Preparation method of nano super-hydrophobic material

Abstract

The invention provides a preparation method of a nano super-hydrophobic material. The preparation method comprises the following steps: firstly, selecting nano silicon dioxide particles with the particle size of 20-50 nanometers, and matching the nano silicon dioxide particles with heptadecafluorodecyl trimethoxysilane and other raw materials; the nano silicon dioxide particles are subjected to surface modification for 3-5 hours at 40-60 DEG C by controlling the volume ratio of absolute ethyl alcohol to deionized water to be (3-5): 1 and the mass ratio of the long-chain alkyl silane coupling agent to the nano silicon dioxide particles to be (0.5-1.5): 1. Adding 0.1-0.5% hydrochloric acid or sulfuric acid for catalysis, and stirring at room temperature for 2-4 hours to form a sol-gel system; ultrasonically cleaning the substrate, activating with a sodium hydroxide solution, coating by a spraying, dip-coating or spin-coating method, and drying and curing at 60-80 DEG C for 2-3 hours to obtain a finished product. The water contact angle of the prepared material is not lower than 150 degrees, the rolling angle is not higher than 5 degrees, the performance is stable in the environment with the temperature ranging from-20 DEG C to 80 DEG C and the humidity ranging from 20% to 90%, and the water contact angle is still not lower than 140 degrees after more than 500 times of abrasive paper friction tests.

Description

Technical Field

[0001] The present invention relates to a preparation method of a nano superhydrophobic material. Background Art

[0002] In the field of materials science, nano superhydrophobic materials have broad application prospects in many industries due to their excellent properties such as waterproof and anti-fouling. However, there are many problems in the existing preparation methods of nano superhydrophobic materials, which limit the improvement of their performance and wide application.

[0003] From the perspective of raw materials, the particle size of the nano-particles selected by the traditional preparation method is poorly controlled, with a wide range and often exceeding the optimal range of 20 - 50 nanometers, making it difficult to form an ideal micro-rough structure, resulting in limited superhydrophobic performance. At the same time, the selection of long-chain alkyl silane coupling agents is limited by their chemical structure and surface energy characteristics. For example, commonly used short-chain or non-fluorinated coupling agents (such as octyltriethoxysilane) have a relatively high surface energy, and it is difficult to significantly reduce the surface energy of the material after grafting, resulting in a water contact angle usually lower than 150°. In addition, the existing technology lacks optimization of the grafting efficiency of the coupling agent, and there is a lack of precise control over the volume ratio of absolute ethanol to deionized water, the mass ratio of long-chain alkyl silane coupling agent to nano-particles, etc., unable to provide a suitable environment for the reaction, resulting in uneven grafting or degradation of the coupling agent, and unable to fully utilize its low surface energy advantage.

[0004] In terms of the preparation process, in the surface modification step, the reaction temperature and time are not accurately controlled. If the temperature is too high or the time is too long, it is easy to cause excessive condensation of the coupling agent or agglomeration of nano-particles; if the temperature is too low or the time is too short, the grafting reaction is insufficient, and it is difficult to form a stable and uniform low-surface-energy modification layer. When preparing the sol-gel, the type of catalyst is single and the dosage is inaccurate, unable to effectively promote the dispersion and reaction of nano-particles, resulting in an unstable sol-gel system and affecting the uniformity and stability of the coating. The substrate pretreatment is rough and the cleaning method is simple, making it difficult to completely remove oil stains and impurities; the activation treatment is not in place, and the adhesion between the substrate and the coating is insufficient, resulting in easy peeling of the coating and reducing the durability of the material. During the coating preparation process, the process parameters of spraying, dipping, spin coating, etc. lack fine regulation, unable to ensure uniform coating thickness, and thus affecting the overall performance of the material.

[0005] In terms of the performance of the finished product, the water contact angle of the existing nano superhydrophobic materials is usually lower than 150°, and the rolling angle is greater than 5°, resulting in poor waterproof and anti-fouling effects. Under different environmental temperatures and humidities, the performance fluctuates greatly, and it is impossible to maintain stable superhydrophobic performance under the wide conditions of -20°C - 80°C and humidity of 20% - 90%. Moreover, the wear resistance is poor, and after a small amount of sandpaper friction test, the water contact angle drops significantly, making it difficult to meet the requirements of long-term use and easy-to-friction scenarios such as industrial equipment and transportation vehicles. Summary of the Invention

[0006] The object of the present invention is to provide a preparation method of a nano superhydrophobic material, which breaks through the traditional limitations through the combined innovation of "specific coupling agent + process optimization" to solve the problems raised in the above-mentioned background technology.

[0007] To solve the above technical problems, the technical solution provided by the present invention is: a preparation method of a nano superhydrophobic material, comprising the following steps:

[0008] Prepare raw materials: Select nano-silica particles, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-heptadecafluorodecyltrimethoxysilane, absolute ethanol, deionized water and an organic solvent. The particle size range of the nano-silica particles is 20-50 nanometers.

[0009] Surface modification of nano-silica particles: Disperse the nano-silica particles in a mixed solution of absolute ethanol and deionized water to form a uniform suspension. Add 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-heptadecafluorodecyltrimethoxysilane to the suspension and stir and react at a temperature of 40-60 °C for 3-5 hours to graft 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-heptadecafluorodecyltrimethoxysilane onto the surface of the nano-silica particles.

[0010] Sol-gel preparation: Disperse the surface-modified nano-silica particles in an organic solvent, add a catalyst, and stir and react at room temperature for 2-4 hours to form a stable sol-gel system.

[0011] Substrate pretreatment: Clean and activate the substrate to be coated, remove surface impurities and oil stains, and enhance the active sites on the substrate surface.

[0012] Coating preparation: Uniformly coat the sol-gel system on the surface of the pretreated substrate by spraying, dip coating or spin coating, and then dry and cure at a temperature of 60-80 °C for 2-3 hours to obtain the nano superhydrophobic material.

[0013] Preferably, in the step of preparing raw materials, the organic solvent is toluene or xylene.

[0014] Preferably, in the step of surface modification of nano-silica particles, the volume ratio of absolute ethanol to deionized water is (3-5):1, and the mass ratio of 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-heptadecafluorodecyltrimethoxysilane to nano-silica particles is (0.5-1.5):1.

[0015] Preferably, in the step of sol-gel preparation, the catalyst is hydrochloric acid or sulfuric acid, and the addition amount of the catalyst is 0.1%-0.5% of the total mass of the sol-gel system.

[0016] Preferably, in the substrate pretreatment step, the cleaning method is ultrasonic cleaning, and the substrate is ultrasonically cleaned with acetone and ethanol for 15 - 30 minutes each; the activation treatment is to immerse the substrate in a sodium hydroxide solution with a concentration of 0.1 - 0.5 mol / L for 10 - 20 minutes.

[0017] Preferably, in the coating preparation step, when using the spraying method, the pressure of the spray gun is controlled at 0.2 - 0.4 MPa, and the spraying distance is 15 - 25 cm; when using the dip coating method, the dip coating speed is 1 - 3 cm / min; when using the spin coating method, the spin coating speed is 1000 - 3000 r / min, and the spin coating time is 30 - 60 seconds.

[0018] Preferably, the water contact angle of the prepared nano - superhydrophobic material is not less than 150°, and the rolling angle is not higher than 5°.

[0019] The advantages of the present invention are as follows: the advantage of precise raw material screening and ratio

[0020] Properties of nano - silica particles: Nano - silica particles with a particle size in the range of 20 - 50 nm are selected. This particle size range can effectively construct a micro - rough structure after forming the coating. This micro - structure and the subsequent modified low - surface - energy substances act synergistically, greatly enhancing the superhydrophobic performance of the material. The smaller particle size can provide a larger specific surface area, which is beneficial to the grafting of long - chain alkylsilane coupling agents, thereby increasing the number of hydrophobic groups on the surface.

[0021] Selection of long - chain alkylsilane coupling agent: Tridecafluoro - 1,1,2,2 - tetrahydrooctyltrimethoxysilane is used as the long - chain alkylsilane coupling agent. Its molecular structure contains multiple fluorine atoms, and fluorine atoms have an extremely low surface energy. This significantly reduces the surface energy of the grafted nano - silica particles, making it difficult for water to adhere to their surface and greatly improving the hydrophobic performance of the material. At the same time, the trimethoxysilane part can chemically react with the hydroxyl groups on the surface of nano - silica particles to form stable chemical bonds, ensuring that the coupling agent is firmly grafted on the particle surface.

[0022] Ratio of solvent to other raw materials: In the surface modification step of nano - silica particles, the volume ratio of anhydrous ethanol to deionized water is controlled at (3 - 5):1. This ratio can not only ensure the good dispersion of nano - silica particles in the mixed solution but also provide a suitable environment for the hydrolysis and condensation reactions of long - chain alkylsilane coupling agents. The mass ratio of long - chain alkylsilane coupling agent to nano - silica particles is (0.5 - 1.5):1. After a large number of experiments, this ratio can make the nano - silica particle surface fully and evenly grafted with the coupling agent, thus achieving the best hydrophobic effect.

[0023] The advantage of a fine preparation process

[0024] Surface modification process: The surface modification of nano-silica particles is carried out by stirring and reacting at a temperature of 40 - 60 °C for 3 - 5 hours. This temperature and time range can not only ensure the full progress of the hydrolysis and grafting reactions of the long-chain alkyl silane coupling agent, but also avoid the over-condensation of the coupling agent or the agglomeration of nano-silica particles caused by too high temperature or too long reaction time. By precisely controlling the reaction conditions, it is ensured that the low-surface-energy coupling agent molecules are evenly grafted onto the surface of the nano-silica particles, laying a foundation for the subsequent formation of a superhydrophobic coating.

[0025] Sol-gel preparation process: In the sol-gel preparation step, hydrochloric acid or sulfuric acid is selected as the catalyst, and the addition amount is 0.1% - 0.5% of the total mass of the sol-gel system. These two catalysts can effectively promote the dispersion and reaction of the surface-modified nano-silica particles in the organic solvent to form a stable sol-gel system. By precisely controlling the type and amount of the catalyst, the formation rate and network structure of the sol-gel can be regulated to ensure the uniformity and stability of the coating. Stir and react at room temperature for 2 - 4 hours, which can not only make the reaction proceed fully, but also avoid the too fast volatilization of the solvent or the instability of the system caused by too high reaction temperature.

[0026] Substrate pretreatment process: Ultrasonic cleaning is adopted, and the substrate is ultrasonically cleaned with acetone and ethanol in turn for 15 - 30 minutes each, which can effectively remove pollutants such as oil stains, impurities and dust on the substrate surface and ensure the cleanliness of the substrate surface. Subsequently, the substrate is soaked in a sodium hydroxide solution with a concentration of 0.1 - 0.5 mol / L for 10 - 20 minutes for activation treatment. The sodium hydroxide solution can react with metal oxides or other impurities on the substrate surface to form active sites, enhance the adhesion between the substrate and the sol-gel coating, ensure that the coating adheres firmly to the substrate surface, and improve the overall stability and durability of the nano-superhydrophobic material.

[0027] Coating preparation process: In the coating preparation step, the process parameters are precisely controlled according to different coating methods. When using the spraying method, the pressure of the spray gun is controlled at 0.2 - 0.4 MPa, and the spraying distance is 15 - 25 cm, which can ensure that the sol-gel system is evenly sprayed on the substrate surface to form a coating with a uniform thickness. When using the dip-coating method, the dip-coating speed is 1 - 3 cm / min. This speed can not only ensure that the substrate is fully immersed in the sol-gel system, but also control the thickness of the coating. When using the spin-coating method, the spin-coating speed is 1000 - 3000 r / min, and the spin-coating time is 30 - 60 seconds. By precisely controlling the spin-coating speed and time, a coating with a uniform thickness and meeting the requirements can be obtained. Dry and cure at a temperature of 60 - 80 °C for 2 - 3 hours. This temperature and time range can not only make the solvent volatilize fully, but also further crosslink and cure the chemical bonds in the sol-gel system to form a stable superhydrophobic coating structure.

[0028] Excellent finished product performance advantages

[0029] Outstanding superhydrophobic performance: The water contact angle of the prepared nano-superhydrophobic material is not less than 150°, and the rolling angle is not higher than 5°, indicating that water is almost spherical on the surface of this material and can roll easily. This excellent superhydrophobic performance enables the material to have excellent waterproof and anti-fouling effects, effectively resisting the erosion of external moisture and stains, and is widely used in fields such as building facades, automotive glass, textiles, etc., extending the service life of the material and reducing the cleaning and maintenance costs.

[0030] Strong environmental adaptability: The nano-superhydrophobic material maintains stable superhydrophobic performance under different environmental temperatures (-20°C - 80°C) and humidities (20% - 90%). This benefits from its carefully designed raw material formula and preparation process, making the coating structure stable and able to adapt to different environmental conditions. Whether in the cold winter or the hot summer, in a humid environment or a dry environment, the material can continuously exert its superhydrophobic effect, broadening its application scenarios, such as having important application values in outdoor buildings, marine equipment and other fields.

[0031] Good abrasion resistance: After more than 500 times of sandpaper friction tests, the water contact angle is still not less than 140°, indicating that the nano-superhydrophobic material has good abrasion resistance. This is because during the preparation process, by precisely controlling the parameters of each step, the coating has a strong adhesion to the substrate, and the coating itself has a certain flexibility and strength. Even after multiple frictions, the coating structure can still remain relatively intact and maintain its superhydrophobic performance, making it have obvious advantages in surface protection of occasions that need to be used for a long time and are easily subject to friction, such as industrial equipment, transportation tools, etc. Specific implementation manners

[0032] For the purposes of the following detailed description, it should be understood that the present invention may take various alternative variations and step sequences, unless explicitly specified to the contrary. In addition, except in any operating examples, or otherwise indicated, all numbers representing the amounts of ingredients used in the specification and claims should be understood to be modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in accordance with the number of reported significant digits and by applying ordinary rounding techniques.

[0033] While the numerical ranges and parameters setting forth the broad scope of the present invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in their respective test measurements.

[0034] In addition, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of "1 to 10" is intended to include all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

[0035] Example 1: Preparation of superhydrophobic coating for architectural glass

[0036] Prepare raw materials: Select nano-silica particles with a particle size of 30 nanometers, and 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-heptadecafluorodecyltrimethoxysilane as the long-chain alkylsilane coupling agent, and anhydrous ethanol, deionized water, and toluene as organic solvents. Prepare the dosage of each raw material according to the volume ratio of anhydrous ethanol to deionized water of 4:1 and the mass ratio of the long-chain alkylsilane coupling agent to nano-silica particles of 1:1.

[0037] Surface modification of nano-silica particles: Disperse the nano-silica particles in a mixed solution of anhydrous ethanol and deionized water prepared according to the ratio to form a suspension. Add 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-heptadecafluorodecyltrimethoxysilane to the suspension and stir and react at a temperature of 50 °C for 4 hours to allow the coupling agent to be fully grafted onto the surface of the nano-silica particles.

[0038] Sol-gel preparation: Disperse the surface-modified nano-silica particles in toluene, add hydrochloric acid accounting for 0.3% of the total mass of the sol-gel system as a catalyst, and stir and react at room temperature for 3 hours to obtain a stable sol-gel system.

[0039] Substrate pretreatment: Ultrasonically clean the architectural glass substrate, first ultrasonically clean with acetone for 20 minutes, and then ultrasonically clean with ethanol for 20 minutes to remove surface oil stains and impurities. Then immerse the glass substrate in a sodium hydroxide solution with a concentration of 0.3 mol / L for 15 minutes for activation treatment to enhance the surface active sites of the substrate.

[0040] Coating preparation: Coat the sol-gel system on the surface of the pretreated architectural glass substrate by spraying. Set the spray gun pressure to 0.3 MPa and control the spraying distance at 20 cm to ensure a uniform coating. After coating, dry and cure the glass at a temperature of 70 °C for 2.5 hours. The finally prepared nano-superhydrophobic material is coated on the glass, the water contact angle reaches 155°, and the rolling angle is 3°. Under the conditions of daily rainwashing and stain contamination, the glass surface always remains clean, effectively reducing the number of cleaning times.

[0041] In the comparative experiment, when octyltriethoxysilane (non-fluorinated coupling agent) was used as the coupling agent, the water contact angle was only 142° and the rolling angle was 8°. When heptadecafluorodecyltrimethoxysilane was used, but the reaction temperature was set at 30 °C and the reaction time was shortened to 2 hours, the water contact angle was 148° and the rolling angle was 6°, and the coating uniformity was poor with cracks appearing locally. This difference is due to the low surface energy characteristics of the fluorinated coupling agent, which, combined with the optimized grafting process of the present invention, makes its performance significantly superior to that of traditional coupling agents.

[0042] Example 2: Superhydrophobic protection of automotive metal components

[0043] Prepare raw materials: Select nano-silica particles with a particle size of 40 nm. The long-chain alkylsilane coupling agent is still heptadecafluorodecyltrimethoxysilane, and xylene is used as the organic solvent. The volume ratio of absolute ethanol to deionized water is set at 3.5:1, and the mass ratio of the long-chain alkylsilane coupling agent to the nano-silica particles is 1.2:1.

[0044] Surface modification of nano-silica particles: The nano-silica particles are uniformly dispersed in a mixed solution of absolute ethanol and deionized water. After adding heptadecafluorodecyltrimethoxysilane, the mixture is stirred and reacted at 45 °C for 4.5 hours to complete the surface modification of the nano-silica particles.

[0045] Sol-gel preparation: The modified nano-silica particles are dispersed in xylene, and 0.2% of sulfuric acid based on the total mass of the system is added as a catalyst, and the mixture is stirred and reacted at room temperature for 2.5 hours to form a stable sol-gel system.

[0046] Substrate pretreatment: The automotive metal component substrate is first ultrasonically cleaned with acetone for 15 minutes, and then ultrasonically cleaned with ethanol for 25 minutes to thoroughly remove surface impurities. Then it is immersed in a 0.2 mol / L sodium hydroxide solution for 18 minutes for activation to improve the adhesion between the substrate and the coating.

[0047] Coating preparation: Using the dip coating method, the dipping speed is controlled at 2 cm / min, and the automotive metal components are immersed in the sol-gel system for coating. After coating, it is dried and cured at 65 °C for 2 hours. After testing, the water contact angle of this nano-superhydrophobic material on the surface of automotive metal components is 153° and the rolling angle is 4°. After simulating 500 times of sand and wind friction, the contact angle is still ≥145° and the rolling angle is ≤6°; the adhesion between the coating and the metal substrate is strong, and it reaches grade 4B through the cross-cut test (ASTM D3359). After testing in different temperature and humidity environments and simulating the sand and wind friction during multiple automotive driving processes, the superhydrophobic performance remains stable, effectively protecting the metal components from rainwater corrosion and extending the service life of the components.

[0048] In the comparative experiment, when methyltrimethoxysilane (short-chain coupling agent) was used as the coupling agent, the water contact angle was 138° and the rolling angle was 9°. After simulating 100 times of sand and wind friction, the contact angle decreased to 120°. By changing the solution ratio to make the volume ratio of absolute ethanol to deionized water 2:1, nanoparticle aggregation occurred, the water contact angle was 145°, the rolling angle was 7°, the coating adhesion was poor and it was easy to fall off. This difference is due to the optimized solvent ratio and the characteristics of the fluorinated coupling agent itself, thus significantly enhancing the wear resistance and adhesion of the coating.

[0049] Example 3: Superhydrophobic finishing of textiles

[0050] Prepare raw materials: Select nano-silica particles with a particle size of 25 nm, use 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-heptadecafluorodecyltrimethoxysilane as the long-chain alkylsilane coupling agent, and use absolute ethanol, deionized water and toluene as organic solvents. Set the volume ratio of absolute ethanol to deionized water to 3:1, and the mass ratio of the long-chain alkylsilane coupling agent to the nano-silica particles to 0.8:1.

[0051] Surface modification of nano-silica particles: Disperse the nano-silica particles in the mixed solution of absolute ethanol and deionized water with the above ratio to form a uniform suspension. Add 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-heptadecafluorodecyltrimethoxysilane and stir and react at a temperature of 48 °C for 3.5 hours to allow the coupling agent to be fully grafted onto the surface of the nano-silica particles.

[0052] Sol-gel preparation: Disperse the surface-modified nano-silica particles in toluene, add hydrochloric acid accounting for 0.4% of the total mass of the sol-gel system as a catalyst, and stir and react at room temperature for 2.8 hours to form a stable sol-gel system.

[0053] Substrate pretreatment: Put the textile substrate into acetone and ultrasonically clean it for 15 minutes, then put it into ethanol and ultrasonically clean it for 20 minutes to remove the oil stains, impurities and residues of auxiliaries in the textile processing process. Then soak the textile in a sodium hydroxide solution with a concentration of 0.4 mol / L for 12 minutes for activation treatment to increase the active groups on the substrate surface and improve the bonding force with the coating.

[0054] Coating preparation: Adopt the dip-coating method, immerse the textile into the sol-gel system at a speed of 1.5 cm / min to ensure that the textile uniformly adsorbs the sol-gel. After taking it out, dry and cure it at a temperature of 75 °C for 2.2 hours. After testing, the water contact angle of the treated textile reaches 152° and the rolling angle is 4.5°. After washing 50 times, the contact angle is still ≥145° and the rolling angle ≤7°; the coating uniformly covers the fiber surface, and scanning electron microscopy (SEM) shows that the nanoparticles are evenly distributed. After multiple washes and daily wearing and friction, it can still maintain good superhydrophobic performance, effectively prevent water and stains from contaminating, and improve the durability and easy cleanability of the textile.

[0055] In the comparative experiment, when dodecyltrimethoxysilane (a non-fluorinated coupling agent) was used, the water contact angle was 135° and the rolling angle was 10°. After washing 10 times with water, the contact angle decreased to 110°. When the dip-coating speed was increased to 5 cm / min, the water contact angle was 140° and the rolling angle was 8°, resulting in uneven coating thickness and hydrophobic failure in local areas. This difference stems from the combination of a specific fluorinated coupling agent and a precise dip-coating process, thus achieving long-term superhydrophobic performance of textiles.

[0056] Example 4: Preparation of a protective coating for outdoor power equipment

[0057] Prepare raw materials: Select nano-silica particles with a particle size of 45 nm, and 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-heptadecafluorodecyltrimethoxysilane as the long-chain alkylsilane coupling agent. The organic solvent is xylene. Mix anhydrous ethanol and deionized water at a volume ratio of 4.5:1, and set the mass ratio of the long-chain alkylsilane coupling agent to nano-silica particles to 1.4:1.

[0058] Surface modification of nano-silica particles: Disperse the nano-silica particles in the mixed solution. After adding the long-chain alkylsilane coupling agent, stir and react at a temperature of 55°C for 4.2 hours to complete the surface modification of the nano-silica particles.

[0059] Sol-gel preparation: Disperse the modified nano-silica particles in xylene, add sulfuric acid accounting for 0.15% of the total mass of the system as a catalyst, and stir and react at room temperature for 3.5 hours to obtain a stable sol-gel system.

[0060] Substrate pretreatment: For the metal substrate of outdoor power equipment, first ultrasonically clean it with acetone for 30 minutes, and then ultrasonically clean it with ethanol for 15 minutes to remove dust, oil, and oxide layers on the surface. Then soak the substrate in a sodium hydroxide solution with a concentration of 0.15 mol / L for 20 minutes for activation to enhance the adhesion between the substrate and the coating.

[0061] Coating preparation: Adopt the spraying method, set the spray gun pressure to 0.25 MPa, and keep the spraying distance at 22 cm. Uniformly spray the sol-gel system on the surface of the power equipment substrate. After spraying, dry and cure it at a temperature of 68°C for 2.8 hours. After testing, the water contact angle of this nano-superhydrophobic material on the surface of outdoor power equipment is 154°, and the rolling angle is 3.5°. After being exposed in an environment with a humidity of 90% for 60 days, the contact angle is still ≥150°, and the rolling angle ≤5°; there is no sign of corrosion after 500 hours of salt spray test (ASTM B117). After experiencing temperature changes, humidity fluctuations, and rain erosion in different seasons, the superhydrophobic performance is stable, effectively preventing problems such as short circuits and corrosion caused by moisture absorption of power equipment, and ensuring the safe and stable operation of power equipment.

[0062] In the comparative experiment, when phenyltrimethoxysilane (aromatic coupling agent) was used, the water contact angle was 130° and the rolling angle was 12°. After being placed in an environment with 90% humidity for 30 days, the contact angle decreased to 115°. The curing temperature was set at 50°C, resulting in solvent residue, with a water contact angle of 147° and a rolling angle of 6°. There were micropores on the coating surface and the corrosion resistance was poor. This difference is due to the synergistic effect of the fluorinated coupling agent and the high-temperature curing process, thus significantly improving the environmental adaptability and corrosion resistance of the coating.

[0063] As described above, it is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, should be covered within the protection scope of the present invention.

Claims

1. A preparation method of a nano superhydrophobic material, characterized in that, It includes the following steps: Prepare raw materials: Select nano-silica particles, 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, absolute ethanol, deionized water and an organic solvent. The particle size range of the nano-silica particles is 20 - 50 nanometers. Surface modification of nano-silica particles: Disperse the nano-silica particles in a mixed solution of absolute ethanol and deionized water to form a uniform suspension. Add 1H,1H,2H,2H-perfluorodecyltrimethoxysilane to the suspension and stir and react at a temperature of 40 - 60 °C for 3 - 5 hours to graft 1H,1H,2H,2H-perfluorodecyltrimethoxysilane onto the surface of the nano-silica particles. Sol-gel preparation: Disperse the surface-modified nano-silica particles in an organic solvent, add a catalyst, and stir and react at room temperature for 2 - 4 hours to form a stable sol-gel system. Substrate pretreatment: Clean and activate the substrate to be coated, remove surface impurities and oil stains, and enhance the active sites on the substrate surface. Coating preparation: Uniformly coat the sol-gel system on the surface of the pretreated substrate by spraying, dip coating or spin coating, and then dry and cure at a temperature of 60 - 80 °C for 2 - 3 hours to obtain a nano-superhydrophobic material.

2. The preparation method of the nano superhydrophobic material according to claim 1, characterized in that, In the step of preparing raw materials, the organic solvent is toluene or xylene.

3. The preparation method of the nano superhydrophobic material according to claim 1, characterized in that In the step of surface modification of nano-silica particles, the volume ratio of absolute ethanol to deionized water is (3 - 5):1, and the mass ratio of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane to nano-silica particles is (0.5 - 1.5):

1.

4. The preparation method of the nano superhydrophobic material according to claim 1, characterized in that, In the step of sol-gel preparation, the catalyst is hydrochloric acid or sulfuric acid, and the addition amount of the catalyst is 0.1% - 0.5% of the total mass of the sol-gel system.

5. The preparation method of the nano superhydrophobic material according to claim 1, characterized in that, In the step of substrate pretreatment, the cleaning method is ultrasonic cleaning, and the substrate is ultrasonically cleaned with acetone and ethanol for 15 - 30 minutes each; the activation treatment is to immerse the substrate in a sodium hydroxide solution with a concentration of 0.1 - 0.5 mol / L for 10 - 20 minutes.

6. The preparation method of the nano superhydrophobic material according to claim 1, wherein In the step of coating preparation, when using the spraying method, the pressure of the spray gun is controlled at 0.2 - 0.4 MPa, and the spraying distance is 15 - 25 cm; when using the dip coating method, the dip coating speed is 1 - 3 cm / min; when using the spin coating method, the spin coating speed is 1000 - 3000 r / min, and the spin coating time is 30 - 60 seconds.

7. The preparation method of the nano superhydrophobic material according to claim 1, characterized in that The water contact angle of the prepared nano-superhydrophobic material is not less than 150°, and the rolling angle is not higher than 5°.