A super-hydrophobic coating with photothermal properties and preparation method thereof

Abstract

The present invention discloses a kind of super-hydrophobic coating with photothermal performance and preparation method thereof, wherein preparation method comprises the following steps:S1. fluorocarbon resin is sprayed on substrate as matrix resin, semi-cured stand-by;S2. super-hydrophobic tungsten carbide is dispersed in solvent and ultrasonically processed, form uniform suspension;S3. super-hydrophobic tungsten carbide suspension of S2 is sprayed on the semi-cured matrix resin of S1, photothermal layer is formed after solidification. The super-hydrophobic coating of the present invention has excellent water repellency and photothermal property simultaneously, can rely on the super-hydrophobic property of coating surface to suppress ice adhesion, and can carry out active deicing by photothermal effect after freezing.

Description

Technical Field

[0001] The present invention relates to the technical field of photothermal super-hydrophobic materials, and in particular to a super-hydrophobic coating with photothermal properties and a preparation method thereof. Background Art

[0002] Ice formation is a common phenomenon in nature and has a negative impact on industries such as aviation, electricity, transportation, and shipping. In severe cases, it can even cause personal injury and property damage. In order to reduce the damage caused by ice formation, many technologies have been applied. Applying anti-icing / de-icing coatings is a widely used anti-icing / de-icing technology. Anti-icing coatings are applied to reduce the adhesion strength between ice and the surface, making it easy to remove ice, and can also make water droplets fall off before freezing when they fall onto the coating surface. Due to the water repellency of its surface, super-hydrophobic coatings can make droplets that fall on the surface bounce, allowing surface water to quickly detach from the surface, which can effectively reduce the freezing of water droplets on the coating surface under low temperature conditions and achieve an anti-icing effect. However, due to the microstructure of its surface, a single super-hydrophobic coating allows ice crystals to enter its gaps in a high humidity environment, which in turn promotes growth, increases the bonding strength between the ice layer and the coating, and is not easy to de-ice. Composite materials with photothermal properties with super-hydrophobic coatings can make up for the defects of single super-hydrophobic coatings.

[0003] After searching, Chinese patent document CN116925640A discloses the preparation and application of a HCMT@PPY photothermal super-hydrophobic composite material. The preparation method first uses simple carbonization without a template to obtain hollow microtubes (HCMT) with a hollow structure, and then in situ polymerizes polypyrrole (PPy) to modify the HCMT surface. Finally, organochlorosilane is used for hydrophobic grafting to prepare a photothermal super-hydrophobic HCMT@PPY coating. However, its curing time is too long, 1-5 hours, and the curing temperature is too high, 60-120°C.

[0004] Chinese patent document CN115873490A discloses a self-regulating photothermal anti-icing and de-icing coating comprising the following components by weight: 60-90% resin prepolymer; 10-40% thermochromic dye microcapsules. The thermochromic dye microcapsules comprise a capsule wall and a core, the core comprising a thermochromic dye and a higher fatty alcohol; the capsule wall is composed of a polymer. In this invention, the thermochromic dye gives the coating a dark color at low temperatures below 0°C in winter, exhibiting high photothermal conversion efficiency and providing anti-icing and de-icing benefits; and a light color at high temperatures in summer, exhibiting low photothermal conversion efficiency and preventing overheating. However, the coating utilizes thermochromic dye microcapsules, and the dosage of these microcapsules in the system is as high as 10-40%.

[0005] Chinese patent document CN116887459A discloses an active synergistic anti-icing material, comprising a substrate, an electric heating layer, and a photothermal layer. The substrate comprises a cleaned carbon cloth layer, the electric heating layer is supported on the substrate, the electric heating layer comprises a PPy film and a conductive structure, the PPy film is coated on the surface of the substrate, the conductive structure comprises a positive electrode and a negative electrode, the positive and negative electrodes are respectively electrically connected to the upper surface of the PPy film, and the photothermal layer comprises a carbon nanotube deposition layer electrophoretically deposited on the upper surface of the electric heating layer. This invention achieves active anti-icing of the protected object both during the day and at night through the synergistic effect of the electric heating layer and the photothermal layer. However, the surface temperature after irradiation for 480 seconds in the dark with power on is only 74.25°C.

[0006] Based on the technical defects of the above-mentioned prior art, the present invention has developed a coating that is not available in the prior art. The coating is a superhydrophobic coating that is simple to manufacture, has a short curing time, high photothermal conversion capability and significant temperature resistance. Based on the above-mentioned excellent performance, the coating not only has good anti-icing / de-icing performance and excellent ice-melting ability, but also can inhibit the reproduction of bacteria on the coating surface through the non-adhesive properties of the superhydrophobic surface and the local high temperature caused by photothermal heat. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a super-hydrophobic coating with photothermal properties and a preparation method thereof. The coating is a super-hydrophobic coating that can achieve excellent photothermal effects with a small amount of photothermal material. The coating has excellent water repellency and photothermal properties. It can not only inhibit ice adhesion by relying on the super-hydrophobic properties of the coating surface, but also actively remove ice through the photothermal effect after ice formation.

[0008] The technical solutions adopted are:

[0009] A method for preparing a super-hydrophobic coating with photothermal properties of the present invention comprises the following steps:

[0010] S1. Spraying fluorocarbon resin on the substrate as a base resin, semi-cured standby;

[0011] S2. The super-hydrophobic tungsten carbide is dispersed in a solvent and ultrasonically treated to form a uniform suspension;

[0012] S3. Spray the super-hydrophobic tungsten carbide suspension of S2 onto the semi-cured base resin of S1, and form a photothermal layer after curing.

[0013] Furthermore, in S1, the substrate is one of glass, steel sheet, tinplate, wood, and acrylic board.

[0014] Furthermore, in S1, the fluorocarbon resin is added to an organic solvent, and the viscosity is adjusted to 50-70s by using a Tu-4 viscometer, and then sprayed on the substrate.

[0015] Furthermore, in S1, the organic solvent used to adjust the viscosity is one or more of butyl acetate, ethyl acetate, n-hexane, xylene, and propylene glycol methyl ether.

[0016] Furthermore, in S2, the solvent is one or more of N,N-dimethylformamide, anhydrous ethanol, propylene glycol methyl ether, and ethyl acetate, and the mass fraction of the super-hydrophobic tungsten carbide in the solvent is 0.5%-7%, for example, 0.5%, 1%, 2%, 5%, or 7%.

[0017] Furthermore, in S2, the super-hydrophobic tungsten carbide is super-hydrophobic spherical tungsten carbide, which is prepared by the following method, comprising the following steps:

[0018] S211. Dissolve the required amount of glucose and ammonium metatungstate in deionized water and stir to form a clear transparent solution;

[0019] S212. The clear and transparent solution is heated in a sealed hydrothermal reactor to react;

[0020] S213. The reaction product was filtered, washed several times and dried;

[0021] S214. The dried sample is calcined to obtain spherical tungsten carbide;

[0022] S215. The fluorinated silane coupling agent and ethanol are mixed uniformly to form a first solution;

[0023] S216. Dilute ammonium hydroxide with deionized water to form a second solution;

[0024] S217. Spherical tungsten carbide is added to the second solution, and continuously dispersed to form a uniform suspension of tungsten carbide as a third solution;

[0025] S218. Slowly add the third solution to the first solution to react. After the reaction is completed, separate the precipitate and dry it to obtain super-hydrophobic spherical tungsten carbide.

[0026] Furthermore, in S215, the fluorine-containing silane coupling agent is one or more of triethoxyfluorosilane, n-octyltriethoxysilane, and 1H,1H,2H,2H-perfluorodecyltriethoxysilane.

[0027] Furthermore, in S211, the required mass ratio of glucose to ammonium metatungstate is (6-10): 1. For example, it can be 6:1, 7:1, 8:1, 9:1 or 10:1.

[0028] Alternatively, the super-hydrophobic tungsten carbide is a super-hydrophobic sheet tungsten carbide, which is prepared by the following method, comprising the steps of:

[0029] S221. Dicyandiamide and the required amount of ammonium metatungstate are fully ground in an agate grinding jar;

[0030] S222. The obtained solid mixture is pyrolyzed and calcined to obtain lamellar tungsten carbide;

[0031] S223. The fluorinated silane coupling agent and ethanol are mixed uniformly to form a first solution;

[0032] S224. Dilute ammonium hydroxide with deionized water to form a second solution;

[0033] S225. The tungsten carbide flakes are added to the second solution and continuously dispersed to form a uniform suspension of tungsten carbide as a third solution;

[0034] S226. Slowly add the third solution to the first solution to react. After the reaction is completed, separate the precipitate and dry it to obtain super-hydrophobic tungsten carbide sheets.

[0035] Furthermore, in S223, the fluorine-containing silane coupling agent is one or more of triethoxyfluorosilane, n-octyltriethoxysilane, and 1H,1H,2H,2H-perfluorodecyltriethoxysilane.

[0036] Furthermore, in S221, the mass ratio of dicyandiamide to ammonium metatungstate is (0.3-5):1. For example, it can be 0.3:1, 1:1, 3:1 or 5:1.

[0037] The present invention provides a super-hydrophobic coating with photothermal properties, which is prepared by the above-mentioned method for preparing a super-hydrophobic coating with photothermal properties.

[0038] Thus, the super-hydrophobic coating with photothermal properties is prepared by spraying fluorocarbon resin as a base resin on a substrate, and spraying super-hydrophobic tungsten carbide on the base resin to form a photothermal layer on the surface of the coating.

[0039] The superhydrophobicity of tungsten carbide is achieved by grafting fluorosilane on its surface, and the fluorosilane includes but is not limited to triethoxyfluorosilane, n-octyltriethoxysilane or 1H,1H,2H,2H-perfluorodecyltriethoxysilane.

[0040] The thickness of the fluorocarbon resin matrix of the prepared super-hydrophobic photothermal coating is 7-10 μm, and the thickness of the photothermal layer is 1-5 μm.

[0041] The photothermal layer has a black rough surface that can provide good photothermal performance. Compared with the flat surface that strongly reflects light, the tungsten carbide surface with a hierarchical structure has a micron-scale feature size and can effectively capture light.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) The tungsten carbide material provided by the present invention has photothermal, superhydrophobic and antibacterial properties. Long-chain fluorocarbon functional groups -CF2 and -CF3 are grafted onto its surface to enhance the hydrophobic effect of the surface. After being compounded with fluorocarbon resin, it has good anti-icing and deicing properties. Tungsten carbide itself has an excellent photothermal conversion rate that can melt ice on the surface, reducing the difficulty of deicing. The local heat generated by the photothermal conversion rate can effectively kill bacteria adhering to the coating surface by rupturing the cell membrane, thereby achieving the ability to inhibit bacterial reproduction.

[0044] (2) The super-hydrophobic coating based on tungsten carbide of the present invention is prepared by a spraying method, and the operation process is simple and convenient, suitable for large-scale construction over a large area, and easy to construct on the surfaces of different objects.

[0045] (3) The coating of the present invention has good hydrophobicity, heat absorption, anti-icing and antibacterial properties. It can not only inhibit ice formation in the early stage through the super-hydrophobicity of the coating, but also actively de-ice through photothermal after ice formation. The non-adhesive property of the super-hydrophobic surface can prevent bacteria from adhering to the surface, and the photothermal property gives the coating the ability to inhibit bacterial reproduction on the surface. The photothermal material prepared. In particular, under an embodiment of a super-hydrophobic spherical tungsten carbide photothermal layer, after 170 seconds of irradiation by a solar simulator, the temperature of the irradiated area can reach above 85°C, and has photothermal conversion capability; after 233 seconds of irradiation by the solar simulator when the coating is covered with ice, the temperature begins to rise significantly, causing the ice to completely melt, and stabilizes at 42°C in about 24 minutes, having photothermal de-icing performance, and the local heat generated can effectively kill bacteria adhering to the coating surface by rupturing the cell membrane.

[0046] (4) The coating preparation process of the present invention is simple, controllable, low-cost, has a dual protective effect, and is suitable for large-scale industrial production and commercial promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a TEM image of S-WC of Example 1;

[0048] Figure 2 The SEM image of the F / S-WC-5% / F coating of Example 1 is shown in FIG. Figure 2 a is the SEM image of the coating surface, the right Figure 2 b is the SEM image of the coating cross section;

[0049] Figure 3 The contact angles of the coatings of Example 1 and Comparative Example 1 with water are shown in FIG. Figure 3 a is the contact angle diagram of F / S-WC-5% / F and water in Example 1, and the right side Figure 3 b is the contact angle diagram of FEVE and water in comparative example 1;

[0050] Figure 4 1 is a process diagram of the vertical movement of a single water droplet on the coating surface of Example 1 and Comparative Example 1; the arrow in the figure indicates the movement direction of the needle used for dripping water;

[0051] Figure 5 Graph showing temperature changes over time for the photothermal materials of Example 1 and Example 6;

[0052] Figure 6 Graph showing the change of ice coverage on the surface of the super-hydrophobic photothermal coating over time in Example 1 and Example 6;

[0053] Figure 7 The TEM images of the bacterial morphology after the coating of Example 1 and Comparative Example 1 was co-cultured with Escherichia coli; Figure 7 a is a TEM image of the bacterial morphology after the coating of Example 1 was co-cultured with Escherichia coli; Figure 7 b is a TEM image of the bacterial morphology after the coating of Comparative Example 1 was co-cultured with Escherichia coli. DETAILED DESCRIPTION

[0054] The present invention will be described in detail below with reference to the accompanying drawings and specific examples. However, the uses and purposes of these exemplary embodiments are only used to illustrate the present invention and do not constitute any form of limitation on the actual protection scope of the present invention, nor do they limit the protection scope of the present invention to them.

[0055] In the following examples and comparative examples, unless otherwise specified, raw materials or processing techniques are conventional commercially available raw materials or conventional processing techniques in the art.

[0056] Example 1

[0057] A method for preparing a super-hydrophobic coating with photothermal properties in this embodiment includes the following steps:

[0058] Step 1: Preparation of base fluorocarbon resin

[0059] Propylene glycol methyl ether was added to the fluorocarbon resin and its viscosity was adjusted to 50-70s (Tu-4, 25°C) to obtain a mixed resin solution. 8g of the obtained mixed resin solution (sample size was 76mm*26mm) was added to the liquid reservoir of the spray gun. Under the action of air power, the mixture was atomized, sprayed and deposited on the substrate to form a matrix resin, which was semi-cured for standby use.

[0060] The process parameters of spraying are as follows: the nozzle diameter of the spray gun is 0.2-0.5 mm; the distance between the nozzle and the substrate during spraying is 6-16 cm; the spraying time is 2-25 s; and the air pressure range is 15-30 psi.

[0061] 50-70s (Tu-4, 25°C) refers to the viscosity range of 50-70s measured at room temperature (25°C) using a Tu-4 viscometer. The measurement method is the time it takes for 100ml of mixed resin solution sample to flow out of the Tu-4 cup, expressed in seconds.

[0062] Step 2: Preparation of tungsten carbide (S-WC)

[0063] The required amount of 1.8016 g glucose and 0.2974 g ammonium metatungstate were dissolved in 50 mL of deionized water and stirred to form a clear solution.

[0064] The above solution was heated in a sealed hydrothermal reactor at 5 °C·min -1 The product was heated to 170°C at a rate of 1000 ℃ and maintained for 12 hours. The obtained product was filtered and washed several times with deionized water and ethanol in sequence, and finally dried in a vacuum drying oven at 70°C for 6 hours. The dried sample was calcined at 950°C in Ar2 for 2 hours to obtain S-WC. Figure 1 TEM image of S-WC.

[0065] Step 3: Preparation of super-hydrophobic tungsten carbide (F / S-WC)

[0066] First, 0.6 mL of 1H,1H,2H,2H-perfluorodecyltriethoxysilane was mixed with 80 mL of anhydrous ethanol and the solution was stirred continuously for 60 minutes. Then, 4 mL of ammonium hydroxide was diluted to 20 mL with deionized water. 3 g of S-WC was added to the solution and sonicated for 20 minutes to form a uniform S-WC suspension. Finally, the tungsten carbide suspension was slowly added dropwise to the 1H,1H,2H,2H-perfluorodecyltriethoxysilane solution and stirred at 40°C for 24 hours. The suspension was centrifuged at 10,000 rpm for 5 minutes, washed multiple times with deionized water and anhydrous ethanol, and then vacuum-dried to obtain F / S-WC.

[0067] Step 4: Preparation of photothermal layer

[0068] 0.5g of F / S-WC was ultrasonically dispersed in 10g of N,N-dimethylformamide (DMF) for 40 minutes to obtain a uniform suspension. This suspension was then added to the reservoir of a spray gun. Under the action of air power, the suspension was atomized, sprayed, and deposited on the semi-cured FEVE surface prepared in step 1. Through a single-coating spraying method, it was deposited on the resin surface to produce a photothermal layer.

[0069] Step 5: Preparation of super-hydrophobic photothermal coating

[0070] The above step 4 was placed in a 60℃ forced air drying oven for 2 hours to obtain the F / S-WC-5% / F coating. Figure 2 As shown, Figure 2 On the left Figure 2 a is the SEM of the F / S-WC-5% / F coating surface. Figure 2 on the right Figure 2 b is the cross-sectional SEM image of the F / S-WC-5% / F coating.

[0071] The following experiments were performed to test the performance of the coating:

[0072] Water contact angle test on coating surface:

[0073] A 5 μL drop of deionized water was dropped onto the F / S-WC-5% / F coating in Example 1. The image of the droplet was recorded using a camera, and the droplet profile was fitted in analysis software to determine the contact angle of the droplet on the coating surface. Due to the rough structure of the coating surface, the droplet exhibited a superhydrophobic state on the coating surface, and the contact angle of the F / S-WC-5% / F was 152 ± 1°. Figure 3 on the left Figure 3 As shown in a.

[0074] Water repellency test:

[0075] The vertical motion of a single water droplet on the F / S-WC-5% / F coating in Example 1 was measured using a video optical contact angle meter. Figure 4 on the left Figure 4 In a, the water droplets can follow the up and down movement of the needle and do not drip onto the F / S-WC-5% / F surface. This shows that the accumulated water on the coating surface can be detached from the surface, thereby effectively reducing the freezing of water droplets on the coating surface under low temperature conditions, achieving an anti-icing effect.

[0076] Photothermal testing:

[0077] 5 g of S-WC powder was evenly spread in a glass petri dish and placed under a solar simulator with the light intensity adjusted to 1 kW m -2 , using an infrared camera to record the changes in the S-WC surface over time, its temperature reached 85℃ at 170s, and the temperature remained at 85℃ and above after continuous irradiation for 30min, showing good stability. Figure 5 shown.

[0078] Ice test:

[0079] The ice coverage rate was tested at an ambient temperature of -20°C and a humidity of 20%. The test sample, F / S-WC-5% / F, was 76mm*26mm in size. The sample was first placed in a culture dish and an appropriate amount of deionized water was added to the dish, completely submerging the F / S-WC-5% / F. The dish was then placed in a -20°C environment for 180 minutes to allow a thick layer of ice to form on the coating surface. The solar simulator was then turned on and the intensity of the sunlight was adjusted to 1kW·m -2 , the surface ice melting time is recorded by infrared camera. As the light irradiates, the surface ice gradually melts, and the results are as follows Figure 6 As shown in the figure, due to the photothermal conversion, the surface temperature of the F / S-WC-5% / F coating gradually increased. After about 18 seconds, the temperature rose slightly to 1.8°C, and the ice layer gradually melted. After 233 seconds, the temperature began to rise sharply, and the remaining ice layer slid down in large pieces. The ice completely melted and stabilized at 42°C in about 24 minutes.

[0080] Bacterial morphology test:

[0081] First, pour 50mL of LB liquid culture medium into a conical flask, inoculate E. coli into it, and co-culture F / S-WC-5% / F with E. coli at 37°C for 12 hours. Place the conical flask under a solar simulator for 1 hour for irradiation. Then, aspirate 10mL of the culture medium and centrifuge it. Add glutaraldehyde to fix it, wash it with PBS buffer, and centrifuge it three times. Finally, dilute the precipitate with sterile water and drop it on the microgrid to observe the morphology of E. coli. The test results are as follows: Figure 7 On the left Figure 7 As shown in a, Escherichia coli co-cultured with the F / S-WC-5% / F coating produces local high temperature under the stimulation of the solar simulator, which can rupture the cell membrane and effectively kill the Escherichia coli adhered to the coating surface.

[0082] Example 2

[0083] Referring to Example 1, the difference from Example 1 is that in the preparation process of a super-hydrophobic coating with photothermal properties in this embodiment, the amount of F / S-WC added is 0.7 g, and the other methods remain unchanged, as shown in Example 1.

[0084] Example 3

[0085] Referring to Example 1, the difference from Example 1 is that in the preparation process of a super-hydrophobic coating with photothermal properties in this embodiment, the amount of F / S-WC added is 0.2 g, and the other methods remain unchanged, as shown in Example 1.

[0086] Example 4

[0087] Referring to Example 1, the difference from Example 1 is that in the preparation process of a super-hydrophobic coating with photothermal properties in this embodiment, the amount of F / S-WC added is 0.1 g, and the other methods remain unchanged, as shown in Example 1.

[0088] Example 5

[0089] Referring to Example 1, the difference from Example 1 is that in the preparation process of a super-hydrophobic coating with photothermal properties in this embodiment, the amount of F / S-WC added is 0.05 g, and the other methods remain unchanged, as shown in Example 1.

[0090] Example 6

[0091] Referring to Example 1, different from Example 1, a super-hydrophobic coating with photothermal properties of the present embodiment, during the preparation process, the sprayed photothermal layer is F / L-WC with an addition amount of 0.5g, and the rest of the method remains unchanged, and the specific steps are as follows:

[0092] Step 1: Preparation of base fluorocarbon resin

[0093] Same as step 1 in Example 1;

[0094] Step 2: Preparation of tungsten carbide (L-WC)

[0095] First, 3 g of dicyandiamide and 1 g of ammonium metatungstate were fully ground in an agate grinder. The resulting solid mixture was then pyrolyzed at 400 °C for 0.5 h and calcined in N2 at 800 °C for 5 h. The product obtained after cooling was recorded as L-WC.

[0096] Step 3: Preparation of super-hydrophobic tungsten carbide (F / L-WC)

[0097] Referring to Example 1, the difference from Example 1 is that 3 g of L-WC is added in this comparative example, and the other methods remain unchanged.

[0098] Step 4: Preparation of photothermal layer

[0099] Referring to Example 1, the difference from Example 1 is that 0.5 g of F / L-WC is added in this comparative example, and the other methods remain unchanged.

[0100] Step 5: Preparation of super-hydrophobic photothermal coating

[0101] The same method as step 5 in Example 1 was used to obtain an F / L-WC-5% / F coating.

[0102] Test according to the test method of Example 1, see Figure 5 and Figure 6As shown in the figure, the temperature of the L-WC surface changes over time was recorded by an infrared imaging camera. The temperature reached 79°C at 298s and remained at 80°C or above after 30 minutes of continuous irradiation. The surface ice melting time was recorded by an infrared camera. The surface temperature of the F / L-WC-5% / F coating rose slowly. After about 345s, the temperature reached 2.5°C. The ice layer gradually melted. After 457s, the temperature rose slightly and reached 37°C at 30 minutes.

[0103] Comparative Example 1

[0104] Referring to Example 1, the difference from Example 1 is that in the preparation process of this embodiment, F / S-WC is not sprayed, and the coating has no super-hydrophobic photothermal layer. The other methods remain unchanged, as shown in Example 1. Tests were carried out according to the test method of Example 1, see Figure 3 on the right Figure 3 b and Figure 4 on the right Figure 4 As shown in Figure b, since the coating surface is not sprayed with superhydrophobic material and has no rough structure, the water contact angle is only 86°; and when a single water droplet moves vertically, the water droplet directly falls onto the FEVE surface, which shows that the coating surface is prone to water accumulation and cannot achieve the anti-icing effect; in addition, when observing the bacterial morphology, under the same irradiation conditions, the Escherichia coli morphology is intact without any damage, and it cannot have the ability to inhibit bacterial reproduction.

[0105] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a super-hydrophobic coating with photothermal properties, characterized in that: The steps include: S1. Spraying fluorocarbon resin on the substrate as a base resin, semi-cured standby; S2. The super-hydrophobic tungsten carbide is dispersed in a solvent and ultrasonically treated to form a uniform suspension; the super-hydrophobic tungsten carbide is a super-hydrophobic spherical tungsten carbide, which is prepared by the following method, comprising the steps of: S211. Dissolve the required amount of glucose and ammonium metatungstate in deionized water and stir to form a clear transparent solution; the required mass ratio of glucose to ammonium metatungstate is (6-10):1; S212. The clear and transparent solution is heated in a sealed hydrothermal reactor to react; S213. The reaction product was filtered, washed several times and dried; S214. The dried sample is calcined to obtain spherical tungsten carbide; S215. The fluorinated silane coupling agent and ethanol are mixed uniformly to form a first solution; S216. Dilute ammonium hydroxide with deionized water to form a second solution; S217. Spherical tungsten carbide is added to the second solution, and continuously dispersed to form a uniform suspension of tungsten carbide as a third solution; S218. The third solution is slowly added to the first solution to react, and the precipitate is separated and dried to obtain super-hydrophobic spherical tungsten carbide; Alternatively, the super-hydrophobic tungsten carbide is a super-hydrophobic sheet tungsten carbide, which is prepared by the following method, comprising the following steps: S221. Dicyandiamide and the required amount of ammonium metatungstate are fully ground in an agate grinding jar; the mass ratio of dicyandiamide and ammonium metatungstate (0.3-5): 1; S222. The obtained solid mixture is pyrolyzed and calcined to obtain lamellar tungsten carbide; S223. The fluorinated silane coupling agent and ethanol are mixed uniformly to form a first solution; S224. Dilute ammonium hydroxide with deionized water to form a second solution; S225. The tungsten carbide flakes are added to the second solution and continuously dispersed to form a uniform suspension of tungsten carbide as a third solution; S226. The third solution is slowly added to the first solution to react, and the precipitate is separated and dried to obtain super-hydrophobic tungsten carbide sheets; S3. Spray the super-hydrophobic tungsten carbide suspension of S2 onto the semi-cured base resin of S1, and form a photothermal layer after curing.

2. The method for preparing a super-hydrophobic coating having photothermal properties according to claim 1, wherein In S1, the substrate is one of glass, steel sheet, tinplate, wood, and acrylic board.

3. The method for preparing a super-hydrophobic coating having photothermal properties according to claim 1, wherein In S1, the fluorocarbon resin is added to an organic solvent, and the viscosity is adjusted to 50-70 s by using a Tu-4 viscometer, and then sprayed on the substrate.

4. The method for preparing a super-hydrophobic coating having photothermal properties according to claim 3, wherein In S1, the organic solvent used to adjust the viscosity is one or more of butyl acetate, ethyl acetate, n-hexane, xylene, and propylene glycol methyl ether.

5. The method for preparing a super-hydrophobic coating having photothermal properties according to claim 1, wherein In S2, the solvent is one or more of N, N-dimethylformamide, anhydrous ethanol, propylene glycol methyl ether, and ethyl acetate, and the mass fraction of superhydrophobic tungsten carbide in the solvent is 0.5%-7%.

6. A super-hydrophobic coating with photothermal properties, which is prepared by the preparation method described in any one of claims 1 to 5.

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