A photothermal superhydrophobic coating, its preparation method and application

Abstract

The present invention relates to the technical field of coatings, and specifically relates to a photothermal superhydrophobic coating, a preparation method thereof, and an application thereof. The present invention provides a photothermal superhydrophobic coating, which comprises the following raw materials in parts by weight: 3-5 parts of organosilicon polysilazane, 5-7 parts of methylphenyl polysiloxane, 3-5 parts of vinyl chloride-vinyl acetate copolymer, 4-6 parts of modified iron oxide, 5-7 parts of fluorinated multi-walled carbon nanotubes, 4-6 parts of fluorinated black titanium dioxide, 59-82 parts of organic solvent, and 0.02-0.2 parts of defoamer; wherein the modified iron oxide is iron oxide coated with copper chloride. The photothermal superhydrophobic coating provided by the present invention has ultra-high hydrophobic performance and good photothermal conversion performance, the water contact angle can reach more than 155°, the rolling angle is less than 10°, and the surface hardness of the coating is 4H or above, and the adhesion is grade 0, with excellent comprehensive performance.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and particularly relates to a photothermal superhydrophobic coating, a preparation method thereof, and an application thereof. Background Art

[0002] Transmission lines are exposed to complex atmospheric environments for a long time and are extremely vulnerable to the influence of extreme weather such as rain, snow, and icing, which seriously threatens the safe and stable operation of the power grid. Especially in cold and humid regions, ice and snow are likely to accumulate on the surfaces of power insulators and cables, resulting in a decline in insulation performance, and further causing electrical faults such as flashover and pollution flashover. In addition, icing will also increase the mechanical load of the line, causing accidents such as wire breakage and tower collapse, which not only brings huge economic losses but also may affect the normal power supply of society.

[0003] Currently, to reduce the impact of ice and snow disasters on transmission lines, superhydrophobic coatings are usually coated on the surfaces of insulators or cables, and their low surface energy characteristics are used to reduce the adhesion of ice and snow. However, the existing superhydrophobic coatings still have the following technical defects: (1) After being exposed to external environments such as ultraviolet rays, temperature changes, and mechanical friction for a long time, the microscopic rough structure of the coating is easily damaged, resulting in a significant decrease in the hydrophobic performance (such as water contact angle and rolling angle); (2) Traditional superhydrophobic coatings lack the ability to actively de-ice and only rely on passive anti-icing, and ice accumulation may still occur under continuous low-temperature and high-humidity conditions; (3) Some fluorine-containing low-surface-energy substances such as polytetrafluoroethylene are prone to degradation after long-term outdoor use, further reducing the durability of the coating.

[0004] Therefore, the existing superhydrophobic coatings are still difficult to effectively prevent pollution flashover accidents for a long time, and there is an urgent need to develop a new type of protective material with both high hydrophobic stability and active de-icing function. Summary of the Invention

[0005] In view of this, the present invention provides a photothermal superhydrophobic coating, a preparation method thereof, and an application thereof. The photothermal superhydrophobic coating has ultra-high hydrophobic performance and good photothermal conversion performance, and the water contact angle can reach more than 155°, and the rolling angle is less than 10°.

[0006] To solve the above technical problems, the present invention provides a photothermal superhydrophobic coating, which comprises the following raw materials in parts by weight: 3-5 parts of organosilicon polysilazane, 5-7 parts of methylphenyl polysiloxane, 3-5 parts of vinyl chloride-vinyl acetate copolymer, 4-6 parts of modified iron oxide, 5-7 parts of fluorinated multi-walled carbon nanotubes, 4-6 parts of fluorinated black titanium dioxide, 59-82 parts of organic solvent, and 0.02-0.2 parts of defoamer; the modified iron oxide is iron oxide coated with copper chloride.

[0007] The present invention uses organosilicon polysilazane, methylphenyl polysiloxane, and a copolymer of vinyl chloride and vinyl acetate as a mixed film-forming substance to obtain a coating film that is firm, wear-resistant, and has long-lasting weather resistance. Among them, organosilicon polysilazane and methylphenyl polysiloxane have good electrical properties, mechanical properties, and weather resistance, ensuring that the coating has good comprehensive properties; the copolymer of vinyl chloride and vinyl acetate serves as the main bonding force, which can enhance the adhesion of the coating and the cohesion of the coating to the powder filler. Copper chloride-coated iron oxide, fluorinated black titanium dioxide, and fluorinated multi-walled carbon nanotubes are used as metal-based, ceramic-based, and carbon-based materials in the photothermal conversion unit respectively. When used in combination, they can produce effects such as high conversion efficiency and long-lasting conversion time, enabling the coating surface to have a superhydrophobic biomimetic micro-nano structure and an extremely low surface tension, thus taking into account both superhydrophobic and photothermal effects.

[0008] Moreover, the present invention utilizes the differences in density and particle size of copper chloride-coated iron oxide, fluorinated black titanium dioxide, and fluorinated multi-walled carbon nanotubes. After spraying them on the surface of an object as fillers, the heat-generating unit, copper chloride-coated iron oxide, and fluorinated black titanium dioxide are intertwined with each other, and the fluorinated multi-walled carbon nanotubes are located on the outermost layer of the coating, forming a finer micro-nano structure on the coating surface, ensuring that the photothermal unit can receive direct sunlight and increase the temperature of the coating surface.

[0009] Combined with the first aspect, the modified iron oxide is prepared by the following method: adding iron oxide to an aqueous solution of copper chloride and stirring for 4 - 6 h, then separating the solid and liquid, collecting the iron oxide, and drying the moisture. Then, sintering is carried out at 650 - 750 °C for 1 - 3 h.

[0010] Exemplarily, the modified iron oxide is prepared by the following method: adding 180 - 220 g of copper chloride powder to 1 L of water to obtain an aqueous solution of copper chloride, adding 100 g of iron oxide powder, and stirring for 4 - 6 h. Then, separating the solid and liquid, collecting the solid iron oxide powder, and drying it in an oven to volatilize the moisture. Then, transferring the dried iron oxide powder into a crucible and sintering it at 700 °C for 2 h to melt the copper chloride on the surface of the iron oxide. After that, cooling and sieving are carried out to obtain copper chloride-coated iron oxide powder.

[0011] Coating the iron oxide powder with copper chloride can not only ensure good photothermal conversion efficiency of the coating but also reduce the surface tension of the iron oxide powder, enabling it to be more evenly dispersed in the coating and avoiding agglomeration.

[0012] Combined with the first aspect, the particle size of the modified iron oxide is 2 - 6 μm, preferably 2.6 - 5.5 μm.

[0013] Combined with the first aspect, both the fluorinated multi-walled carbon nanotubes and the fluorinated black titanium dioxide are fluorinated using ammonium hexafluorotitanate and boric acid. The steps include:

[0014] Add multi-walled carbon nanotubes and black titanium dioxide into water to obtain a suspension. After heating the suspension to 55 - 75 °C, add ammonium hexafluorotitanate under stirring, and adjust the pH of the suspension to 2.5 - 3 with boric acid. Continue stirring for 3 - 4 h, followed by solid-liquid separation, washing, and drying to obtain fluorinated multi-walled carbon nanotubes and fluorinated black titanium dioxide.

[0015] Exemplarily, both the fluorinated multi-walled carbon nanotubes and the fluorinated black titanium dioxide are fluorinated using ammonium hexafluorotitanate and boric acid. The steps include: adding 28 - 32 g of multi-walled carbon nanotubes and 23 - 28 g of black titanium dioxide into 1 L of water, ultrasonically homogenizing to obtain a suspension, magnetically stirring and heating to 55 - 75 °C, dropping 10 g of ammonium hexafluorotitanate under stirring, adjusting the pH value to 2.5 - 3 by dropping boric acid, continuously stirring for 3 - 4 hours, then performing solid-liquid separation, washing the solid with water to remove free ammonium hexafluorotitanate, and drying to obtain fluorinated multi-walled carbon nanotubes and fluorinated black titanium dioxide.

[0016] Combined with the first aspect, the outer diameter of the fluorinated multi-walled carbon nanotubes is 5 - 30 nm, and the length is 2 - 10 μm.

[0017] Preferably, the outer diameter of the fluorinated multi-walled carbon nanotubes is 10 - 20 nm, and the length is 2 - 8 μm.

[0018] Combined with the first aspect, the organic solvent includes 50 - 68 parts of ethyl acetate and / or butyl acetate, and 9 - 14 parts of cyclohexanone and / or xylene.

[0019] Preferably, the organic solvent includes 56 parts of ethyl acetate and / or butyl acetate, and 11 parts of cyclohexanone and / or xylene.

[0020] Combined with the first aspect, the defoaming agent is an organosilicon defoaming agent. The surface tension of the organosilicon defoaming agent is extremely low, and it has strong diffusibility, which can break bubbles, remove bubbles, and inhibit foaming of the coating, making the surface of the coating smooth and the internal structure dense.

[0021] Combined with the first aspect, the particle size of the fluorinated black titanium dioxide is 1 - 3 μm, preferably 1 - 2 μm.

[0022] The second aspect of the present invention provides a preparation method of the above-mentioned photothermal superhydrophobic coating. The steps include: by mass, adding the organosilicon polysilazane, methylphenyl polysiloxane, and vinyl chloride-vinyl acetate copolymer into the organic solvent and mixing evenly, adding the defoaming agent and mixing evenly to obtain a diluted solution of the film-forming substance; continuing to add the modified magnetite, fluorinated multi-walled carbon nanotubes, and fluorinated black titanium dioxide while stirring, and ultrasonically dispersing the raw materials evenly for 2 - 3 h to obtain the photothermal superhydrophobic coating.

[0023] To ensure the texture uniformity of the obtained coating, the coating can be filtered after ultrasonic treatment for 2 - 3 hours to better meet the application requirements.

[0024] Exemplarily, an 80 - mesh nylon filter cloth can be used for filtration, or other filtration methods can also be adopted.

[0025] The third aspect of the present invention also provides an application of the above - mentioned photothermal superhydrophobic coating or the photothermal superhydrophobic coating prepared according to the above - mentioned preparation method in power cables, building materials, transportation vehicles, and industrial facilities.

[0026] Coating the photothermal superhydrophobic coating provided by the present invention on a power cable or an insulator can effectively prevent the external environment from damaging the power line. Especially after the power line is covered with ice, the coating formed by this coating can increase the surface temperature under sunlight irradiation to accelerate the melting of ice and snow, thereby reducing or even avoiding the occurrence of flashover phenomena and effectively ensuring the safe operation of the power system.

[0027] The photothermal superhydrophobic coating provided by the present invention has significant advantages in the field of power system protection. When this coating is applied to the surface of a power cable or an insulator, a functional coating with excellent protective performance can be formed. On the one hand, this coating effectively blocks the erosion of the external environment on the power line through its superhydrophobic property. On the other hand, relying on its photothermal conversion performance, it can significantly increase the surface temperature under sunlight irradiation. This property enables the coating to accelerate the melting process of ice and snow in winter icing conditions, thereby greatly reducing the probability of flashover accidents. Coating this coating on power equipment can significantly improve its operation reliability in harsh environments and provide an important guarantee for the safe and stable operation of the power system.

[0028] Through specific selection of the formulation composition, the present invention obtains a superhydrophobic coating with a water contact angle greater than 150° and a water rolling angle less than 10°. After being irradiated by natural light, the surface temperature of this coating will be significantly higher than the ambient temperature, which can promote the melting of ice and snow on the coating surface and avoid line failures. Moreover, the coating formed after the coating is cured also has a high hardness, and the water contact angle is still above 150° after being polished 10 times with an 80 - mesh sandpaper under a load of 500 g. Description of the Drawings

[0029] Figure 1 It is the hydrophobic effect diagram of the coating corresponding to the coating obtained in Example 1;

[0030] Figure 2 It is the test diagram of the water contact angle of the coating corresponding to the coating obtained in Example 1;

[0031] Figure 3 It is the test diagram of the rolling angle of the coating corresponding to the coating obtained in Example 1;

[0032] Figure 4Photothermal effect on-site test photos of the coating corresponding to the coating obtained in Example 1. Detailed implementation mode

[0033] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following further elaborates on the present invention in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] Those skilled in the art of the present technology can understand that unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with the meaning in the context of the prior art and will not be interpreted with an idealized or overly formal meaning unless specifically defined.

[0035] Existing superhydrophobic coatings are prone to damage to the microscopic structure of the coating and degradation of the main materials may also occur when exposed to external environments such as ultraviolet rays or mechanical friction for a long time, significantly reducing the hydrophobic performance; moreover, traditional superhydrophobic coatings hardly have a photothermal effect and icing accumulation may occur under continuous low-temperature and high-humidity conditions, increasing potential safety hazards. For this reason, the present invention provides a photothermal superhydrophobic coating, which has excellent superhydrophobic performance, good surface hardness and photothermal conversion ability. It can not only reduce the adhesion of ice, snow and rainwater on its surface, but also increase the surface temperature under natural light irradiation, thereby accelerating the melting of icing and avoiding the occurrence of flashover accidents.

[0036] The preparation method provided by the present invention is described below through specific embodiments.

[0037] The raw material reagents and equipment used in the present invention are all conventional commercially available ordinary reagents and ordinary equipment.

[0038] Among them, the organosilicon polysilazane used has a main chain formed by covalent bonding of silicon atoms and nitrogen atoms, and also contains organic groups as side chains. Its typical structural formula is shown in Formula I, where the methyl groups in the side chain groups can be partially or completely replaced by ethyl, vinyl, hydrogen or phenyl groups. Methylphenyl polysiloxane is a polymer with a silicon-oxygen bond as the main chain and containing methyl and phenyl organic groups. Among them, some methyl and phenyl groups can be replaced by hydrogen, or the hydrogen in methyl or phenyl can be replaced by halogen or methyl. The copolymer of vinyl chloride and vinyl acetate is a high molecular compound formed by polymerization of these two monomers, and its molecular formula is (C2H3Cl) x (C4H6O2) y . The defoamer used is a commercially available organosilicon defoamer. For example, the defoamer with the model number BYK141 can be selected.

[0039]

[0040] Formula Ⅰ

[0041] Example 1

[0042] This example provides a photothermal superhydrophobic coating, which comprises raw materials in the following parts by weight:

[0043] 4 parts of organosilicon polysilazane, 6 parts of methylphenyl polysiloxane, 4 parts of vinyl chloride-vinyl acetate copolymer, 5 parts of copper chloride-coated iron oxide powder, 6 parts of fluorinated multi-walled carbon nanotubes, 5 parts of fluorinated black titanium dioxide, 56 parts of ethyl acetate, 11 parts of cyclohexanone, and 0.05 part of organosilicon defoamer.

[0044] The photothermal superhydrophobic coating is prepared according to the following method:

[0045] According to the above parts by mass, add organosilicon polysilazane, methylphenyl polysiloxane, and vinyl chloride-vinyl acetate copolymer into the mixed solution of ethyl acetate and cyclohexanone, stir evenly, then add organosilicon defoamer and mix evenly to obtain a diluent of the film-forming substance. Continuously add copper chloride-coated iron oxide powder, fluorinated multi-walled carbon nanotubes, and fluorinated black titanium dioxide while stirring, and ultrasonically disperse each component evenly for 2 h to obtain the photothermal superhydrophobic coating.

[0046] Among them, the above copper chloride-coated iron oxide powder is prepared according to the following method:

[0047] Add 200 g of copper chloride powder into 1 L of water to obtain an aqueous copper chloride solution, add 100 g of iron oxide powder, stir for 5 h, then perform solid-liquid separation, collect the solid iron oxide powder, and dry it in an oven at 100 °C for 1 h to volatilize the water. Then transfer the dried iron oxide powder into a crucible and sinter it at 700 °C for 2 h to melt the copper chloride on the surface of the iron oxide. After cooling and sieving, copper chloride-coated iron oxide powder is obtained.

[0048] The above fluorinated multi-walled carbon nanotubes and fluorinated black titanium dioxide are prepared according to the following method:

[0049] Add 30 g of multi-walled carbon nanotubes and 25 g of black titanium dioxide into 1 L of water, ultrasonically disperse to obtain a suspension, stir magnetically and heat to 70 °C, drop 10 g of ammonium hexafluorotitanate while stirring, then dropwise add boric acid to adjust the pH value to 2.5 - 3 while stirring, continuously stir for 4 hours (keep the pH value at 2.5 - 3), then perform solid-liquid separation, wash the solid with water to remove free ammonium hexafluorotitanate, and dry the water to obtain fluorinated multi-walled carbon nanotubes and fluorinated black titanium dioxide.

[0050] In addition, the particle size of the copper chloride-coated iron oxide powder used in this example is 2-4 μm, the outer diameter of the fluorinated multi-walled carbon nanotubes is 20-30 nm, the tube length is 2-10 μm, and the particle size of the fluorinated black titanium dioxide is 1-2 μm.

[0051] Example 2

[0052] This example provides a photothermal superhydrophobic coating, which comprises raw materials in the following parts by weight:

[0053] 5 parts of organosilicon polysilazane, 7 parts of methylphenyl polysiloxane, 3 parts of vinyl chloride-vinyl acetate copolymer, 5 parts of copper chloride-coated iron oxide powder, 5 parts of fluorinated multi-walled carbon nanotubes, 6 parts of fluorinated black titanium dioxide, 52 parts of ethyl acetate, 14 parts of xylene, and 0.02 part of organosilicon defoamer.

[0054] The photothermal superhydrophobic coating is prepared according to the following method:

[0055] According to the above parts by mass, add organosilicon polysilazane, methylphenyl polysiloxane, and vinyl chloride-vinyl acetate copolymer into the mixed solution of ethyl acetate and cyclohexanone, stir evenly, then add organosilicon defoamer and mix evenly to obtain a diluent of the film-forming substance. Continuously add the copper chloride-coated iron oxide powder, fluorinated multi-walled carbon nanotubes, and fluorinated black titanium dioxide while stirring, and ultrasonicate for 3 h to disperse each component evenly to obtain the photothermal superhydrophobic coating.

[0056] Among them, the above copper chloride-coated iron oxide powder is prepared according to the following method:

[0057] Add 180 g of copper chloride powder into 1 L of water to obtain an aqueous copper chloride solution, add 100 g of iron oxide powder, stir for 4 h, then perform solid-liquid separation, collect the solid iron oxide powder, and dry it in an oven at 100 °C for 1 h to volatilize the water. Then transfer the dried iron oxide powder into a crucible and sinter it at 650 °C for 3 h to melt the copper chloride on the surface of the iron oxide. After that, cool and screen to obtain the copper chloride-coated iron oxide powder.

[0058] The above fluorinated multi-walled carbon nanotubes and fluorinated black titanium dioxide are prepared according to the following method:

[0059] Add 28 g of multi-walled carbon nanotubes and 28 g of black titanium dioxide into 1 L of water, ultrasonicate evenly to obtain a suspension, stir magnetically and heat to 60 °C, drop 10 g of ammonium hexafluorotitanate while stirring, then dropwise add boric acid while stirring to adjust the pH value to 2.5-3, continuously stir for 3.5 hours (keep the pH value at 2.5-3), then perform solid-liquid separation, wash the solid with water to remove the free ammonium hexafluorotitanate, and dry the water to obtain the fluorinated multi-walled carbon nanotubes and fluorinated black titanium dioxide.

[0060] In addition, the particle size of the copper chloride-coated iron oxide powder used in this example is 3-6 μm, the outer diameter of the fluorinated multi-walled carbon nanotubes is 5-15 nm, the tube length is 2-6 μm, and the particle size of the fluorinated black titanium dioxide is 1-3 μm.

[0061] Example 3

[0062] This example provides a photothermal superhydrophobic coating, which includes the following raw materials in parts by weight:

[0063] 3 parts of organosilicon polysilazane, 5 parts of methylphenyl polysiloxane, 5 parts of vinyl chloride-vinyl acetate copolymer, 6 parts of copper chloride-coated iron oxide powder, 7 parts of fluorinated multi-walled carbon nanotubes, 4 parts of fluorinated black titanium dioxide, 68 parts of butyl acetate, 9 parts of cyclohexanone, and 0.18 part of organosilicon defoamer.

[0064] The photothermal superhydrophobic coating is prepared according to the following method:

[0065] According to the above parts by mass, add organosilicon polysilazane, methylphenyl polysiloxane, and vinyl chloride-vinyl acetate copolymer to the mixed solution of ethyl acetate and cyclohexanone, stir evenly, then add organosilicon defoamer and mix evenly to obtain a diluent of the film-forming substance. Continue to add the copper chloride-coated iron oxide powder, fluorinated multi-walled carbon nanotubes, and fluorinated black titanium dioxide while stirring, and ultrasonically disperse the components evenly for 2.5 h to obtain the photothermal superhydrophobic coating.

[0066] Among them, the above-mentioned copper chloride-coated iron oxide powder is prepared according to the following method:

[0067] Add 220 g of copper chloride powder to 1 L of water to obtain an aqueous copper chloride solution, add 100 g of iron oxide powder, stir for 6 h, then separate the solid and liquid, collect the solid iron oxide powder, and dry it in an oven at 100 °C for 1 h to volatilize the water. Then transfer the dried iron oxide powder into a crucible and sinter it at 750 °C for 1 h to melt the copper chloride on the surface of the iron oxide. Then cool and sieve to obtain the copper chloride-coated iron oxide powder.

[0068] The above-mentioned fluorinated multi-walled carbon nanotubes and fluorinated black titanium dioxide are prepared according to the following method:

[0069] Add 32 g of multi-walled carbon nanotubes and 23 g of black titanium dioxide to 1 L of water and ultrasonically disperse them evenly to obtain a suspension. Stir magnetically and heat to 75 °C. Drop 10 g of ammonium hexafluorotitanate while stirring, and then dropwise add boric acid while stirring to adjust the pH value to 2.5-3. Continuously stir for 4 hours (maintaining the pH value at 2.5-3), then separate the solid and liquid, wash the solid with water to remove the free ammonium hexafluorotitanate, and dry the water to obtain the fluorinated multi-walled carbon nanotubes and fluorinated black titanium dioxide.

[0070] In addition, the particle size of the copper chloride-coated iron oxide powder used in this example is 2 - 6 μm, the outer diameter of the fluorinated multi-walled carbon nanotubes is 10 - 30 nm, the tube length is 3 - 6 μm, and the particle size of the fluorinated black titanium dioxide is 1.5 - 3 μm.

[0071] Comparative Example 1

[0072] This comparative example provides a coating, including raw materials in the following parts by weight:

[0073] 4 parts of organosilicon polysilazane, 6 parts of methylphenyl polysiloxane, 4 parts of vinyl chloride-vinyl acetate copolymer, 5 parts of iron oxide powder, 6 parts of fluorinated multi-walled carbon nanotubes, 5 parts of fluorinated black titanium dioxide, 56 parts of ethyl acetate, 11 parts of cyclohexanone, and 0.05 part of organosilicon defoamer.

[0074] The difference between the coating composition of this comparative example and that of Example 1 lies in that the used iron oxide powder is not coated with copper chloride, and the remaining raw materials and preparation method are the same as those of Example 1, which will not be elaborated here.

[0075] Comparative Example 2

[0076] This comparative example provides a coating, including raw materials in the following parts by weight:

[0077] 4 parts of organosilicon polysilazane, 6 parts of methylphenyl polysiloxane, 4 parts of vinyl chloride-vinyl acetate copolymer, 5 parts of copper chloride-coated iron oxide powder, 6 parts of multi-walled carbon nanotubes, 5 parts of black titanium dioxide, 56 parts of ethyl acetate, 11 parts of cyclohexanone, and 0.05 part of organosilicon defoamer.

[0078] The difference between the coating composition of this comparative example and that of Example 1 lies in the use of unfluorinated multi-walled carbon nanotubes and black titanium dioxide, and the remaining raw materials and preparation method are the same as those of Example 1, which will not be elaborated here.

[0079] Comparative Example 3

[0080] This comparative example provides a coating, including raw materials in the following parts by weight:

[0081] 8 parts of methylphenyl polysiloxane, 6 parts of vinyl chloride-vinyl acetate copolymer, 5 parts of copper chloride-coated iron oxide powder, 6 parts of fluorinated multi-walled carbon nanotubes, 5 parts of fluorinated black titanium dioxide, 56 parts of ethyl acetate, 11 parts of cyclohexanone, and 0.05 part of organosilicon defoamer.

[0082] The difference between the coating composition of this comparative example and that of Example 1 lies in the non-addition of organosilicon polysilazane, and the remaining raw materials and preparation method are the same as those of Example 1, which will not be elaborated here.

[0083] Comparative Example 4

[0084] This comparative example provides a coating, comprising raw materials in the following parts by weight:

[0085] 7 parts of organosilicon polysilazane, 7 parts of vinyl chloride-vinyl acetate copolymer, 5 parts of copper chloride-coated iron oxide powder, 6 parts of fluorinated multi-walled carbon nanotubes, 5 parts of fluorinated black titanium dioxide, 56 parts of ethyl acetate, 11 parts of cyclohexanone, 0.05 part of organosilicon defoamer.

[0086] The difference between the coating composition of this comparative example and that of Example 1 lies in that methylphenyl polysiloxane is not added, and the remaining raw materials and preparation methods are the same as those of Example 1, which will not be elaborated herein.

[0087] Comparative Example 5

[0088] This comparative example provides a coating, comprising raw materials in the following parts by weight:

[0089] 6 parts of organosilicon polysilazane, 8 parts of methylphenyl polysiloxane, 5 parts of copper chloride-coated iron oxide powder, 6 parts of fluorinated multi-walled carbon nanotubes, 5 parts of fluorinated black titanium dioxide, 56 parts of ethyl acetate, 11 parts of cyclohexanone, 0.05 part of organosilicon defoamer.

[0090] The difference between the coating composition of this comparative example and that of Example 1 lies in that vinyl chloride-vinyl acetate copolymer is not added, and the remaining raw materials and preparation methods are the same as those of Example 1, which will not be elaborated herein.

[0091] Comparative Example 6

[0092] This comparative example provides a coating, comprising raw materials in the following parts by weight:

[0093] 4 parts of organosilicon polysilazane, 6 parts of methylphenyl polysiloxane, 4 parts of vinyl chloride-vinyl acetate copolymer, 9 parts of fluorinated multi-walled carbon nanotubes, 7 parts of fluorinated black titanium dioxide, 56 parts of ethyl acetate, 11 parts of cyclohexanone, 0.05 part of organosilicon defoamer.

[0094] The difference between the coating composition of this comparative example and that of Example 1 lies in that copper chloride-coated iron oxide powder is not added, and the remaining raw materials and preparation methods are the same as those of Example 1, which will not be elaborated herein.

[0095] Comparative Example 7

[0096] This comparative example provides a coating, comprising raw materials in the following parts by weight:

[0097] 4 parts of organosilicon polysilazane, 6 parts of methylphenyl polysiloxane, 4 parts of vinyl chloride-vinyl acetate copolymer, 9 parts of copper chloride-coated iron oxide powder, 10 parts of fluorinated black titanium dioxide, 56 parts of ethyl acetate, 11 parts of cyclohexanone, 0.05 part of organosilicon defoamer.

[0098] The difference in the coating composition between this comparative example and Example 1 lies in that fluorinated multi-walled carbon nanotubes are not added, and the remaining raw materials and preparation methods are the same as those in Example 1, which will not be elaborated here.

[0099] Comparative Example 8

[0100] This comparative example provides a coating, including the following raw materials in parts by weight:

[0101] 4 parts of organosilicon polysilazane, 6 parts of methylphenyl polysiloxane, 4 parts of vinyl chloride-vinyl acetate copolymer, 8 parts of copper chloride-coated iron oxide powder, 8 parts of fluorinated multi-walled carbon nanotubes, 56 parts of ethyl acetate, 11 parts of cyclohexanone, 0.05 part of organosilicon defoamer.

[0102] The difference in the coating composition between this comparative example and Example 1 lies in that fluorinated black titanium dioxide is not added, and the remaining raw materials and preparation methods are the same as those in Example 1, which will not be elaborated here.

[0103] Inspection Example

[0104] The coatings obtained in Examples 1 to 3 and Comparative Examples 1 to 8 were respectively coated on the surface of the substrate with a film thickness of 15 ± 2 μm and dried at room temperature of 25°C for 24 hours. The water contact angle and rolling angle (refer to the standard GB / T 45017-2024 "Mechanical Stability Test Method for Superhydrophobic Surfaces"), adhesion (refer to the standard GB / T1720-2020 "Cross-Cut Test for Paint Films"), photothermal effect (irradiated with natural light with a light intensity of 500 W / m² for 30 min), and hardness (refer to the standard GB / T 6739-2006 "Determination of Film Hardness by Pencil Method for Paints and Varnishes") of the obtained coatings were respectively tested, and the test results are shown in Table 1.

[0105] Table 1

[0106]

[0107] It can be seen from the data in Table 1 that the water contact angles of the photothermal superhydrophobic coatings provided by the present invention are all above 155°, the rolling angles are all less than 10°, and they have good adhesion and photothermal conversion performance. The adhesion to glass substrates and stainless steel substrates is both grade 0, the surface hardness of the coating is 4H, and the water contact angle can still remain above 150° after being polished, indicating that the photothermal superhydrophobic coatings provided by the present invention have excellent comprehensive performance.

[0108] The hydrophobic effect diagram of the coating corresponding to the coating obtained in Example 1 is as Figure 1 shown, and the test diagrams of the water contact angle and rolling angle of the corresponding coating are respectively Figures 2-3 shown, and the on-site test photos of the surface temperature and the surrounding environment temperature after being irradiated with natural light with a power of 500 W / m² for 30 min are as Figure 4As shown, it can be seen that after illumination, the temperature on the surface of the coating is much higher than that of the surrounding environment, indicating that the coating has good photothermal conversion performance.

[0109] The above are only the preferred specific embodiments 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 photothermal superhydrophobic coating, characterized in that, It comprises raw materials in the following parts by weight: 3 - 5 parts of organosilicon polysilazane, 5 - 7 parts of methylphenyl polysiloxane, 3 - 5 parts of vinyl chloride - vinyl acetate copolymer, 4 - 6 parts of modified iron oxide, 5 - 7 parts of fluorinated multi - walled carbon nanotubes, 4 - 6 parts of fluorinated black titanium dioxide, 59 - 82 parts of organic solvent, and 0.02 - 0.2 parts of defoamer; The modified iron oxide is prepared as follows: Iron oxide is added to an aqueous solution of copper chloride and stirred for 4 - 6 h, then solid - liquid separation is carried out, the iron oxide is collected and dried to remove moisture, and then sintered at 650 - 750 °C for 1 - 3 h; Both the fluorinated multi - walled carbon nanotubes and the fluorinated black titanium dioxide are fluorinated with ammonium hexafluorotitanate and boric acid. The steps include: adding multi - walled carbon nanotubes and black titanium dioxide into water to obtain a suspension, heating to 55 - 75 °C, then adding ammonium hexafluorotitanate under stirring, adjusting the pH of the suspension to 2.5 - 3 with boric acid, and continuing to stir for 3 - 4 h. After solid - liquid separation, washing and drying, fluorinated multi - walled carbon nanotubes and fluorinated black titanium dioxide are obtained.

2. The photothermal superhydrophobic coating according to claim 1, wherein The particle size of the modified iron oxide is 2 - 6 μm.

3. The photothermal superhydrophobic coating according to claim 1, wherein The tube diameter of the fluorinated multi - walled carbon nanotubes is 5 - 30 nm, and the length is 2 - 10 μm.

4. The photothermal superhydrophobic coating according to claim 1, wherein The particle size of the fluorinated black titanium dioxide is 1 - 3 μm.

5. The photothermal superhydrophobic coating according to claim 1, wherein The organic solvent includes 50 - 68 parts of ethyl acetate and / or butyl acetate, and 9 - 14 parts of cyclohexanone and / or xylene.

6. The photothermal superhydrophobic coating according to claim 1, wherein The defoamer is an organosilicon defoamer.

7. The preparation method of the photothermal superhydrophobic coating according to any one of claims 1 to 6, characterized in that the steps It includes: By mass fraction, the organosilicon polysilazane, methylphenyl polysiloxane and vinyl chloride - vinyl acetate copolymer are added to the organic solvent and mixed evenly, the defoamer is added and mixed evenly to obtain a diluent of the film - forming substance; Then, while stirring, the modified iron oxide, fluorinated multi - walled carbon nanotubes and fluorinated black titanium dioxide are added, and ultrasonic treatment is carried out for 2 - 3 h to disperse all raw materials evenly, thus obtaining the photothermal super - hydrophobic coating.

8. Application of the photothermal super - hydrophobic coating according to any one of claims 1 - 6 or the photothermal super - hydrophobic coating prepared by the preparation method according to claim 7 in power cables, building materials, transportation vehicles and industrial facilities.

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