace the substrate. If there are oxide layers, use sandpaper to polish the surface of the substrate to remove the oxide layers.

[0016] Step 1.2: Clean the polished substrate material with acetone using ultrasonic cleaning, then clean it with deionized water, and dry it after cleaning for later use.

[0017] Preferably, in step 2, the preparation of the fluorinated multi-walled carbon nanotubes specifically involves:

[0018] Step 2.1: Add glacial acetic acid dropwise to 30-60 mL of deionized water to adjust the pH to 4-5. Add 5-10 g of multi-walled carbon nanotube powder. Adding glacial acetic acid during the fluorination process can better dissolve the multi-walled carbon nanotube powder, provide an acidic environment, and promote the reaction. Stir thoroughly to obtain solution A, which is ready for use.

[0019] Step 2.2: Add perfluorodecyltriethoxysilane dropwise to anhydrous ethanol. After the addition is complete, stir magnetically for 1 hour and record as solution B. The fluorine-containing modifier used in this step is 1H,1H,2H,2H-perfluorodecyltriethoxysilane.

[0020] The volume fraction of perfluorodecyltriethoxysilane in anhydrous ethanol is 0.5-1%. Appropriately increasing the volume fraction of perfluorodecyltriethoxysilane in anhydrous ethanol can shorten the reaction time.

[0021] Step 2.3: After solutions A and B are prepared, slowly add solution B to solution A to obtain solution C. Stir magnetically, centrifuge, and wash 2-3 times to remove impurities. Place the centrifuged product at 80°C for 24 hours to obtain fluorinated modified multi-walled carbon nanotubes.

[0022] Preferably, in step 3, the preparation of the bottom adhesive layer specifically involves:

[0023] Step 3.1: Add epoxy resin and curing agent to anhydrous ethanol, stir, and obtain solution D; wherein the components are used in the following proportions: the mass ratio of epoxy resin, curing agent and anhydrous ethanol is 10:3:(50~100);

[0024] Step 3.2: Apply solution D to the substrate surface using an air spraying device and cure for 1 hour to obtain an adhesive layer.

[0025] Preferably, in step 4, the preparation of the epoxy resin superhydrophobic coating specifically involves:

[0026] Step 4.1: Add epoxy resin and curing agent to anhydrous ethanol, then add fluorinated multi-walled carbon nanotubes, and stir thoroughly to obtain solution E; wherein, the mass ratio of epoxy resin, curing agent and anhydrous ethanol is 10:3:(50-60); the mass ratio of epoxy resin, curing agent and fluorinated multi-walled carbon nanotubes is 10:3:(3-9);

[0027] Step 4.2: Apply solution E to the adhesive layer prepared in step 3 using a spraying device, and cure and dry at room temperature for 24 hours to obtain a double-layer embedded epoxy resin superhydrophobic coating.

[0028] Preferably, the substrate material includes carbon steel, glass, or aluminum sheet. The selection of different substrate materials is to demonstrate that the epoxy superhydrophobic coating is applicable to a wide range of materials and has universal applicability.

[0029] Preferably, the epoxy resin is GIN2 epoxy superimposed resin, and the curing agent is a suitable AT30 slow curing agent; slow curing is carried out at room temperature to prevent the coating from cracking during the drying process.

[0030] The present invention has the following advantages:

[0031] (1) The adhesive layer involved in this invention uses the same material as the superhydrophobic coating substrate, which avoids chemical reaction between the adhesive layer and the superhydrophobic coating and effectively avoids the phenomenon of interaction between different materials. Through this design, the rough structure of the coating surface is controlled, which significantly improves the water contact angle of the coating, even far exceeding the hydrophobic performance of traditional superhydrophobic coatings, and effectively solves the problem of insufficient adhesion between epoxy resin superhydrophobic coatings and substrates.

[0032] (2) By introducing a robust adhesive layer and an optimized rough structure, the present invention can significantly improve the wear resistance of the superhydrophobic coating. After multiple friction cycle experiments, the coating still maintains its superhydrophobicity. Compared with the single-layer superhydrophobic coating that is prone to cracking, the double-layer embedded superhydrophobic coating with resin adhesive layer prepared by the present invention has stronger adhesion to the substrate. Through tests such as tape peel test, the strong bond between the coating and the substrate is finally verified, ensuring the stability and durability of the coating in practical applications.

[0033] (3) The double-layer embedded epoxy resin superhydrophobic coating involved in this invention has good environmental and chemical stability, and can maintain good hydrophobic properties in air, water and solutions with different pH values; even after long-term exposure in harsh environments, the coating can maintain its superhydrophobic properties. The sealed structure formed by the epoxy resin matrix effectively prevents corrosive substances from entering and damaging the coating, and can resist the erosion of corrosive aqueous solutions. Attached Figure Description

[0034] Figure 1 This is a schematic diagram illustrating the preparation of a double-layer embedded epoxy resin superhydrophobic coating.

[0035] Figure 2 This is a diagram showing the static contact angle of the adhesive layer in this invention;

[0036] Figure 3 The following are test images for Example 1; where (a) is a state diagram of droplets on the surface of epoxy superhydrophobic coating, (b) is a contact angle effect diagram of epoxy superhydrophobic coating, (c) is a microscopic morphology diagram of coating surface under 50μm magnification, and (d) is a microscopic morphology diagram of coating surface under 500nm magnification.

[0037] Figure 4 The following are test images for Example 2; (a) is a state diagram of droplets on the surface of epoxy superhydrophobic coating, (b) is a contact angle effect diagram of epoxy superhydrophobic coating, (c) is a microscopic morphology diagram of coating surface under 100μm magnification, and (d) is a microscopic morphology diagram of coating surface under 500nm magnification.

[0038] Figure 5 The following are test images for Example 3; where (a) is a state diagram of droplets on the surface of the epoxy superhydrophobic coating, and (b) is a contact angle effect diagram of the epoxy superhydrophobic coating.

[0039] Figure 6 This is a graph showing the contact angle variation trend of the double-layer epoxy resin superhydrophobic coating prepared in this invention under 500 sandpaper abrasion cycles. Detailed Implementation

[0040] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are merely further illustrations of the present invention, but the scope of protection of the present invention is not limited to the following embodiments.

[0041] Example 1

[0042] This embodiment relates to a method for preparing a double-layer embedded resin superhydrophobic coating, see [link to documentation]. Figure 1 As shown, the specific steps are as follows:

[0043] S1. Inspection and cleaning of the substrate surface: Prepare a Q235 carbon steel with dimensions of 3×3cm and a thickness of 1mm. Visually inspect the carbon steel surface for defects such as cracks and voids. If defects are found, replace it with a new substrate material. The surface of the new substrate material often has an oxide layer and other impurities. It needs to be sanded with 240#, 400#, and 600# sandpaper to make its surface smooth. Then, it should be ultrasonically cleaned with acetone for 15 minutes, followed by ultrasonic cleaning with deionized water for 15 minutes. After cleaning, put the substrate into an oven to dry at 60℃ for 30 minutes. The substrate is now ready for use.

[0044] S2, Surface fluorination modification of multi-walled carbon nanotubes: The multi-walled carbon nanotubes used have a diameter of approximately 10–20 nm and a length of approximately 10–30 μm; the fluorination modification is carried out in an acidic environment; 60 mL of deionized water is measured using a graduated cylinder and poured into a 500 mL beaker. Glacial acetic acid is added dropwise using a dropper to adjust the pH to 4, and the mixture is stirred until fully mixed; 5 g of multi-walled carbon nanotube powder is weighed and added to the above glacial acetic acid solution. The mixture is stirred with a magnetic stirrer for 1 hour to ensure that the multi-walled carbon nanotube powder is uniformly dissolved in the glacial acetic acid solution, thereby accelerating the fluorination process. This solution is denoted as solution A.

[0045] Prepare a 5% (v / v) solution of perfluorodecyltriethoxysilane. Measure 45 mL of anhydrous ethanol using a graduated cylinder and pour it into a beaker for later use. Then, use a pipette to transfer 2.5 mL of perfluorodecyltriethoxysilane and slowly add it dropwise to the anhydrous ethanol. During the dropwise addition, stir the solution with a magnetic stirrer to ensure thorough mixing. After all the dropwise addition is complete, stir magnetically for 1 hour and record this solution as solution B.

[0046] After solutions A and B are prepared, solution B is slowly added to solution A to obtain solution C. Solution C needs to be magnetically stirred at 50°C for 24 hours until the carbon nanotubes are completely fluorinated. After the reaction is complete, the mixed solution is centrifuged to obtain the reaction product. Since the product contains impurities such as glacial acetic acid, it needs to be washed with anhydrous ethanol and then centrifuged again. This operation is repeated 3 times. After centrifugation and washing, the product is dried in an oven at 80°C for 24 hours to obtain fluorinated modified multi-walled carbon nanotubes.

[0047] S3, Preparation of the bottom adhesive layer: Weigh 2g of epoxy resin and 0.6g of curing agent into a beaker, add 20mL of anhydrous ethanol, and stir magnetically for 1h. Observe whether the epoxy resin and curing agent are completely dissolved in the anhydrous ethanol. After stirring evenly, solution D is obtained. After stirring, under a pressure of 4 bar, use a nozzle (nozzle diameter 3mm) to spray solution D onto the substrate surface. During this process, the spray gun is tilted at a 45° angle and the nozzle is kept 15cm above the substrate to ensure that the solution is evenly distributed on the substrate. After spraying, the substrate with the adhesive layer is pre-cured at room temperature for 1h to obtain the adhesive layer. See [link to relevant documentation]. Figure 2 As shown, the measured contact angle of the adhesive layer is 76.10 ± 0.29°.

[0048] S4, Preparation of epoxy resin superhydrophobic coating: Weigh 1g of epoxy resin and 0.3g of curing agent into a beaker, add 10mL of anhydrous ethanol, and stir magnetically for 15min. Weigh 0.3g of fluorinated multi-walled carbon nanotubes and add them to the epoxy resin solution. Stir with a magnetic stirrer for 1h. After stirring, solution E is obtained. Apply solution E uniformly to the pre-cured substrate using the spraying operation in S3. After spraying, allow the coating to cure at room temperature for 24h to obtain a double-layer embedded epoxy resin superhydrophobic coating. Figure 3 As shown, droplets aggregate into spherical shapes on the surface of the epoxy superhydrophobic coating. The contact angle of the coating was measured to be 157.78 ± 0.15°. Scanning electron microscopy revealed numerous papillary protrusions on the coating surface, with filamentous material inside these structures. This indicates that the epoxy superhydrophobic coating has a high surface roughness, leading to improved non-wetting properties and achieving superhydrophobic characteristics.

[0049] Example 2

[0050] This embodiment relates to a method for preparing a double-layer embedded resin superhydrophobic coating, the specific steps of which are as follows:

[0051] S1. Inspection and cleaning of the substrate surface: Prepare a 3×3cm Q235 carbon steel substrate with a thickness of 1mm. Visually inspect the carbon steel surface for defects such as cracks and voids. If defects are found, replace the substrate with a new one. The new substrate often has an oxide layer and other impurities on its surface. It needs to be sanded with 240#, 400#, and 600# sandpaper to make its surface smooth. Then, ultrasonically clean it with acetone for 15 minutes, followed by ultrasonic cleaning with deionized water for 15 minutes. After cleaning, place the substrate in an oven to dry at 60℃ for 30 minutes. The substrate is now ready for use.

[0052] S2, Surface fluorination modification of multi-walled carbon nanotubes: The multi-walled carbon nanotubes used in this invention have a diameter of approximately 10–20 nm and a length of approximately 10–30 μm; the fluorination modification is carried out in an acidic environment; 60 mL of deionized water is measured using a graduated cylinder and poured into a 500 mL beaker. Glacial acetic acid is added dropwise using a dropper to adjust the pH to 4, and the mixture is stirred until fully mixed. 5 g of multi-walled carbon nanotube powder is weighed and added to the above glacial acetic acid solution. The mixture is stirred with a magnetic stirrer for 1 hour to ensure that the multi-walled carbon nanotubes are uniformly dissolved in the glacial acetic acid solution, thus accelerating the fluorination process. This solution is denoted as solution A.

[0053] Prepare a 5% (v / v) solution of perfluorodecyltriethoxysilane. Measure 45 mL of anhydrous ethanol using a graduated cylinder and pour it into a beaker for later use. Then, use a pipette to transfer 2.5 mL of perfluorodecyltriethoxysilane and slowly add it dropwise to the anhydrous ethanol. During the dropwise addition, stir the solution with a magnetic stirrer to ensure thorough mixing. After all the dropwise addition is complete, stir magnetically for 1 hour and record this solution as solution B.

[0054] After solutions A and B are prepared, solution B is slowly added to solution A to obtain solution C. Solution C needs to be magnetically stirred at 50°C for 24 hours until the carbon nanotubes are completely fluorinated. After the reaction is complete, the mixed solution is centrifuged to obtain the reaction product. Since the product contains impurities such as glacial acetic acid, it needs to be washed with anhydrous ethanol and then centrifuged again. This operation is repeated 3 times. After centrifugation and washing, the product is dried in an oven at 80°C for 24 hours to obtain fluorinated modified multi-walled carbon nanotubes.

[0055] S3, Preparation of the bottom adhesive layer: Weigh 2g of epoxy resin and 0.6g of curing agent into a beaker, add 20mL of anhydrous ethanol, and stir magnetically for 1h. Observe whether the epoxy resin and curing agent are completely dissolved in the anhydrous ethanol. After stirring evenly, solution D is obtained. After stirring, under a pressure of 4 bar, use a nozzle (nozzle diameter 3mm) to spray solution D onto the substrate surface. During this process, the spray gun is tilted at a 45° angle and the nozzle is kept 15cm above the substrate to ensure that the solution is evenly distributed on the substrate. After spraying, the substrate with the adhesive layer is pre-cured at room temperature for 1h to obtain the adhesive layer.

[0056] S4, Preparation of epoxy resin superhydrophobic coating: Weigh 1g of epoxy resin and 0.3g of curing agent into a beaker, add 10mL of anhydrous ethanol, and stir magnetically for 15min. Weigh 0.6g of fluorinated multi-walled carbon nanotubes and add them to the epoxy resin solution, stir with a magnetic stirrer for 1h. After stirring, solution E is obtained. Solution E is uniformly sprayed onto the pre-cured substrate using the spraying operation in S3. After spraying, the coating is left to cure at room temperature for 24h to obtain a double-layer embedded epoxy resin superhydrophobic coating. Figure 4 As shown, droplets aggregate into spherical shapes on the surface of the epoxy superhydrophobic coating. The contact angle of the coating was measured to be 158.60 ± 0.80°. Scanning electron microscopy revealed an increase in the number of papillary protrusions on the coating surface, indicating that increasing the content of fluorinated multi-walled carbon nanotubes improves the non-wetting properties of the epoxy superhydrophobic coating.

[0057] Example 3

[0058] This embodiment relates to a method for preparing a double-layer embedded resin superhydrophobic coating, the specific steps of which are as follows:

[0059] S1. Inspection and cleaning of the substrate surface: Prepare a 3×3cm Q235 carbon steel substrate with a thickness of 1mm. Visually inspect the carbon steel surface for defects such as cracks and voids. If defects are found, replace the substrate with a new one. The new substrate often has an oxide layer and other impurities on its surface. It needs to be sanded with 240#, 400#, and 600# sandpaper to make its surface smooth. Then, ultrasonically clean it with acetone for 15 minutes, followed by ultrasonic cleaning with deionized water for 15 minutes. After cleaning, place the substrate in an oven to dry at 60℃ for 30 minutes. The substrate is now ready for use.

[0060] S2, Surface fluorination modification of multi-walled carbon nanotubes: The multi-walled carbon nanotubes used have a diameter of approximately 10–20 nm and a length of approximately 10–30 μm; the fluorination modification is carried out in an acidic environment; 60 mL of deionized water is measured using a graduated cylinder and poured into a 500 mL beaker. Glacial acetic acid is added dropwise using a dropper to adjust the pH to approximately 3, and the mixture is stirred until fully combined. 5 g of multi-walled carbon nanotube powder is weighed and added to the above glacial acetic acid solution. The mixture is stirred with a magnetic stirrer for 1 hour to ensure that the multi-walled carbon nanotubes are uniformly dissolved in the glacial acetic acid solution, thus accelerating the fluorination process. This solution is denoted as solution A.

[0061] Prepare a 5% (v / v) solution of perfluorodecyltriethoxysilane. Measure 45 mL of anhydrous ethanol using a graduated cylinder and pour it into a beaker for later use. Then, use a pipette to transfer 2.5 mL of perfluorodecyltriethoxysilane and slowly add it dropwise to the anhydrous ethanol. During the dropwise addition, use a magnetic stirrer to stir the solution to ensure thorough mixing. After all the dropwise addition is complete, stir magnetically for 1 hour and record this solution as solution B.

[0062] After solutions A and B are prepared, solution B is slowly added to solution A to obtain solution C. Solution C needs to be magnetically stirred at 50°C for 24 hours to ensure complete fluorination of the carbon nanotubes. After the reaction is complete, the mixed solution is centrifuged to obtain the reaction product. Since the product contains impurities such as glacial acetic acid, it needs to be washed with anhydrous ethanol and then centrifuged again. This operation is repeated 3 times. After centrifugation and washing, the product is dried in an oven at 80°C for 24 hours to obtain fluorinated modified multi-walled carbon nanotubes.

[0063] S3, Preparation of the bottom adhesive layer: Weigh 1g of epoxy resin and 0.3g of curing agent into a beaker, add 20mL of anhydrous ethanol, and stir magnetically for 1h. Observe whether the epoxy resin and curing agent are completely dissolved in the anhydrous ethanol. After stirring evenly, solution D is obtained. After stirring, under a pressure of 3 bar, use a nozzle (nozzle diameter 3mm) to spray solution D onto the substrate surface. During this process, the spray gun is tilted at a 45° angle and the nozzle is kept 15cm above the substrate to ensure that the solution is evenly distributed on the substrate. After spraying, the substrate with the adhesive layer is pre-cured at room temperature for 1h to obtain the adhesive layer.

[0064] S4, Preparation of epoxy resin superhydrophobic coating: Weigh 1g of epoxy resin and 0.3g of curing agent into a beaker, add 10mL of anhydrous ethanol, and stir magnetically for 15min. Weigh 0.9g of fluorinated multi-walled carbon nanotubes and add them to the epoxy resin solution, stir with a magnetic stirrer for 1h. After stirring, solution E is obtained. Solution E is uniformly sprayed onto the pre-cured substrate using the spraying operation in S3. After spraying, the coating is left to cure at room temperature for 24h to obtain a double-layer embedded epoxy resin superhydrophobic coating. Figure 5As shown, droplets aggregate into spherical shapes on the surface of the epoxy superhydrophobic coating. The contact angle of the coating is measured to be 160.31 ± 0.31°.

[0065] The contact angle of the double-layer epoxy resin superhydrophobic coating prepared in Example 1 under 500 sandpaper abrasion cycles is shown in the figure. Figure 6 As shown, after 125 sandpaper abrasions, the contact angle of the epoxy resin superhydrophobic coating decreased to 141.28°. As the sandpaper abrasion continued, the contact angle of the sample surface showed a stable plateau (the contact angle was approximately 141.28°, lasting for 250 abrasions). Subsequently, as the number of abrasion cycles increased, the contact angle of the sample decreased. When the number of abrasion cycles increased to 450, another stable plateau appeared, lasting until 500 cycles, at which point the contact angle was approximately 128.18°. The sandpaper abrasion experiment shows that the epoxy resin superhydrophobic coating has high wear resistance.

[0066] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for preparing a double-layer embedded epoxy resin superhydrophobic coating, characterized in that, Includes the following steps: Step 1: Inspect and clean the base material; Step 2, Preparation of fluorinated multi-walled carbon nanotubes: First, add glacial acetic acid to deionized water to prepare a glacial acetic acid solution with a certain pH value. Then, add a certain amount of multi-walled carbon nanotube powder to the solution and stir thoroughly to obtain solution A, which is ready for use. Next, a solution of perfluorodecyltriethoxysilane was prepared with anhydrous ethanol and stirred thoroughly to obtain solution B; Finally, solution B was slowly added to solution A to obtain solution C. After magnetic stirring, centrifugation, washing, and drying, fluorinated multi-walled carbon nanotubes were obtained. Step 3, Preparation of the bottom adhesive layer: Add epoxy resin and curing agent to anhydrous ethanol, and after magnetic stirring, obtain solution D. Spray solution D onto the substrate surface cleaned in step 1, and cure at room temperature to obtain the adhesive layer. Step 4, Preparation of epoxy resin superhydrophobic coating: Add epoxy resin and curing agent to anhydrous ethanol, add fluorinated multi-walled carbon nanotubes, stir thoroughly to obtain solution E; use a spraying device to spray solution E onto the adhesive layer prepared in step 3, cure and dry at room temperature to obtain a double-layer embedded epoxy resin superhydrophobic coating.

2. The method for preparing the double-layer embedded epoxy resin superhydrophobic coating as described in claim 1, characterized in that, In step 1, the inspection and cleaning of the substrate material specifically includes: Step 1.1: Observe whether there are defects and oxide layers on the surface of the substrate material, and polish the surface of the substrate material with oxide layers; Step 1.2: Clean the polished substrate material with acetone using ultrasonic cleaning, then clean it with deionized water, and dry it after cleaning for later use.

3. The method for preparing the double-layer embedded epoxy resin superhydrophobic coating as described in claim 1, characterized in that, In step 2, the preparation of the fluorinated multi-walled carbon nanotubes specifically involves: Step 2.1: Add glacial acetic acid dropwise to 30-60 mL of deionized water to adjust the pH to 4-5, add 5-10 g of multi-walled carbon nanotube powder, stir thoroughly to obtain solution A, and set aside for use; Step 2.2: Add perfluorodecyltriethoxysilane dropwise to anhydrous ethanol. After the addition is complete, stir magnetically for 1 hour and record this as solution B. The volume fraction of perfluorodecyltriethoxysilane in anhydrous ethanol is 0.5%–1%. Step 2.3: After solutions A and B are prepared, slowly add solution B to solution A to obtain solution C. Stir magnetically, centrifuge, and wash 2-3 times to remove impurities. Place the centrifuged product at 80°C for 24 hours to obtain fluorinated modified multi-walled carbon nanotubes.

4. The method for preparing the double-layer embedded epoxy resin superhydrophobic coating as described in claim 1, characterized in that, In step 3, the preparation of the bottom adhesive layer specifically involves: Step 3.1: Add epoxy resin and curing agent to anhydrous ethanol, stir, and obtain solution D; wherein the components are used in the following proportions: the mass ratio of epoxy resin, curing agent and anhydrous ethanol is 10:3:50~100. Step 3.2: Apply solution D to the substrate surface using an air spraying device and cure for 1 hour to obtain an adhesive layer.

5. The method for preparing the double-layer embedded epoxy resin superhydrophobic coating as described in claim 1, characterized in that, In step 4, the preparation of the epoxy resin superhydrophobic coating specifically involves: Step 4.1: Add epoxy resin and curing agent to anhydrous ethanol, then add fluorinated multi-walled carbon nanotubes, and stir thoroughly to obtain solution E; wherein, the mass ratio of epoxy resin, curing agent and anhydrous ethanol is 10:3:50-60; the mass ratio of epoxy resin, curing agent and fluorinated multi-walled carbon nanotubes is 10:3:(3-9); Step 4.2: Apply solution E to the adhesive layer prepared in step 3 using a spraying device, and cure and dry at room temperature for 24 hours to obtain a double-layer embedded epoxy resin superhydrophobic coating.

6. The method for preparing the double-layer embedded epoxy resin superhydrophobic coating as described in claim 1, characterized in that, The matrix material includes carbon steel, glass, or aluminum sheet.

7. The method for preparing the double-layer embedded epoxy resin superhydrophobic coating as described in claim 1, characterized in that, The epoxy resin is GIN2 epoxy superplastic resin.

8. The method for preparing the double-layer embedded epoxy resin superhydrophobic coating as described in claim 1, characterized in that, The curing agent is a suitable AT30 slow-curing agent.

9. The method for preparing the double-layer embedded epoxy resin superhydrophobic coating as described in claim 1, characterized in that, The fluorinated multi-walled carbon nanotubes have a diameter of 10–20 nm and a length of 10–30 μm.

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