Preparation method of double-layer inlaid epoxy resin super-hydrophobic coating

Abstract

The invention provides a preparation method of a double-layer inlaid epoxy resin super-hydrophobic coating. Comprising the following steps: step 1, checking and cleaning a matrix material; step 2, preparation of a fluorinated multi-walled carbon nanotube; step 3, preparing a bottom bonding layer; step 4, adding epoxy resin and a curing agent into absolute ethyl alcohol, adding fluorinated multi-walled carbon nanotubes, and fully stirring to obtain a solution E; and spraying the solution E on the bonding layer, curing and drying. The bonding layer is made of the same material as the super-hydrophobic coating substrate, chemical reaction between the bonding layer and the super-hydrophobic coating is avoided, the phenomenon of interaction between different materials is effectively avoided, the rough structure of the surface of the coating is regulated and controlled through the design, the water contact angle of the coating is remarkably increased, and the service life of the super-hydrophobic coating is prolonged. The hydrophobic performance of the epoxy resin super-hydrophobic coating is even far better than that of a traditional super-hydrophobic coating, and the problem that the adhesive force between the epoxy resin super-hydrophobic coating and a substrate is insufficient is effectively solved.

Description

Technical Field

[0001] The invention belongs to the field of marine anticorrosion / antifouling, and in particular relates to a method for preparing a double-layer embedded epoxy resin super-hydrophobic coating. Background Art

[0002] Superhydrophobic coating is a functional coating developed based on organisms with self-cleaning phenomena in nature. Superhydrophobic coating refers to a coating with a contact angle of water droplets on its surface greater than 150° and a rolling angle less than 5°. Superhydrophobic coating has great application prospects in the fields of shipbuilding and aviation, medical treatment, construction, automobiles, etc. due to its unique characteristics: hydrophobicity, corrosion resistance, wear resistance, low adhesion, anti-icing and other properties. The preparation methods of superhydrophobic coating mainly include: physical method and chemical method; among them, the physical method is to deposit superhydrophobic materials on the surface of the substrate by physical means (spraying, sputtering, etc.); the chemical method is to form a superhydrophobic coating on the surface of the substrate by chemical reaction (sol-gel, chemical vapor deposition, electrochemical deposition, etc.).

[0003] The super-hydrophobic coating developed from bionics plays an important role in the protection field of corrosion and fouling. The synergistic effect of the microscopic rough structure and low surface free energy of the super-hydrophobic coating can induce the capture of a large amount of air between the solid-liquid surface, forming an air layer, and obtaining a stable solid-liquid-gas composite contact interface configuration. Based on this configuration, the droplet is mainly point-contacted at the interface, which can greatly reduce the actual contact area of ​​the corrosive medium and the matrix material, thereby preventing the corrosive medium from eroding the matrix material. At the same time, the air layer formed can effectively reduce the adhesion strength of marine organisms, so that the marine organisms attached to the coating can be separated from the coating surface under the impact of the water flow. However, due to the long-term immersion of the coating in a high-salt, high-humidity marine environment, the adhesion strength between the super-hydrophobic coating and the substrate will decrease after long-term seawater erosion and friction, resulting in a reduction in the protective performance of the super-hydrophobic coating. Therefore, the stability of the super-hydrophobic coating performance is also facing major problems. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a double-layer mosaic epoxy resin super-hydrophobic coating. The present invention is directed to the long-term protective performance of a super-hydrophobic coating, and proposes a method for preparing a mosaic epoxy resin super-hydrophobic coating by a double-layer structure and wet chemical surface modification and organic / inorganic composite, which effectively overcomes the problem that the super-hydrophobic coating has a reduced adhesion strength between the coating and the substrate under long-term seawater immersion conditions, improves its stability, and realizes long-term protection of the super-hydrophobic coating.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention relates to a method for preparing a double-layer embedded epoxy resin super-hydrophobic coating, comprising the following steps:

[0007] Step 1, inspecting and cleaning 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, and a certain amount of multi-walled carbon nanotube powder is added thereto. After being fully stirred, a solution A is obtained and set aside;

[0010] Secondly, prepare a perfluorodecyltriethoxysilane solution with anhydrous ethanol and stir it thoroughly to obtain solution B;

[0011] Finally, after the preparation of solution A and solution B is completed, solution B is slowly added to solution A to obtain solution C, and after magnetic stirring, centrifugation, washing, and drying, fluorinated modified multi-walled carbon nanotubes are obtained;

[0012] Step 3, preparation of the bottom bonding layer: adding epoxy resin and curing agent into anhydrous ethanol, after magnetic stirring, obtaining solution D, spraying solution D on the surface of the substrate cleaned in step 1, and curing at room temperature to obtain a bonding layer;

[0013] Step 4, preparation of epoxy resin super-hydrophobic coating: adding epoxy resin and curing agent to anhydrous ethanol, adding fluorinated multi-walled carbon nanotubes thereto, stirring thoroughly to obtain solution E; spraying solution E on the bonding layer prepared in step 3 with a spraying device, curing and drying at room temperature to obtain a double-layer mosaic epoxy resin super-hydrophobic coating.

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

[0015] 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 an oxide layer; if there are defects, replace the substrate; if there is an oxide layer, polish the substrate surface with sandpaper to remove the oxide layer;

[0016] Step 1.2, the polished base material is ultrasonically cleaned with acetone, then cleaned with deionized water, and then dried for standby use.

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

[0018] Step 2.1: Add glacial acetic acid dropwise to 30-60 mL of deionized water, adjust the pH value to 4-5, add 5-10 g of multi-walled carbon nanotube powder, add glacial acetic acid during the fluorination process to better dissolve the multi-walled carbon nanotube powder, provide an acidic environment, and promote the reaction, stir well to obtain solution A, and set aside;

[0019] Step 2.2: perfluorodecyltriethoxysilane was added dropwise to anhydrous ethanol, and after the addition was completed, magnetic stirring was performed for 1 hour, which was recorded as solution B; the fluorine-containing modifier used in this step was 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane;

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

[0021] Step 2.3: After solution A and solution B are prepared, solution B is slowly added to solution A to obtain solution C, magnetically stirred, centrifuged, and washed 2 to 3 times to remove impurities. The centrifuged product is placed 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 is specifically as follows:

[0023] Step 3.1, adding epoxy resin and curing agent into anhydrous ethanol, stirring, and obtaining solution D; wherein each component is used in the following proportion: the mass ratio of epoxy resin, curing agent and anhydrous ethanol is 10:3:(50-100);

[0024] Step 3.2, spray solution D on the surface of the substrate using an air spray device and cure for 1 hour to obtain a bonding layer.

[0025] Preferably, in step 4, the preparation of the epoxy resin super-hydrophobic coating is specifically as follows:

[0026] Step 4.1, adding epoxy resin and curing agent to anhydrous ethanol, then adding fluorinated multi-walled carbon nanotubes, and stirring thoroughly to obtain solution E; wherein the amount of each component is: 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, spraying solution E onto the bonding layer prepared in step 3 with a spraying device, curing and drying at room temperature for 24 hours to obtain a double-layer embedded epoxy resin super hydrophobic coating.

[0028] Preferably, the substrate material includes carbon steel, glass or aluminum sheet. Different substrate materials are selected to prove that the epoxy resin super-hydrophobic coating can be applied to various materials and has universal applicability.

[0029] Preferably, the epoxy resin is GIN2 epoxy flow-conducting resin, and the curing agent is an adapted AT30 slow curing agent; slow curing is performed at room temperature to prevent cracking of the coating during the drying process.

[0030] The present invention has the following advantages:

[0031] (1) The bonding layer involved in the present invention adopts the same material as the super-hydrophobic coating substrate, thereby avoiding chemical reaction between the bonding layer and the super-hydrophobic coating, and effectively avoiding the phenomenon of interaction between different materials. Through this design, the rough structure of the coating surface is regulated, so that the water contact angle of the coating is significantly improved, even far exceeding the hydrophobic performance of traditional super-hydrophobic coatings, effectively solving the problem of insufficient adhesion between the epoxy resin super-hydrophobic coating and the substrate.

[0032] (2) The present invention can significantly improve the wear resistance of the super-hydrophobic coating by introducing a strong bonding layer and an optimized rough structure. After multiple friction cycle experiments, the coating still maintains super-hydrophobicity. Compared with the single-layer super-hydrophobic coating that is easy to crack, the double-layer inlaid super-hydrophobic coating prepared by the present invention has stronger adhesion to the substrate. The strong bonding between the coating and the substrate is finally verified by testing methods such as tape stripping test, ensuring the stability and durability of the coating in practical applications.

[0033] (3) The double-layer mosaic epoxy resin super-hydrophobic coating of the present invention has good environmental stability and chemical stability, and can maintain good hydrophobic properties in air, water, and solutions of different pH values; even if exposed for a long time in a harsh environment, the coating can maintain its super-hydrophobic properties. The tightly sealed closed structure formed by the epoxy resin matrix effectively prevents corrosive substances from entering and destroying the coating, and can resist the erosion of corrosive aqueous solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the preparation of a double-layer embedded epoxy resin super-hydrophobic coating;

[0035] Figure 2 It is a static contact angle display diagram of the bonding layer in the present invention;

[0036] Figure 3 It is a test diagram of Example 1; wherein, (a) is a state diagram of a droplet on the surface of an epoxy resin super-hydrophobic coating, (b) is a contact angle effect diagram of an epoxy resin super-hydrophobic coating, (c) is a microscopic morphology diagram of the coating surface under a magnification of 50 μm; (d) is a microscopic morphology diagram of the coating surface under a magnification of 500 nm;

[0037] Figure 4 It is a test diagram of Example 2; wherein, (a) is a state diagram of a droplet on the surface of an epoxy resin super-hydrophobic coating, (b) is a contact angle effect diagram of an epoxy resin super-hydrophobic coating, (c) is a microscopic morphology diagram of the coating surface under a magnification of 100 μm, and (d) is a microscopic morphology diagram of the coating surface under a magnification of 500 nm;

[0038] Figure 5 It is a test diagram of Example 3; wherein (a) is a state diagram of a droplet on the surface of an epoxy resin super-hydrophobic coating, and (b) is a contact angle effect diagram of the epoxy resin super-hydrophobic coating;

[0039] Figure 6 The figure is a contact angle variation trend diagram of the double-layer epoxy resin super-hydrophobic coating prepared in the present invention after 500 sandpaper abrasion cycles. DETAILED DESCRIPTION

[0040] The present invention is described in detail below in conjunction with specific embodiments. It should be noted that the following embodiments are only further descriptions of the present invention, but the protection scope 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 super-hydrophobic coating, see Figure 1 As shown, the specific steps are as follows:

[0043] S1. Inspection and cleaning of substrate surface: prepare Q235 carbon steel with a size of 3×3cm and a thickness of 1mm, and observe with naked eyes whether there are cracks, gaps and other defects on the surface of the carbon steel. If there are defects, replace the substrate material with a new one; there are often oxide layers and other impurities on the surface of new substrate materials. It is necessary to first grind the substrate with 240#, 400#, and 600# sandpaper to make its surface smooth, and then ultrasonically clean it with acetone for 15 minutes, and then ultrasonically clean it with deionized water for 15 minutes. After cleaning, put the substrate into an oven to dry, and the drying temperature is set to 60°C and the drying time is 30 minutes. After the substrate is prepared, it is ready for use.

[0044] S2, surface fluorination modification of multi-walled carbon nanotubes: the multi-walled carbon nanotubes used have a diameter of about 10 to 20 nm and a length of about 10 to 30 μm; the fluorination modification is carried out in an acidic environment; 60 mL of deionized water is measured with a measuring cylinder, poured into a 500 mL beaker, and glacial acetic acid is added thereto with a rubber-tipped dropper to adjust the pH value to 4, and stirred until fully mixed; 5 g of multi-walled carbon nanotube powder is weighed, added to the above-mentioned glacial acetic acid solution, and stirred with a magnetic stirrer for 1 hour to uniformly dissolve the multi-walled carbon nanotube powder in the glacial acetic acid solution to accelerate the fluorination process, which is recorded as solution A;

[0045] Prepare a 5% perfluorodecyltriethoxysilane solution by volume. Use a measuring cylinder to measure 45 mL of anhydrous ethanol and pour it into a beaker for later use. Use a pipette to transfer 2.5 mL of perfluorodecyltriethoxysilane and slowly drop it into the anhydrous ethanol. During the dropwise addition, use a magnetic stirrer to stir the solution and mix it thoroughly. After all the dropwise addition is completed, stir it magnetically for 1 hour. This is recorded as solution B.

[0046] After the preparation of solution A and solution B, 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, the product needs to be washed with anhydrous ethanol and then centrifuged. The operation is repeated 3 times. After the centrifugal washing is completed, it is dried in an oven for 24 hours at a temperature set to 80°C to obtain fluorinated modified multi-walled carbon nanotubes;

[0047] S3, preparation of the bottom bonding layer: weigh 2g of epoxy resin and 0.6g of curing agent in a beaker, add 20mL of anhydrous ethanol, stir magnetically for 1h, observe whether the epoxy resin and curing agent are completely dissolved in the anhydrous ethanol, and stir evenly to obtain solution D. After stirring, under a pressure of 4bar, use a nozzle (nozzle diameter 3mm) to spray solution D on the surface of the substrate. During this process, the spray gun is tilted at an angle of 45° and the height between the nozzle and the substrate is kept at 15cm to ensure that the solution is evenly distributed on the substrate. After spraying, the substrate coated with the bonding layer is placed at room temperature for pre-curing for 1h to obtain the bonding layer. Figure 2 As shown, the contact angle of the bonding layer was measured to be 76.10±0.29°.

[0048] S4, preparation of epoxy resin super hydrophobic coating: weigh 1g epoxy resin and 0.3g curing agent in a beaker, add 10mL anhydrous ethanol, stir magnetically for 15min, weigh 0.3g fluorinated multi-walled carbon nanotubes and add them to the epoxy resin solution, stir with a magnetic stirrer for 1h, after stirring, obtain solution E, spray solution E evenly on the substrate after pre-curing through the spraying operation in S3, after spraying, place the coating at room temperature for 24h to obtain a double-layer mosaic epoxy resin super hydrophobic coating. Figure 3 As shown in the figure, the droplets gathered into spheres on the surface of the epoxy resin super-hydrophobic coating. The contact angle of the coating was measured to be 157.78±0.15°. Scanning electron microscopy was used to observe that a large number of papillary protrusions appeared on the coating surface, and there were filamentous substances inside the papillary structures, which indicated that the epoxy resin super-hydrophobic coating had a large surface roughness, which increased its non-wettability and achieved super-hydrophobic properties.

[0049] Example 2

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

[0051] S1, inspection and cleaning of the substrate surface: prepare Q235 carbon steel with a size of 3×3cm and a thickness of 1mm, and observe with the naked eye whether there are cracks, gaps and other defects on the surface of the carbon steel. If there are defects, replace the new substrate material. There are often oxide layers and other impurities on the surface of the new substrate material. It is necessary to first grind the substrate with 240#, 400#, and 600# sandpaper to make the surface flat, and then ultrasonically clean it with acetone for 15 minutes, and then ultrasonically clean it with deionized water for 15 minutes. After cleaning, put the substrate into the oven to dry, the drying temperature is set to 60℃, and the drying time is 30 minutes. After the substrate is prepared, it is ready for use.

[0052] S2, surface fluorination modification of multi-walled carbon nanotubes: The multi-walled carbon nanotubes used in the present invention have a diameter of about 10 to 20 nm and a length of about 10 to 30 μm; the fluorination modification is carried out in an acidic environment; 60 mL of deionized water is measured with a measuring cylinder, poured into a 500 mL beaker, and glacial acetic acid is added thereto with a rubber-tipped dropper to adjust the pH value to 4, and stirred until fully mixed. Weigh 5 g of multi-walled carbon nanotube powder, add it to the above-mentioned glacial acetic acid solution, and stir it with a magnetic stirrer for 1 hour to uniformly dissolve the multi-walled carbon nanotubes in the glacial acetic acid solution to accelerate the fluorination process, which is recorded as solution A;

[0053] Prepare a 5% volume fraction perfluorodecyltriethoxysilane solution, use a measuring cylinder to measure 45 mL of anhydrous ethanol, pour it into a beaker for later use, use a pipette to transfer 2.5 mL of perfluorodecyltriethoxysilane, and slowly add it dropwise to the anhydrous ethanol. During the addition, use a magnetic stirrer to stir the solution and mix it thoroughly. After all the addition is completed, stir magnetically for 1 hour. Record it as solution B.

[0054] After the preparation of solution A and solution B, 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, the product needs to be washed with anhydrous ethanol and then centrifuged. The operation is repeated 3 times. After the centrifugal washing is completed, it is dried in an oven for 24 hours at 80°C to obtain fluorinated modified multi-walled carbon nanotubes;

[0055] S3, preparation of the bottom bonding layer: weigh 2g of epoxy resin and 0.6g of curing agent in a beaker, add 20mL of anhydrous ethanol, stir magnetically for 1h, observe whether the epoxy resin and curing agent are completely dissolved in the anhydrous ethanol, and stir evenly to obtain solution D. After stirring, spray solution D on the surface of the substrate using a nozzle (nozzle diameter 3mm) at an air pressure of 4bar. During this process, the spray gun is tilted at an angle of 45° and the height between the nozzle and the substrate is kept at 15cm to ensure that the solution is evenly distributed on the substrate. After spraying, the substrate coated with the bonding layer is pre-cured at room temperature for 1h to obtain the bonding layer;

[0056] S4, preparation of epoxy resin super hydrophobic coating: weigh 1g epoxy resin and 0.3g curing agent in a beaker, add 10mL 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, and after stirring, obtain solution E. Spray solution E evenly on the pre-cured substrate through the spraying operation in S3. After spraying, place the coating at room temperature for 24h to obtain a double-layer mosaic epoxy resin super hydrophobic coating. Figure 4 As shown, the droplets aggregated into spheres on the surface of the epoxy resin superhydrophobic coating. The contact angle of the coating was measured to be 158.60±0.80°. Scanning electron microscopy observed an increase in the number of papillary protrusions on the coating surface, which indicates that increasing the content of fluorinated multi-walled carbon nanotubes will improve the non-wettability of the epoxy resin superhydrophobic coating.

[0057] Example 3

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

[0059] S1, inspection and cleaning of the substrate surface: prepare Q235 carbon steel with a size of 3×3cm and a thickness of 1mm, and observe with the naked eye whether there are cracks, gaps and other defects on the surface of the carbon steel. If there are defects, replace the new substrate material. There are often oxide layers and other impurities on the surface of the new substrate material. It is necessary to first grind the substrate with 240#, 400#, and 600# sandpaper to make the surface flat, and then ultrasonically clean it with acetone for 15 minutes, and then ultrasonically clean it with deionized water for 15 minutes. After cleaning, put the substrate into the oven to dry, the drying temperature is set to 60℃, and the drying time is 30 minutes. After the substrate is prepared, it is ready for use.

[0060] S2, surface fluorination modification of multi-walled carbon nanotubes: The multi-walled carbon nanotubes used have a diameter of about 10 to 20 nm and a length of about 10 to 30 μm; the fluorination modification is carried out in an acidic environment; 60 mL of deionized water is measured with a measuring cylinder, poured into a 500 mL beaker, and glacial acetic acid is added to it with a rubber-tipped dropper to adjust the pH value to about 3, and stirred until fully mixed. Weigh 5 g of multi-walled carbon nanotube powder, add it to the above-mentioned glacial acetic acid solution, and stir it with a magnetic stirrer for 1 hour to evenly dissolve the multi-walled carbon nanotubes in the glacial acetic acid solution to accelerate the fluorination process, which is recorded as solution A;

[0061] Prepare a 5% perfluorodecyltriethoxysilane solution by volume. Use a measuring cylinder to measure 45 mL of anhydrous ethanol and pour it into a beaker for later use. Use a pipette to transfer 2.5 mL of perfluorodecyltriethoxysilane and slowly drop it into the anhydrous ethanol. During the dropwise addition, use a magnetic stirrer to stir the solution to fully mix the two. After all the dropwise addition is completed, stir magnetically for 1 hour. This is recorded as solution B.

[0062] After the preparation of solution A and solution B, 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 completely fluorinate 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, the product needs to be washed with anhydrous ethanol and then centrifuged. The operation is repeated 3 times. After the centrifugal washing is completed, it is dried in an oven for 24 hours at 80°C to obtain fluorinated modified multi-walled carbon nanotubes.

[0063] S3, preparation of the bottom bonding layer: weigh 1g of epoxy resin and 0.3g of curing agent in a beaker, add 20mL of anhydrous ethanol, stir magnetically for 1h, observe whether the epoxy resin and curing agent are completely dissolved in the anhydrous ethanol, and stir evenly to obtain solution D. After stirring, spray solution D on the surface of the substrate using a nozzle (nozzle diameter 3mm) at an air pressure of 3bar. During this process, the spray pen is tilted at an angle of 45° and the height between the nozzle and the substrate is kept at 15cm to ensure that the solution is evenly distributed on the substrate. After spraying, the substrate coated with the bonding layer is pre-cured at room temperature for 1h to obtain the bonding layer;

[0064] S4, preparation of epoxy resin super hydrophobic coating: weigh 1g epoxy resin and 0.3g curing agent in a beaker, add 10mL 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 for 1h with a magnetic stirrer, and after stirring, obtain solution E. Spray solution E evenly on the pre-cured substrate through the spraying operation in S3. After spraying, place the coating at room temperature for 24h to obtain a double-layer mosaic epoxy resin super hydrophobic coating. Figure 5As shown, the droplets aggregated into spheres on the surface of the epoxy resin superhydrophobic coating. After measurement, the contact angle of the coating was 160.31±0.31°.

[0065] The contact angle variation trend of the double-layer epoxy resin super-hydrophobic coating prepared in Example 1 is shown in Figure 2 after 500 sandpaper abrasion cycles. Figure 6 As shown in the figure, after 125 times of sandpaper abrasion, the contact angle of the epoxy resin super hydrophobic coating has been reduced to 141.28°. The sandpaper abrasion continues. At this time, the contact angle of the sample surface presents a stable platform (the contact angle is about 141.28°, which lasts for 250 times). Subsequently, the number of abrasions continues to increase, and the contact angle of the sample decreases. When the number of abrasions increases to 450 times, a stable platform appears again, which lasts to 500 times, and the contact angle is about 128.18°. The sandpaper abrasion experiment shows that the epoxy resin super hydrophobic coating has high wear resistance.

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

Claims

1. A method for preparing a double-layer embedded epoxy resin super-hydrophobic coating, characterized in that, The following steps are involved: Step 1, inspecting and cleaning the base material; Step 2, preparation of fluorinated multi-walled carbon nanotubes: 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 added thereto, and the mixture is stirred thoroughly to obtain a solution A for standby use; Secondly, prepare a perfluorodecyltriethoxysilane solution with anhydrous ethanol and stir it thoroughly to obtain solution B; Finally, solution B is slowly added to solution A to obtain solution C, which is magnetically stirred, centrifuged, washed, and dried to obtain fluorinated multi-walled carbon nanotubes; Step 3, preparation of the bottom bonding layer: adding epoxy resin and curing agent into anhydrous ethanol, after magnetic stirring, obtaining solution D, spraying solution D on the surface of the substrate cleaned in step 1, and curing at room temperature to obtain a bonding layer; Step 4, preparation of epoxy resin super-hydrophobic coating: adding epoxy resin and curing agent to anhydrous ethanol, adding fluorinated multi-walled carbon nanotubes thereto, stirring thoroughly to obtain solution E; spraying solution E on the bonding layer prepared in step 3 with a spraying device, curing and drying at room temperature to obtain a double-layer mosaic epoxy resin super-hydrophobic coating.

2. The preparation method of double-layer mosaic type epoxy resin super-hydrophobic coating as claimed in claim 1, characterized in that, In step 1, the inspection and cleaning of the base material is specifically as follows: Step 1.1, observe whether there are defects and oxide layers on the surface of the base material, and polish the surface of the base material with the oxide layer; Step 1.2, the polished base material is ultrasonically cleaned with acetone, then cleaned with deionized water, and then dried for standby use.

3. the preparation method of double-layer mosaic type epoxy resin super hydrophobic coating as claimed in claim 1, is characterized in that, In step 2, the preparation of the fluorinated multi-walled carbon nanotubes is specifically as follows: Step 2.1, add glacial acetic acid dropwise to 30-60 mL of deionized water to adjust the pH value to 4-5, add 5-10 g of multi-walled carbon nanotube powder, stir well, and obtain solution A for standby use; Step 2.2, perfluorodecyltriethoxysilane was added dropwise to anhydrous ethanol, and after the addition was completed, magnetic stirring was performed for 1 hour, which was recorded as solution B; Wherein, the volume fraction of perfluorodecyltriethoxysilane in anhydrous ethanol is 0.5-1%; Step 2.3, after solution A and solution B are prepared, solution B is slowly added to solution A to obtain solution C, magnetically stirred, centrifuged, and washed 2 to 3 times to remove impurities, and the centrifuged product is placed at 80° C. for 24 hours to obtain fluorinated modified multi-walled carbon nanotubes.

4. The preparation method of double-layer mosaic type epoxy resin super-hydrophobic coating as claimed in claim 1, characterized in that, In step 3, the preparation of the bottom bonding layer is specifically as follows: Step 3.1, adding epoxy resin and curing agent into anhydrous ethanol, stirring, and obtaining 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, spray solution D on the surface of the substrate using an air spray device and cure for 1 hour to obtain a bonding layer.

5. The preparation method of double-layer mosaic type epoxy resin super-hydrophobic coating as claimed in claim 1, characterized in that, In step 4, the preparation of the epoxy resin super-hydrophobic coating is specifically as follows: Step 4.1, adding epoxy resin and curing agent to anhydrous ethanol, then adding fluorinated multi-walled carbon nanotubes, and stirring thoroughly to obtain solution E; wherein the amount of each component is: 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, spraying solution E onto the bonding layer prepared in step 3 with a spraying device, curing and drying at room temperature for 24 hours to obtain a double-layer embedded epoxy resin super hydrophobic coating.

6. The preparation method of double-layer mosaic epoxy resin super-hydrophobic coating as claimed in claim 1, characterized in that, The base material includes carbon steel, glass or aluminum sheet.

7. The preparation method of double-layer mosaic epoxy resin super-hydrophobic coating as claimed in claim 1, characterized in that, The epoxy resin is GIN2 epoxy flow-conducting resin.

8. The preparation method of double-layer mosaic epoxy resin super-hydrophobic coating as claimed in claim 1, characterized in that, The curing agent is an adapted AT30 slow curing agent.

9. The preparation method of double-layer mosaic epoxy resin super-hydrophobic coating as claimed in claim 1, characterized in that, The fluorinated multi-walled carbon nanotube has a diameter of 10 to 20 nm and a length of 10 to 30 μm.

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