High-transparency super-hydrophobic coating for outdoor atmosphere laser radome and preparation method of high-transparency super-hydrophobic coating

Abstract

The invention discloses a high-transparency super-hydrophobic coating for an outdoor atmosphere laser radome and a preparation method of the high-transparency super-hydrophobic coating. The high-transparency super-hydrophobic coating comprises a doping type modified silicon dioxide base layer, a composite coarse structure layer and a low-surface-energy modified layer which are sequentially formed on the surface of a glass base material. The doped modified silicon dioxide base layer is formed by in-situ growth of a silicon dioxide precursor, a nano zinc oxide dopant and a modifier, the composite coarse structure layer is formed by high-temperature annealing treatment of candle ash, and the low-surface-energy modified layer is formed by a composite low-surface-energy modifier. The coating has high light transmittance (greater than or equal to 90%) and excellent super-hydrophobic performance (static contact angle is greater than or equal to 160 degrees), has excellent mechanical stability and weather resistance, can effectively prevent laser radar signal attenuation caused by rainwater and pollutants, prolongs the service life of a radome, and is economical in preparation process and easy to industrialize.

Description

Technical Field

[0001] This invention relates to the field of superhydrophobic coating technology, specifically to a highly transparent superhydrophobic coating for outdoor atmospheric lidar radomes and its preparation method. Background Technology

[0002] Atmospheric lidar technology is increasingly widely used in environmental monitoring, becoming an indispensable tool. The atmospheric lidar radome (protective window) is a crucial component of the atmospheric lidar system, protecting signal transmission from interference from harsh environmental factors and ensuring the integrity of the laser signal. However, atmospheric lidar radomes are typically exposed to complex outdoor environments, facing harsh climatic conditions such as rain, dust erosion, ultraviolet radiation, corrosive media, and extreme temperatures during actual use. This makes the atmospheric lidar radome highly susceptible to contamination and physical damage, forming water films or dirt films on its surface. These contaminated films significantly increase laser beam reflection and absorption, leading to severe signal attenuation and even system malfunction. For example, in atmospheric monitoring, signal attenuation can result in inaccurate measurements of particulate matter (such as PM2.5) or aerosol distribution.

[0003] In existing technologies, superhydrophobic coatings have been attempted to be applied to optical components due to their self-cleaning properties, but there are three major technical bottlenecks: First, it is difficult to balance hydrophobicity and light transmittance. Most coatings achieve superhydrophobicity by introducing micro- and nano-scale rough structures, but this significantly reduces light transmittance. Second, they lack mechanical stability, and the coatings are prone to failure after being washed by wind and sand or wiped. Third, they lack weather resistance, and long-term ultraviolet irradiation or high and low temperature cycling will cause the surface energy to increase and the hydrophobic properties to degrade.

[0004] CN118126393B discloses a radome with a superhydrophobic nano-coating, which achieves antistatic and rapid ice / snow melting functions by introducing nano-metal particles. However, its coating design is geared towards electromagnetic shielding requirements in the aerospace field and does not consider the stringent requirements of lidar for light transmittance (≥90%). In this design, the superposition of the sealing coating and the antistatic layer increases light reflection loss, and the addition of nano-metal particles may lead to a decrease in light transmittance, failing to meet the high-precision signal transmission requirements of atmospheric lidar.

[0005] Therefore, developing a coating that combines high light transmittance (close to bare glass), superhydrophobic properties (static contact angle ≥150°), strong mechanical stability, and weather resistance has become the key to solving the problem of signal attenuation in outdoor lidar. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a highly transparent superhydrophobic coating for outdoor atmospheric lidar covers and a preparation method thereof. The coating can achieve superhydrophobic self-cleaning function while ensuring a light transmittance of more than 90%, and has excellent mechanical stability and weather resistance.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A highly transparent superhydrophobic coating for outdoor atmospheric lidar domes comprises a doped modified silica base layer, a composite rough structure layer, and a low surface energy modified layer sequentially formed on the surface of a glass substrate. The doped modified silica base layer is formed by in-situ growth of a silica precursor, a nano-zinc oxide dopant, and a modifier on the surface of the glass substrate, providing substrate adhesion and initial hydrophobicity. The composite rough structure layer is formed by candle soot deposition followed by high-temperature annealing, retaining the nanoscale rough structure while removing carbon black impurities to ensure light transmittance. The low surface energy modified layer is one or a combination of two of fluorosilanes and non-fluorosilanes, which, when combined, provide low surface energy and improve durability.

[0009] Preferably, the silica precursor is one or a combination of two of tetraethyl orthosilicate and tetramethyl orthosilicate in a mass ratio of (0.5-2):1, the modifier is one of polydimethylsiloxane, stearic acid, and 3-aminopropyltriethoxysilane, and the amount of nano zinc oxide dopant added is 0.5%-2% of the mass of the silica precursor.

[0010] Preferably, the high-temperature annealing conditions for the composite rough structure layer are: holding at 440-500℃ for 2 hours, with a heating rate of 10℃ / minute. After annealing, the rough structure layer is a ZnO / SiO2 composite nanostructure formed by the oxidation of the carbon skeleton of soot.

[0011] Preferably, the low surface energy modifier is one or a combination of two of fluorosilanes and non-fluorosilanes.

[0012] More preferably, the low surface energy modifier is one of 1H,1H,2H,2H-perfluorooctyltriethoxysilane and octyltrimethoxysilane, or a combination of 1H,1H,2H,2H-perfluorooctyltriethoxysilane and octyltrimethoxysilane in a mass ratio of (1-3):1.

[0013] Preferably, the low surface energy modified layer is formed by immersion, coating, spraying or dripping.

[0014] After being placed in an outdoor environment for 90 days, the static contact angle attenuation rate of the coating is ≤5%.

[0015] Preferably, the glass substrate is pretreated with ethanol and deionized water by ultrasonication.

[0016] A method for preparing a highly transparent superhydrophobic coating for outdoor atmospheric lidar radomes includes the following steps:

[0017] S1. The modifier, silica precursor, nano zinc oxide dopant, catalyst and solvent are stirred and mixed to prepare a doped silica modified solution; the doped silica modified solution is coated on the surface of the pretreated glass substrate using a coating rod, and then left to stand and cure to obtain a ZnO-SiO2@glass coating.

[0018] S2. Place the cured ZnO-SiO2@glass coating in the inner flame of a candle and move it back and forth for 3-7 minutes to deposit dense soot. After cooling, a ZnO-SiO2 / CS@glass coating is obtained.

[0019] S3. The ZnO-SiO2 / CS@glass coating is subjected to high-temperature annealing and cooled to obtain the ZnO-SiO2 / CS(O)@glass coating.

[0020] S4. One or two low surface energy modifiers are ultrasonically mixed with a solvent to obtain a low surface energy modified solution. This solution is then coated onto the surface of a ZnO-SiO2 / CS(O)@glass coating and allowed to dry at room temperature to obtain a highly transparent hydrophobic ZnO-SiO2 / F-CS(O)@glass coating for outdoor atmospheric lidar.

[0021] Preferably, in step S1, the mass ratio of the added modifier, silica precursor, nano zinc oxide dopant, catalyst and solvent is 4:1.2:0.006-0.024:0.1:100.

[0022] Preferably, in step S1, the stirring time of the silica-modified solution is 3-12 hours; the thickness of the coating applied by the coating rod is 60-180 μm; and the curing conditions are drying at 80°C for 3 hours.

[0023] Preferably, in step S1, the catalyst is dibutyltin dilaurate and the solvent is n-hexane.

[0024] Preferably, in step S1, the glass substrate pretreatment method is to sequentially sonicate in ethanol and deionized water for 30 minutes each, and then air dry at room temperature.

[0025] Preferably, in step S2, the candle is made of paraffin wax, the wick height is 8-10mm, and the flame temperature is 600-800℃; during deposition, the substrate is 1-2cm away from the wick, and the moving speed is 10-15cm / s to ensure the uniformity of the soot layer thickness.

[0026] Preferably, in step S3, the annealing temperature is 440-500℃, the annealing time is 2 hours, and the heating rate is 10℃ / minute.

[0027] Preferably, in step S4, the ultrasonic mixing time is 0.5-2 hours; the coating method is immersion, coating rod coating, spraying, or drip coating; and the standing drying time is 6-12 hours.

[0028] Preferably, in step S4, the solvent is ethanol.

[0029] One application of the above-mentioned highly transparent superhydrophobic coating is to coat the coating onto the surface of an outdoor atmospheric lidar cover to prevent signal attenuation caused by rain or surface contamination.

[0030] The technical solution of this invention has the following advantages:

[0031] A. High light transmittance ensures accurate signal transmission: The light transmittance of the coating of this invention can reach 92.4%, which is close to the 93.2% of bare glass. This ensures the complete and accurate transmission of the lidar light signal and meets the requirements of atmospheric monitoring for signal fidelity.

[0032] B. Superhydrophobic properties enable self-cleaning: The coating of this invention has a contact angle of up to 165.04°, which has excellent liquid repellency, allowing water droplets and dirt to slide off quickly, effectively preventing surface contamination and reducing signal attenuation caused by water film or dirt.

[0033] C. Excellent stability and durability: The coating of this invention has strong mechanical and chemical stability and weather resistance, with a wear resistance distance of up to 2400cm. It can withstand harsh environments such as high temperature, low temperature, ultraviolet radiation, and acid and alkali corrosion, thus extending the service life of the radome.

[0034] D. Ensure outdoor monitoring stability: Radar covers coated with this coating can remain clean even after 90 days of outdoor placement, and signal transmission remains stable under conditions such as rain attenuation, effectively avoiding data distortion caused by severe weather.

[0035] E. This invention achieves a synergistic effect of high transparency and superhydrophobicity through an innovative process of "in-situ growth of doped nanoparticles - construction of a composite structure from candle soot - high-temperature carbon removal - low surface energy grafting". The invention utilizes the nanoscale porous structure of candle soot to construct a rough surface, combined with high-temperature annealing to remove carbon black, solving the technical challenge of "hydrophobicity necessarily leading to light blocking". The low surface energy modifier enhances the adhesion between the coating and the substrate while ensuring low surface energy. The light transmittance is optimized to meet the signal transmission requirements of lidar, with a measured outdoor signal attenuation rate of ≤3% after 90 days, far lower than that of an uncoated radome (attenuation rate >20%).

[0036] F. The preparation process is economical and easy to industrialize: The coating preparation process of this invention has low equipment requirements, is simple to operate, and has low cost. It can realize large-area production, is suitable for industrial application, and has broad promotion value. Attached Figure Description

[0037] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0038] Figure 1 Macroscopic and wettability diagrams of the highly transparent superhydrophobic coating for an outdoor atmospheric lidar radome prepared in Example 1 of this invention;

[0039] Figure 2 The images show SEM images of the highly transparent superhydrophobic coatings for outdoor atmospheric lidar radomes prepared in Example 1 and Comparative Examples 1-3 of this invention, where a and e are the ZnO-SiO2@glass coating prepared in Comparative Example 1, b and f are the ZnO-SiO2 / CS@glass coating prepared in Comparative Example 2, c and g are the ZnO-SiO2 / CS(O)@glass coating prepared in Comparative Example 3, and d and h are the ZnO-SiO2 / F-CS(O)@glass coating prepared in Example 1.

[0040] Figure 3 The transmittance test diagram shows the highly transparent superhydrophobic coating for outdoor atmospheric lidar obtained in Embodiment 1 of the present invention.

[0041] Figure 4 The mechanical stability diagram of the highly transparent superhydrophobic coating for outdoor atmospheric lidar radome prepared according to Embodiment 1 of the present invention is shown in Figure a, where a is a schematic diagram of sanding and b is the stability of the coating after sanding.

[0042] Figure 5 The chemical stability of the highly transparent superhydrophobic coating for outdoor atmospheric lidar prepared in Embodiment 1 of the present invention is shown in Figure a, where a is the stability of the coating after being immersed in a solution with pH=4 for 120 hours, and b is the stability of the coating after being immersed in a solution with pH=10 for 120 hours.

[0043] Figure 6The environmental stability of the highly transparent superhydrophobic coating for outdoor atmospheric lidar prepared according to Embodiment 1 of the present invention is shown in the following figures: a) schematic diagram of the coating subjected to heavy rain (water flow) impact for 3 hours; b) stability of the coating subjected to heavy rain (water flow) impact for 3 hours; c) schematic diagram of the coating subjected to light rain (shower) impact for 24 hours; d) stability of the coating subjected to light rain (shower) impact for 24 hours; e) stability of the coating after 40 days of high temperature treatment; f) stability of the coating after 40 days of low temperature treatment; and g) stability after ultraviolet aging test (60 days).

[0044] Figure 7 The stability of the highly transparent superhydrophobic coating for an outdoor atmospheric lidar radome prepared according to Embodiment 1 of the present invention after being placed in a real outdoor environment for 90 days.

[0045] Figure 8 The images shown are of the actual application of the highly transparent superhydrophobic coating for outdoor atmospheric lidar obtained in Embodiment 1 of the present invention. Figure a shows a schematic diagram of the surface of different atmospheric lidars after rainfall simulation using dyed water flow; figure b shows a data comparison diagram of monitoring the spatial distribution of coarse atmospheric particles using different lidars; and figure c shows a data comparison diagram of monitoring the spatial distribution of fine atmospheric particles using different lidars. (Note: Cover 1: Uncontaminated original blank lidar; Cover 2: Blank lidar after being impacted by dyed water flow; Cover 3: Lidar modified with superhydrophobic coating after being impacted by dyed water flow). Detailed Implementation

[0046] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Example 1

[0048] This embodiment provides a method for preparing a highly transparent superhydrophobic coating for outdoor atmospheric lidar radomes, including the following steps:

[0049] S0, Glass substrate pretreatment

[0050] The glass substrate was ultrasonically treated in ethanol and deionized water for 30 minutes each to remove surface oil and impurities. After treatment, it was air-dried at room temperature (23±2℃) for later use.

[0051] Preparation of S1, ZnO-SiO2@glass coating

[0052] Weigh out polydimethylsiloxane, tetraethyl orthosilicate, nano-zinc oxide, dibutyltin dilaurate, and n-hexane in a mass ratio of 4:1.2:0.018:0.1:100 and add them to a 200 ml beaker. Stir continuously at room temperature (23±2℃) for 12 hours to prepare a doped modified silica solution. Using a 180 μm coating rod, uniformly coat the doped modified silica solution onto a pretreated glass substrate. After coating, dry at 80℃ for 3 hours to obtain a ZnO-SiO2@glass coating.

[0053] Preparation of S2, ZnO-SiO2 / CS@glass coating

[0054] The cured ZnO-SiO2@glass coating was moved back and forth in the inner flame of a candle for 5 minutes to form a uniform and dense carbon black layer on the surface, thus constructing a composite rough structure and obtaining a ZnO-SiO2 / CS@glass coating. It was then cooled at room temperature (23±2℃) for later use.

[0055] Preparation of S3, ZnO-SiO2 / CS(O)@glass coating

[0056] The ZnO-SiO2 / CS@glass coating was annealed in a muffle furnace at 500℃ for 2 hours at a heating rate of 10℃ / min. After the furnace temperature cooled to room temperature, the ZnO-SiO2 / CS(O)@glass coating was removed.

[0057] Preparation of S4, ZnO-SiO2 / F-CS(O)@glass coating

[0058] 0.3 ml of 1H,1H,2H,2H-perfluorooctyltriethoxysilane and 0.1 ml of octyltrimethoxysilane were measured and added to 50 ml of ethanol. The mixture was magnetically stirred at room temperature (23±2℃) for 2 hours to prepare a low surface energy modification solution. The prepared low surface energy modification solution was uniformly drop-coated onto the surface of the ZnO-SiO2 / CS(O)@glass coating using a drop-coating method and dried at room temperature for 12 hours to obtain the ZnO-SiO2 / F-CS(O)@glass coating, which is a highly transparent superhydrophobic coating for outdoor atmospheric lidar radomes.

[0059] Example 2

[0060] This embodiment provides a method for preparing a highly transparent superhydrophobic coating for outdoor atmospheric lidar radomes, including the following steps:

[0061] S0, Glass substrate pretreatment

[0062] The glass substrate was ultrasonically treated sequentially in ethanol and deionized water for 30 minutes each time to remove surface oil and impurities. After treatment, it was air-dried at room temperature (23±2℃) for later use.

[0063] Preparation of S1, ZnO-SiO2@glass coating

[0064] Weigh out polydimethylsiloxane, tetraethyl orthosilicate, nano-zinc oxide, dibutyltin dilaurate, and n-hexane in a mass ratio of 4:1.2:0.018:0.1:100 and add them to a 200ml beaker. Stir continuously at room temperature (23±2℃) for 3 hours to prepare a doped modified silica solution. Using a 60μm coating rod, uniformly coat the doped modified silica solution onto a pretreated glass substrate. After coating, dry at 80℃ for 3 hours to obtain a ZnO-SiO2@glass coating.

[0065] Preparation of S2, ZnO-SiO2 / CS@glass coating

[0066] The cured ZnO-SiO2@glass coating was moved back and forth in the inner flame of a candle for 3 minutes to form a uniform and dense carbon black layer on the surface, constructing a composite rough structure to obtain the ZnO-SiO2 / CS@glass coating. It was then cooled at room temperature (23±2℃) for later use.

[0067] Preparation of S3, ZnO-SiO2 / CS(O)@glass coating

[0068] The ZnO-SiO2 / CS@glass coating was annealed in a muffle furnace at a temperature of 440℃ for 2 hours at a heating rate of 10℃ / minute. After the furnace temperature dropped to room temperature, the ZnO-SiO2 / CS(O)@glass coating was obtained.

[0069] Preparation of S4, ZnO-SiO2 / F-CS(O)@glass coating

[0070] 0.3 ml of 1H,1H,2H,2H-perfluorooctyltriethoxysilane and 0.1 ml of octyltrimethoxysilane were measured and added to 50 ml of ethanol. The mixture was magnetically stirred at room temperature (23±2℃) for 1 hour to prepare a low surface energy modified solution. The ZnO-SiO2 / CS(O)@glass was immersed in the low surface energy solution for 6 hours using an immersion method and then dried at room temperature for 3 hours to obtain a ZnO-SiO2 / F-CS(O)@glass coating, which is a highly transparent superhydrophobic coating for outdoor atmospheric lidar radomes.

[0071] Example 3

[0072] This embodiment provides a method for preparing a highly transparent superhydrophobic coating for outdoor atmospheric lidar radomes, including the following steps:

[0073] S0, Glass substrate pretreatment

[0074] The glass substrate was ultrasonically treated sequentially in ethanol and deionized water for 30 minutes each time to remove surface oil and impurities. After treatment, it was air-dried at room temperature (23±2℃) for later use.

[0075] Preparation of S1, ZnO-SiO2@glass coating

[0076] Weigh out polydimethylsiloxane, tetraethyl orthosilicate, nano-zinc oxide, dibutyltin dilaurate, and n-hexane in a mass ratio of 4:1.2:0.018:0.1:100 and add them to a 200 ml beaker. Stir continuously at room temperature (23±2℃) for 6 hours to prepare a doped modified silica solution. Using a 120 μm coating rod, uniformly coat the doped modified silica solution onto a pretreated glass substrate. After coating, dry at 80℃ for 3 hours to obtain a ZnO-SiO2@glass coating.

[0077] Preparation of S2, ZnO-SiO2 / CS@glass coating

[0078] The cured ZnO-SiO2@glass coating was moved back and forth in the inner flame of a candle for 5 minutes to form a uniform and dense carbon black layer on the surface, constructing a composite rough structure to obtain the ZnO-SiO2 / CS@glass coating. It was then cooled at room temperature (23±2℃) for later use.

[0079] Preparation of S3, ZnO-SiO2 / CS(O)@glass coating

[0080] The ZnO-SiO2 / CS@glass coating was annealed in a muffle furnace at 460℃ for 2 hours at a heating rate of 10℃ / min. After the furnace temperature cooled to room temperature, the ZnO-SiO2 / CS(O)@glass coating was removed.

[0081] Preparation of S4, ZnO-SiO2 / F-CS(O)@glass coating

[0082] 0.3 ml of 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PTES) and 0.1 ml of octyltrimethoxysilane were respectively added to 50 ml of ethanol. The mixture was magnetically stirred at room temperature (23±2℃) for 1.5 hours to prepare a low surface energy modified solution. Using a 180 μm coating rod, the low surface energy solution was uniformly coated onto the surface of a ZnO-SiO2 / CS(O)@glass coating and dried at room temperature for 6 hours to obtain a ZnO-SiO2 / F-CS(O)@glass coating, which is a highly transparent superhydrophobic coating for outdoor atmospheric lidar radomes.

[0083] Example 4

[0084] This embodiment provides a method for preparing a highly transparent superhydrophobic coating for outdoor atmospheric lidar radomes, including the following steps:

[0085] S0, Glass substrate pretreatment

[0086] The glass substrate was ultrasonically treated sequentially in ethanol and deionized water for 30 minutes each time to remove surface oil and impurities. After treatment, it was air-dried at room temperature (23±2℃) for later use.

[0087] Preparation of S1, ZnO-SiO2@glass coating

[0088] Weigh out polydimethylsiloxane, tetraethyl orthosilicate, nano-zinc oxide, dibutyltin dilaurate, and n-hexane in a mass ratio of 4:1.2:0.018:0.1:100 and add them to a 200ml beaker. Stir continuously at room temperature (23±2℃) for 9 hours to prepare a doped modified silica solution. Using a 180μm coating rod, uniformly coat the doped modified silica solution onto a pretreated glass substrate. After coating, dry at 80℃ for 3 hours to obtain a ZnO-SiO2@glass coating.

[0089] Preparation of S2, ZnO-SiO2 / CS@glass coating

[0090] The cured ZnO-SiO2@glass coating was moved back and forth in the inner flame of a candle for 7 minutes to form a uniform and dense carbon black layer on the surface, thus constructing a composite rough structure and obtaining a ZnO-SiO2 / CS@glass coating; it was then cooled at room temperature (23±2℃) for later use.

[0091] Preparation of S3, ZnO-SiO2 / CS(O)@glass coating

[0092] The ZnO-SiO2 / CS@glass coating was annealed in a muffle furnace at 480℃ for 2 hours at a heating rate of 10℃ / min. After the furnace temperature cooled to room temperature, the ZnO-SiO2 / CS(O)@glass coating was removed.

[0093] Preparation of S4, ZnO-SiO2 / F-CS(O)@glass coating

[0094] 0.3 ml of 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PTES) and 0.1 ml of octyltrimethoxysilane were measured and added to 50 ml of ethanol. The solution was magnetically stirred at room temperature (23±2℃) for 2 hours to prepare a low surface energy modified solution. The low surface energy solution was sprayed onto the surface of the ZnO-SiO2 / CS(O)@glass coating by spraying and dried at room temperature for 9 hours to obtain the ZnO-SiO2 / F-CS(O)@glass coating, which is a highly transparent superhydrophobic coating for outdoor atmospheric lidar radomes.

[0095] Example 5

[0096] The only difference between this embodiment and Embodiment 1 is that tetraethyl silicate is replaced with an equal mass of tetramethyl orthosilicate.

[0097] Example 6

[0098] The only difference between this embodiment and Embodiment 1 is that half the mass of tetraethyl orthosilicate is replaced with an equal amount of tetramethyl orthosilicate.

[0099] Example 7

[0100] The only difference between this implementation and Example 1 is that two-thirds of the mass of tetraethyl orthosilicate is replaced with an equal amount of tetramethyl orthosilicate.

[0101] Example 8

[0102] The only difference between this implementation and Example 1 is that one-third of the mass of tetraethyl orthosilicate is replaced with an equal amount of tetramethyl orthosilicate.

[0103] Example 9

[0104] The only difference between this implementation and Example 1 is that the amount of nano zinc oxide added is replaced with 0.5% of the mass of the silica precursor.

[0105] Example 10

[0106] The only difference between this implementation and Example 1 is that the amount of nano zinc oxide added is replaced with 1% of the mass of the silica precursor.

[0107] Example 11

[0108] The only difference between this implementation and Example 1 is that the amount of nano zinc oxide added is replaced with 2% of the mass of the silica precursor.

[0109] Example 12

[0110] The only difference between this implementation and Example 1 is that polydimethylsiloxane is replaced with an equal mass of stearic acid.

[0111] Example 13

[0112] The only difference between this implementation and Example 1 is that polydimethylsiloxane is replaced with an equal mass of 3-aminopropyltriethoxysilane.

[0113] Example 14

[0114] The only difference between this embodiment and Example 1 is that all three parts by mass of 1H,1H,2H,2H-perfluorooctyltriethoxysilane are replaced with octyltrimethoxysilane.

[0115] Example 15

[0116] The only difference between this embodiment and Example 1 is that 1 part by mass of octyltrimethoxysilane is replaced entirely with 1H,1H,2H,2H-perfluorooctyltriethoxysilane.

[0117] Example 16

[0118] The only difference between this embodiment and Embodiment 1 is that one-third of the mass of 1H,1H,2H,2H-perfluorooctyltriethoxysilane is replaced with an equal mass of octyltrimethoxysilane.

[0119] Example 17

[0120] The only difference between this embodiment and Embodiment 1 is that one-ninth of the mass of 1H,1H,2H,2H-perfluorooctyltriethoxysilane is replaced with an equal mass of octyltrimethoxysilane.

[0121] Comparative Example 1

[0122] This comparative example provides a method for preparing a coating, comprising the following steps:

[0123] S0, Glass substrate pretreatment

[0124] The glass substrate was ultrasonically treated in ethanol and deionized water for 30 minutes each time to remove surface oil and impurities; after treatment, it was air-dried at room temperature (23±2℃) for later use.

[0125] Preparation of S1, ZnO-SiO2@glass coating

[0126] Weigh out polydimethylsiloxane, tetraethyl orthosilicate, nano-zinc oxide, dibutyltin dilaurate, and n-hexane in a mass ratio of 4:1.2:0.018:0.1:100 and add them to a 200ml beaker. Stir continuously at room temperature (23±2℃) for 12 hours to obtain a doped modified silica solution. Using a 180μm coating rod, uniformly coat the doped modified silica solution onto a pretreated glass substrate. After coating, dry at 80℃ for 3 hours to obtain a ZnO-SiO2@glass coating.

[0127] Comparative Example 2

[0128] This comparative example provides a method for preparing a coating, comprising the following steps:

[0129] S0, Glass substrate pretreatment

[0130] The glass substrate was ultrasonically treated sequentially in ethanol and deionized water for 30 minutes each time to remove surface oil and impurities. After treatment, it was air-dried at room temperature (23±2℃) for later use.

[0131] Preparation of S1, ZnO-SiO2@glass coating

[0132] Weigh out polydimethylsiloxane, tetraethyl orthosilicate, nano-zinc oxide, dibutyltin dilaurate, and n-hexane in a mass ratio of 4:1.2:0.018:0.1:100 and add them to a 200ml beaker. Stir continuously at room temperature (23±2℃) for 12 hours to obtain a doped modified silica solution. Using a 180μm coating rod, uniformly coat the doped modified silica solution onto a pretreated glass substrate. After coating, dry at 80℃ for 3 hours to obtain a ZnO-SiO2@glass coating.

[0133] Preparation of S2, ZnO-SiO2 / CS@glass coating

[0134] The cured ZnO-SiO2@glass coating was moved back and forth in the inner flame of a candle for 5 minutes to form a uniform and dense carbon black layer on the surface, thus constructing a composite rough structure and obtaining a ZnO-SiO2 / CS@glass coating; it was then cooled at room temperature (23±2℃) for later use.

[0135] Comparative Example 3

[0136] This comparative example provides a method for preparing a coating, comprising the following steps:

[0137] S0, Glass substrate pretreatment

[0138] The glass substrate was ultrasonically treated in ethanol and deionized water for 30 minutes each time to remove surface oil and impurities; after treatment, it was air-dried at room temperature (23±2℃) for later use.

[0139] Preparation of S1, ZnO-SiO2@glass coating

[0140] Weigh out polydimethylsiloxane, tetraethyl orthosilicate, nano-zinc oxide, dibutyltin dilaurate, and n-hexane in a mass ratio of 4:1.2:0.018:0.1:100 and add them to a 200ml beaker. Stir continuously at room temperature (23±2℃) for 12 hours to obtain a doped modified silica solution. Using a 180μm coating rod, uniformly coat the doped modified silica solution onto a pretreated glass substrate. After coating, dry at 80℃ for 3 hours to obtain a ZnO-SiO2@glass coating.

[0141] Preparation of S2, ZnO-SiO2 / CS@glass coating

[0142] The cured ZnO-SiO2@glass coating was moved back and forth in the inner flame of a candle for 5 minutes to form a uniform and dense carbon black layer on the surface, thus constructing a composite rough structure and obtaining a ZnO-SiO2 / CS@glass coating; it was then cooled at room temperature (23±2℃) for later use.

[0143] Preparation of S3, ZnO-SiO2 / CS(O)@glass coating

[0144] The ZnO-SiO2 / CS@glass coating was annealed in a muffle furnace at a temperature of 500℃ for 2 hours at a heating rate of 10℃ / minute. After the furnace temperature dropped to room temperature, the ZnO-SiO2 / CS(O)@glass coating was obtained.

[0145] like Figure 1 As shown, the contact angle of the superhydrophobic coating prepared in Example 1 was 165.04°C.

[0146] like Figure 2 The images show SEM images of the superhydrophobic coatings prepared in Example 1 and Comparative Examples 1-3. In the images, the coating of Example 1 has a more robust surface roughness and stronger performance.

[0147] The contact angles of the highly transparent superhydrophobic coatings for outdoor atmospheric lidar radomes prepared in Examples 2-17 are all above 150°.

[0148] The light transmittance and abrasion resistance of the superhydrophobic coatings prepared in Examples 1-17 and Comparative Examples 1-3 were characterized respectively:

[0149] Abrasion resistance: Place the sample on 800-grit SiC sandpaper with the coated side facing down in contact with the sandpaper. Then place a 500g weight on a glass slide. Use tweezers to push the glass slide forward in a straight line for 10cm, then rotate the pushing direction 90° clockwise, and then push it forward in a straight line for another 10cm. This is recorded as one wear cycle. The wear distance of each cycle is 20cm. Record the distance at which the coating loses its superhydrophobicity.

[0150] The specific test results are shown in Table 1 below.

[0151] Table 1 Comparison of experimental parameters between Examples 1-17 and Comparative Examples 1-3

[0152]

[0153]

[0154] According to the comparison of the test data of the embodiments and comparative examples in Table 1, the highly transparent superhydrophobic coating for outdoor atmospheric lidar radome obtained by the technical solution of this application has excellent liquid repellency, self-cleaning properties, high transparency and wear resistance.

[0155] The highly transparent superhydrophobic coating for outdoor atmospheric lidar radomes prepared by this method effectively prevents water droplets and dirt from adhering to and penetrating the surface of objects, allowing water droplets and rain / snow to quickly slide off the radome surface, thus achieving a self-cleaning function. Reducing liquid adhesion improves light transmittance and effectively prevents attenuation of the monitoring signal.

[0156] Any aspects not covered in this invention are applicable to existing technologies.

[0157] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A highly transparent superhydrophobic coating for outdoor atmospheric lidar radomes, characterized in that, The material comprises a doped modified silica base layer, a composite rough structure layer, and a low surface energy modified layer sequentially formed on the surface of a glass substrate. The doped modified silica base layer is formed by in-situ growth of a silica precursor, a nano zinc oxide dopant, and a modifier. The composite rough structure layer is formed by high-temperature annealing of candle soot. The low surface energy modified layer is formed by a composite low surface energy modifier.

2. The coating according to claim 1, characterized in that, The silica precursor is one or a combination of two of tetraethyl orthosilicate and tetramethyl orthosilicate in a mass ratio of (0.5-2):

1. The modifier is one of polydimethylsiloxane, stearic acid, and 3-aminopropyltriethoxysilane. The amount of nano zinc oxide dopant added is 0.5%-2% of the mass of the silica precursor.

3. The coating according to claim 1, characterized in that, The high-temperature annealing conditions for the composite rough structure layer are: holding at 440-500℃ for 2 hours, with a heating rate of 10℃ / minute.

4. The coating according to claim 1, characterized in that, The low surface energy modifier is one or a combination of two of fluorosilanes and non-fluorosilanes.

5. The coating according to claim 4, characterized in that, The low surface energy modifier is one of 1H,1H,2H,2H-perfluorooctyltriethoxysilane and octyltrimethoxysilane, or a combination of 1H,1H,2H,2H-perfluorooctyltriethoxysilane and octyltrimethoxysilane in a mass ratio of (1-3):

1.

6. A method for preparing a highly transparent superhydrophobic coating for an outdoor atmospheric lidar radome according to any one of claims 1-5, characterized in that, Includes the following steps: S1. The modifier, silica precursor, nano zinc oxide dopant, catalyst and solvent are stirred and mixed to prepare a doped silica modified solution; the doped silica modified solution is coated on the surface of the pretreated glass substrate using a coating rod, and then left to stand and cure to obtain a ZnO-SiO2@glass coating. S2. Place the cured ZnO-SiO2@glass coating in the inner flame of a candle and move it back and forth for 3-7 minutes to deposit dense soot. After cooling, a ZnO-SiO2 / CS@glass coating is obtained. S3. The ZnO-SiO2 / CS@glass coating is subjected to high-temperature annealing and cooled to obtain the ZnO-SiO2 / CS(O)@glass coating. S4. One or two low surface energy modifiers are ultrasonically mixed with a solvent to obtain a low surface energy modified solution. This solution is then coated onto the surface of a ZnO-SiO2 / CS(O)@glass coating and allowed to dry at room temperature to obtain a highly transparent hydrophobic ZnO-SiO2 / F-CS(O)@glass coating for outdoor atmospheric lidar.

7. The preparation method according to claim 6, characterized in that, In step S1, the mass ratio of the added modifier, silica precursor, nano zinc oxide dopant, catalyst and solvent is 4:1.2:0.006-0.024:0.1:

100.

8. The preparation method according to claim 6, characterized in that, In step S1, the stirring time of the doped silica modified solution is 3-12 hours; the thickness of the coating applied by the coating rod is 60-180 μm. The curing conditions are drying at 80°C for 3 hours; the glass substrate pretreatment method is to ultrasonically treat it in ethanol and deionized water for 30 minutes each, and then air dry it at room temperature.

9. The preparation method according to claim 6, characterized in that, In step S1, the catalyst is dibutyltin dilaurate and the solvent is n-hexane; In step S3, the annealing temperature is 440-500℃, the annealing time is 2 hours, and the heating rate is 10℃ / minute. In step S4, the ultrasonic mixing time is 0.5-2 hours; the coating method is immersion, coating rod coating, spraying, or drip coating; and the standing drying time is 6-12 hours. In step S4, the solvent is ethanol.

10. An application of the highly transparent superhydrophobic coating according to any one of claims 1-5, characterized in that: The coating is applied to the surface of an outdoor atmospheric lidar radome to prevent signal attenuation caused by rain or surface contamination.

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