Low-temperature self-healing photo-thermal ice-resistant coating as well as preparation method and application thereof

Abstract

The invention relates to the field of ice-resistant coatings, and discloses a low-temperature self-healing photo-thermal ice-resistant coating as well as a preparation method and application thereof. The method is carried out in the presence of an organic solvent and comprises the following steps: (1) carrying out first heating treatment on dihydroxyl-terminated polydimethylsiloxane, isophorone diisocyanate and dibutyltin dilaurate to obtain a prepolymer; (2) carrying out second heating treatment on the prepolymer, 4, 4 '-dithio diphenylamine and 4, 4'-bis (hydroxymethyl)-2, 2 '-bipyridine, so as to obtain a polymer SH; and (3) contacting and mixing the polymer SH and graphene oxide to obtain the photo-thermal ice-resistant coating. The photo-thermal ice-resistant coating prepared by the method provided by the invention is applied to the surface of a fan blade as an ice-resistant coating, has good mechanical durability and photo-thermal performance, and is excellent in ice resistance.

Description

Technical Field

[0001] The present invention relates to the field of anti-icing coatings, and in particular to a low-temperature self-healing photothermal anti-icing coating and a preparation method and application thereof. Background Art

[0002] Ice formation is an extremely common natural phenomenon. When the ambient temperature continues to drop below the freezing point of water, condensed water, rain, snow, etc. gathered on the solid surface freeze into ice and wrap the surface layer by layer to form ice. Ice on the surface of outdoor equipment (such as wind turbines, power grids, aircraft, drones, offshore platforms and ships, etc.) will have a serious impact on its safety and performance. For example, in the field of outdoor wind power generation, ice on wind turbine blades will cause power loss, mechanical failure and other problems in wind turbines. Ice on the surface of the blade will change the aerodynamic performance of its surface, causing an imbalance in the aerodynamics and mass of the impeller; and the increase in blade mass will not only increase the torque of the hub and affect the fatigue life at the root of the blade, but also reduce the wind coefficient and wind energy utilization, resulting in power generation loss. Studies have shown that ice on the surface of blades can reduce power generation by more than 80%.

[0003] Anti-icing coatings have the advantages of high anti-icing efficiency, simple operation, no need to consume additional energy, and environmental friendliness, and have become the preferred anti-icing and de-icing method for various engineering applications. However, during the service process, anti-icing coatings will be mechanically damaged due to extremely complex and changeable environments, resulting in scratches or macroscopic defects, which will seriously affect the anti-icing performance of the coating. If the damage is not repaired in a timely and effective manner, it will gradually develop into larger macroscopic defects, and even the coating will peel off and fail, seriously affecting the service life of the coating. Inspired by the fact that biological tissues can heal "wounds" autonomously, self-healing materials have been developed and applied in the field of coatings. Graphene oxide (GO) is an antifreeze protein bionic material that can interact with ice, effectively inhibit ice crystal growth and ice recrystallization, and has good anti-icing activity. At the same time, in addition to its anti-icing activity, graphene oxide also has significant photothermal properties, which can convert solar energy into thermal energy, which helps to improve the photothermal de-icing performance of the coating. These unique properties make graphene oxide an ideal filler for anti-icing coatings. Therefore, by organically combining self-healing materials with GO, it is expected to invent a photothermal anti-icing coating that can self-heal in low-temperature outdoor environments. For example, CN114773977A discloses an anti-icing coating that can self-heal in extreme environments and a preparation method thereof, wherein the anti-icing coating comprises a self-healing polymer SH and a hydrophobic filler; the ratio of the self-healing polymer to the hydrophobic filler is 2:0.01-0.1. The ice shear strength of the self-healing anti-icing coating is about 50 kPa, which is more than 90% lower than that of a bare steel sheet (about 600 kPa), but the anti-icing performance stability of the coating is still poor. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art self-healing coating, such as low healing efficiency and poor anti-icing performance under low temperature conditions.

[0005] In order to achieve the above object, the first aspect of the present invention provides a method for preparing a low-temperature self-healing photothermal anti-icing coating, characterized in that the method is carried out in the presence of an organic solvent, comprising:

[0006] (1) subjecting bihydroxy-terminated polydimethylsiloxane, isophorone diisocyanate and dibutyltin dilaurate to a first heat treatment to obtain a prepolymer;

[0007] (2) subjecting the prepolymer, 4,4'-dithiodiphenylamine and 4,4'-bis(hydroxymethyl)-2,2'-bipyridine to a second heating treatment to obtain a polymer SH;

[0008] (3) contacting and mixing the polymer SH and graphene oxide to obtain the photothermal anti-icing coating;

[0009] Wherein, in step (1), the weight ratio of the dihydroxy-terminated polydimethylsiloxane, the isophorone diisocyanate and the dibutyltin dilaurate is 1:0.08-0.1:0.004-0.005;

[0010] In step (3), the average sheet diameter of the graphene oxide is 1-50 μm, and the average thickness is 4-55 nm.

[0011] Preferably, in step (1), the weight average molecular weight of the dual-terminal hydroxyl polydimethylsiloxane is 4500-6000, and the kinematic viscosity at 25° C. is 1000-5000 mm 2 / s;

[0012] Preferably, the water content of the dual-terminal hydroxyl polydimethylsiloxane is not higher than 0.05 wt %.

[0013] Preferably, in step (2), the weight ratio of the double-terminated hydroxyl polydimethylsiloxane, the 4,4'-dithiodiphenylamine and the 4,4'-bis(hydroxymethyl)-2,2'-bipyridine is 1:0.02-0.025:0.015-0.02.

[0014] Preferably, in step (3), the average sheet diameter of the graphene oxide is 15-50 μm, and the average thickness is 10-50 nm.

[0015] Preferably, in step (3), the weight ratio of the polymer SH to the graphene oxide is 200-400:1.

[0016] Preferably, the conditions of the first heat treatment and the second heat treatment independently include: being carried out in a nitrogen atmosphere, at a temperature of 60-90° C., and for a time of 3-6 hours.

[0017] Preferably, the method further comprises: in step (3), firstly subjecting the graphene oxide and the organic solvent to ultrasonic treatment to obtain a graphene oxide dispersion, and then subjecting the graphene oxide dispersion to the contact mixing.

[0018] Preferably, in the graphene oxide dispersion, the solid content of the graphene oxide at 25° C. is 1-5wt%.

[0019] Preferably, in step (3), the contact mixing conditions include: a stirring speed of 300-500 rpm and a time of 20-60 min.

[0020] The second aspect of the present invention provides a low-temperature self-healing photothermal anti-icing coating prepared by the method described in the first aspect.

[0021] The third aspect of the present invention provides the application of the low-temperature self-healing photothermal anti-icing coating described in the second aspect on the surface of a wind turbine blade.

[0022] Through the above technical solution, the present invention has at least the following advantages over the prior art:

[0023] (1) Compared with traditional anti-icing coatings, the photothermal anti-icing coating prepared by the method provided by the present invention is applied to the surface of wind turbine blades as an anti-icing coating. It can achieve self-healing when damaged under low temperature conditions (0-40°C) and does not require external energy (light, heat, magnetism, etc.), and has good mechanical durability.

[0024] (2) Compared with the traditional self-healing anti-icing coating, the photothermal anti-icing coating provided by the present invention is applied to the surface of the wind turbine blades, which can significantly improve the anti-icing performance of the self-healing anti-icing coating.

[0025] (3) Compared with traditional self-healing anti-icing coatings, the photothermal anti-icing coating provided by the present invention has good anti-icing performance when applied to the surface of wind turbine blades. Its ice shear strength is about 70 kPa, which is about 90% lower than that of bare steel sheets (about 600 kPa).

[0026] (4) Compared with traditional self-healing anti-icing coatings, the photothermal anti-icing coating provided by the present invention is applied to wind turbine blades as an anti-icing coating with good photothermal performance. Under the combined action of sunlight and gravity, the simulated icicles on the surface of the anti-icing coating fall off in 66 seconds, which is easier to fall off than the anti-icing coating in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1This is a principle diagram of the effect of the photothermal anti-icing coatings made from the photothermal anti-icing coatings of Examples 1, 2 and 3 of the present invention;

[0028] Figure 2 It is a comparison chart of ice delay time test of the photothermal anti-icing coatings made of the photothermal anti-icing coatings of Example 1, Example 3, Example 4 and Comparative Example 1 of the present invention;

[0029] Figure 3 It is a comparison chart of ice shear strength tests of photothermal anti-icing coatings made of photothermal anti-icing coatings of Example 1, Example 2, Example 5 and Comparative Example 2 of the present invention;

[0030] Figure 4 These are microscope images of self-healing of the photothermal anti-icing coatings prepared by the photothermal anti-icing coatings of Example 1, Example 2, Example 3 and Comparative Example 1 of the present invention under room temperature, refrigerated (4° C.), and frozen (-20° C.) environments;

[0031] Figure 5 This is a picture showing the deicing effect of the photothermal anti-icing coating made of the photothermal anti-icing coating of Example 1 of the present invention after being damaged / repaired at room temperature;

[0032] Figure 6 This is a graph showing the ice shear strength test results of the photothermal anti-icing coating prepared by the photothermal anti-icing coating of Example 1 of the present invention in 10 damage / repair cycles at room temperature;

[0033] Figure 7 It is a comparison chart of ice shear strength tests of the photothermal anti-icing coatings made of the photothermal anti-icing coatings of Example 1 of the present invention and Comparative Example 1 in 10 damage / self-healing cycles at room temperature. DETAILED DESCRIPTION

[0034] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0035] In the present invention, room temperature refers to a temperature of 23±2°C.

[0036] As mentioned above, the first aspect of the present invention provides a method for preparing a low-temperature self-healing photothermal anti-icing coating, characterized in that the method is carried out in the presence of an organic solvent, comprising:

[0037] (1) subjecting bihydroxy-terminated polydimethylsiloxane, isophorone diisocyanate and dibutyltin dilaurate to a first heat treatment to obtain a prepolymer;

[0038] (2) subjecting the prepolymer, 4,4'-dithiodiphenylamine and 4,4'-bis(hydroxymethyl)-2,2'-bipyridine to a second heating treatment to obtain a polymer SH;

[0039] (3) contacting and mixing the polymer SH and graphene oxide to obtain the photothermal anti-icing coating;

[0040] Wherein, in step (1), the weight ratio of the dihydroxy-terminated polydimethylsiloxane, the isophorone diisocyanate and the dibutyltin dilaurate is 1:0.08-0.1:0.004-0.005;

[0041] In step (3), the average sheet diameter of the graphene oxide is 1-50 μm, and the average thickness is 4-55 nm.

[0042] Preferably, in step (1), the weight average molecular weight of the dual-terminal hydroxyl polydimethylsiloxane is 4500-6000, and the kinematic viscosity at 25° C. is 1000-5000 mm 2 / s.

[0043] Preferably, the water content of the dual-terminal hydroxyl polydimethylsiloxane is not higher than 0.05 wt %.

[0044] Preferably, in step (2), the weight ratio of the bihydroxylated polydimethylsiloxane, the 4,4'-dithiodiphenylamine and the 4,4'-bis(hydroxymethyl)-2,2'-bipyridine is 1:0.02-0.025:0.015-0.02. In this preferred embodiment, the technical solution provided by the present invention can obtain a photothermal anti-icing coating with stronger mechanical durability and better anti-icing performance.

[0045] Preferably, in step (3), the average sheet diameter of the graphene oxide is 15-50 μm, and the average thickness is 10-50 nm. The inventors found that in this preferred case, the technical solution provided by the present invention can obtain a photothermal anti-icing coating with stronger mechanical durability and better anti-icing performance.

[0046] Preferably, in step (3), the weight ratio of the polymer SH to the graphene oxide is 200-400: 1. In this preferred embodiment, the technical solution provided by the present invention can obtain a photothermal anti-icing coating with stronger mechanical durability and better anti-icing performance.

[0047] Preferably, the conditions of the first heat treatment and the second heat treatment independently include: carried out in a nitrogen atmosphere; the temperature is 50-90°C, preferably 60-90°C; the time is 1-5h, preferably 3-6h.

[0048] Preferably, the method further comprises: in step (3), firstly subjecting the graphene oxide and the organic solvent to ultrasonic treatment to obtain a graphene oxide dispersion, and then subjecting the graphene oxide dispersion to the contact mixing.

[0049] Preferably, the conditions of the ultrasonic treatment include: time of 10-30 min, frequency of 20 kHz-50 kHz.

[0050] Preferably, in the graphene oxide dispersion, the solid content of the graphene oxide at 25° C. is 1-5wt%.

[0051] Preferably, in step (3), the contact mixing conditions include: a stirring speed of 300-500 rpm and a time of 20-60 min.

[0052] Preferably, the organic solvent is tetrahydrofuran.

[0053] The present invention has no particular limitation on the instrument used for the contact mixing. Exemplarily, the contact mixing is performed in an electric stirrer.

[0054] The present invention does not particularly limit the amount of the organic solvent, and those skilled in the art can add the organic solvent according to actual conditions, as long as the raw materials in the method are completely dissolved and mixed evenly.

[0055] According to a preferred embodiment, the method further comprises: in step (3), using ultrasound to treat the product obtained by the contact mixing to remove bubbles.

[0056] As mentioned above, the second aspect of the present invention provides a low-temperature self-healing photothermal anti-icing coating prepared by the method described in the first aspect.

[0057] As mentioned above, the third aspect of the present invention provides the application of the low-temperature self-healing photothermal anti-icing coating described in the second aspect on the surface of a wind turbine blade.

[0058] According to a preferred specific embodiment, the application method includes: applying the photothermal anti-icing coating to the upper and lower surfaces of a wind turbine blade and drying it to obtain a low-temperature self-healing photothermal anti-icing coating.

[0059] Preferably, the coating method is at least one of brush coating, spin coating and spray coating.

[0060] Preferably, the drying time is 20-30 hours.

[0061] Preferably, the method further comprises: polishing the wind turbine blade before coating.

[0062] The present invention will be described in detail below by way of examples.

[0063] In the following examples, unless otherwise specified, the instruments, reagents, materials, etc. involved are all conventional instruments, reagents, materials, etc., which can be obtained through conventional commercial channels. In particular, unless otherwise specified, the reagents used are all commercially available analytically pure products.

[0064] Double-terminated hydroxyl polydimethylsiloxane: purchased from Sigma-Aldrich, with the structural formula CAS number is 70131-67-8; weight average molecular weight is 5600, kinematic viscosity at 25°C is 5000mm 2 / s.

[0065] Isophorone diisocyanate: purchased from Shanghai Maimeruier Chemical Technology Co., Ltd., CAS No. 4098-71-9.

[0066] Dibutyltin dilaurate: purchased from Tianjin Yuanli Chemical Co., Ltd., CAS No. 77-58-7.

[0067] 4,4'-Diphenyldisulfide: purchased from Anage (Shanghai) Pharmaceutical Chemistry Co., Ltd., CAS No. 722-27-0.

[0068] 4,4'-Bis(hydroxymethyl)-2,2'-bipyridine: purchased from Shanghai UCHEM Biotechnology Co., Ltd., CAS No. 109073-77-0;

[0069] Graphene oxide: purchased from Suzhou Carbon Graphene Technology Co., Ltd.

[0070] Example 1

[0071] This embodiment is used to illustrate the method for preparing a low-temperature self-healing photothermal anti-icing coating of the present invention. The method is carried out in the presence of an organic solvent and specifically comprises the following steps:

[0072] (1) Add dihydroxy-terminated polydimethylsiloxane into a two-necked flask, stir for 1 h at 100° C. under vacuum conditions to remove moisture, control the water content to 0.05 wt %, and then cool to 70° C.;

[0073] Under nitrogen atmosphere, isophorone diisocyanate and dibutyltin dilaurate were dissolved in 8 mL of ultra-dry N,N-dimethylacetamide and added into a flask, and stirred for a first heating treatment (temperature of 70° C. for 3 h) to obtain a prepolymer having a terminal-isocyanate group.

[0074] (2) dissolving 4,4'-dithiodiphenylamine and 4,4'-bis(hydroxymethyl)-2,2'-bipyridine in 2.5 mL of ultra-dry N,N-dimethylacetamide;

[0075] Then, under the protection of nitrogen atmosphere, the dissolved 4,4'-dithiodiphenylamine and 4,4'-bis(hydroxymethyl)-2,2'-bipyridine were added to the flask and stirred for a second heating treatment (temperature of 70°C for 3 hours) to obtain polymer SH, and the product was dried at 90°C for 24 hours to remove the residual solvent.

[0076] (3) dissolving polymer SH in 10 g of tetrahydrofuran solution, and vigorously stirring the mixture to obtain material A;

[0077] The graphene oxide and the organic solvent (tetrahydrofuran) were subjected to ultrasonic treatment (time of 20 min, frequency of 20 kHz) to obtain material B, i.e., a graphene oxide dispersion having a solid content of 5 wt% at 25° C.;

[0078] Material A and graphene oxide dispersion were stirred for contact mixing (stirring speed was 400 rpm, time was 40 min), and when the reactants were completely dissolved and uniformly dissolved, bubbles were removed by ultrasound (10 min) to obtain material C, which was the photothermal anti-icing coating.

[0079] The materials and their proportions of this embodiment are shown in Table 1.

[0080] Example 2 and Example 3 are both prepared by the same method as Example 1, except that the materials and their proportions are different, as shown in Table 1.

[0081] Table 1 (the amount of double-terminal hydroxyl polydimethylsiloxane is 1g)

[0082]

[0083] Example 4

[0084] This embodiment is carried out in a similar manner to that of Embodiment 1, except that the amount of the dihydroxylated polydimethylsiloxane in this embodiment is kept unchanged, and the weight ratio of the dihydroxylated polydimethylsiloxane, 4,4'-dithiodiphenylamine and 4,4'-bis(hydroxymethyl)-2,2'-bipyridine is adjusted to 1:0.015:0.01 to obtain a photothermal anti-icing coating.

[0085] Example 5

[0086] This embodiment is carried out in a similar manner to that of Embodiment 1, except that the average sheet diameter of graphene oxide in this embodiment is adjusted to 3.5 μm and the average thickness is adjusted to 4.7 nm to obtain a photothermal anti-icing coating.

[0087] Example 6

[0088] This example is carried out in a similar manner to that of Example 1, except that the amount of polymer SH in this example is kept unchanged, and the weight ratio of polymer SH to graphene oxide is adjusted to 50:1 to obtain a photothermal anti-icing coating.

[0089] Comparative Example 1

[0090] This comparative example is carried out in a similar manner to Example 1, except that the amount of dihydroxylated polydimethylsiloxane in this comparative example is kept unchanged, and the weight ratio of dihydroxylated polydimethylsiloxane, isophorone diisocyanate and dibutyltin dilaurate is adjusted to 1:0.15:0.01 to obtain a photothermal anti-icing coating.

[0091] Comparative Example 2

[0092] This comparative example was carried out using a method similar to that of Example 1, except that the average sheet diameter of graphene oxide in this comparative example was adjusted to 65 μm and the average thickness to 70 nm to obtain a photothermal anti-icing coating.

[0093] Test Case

[0094] At room temperature, the photothermal anti-icing coating prepared in the example is applied (brushed) to the upper and lower surfaces of the wind turbine blade that has been polished and cleaned, and dried for 24 hours to obtain a low-temperature self-healing photothermal anti-icing coating;

[0095] The above-mentioned photothermal anti-icing coating was subjected to an icing delay time test, an ice shear strength test, a self-healing test and a photothermal deicing test. The results of the icing delay time test and the ice shear strength test are shown in Table 2.

[0096] Among them, the relevant test methods are as follows:

[0097] Freezing delay time test: Gently wipe the surface of the photothermal anti-icing coating with a dust-free cleaning cloth and place it on a cold table. After the temperature of the coating surface is controlled at -15°C under nitrogen circulation, 5μL of water is added to the coating surface. The time from the moment the water droplet contacts the coating surface to the moment a small tip emerges from the top of the water droplet is recorded. Perform three parallel tests on each coating and take the average value as the freezing delay time of the coating.

[0098] Ice shear strength test: Place the photothermal anti-icing coating on a cold table, and then place a hollow glass cylinder with an inner diameter of 1 cm vertically on the coating surface. After adding 450 μL of deionized water, cover it with a glass cover, control the cold table to make the temperature inside the entire glass cover -15°C, and freeze it in a nitrogen environment for 4 hours to ensure that the water is completely frozen. During the test, the tensile gauge pushes the hollow glass tube on the coating surface at a speed of 0.1 mm / s, and records the maximum shear force from the beginning to the complete detachment of the hollow glass tube from the coating surface, and divides it by the contact area between the ice and the coating surface to obtain the ice shear strength. Each coating is tested three times in parallel.

[0099] Self-healing test: The photothermal anti-icing coating prepared in the example was dripped onto 20×2.5×1mm 3 The coating was placed in a polytetrafluoroethylene mold and scratched with a blade after it was completely dried. The coating was placed at room temperature, 4°C and -20°C for self-healing, and the surface morphology of the coating was observed with an optical microscope to qualitatively test the self-healing performance of the coating.

[0100] Photothermal deicing test: The photothermal anti-icing coating was fixed on a glass slide and then placed on a cold table. A hollow glass cylinder with an inner diameter of 1 cm was placed vertically on the coating surface. After 450 μL of deionized water was added, a glass cover was placed on the cold table. The temperature inside the entire glass cover was controlled to -15°C and frozen in a nitrogen environment for 4 hours to ensure that the water was completely frozen. Then, it was inverted under a light intensity of 1 kW / m 2 on simulated fluorescent lamps.

[0101] Table 2

[0102] Freezing delay time / s Ice shear strength / kPa Example 1 182 69.13 Example 2 153 93.11 Example 3 117 105.67 Example 4 77 130.54 Example 5 97 115.82 Example 6 84 258.69 Comparative Example 1 58 187.51 Comparative Example 2 47 127.75

[0103] The present invention Figure 1 The effect principle diagram of the photothermal anti-icing coating prepared by the photothermal anti-icing coating of Example 1, Example 2 and Example 3 is exemplarily provided; Figure 1 In the figure, "a" corresponds to the structural formula of the photothermal anti-icing coating, "b" corresponds to the effect principle of the photothermal anti-icing coating of the three embodiments, and "c" corresponds to the effect principle of the photothermal anti-icing coating of embodiment 1; among them, embodiment 1, embodiment 2, and embodiment 3 reach the ice nucleation temperature at -28.8°C, -26.0°C, and -23.6°C, respectively, which shows that the method of the present invention can effectively inhibit the formation of ice nuclei and has a significant anti-icing effect.

[0104] The present invention Figure 2 The icing delay time test comparison diagram of the photothermal anti-icing coating prepared by the photothermal anti-icing coating of Example 1, Example 3, Example 4 and Comparative Example 1 is provided as an example; Figure 2It can be seen that the freezing delay time of the photothermal anti-icing coatings prepared by the photothermal anti-icing coatings of Example 1, Example 3, and Example 4 is prolonged to varying degrees compared with the photothermal anti-icing coatings prepared by the photothermal anti-icing coatings of Comparative Example 1, indicating that the photothermal anti-icing coatings prepared by the method provided by the present invention enhance the ice suppression ability of the self-healing anti-icing coating.

[0105] The present invention Figure 3 exemplarily provides a comparison chart of ice shear strength test of the photothermal anti-icing coatings prepared by the photothermal anti-icing coatings of Example 1, Example 2, Example 5 and Comparative Example 2; Figure 3 It can be seen that compared with the ice shear strength (127.75 kPa) of the photothermal anti-icing coating prepared by the photothermal anti-icing coating of comparative example 2, the photothermal anti-icing coatings prepared by the photothermal anti-icing coatings of Example 1, Example 2, and Example 5 are all reduced to varying degrees, among which the photothermal anti-icing coating prepared by the photothermal anti-icing coating of Example 1 has the lowest ice shear strength (69.13 kPa), and the ice shear strength of the photothermal anti-icing coating prepared by the photothermal anti-icing coatings of Example 5 and Example 2 is also reduced to 115.82 kPa and 93.11 kPa respectively. It shows that the photothermal anti-icing coating prepared by the method provided by the present invention improves the deicing performance of the coating.

[0106] The present invention Figure 4 illustratively provides microscopic images of self-healing of the photothermal anti-icing coatings prepared by the photothermal anti-icing coatings of Example 1, Example 2, Example 3 and Comparative Example 1 under room temperature, refrigerated (4°C) and frozen (-20°C) environments; Figure 4 It can be seen that in the absence of external stimulation, the photothermal anti-icing coatings made of the photothermal anti-icing coatings of Example 1, Example 2, Example 3 and Comparative Example 1 can all achieve self-healing at room temperature, 4°C and -20°C. Compared with Comparative Example 1, the photothermal anti-icing coatings made of the photothermal anti-icing coatings of Example 1, Example 2 and Example 3 have faster healing speeds at low temperatures (4°C and -20°C) and have better self-repair properties.

[0107] The present invention Figure 5 The photothermal anti-icing coating prepared by the photothermal anti-icing coating of Example 1 is provided as an example to illustrate the effect of deicing after damage / repair at room temperature; the present invention Figure 6 The figure provides an exemplary ice shear strength test result of the photothermal anti-icing coating prepared by the photothermal anti-icing coating of Example 1 in 10 damage / repair cycles at room temperature. Figure 5 , Figure 6It can be seen that after the photothermal anti-icing coating prepared by the photothermal anti-icing coating of Example 1 was mechanically damaged, the anti-icing performance of the coating was damaged, and the ice shear strength was greatly improved compared with before the damage (about 140 kPa). After the damaged coating was placed at room temperature for repair (self-healing) for 24 hours, its ice shear strength was reduced to about 70 kPa, and the anti-icing performance was restored.

[0108] The present invention Figure 7 , which exemplarily provides a comparison chart of ice shear strength tests of the photothermal anti-icing coatings prepared by the photothermal anti-icing coatings of Example 1 and Comparative Example 1 in 10 damage / self-healing cycles at room temperature; Figure 7 It can be seen that under the combined action of sunlight and gravity, the simulated icicles on the surface of the photothermal anti-icing coating prepared by the photothermal anti-icing coating of Example 1 still exist after 40 seconds of illumination and shed ice at 66 seconds, while the simulated icicles on the coating of Comparative Example 1 remain frozen and motionless.

[0109] It can be seen from the above results that the photothermal anti-icing coating prepared by the method provided by the present invention is applied to the surface of wind turbine blades as an anti-icing coating, has good mechanical durability and photothermal properties, and has excellent anti-icing performance.

[0110] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing a low-temperature self-healing photothermal anti-icing coating, characterized in that: The method is carried out in the presence of an organic solvent and comprises: (1) subjecting bihydroxy-terminated polydimethylsiloxane, isophorone diisocyanate and dibutyltin dilaurate to a first heat treatment to obtain a prepolymer; (2) subjecting the prepolymer, 4,4'-dithiodiphenylamine and 4,4'-bis(hydroxymethyl)-2,2'-bipyridine to a second heating treatment to obtain a polymer SH; (3) contacting and mixing the polymer SH and graphene oxide to obtain the photothermal anti-icing coating; Wherein, in step (1), the weight ratio of the dihydroxy-terminated polydimethylsiloxane, the isophorone diisocyanate and the dibutyltin dilaurate is 1:0.08-0.1:0.004-0.005; In step (3), the average sheet diameter of the graphene oxide is 1-50 μm, and the average thickness is 4-55 nm.

2. The method according to claim 1, wherein: In step (1), the weight average molecular weight of the double-terminal hydroxyl polydimethylsiloxane is 4500-6000, and the kinematic viscosity at 25° C. is 1000-5000 mm 2 / s; And / or, the water content of the dual-terminal hydroxyl polydimethylsiloxane is not higher than 0.05 wt %.

3. The method according to claim 1, wherein: In step (2), the weight ratio of the double-terminal hydroxyl polydimethylsiloxane, the 4,4'-dithiodiphenylamine and the 4,4'-bis(hydroxymethyl)-2,2'-bipyridine is 1:0.02-0.025:0.015-0.

02.

4. The method according to any one of claims 1 to 3, wherein: In step (3), the average sheet diameter of the graphene oxide is 15-50 μm, and the average thickness is 10-50 nm.

5. The method according to any one of claims 1 to 3, wherein: In step (3), the weight ratio of the polymer SH to the graphene oxide is 200-400:

1.

6. The method according to any one of claims 1 to 3, wherein: The conditions of the first heat treatment and the second heat treatment independently include: being carried out in a nitrogen atmosphere, at a temperature of 60-90° C., and for a time of 3-6 hours.

7. The method according to any one of claims 1 to 3, wherein: The method further comprises: in step (3), firstly subjecting the graphene oxide and the organic solvent to ultrasonic treatment to obtain a graphene oxide dispersion, and then subjecting the graphene oxide dispersion to the contact mixing; And / or, in the graphene oxide dispersion, the solid content of the graphene oxide at 25° C. is 1-5wt%.

8. The method according to any one of claims 1 to 3, wherein: In step (3), the contact mixing conditions include: stirring speed of 300-500 rpm, and time of 20-60 min.

9. A low-temperature self-healing photothermal anti-icing coating prepared by the method described in any one of claims 1 to 8.

10. Application of the low-temperature self-healing photothermal anti-icing coating according to claim 9 on the surface of a wind turbine blade.

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