Anti-freezing and anti-fog hydrogel coating as well as preparation method and application thereof

Abstract

The invention discloses an anti-freezing and anti-fog hydrogel coating as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials, the preparation method comprises the following steps: S1, adding modified cellulose nanocrystals into a glycerol-dimethyl sulfoxide-aqueous solution, and performing ultrasonic treatment to obtain a mixed solution; s2, adding a polyvinyl alcohol aqueous solution into the mixed solution prepared in S1, carrying out primary stirring, adding a cross-linking agent and a photoinitiator in a nitrogen environment, carrying out secondary stirring in a dark place, adding modified TiO2, and carrying out third stirring to obtain a precursor solution; s3, spin-coating the precursor solution prepared in the step S2 on the surface of an epoxy resin matrix of the wind power blade, placing the epoxy resin matrix in a nitrogen environment, and irradiating the epoxy resin matrix with gradient ultraviolet lamp light to obtain hydrogel; and S4, cleaning the surface of the hydrogel prepared in S3 to obtain the hydrogel coating. According to the anti-freezing and anti-fog hydrogel coating as well as the preparation method and the application thereof, the anti-freezing and anti-fog hydrogel coating has good freezing resistance and anti-fog performance, and has high adhesive force with a wind power blade matrix.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to an antifreeze and antifog hydrogel coating, its preparation method and application. Background Technology

[0002] Wind power generation is a crucial source of electricity. However, in low-temperature, high-humidity environments (such as frigid regions), wind turbine blades are prone to condensation and icing. Hydrogel coatings, as an emerging coating technology, have garnered significant attention due to their simple application and low pollution levels. However, hydrogel coatings themselves are susceptible to moisture crystallization in low-temperature environments, affecting their performance, and they exhibit poor adhesion to the wind turbine blade substrate. Therefore, there is an urgent need to develop a high-adhesion hydrogel coating for wind turbine blades that resists icing and fogging.

[0003] Cellulose nanocrystals (CNCs) naturally possess hydroxyl groups (·OH) on their surface, which can form a hydrophilic double crosslinked network with the hydroxyl groups of polyvinyl alcohol (PVA). This double crosslinked network binds water molecules through hydrogen bonds, reducing the free water content, which lowers the freezing point. Modified CNCs grafted with amino groups (·NH2) can form stronger hydrogen bonds with water molecules, allowing the hydrogel to adsorb more water molecules into the crosslinked network, further reducing the free water ratio and thus improving the hydrogel's antifreeze ability. The introduction of the cage-like structure of cage-like polysilsesquioxane (POSS) increases the rigidity and steric hindrance of the CNCs, forming a "nano-reinforced framework" for the hydrogel network. This structure has a more significant inhibitory effect on ice crystal growth; ice crystals need to bypass the POSS cage structure, further preventing water molecule crystallization.

[0004] The amino acid residues in silk fibroin hydrolysate contain hydrophilic groups such as hydroxyl and amino groups. Modification of TiO2 imparts good hydrophilicity, enabling TiO2 to bond with PVA via hydrogen bonds. Simultaneously, it reduces the contact angle of TiO2, significantly enhancing hydrophilicity. The hydrophilic surface promotes the spread of water molecules, forming a uniform thin water film and preventing the formation of discrete droplets, thus achieving an anti-fogging effect. Furthermore, the modified titanium dioxide embeds itself into the micron-sized pores on the substrate surface during spin coating, creating a physical interlock between the coating and the substrate, improving the adhesion of the hydrogel coating to the wind turbine blades. Summary of the Invention

[0005] The purpose of this invention is to provide an antifreeze and anti-fog hydrogel coating, its preparation method and application. The hydrogel coating has good antifreeze and anti-fog properties, and has high adhesion to the wind turbine blade substrate.

[0006] To achieve the above objectives, the present invention provides a method for preparing an antifreeze and antifog hydrogel coating, comprising the following steps:

[0007] S1. Modified cellulose nanocrystals are added to an aqueous solution of glycerol-dimethyl sulfoxide and ultrasonically treated to obtain a mixed solution;

[0008] S2. Add polyvinyl alcohol aqueous solution to the mixed solution prepared in S1, stir once, add crosslinking agent and photoinitiator under nitrogen atmosphere, stir a second time in the dark, add modified TiO2, stir a third time to obtain precursor solution.

[0009] S3. Spin-coat the precursor solution prepared in S2 onto the surface of the epoxy resin matrix of the wind turbine blade, and then place it in a nitrogen environment and irradiate it with gradient ultraviolet light to obtain a hydrogel.

[0010] S4. Clean the surface of the hydrogel prepared in S3 to obtain a hydrogel coating.

[0011] Preferably, in S1, the preparation method of modified cellulose nanocrystals includes the following steps: adding carboxylated cellulose nanocrystals to citrate buffer, sonicating under ice-water bath conditions, adding aminated cage-type polysilsesquioxane, magnetically stirring at 40°C for 2 hours, centrifuging at 4°C for 30 minutes, taking the precipitate and freeze-drying for 24 hours to obtain aminated cage-type polysilsesquioxane modified cellulose nanocrystals.

[0012] The mass of carboxylated cellulose nanocrystals was 1.0 wt% of the mass of citrate buffer.

[0013] The mass of the amino-cage-type polysilsesquioxane is 20-30 wt% of the mass of the carboxylated cellulose nanocrystals.

[0014] Preferably, the preparation method of aminated cage-type polysilsesquioxane includes the following steps: adding epoxy-based cage-type polysilsesquioxane to toluene-ethanol solution, stirring magnetically at 40°C for 1 hour, adding 3-aminopropyltriethoxysilane, heating to 80°C, refluxing under nitrogen for 24 hours, centrifuging at high speed for 15 minutes, taking the precipitate, washing it with n-hexane, and then drying it under vacuum at 60°C for 24 hours to obtain aminated cage-type polysilsesquioxane;

[0015] The mass of the epoxy-based cage-type polysilsesquioxane is 0.1 wt% of the mass of the toluene-ethanol solution;

[0016] The mass of 3-aminopropyltriethoxysilane is 0.12 wt% of the mass of the toluene-ethanol solution.

[0017] Preferably, in S1, the volume ratio of glycerol, dimethyl sulfoxide and water in the glycerol-dimethyl sulfoxide-water solution is (1-3):(1-1.5):(7-7.5).

[0018] Preferably, in S2, the mass of polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 6-12 wt%.

[0019] The mass of modified cellulose nanocrystals in the mixed solution is 1.0-1.5 wt% of the mass of polyvinyl alcohol;

[0020] The crosslinking agent is N,N'-methylenebisacrylamide, and the mass of N,N'-methylenebisacrylamide is 0.15-0.18 wt% of the mass of polyvinyl alcohol;

[0021] The photoinitiator is Irgacure184, and the mass of Irgacure184 is 0.15-0.25 wt% of the mass of polyvinyl alcohol;

[0022] The mass of modified TiO2 is 0.6-0.8 wt% of the mass of polyvinyl alcohol.

[0023] Preferably, in S2, the preparation method of modified TiO2 includes the following steps: TiO2 is added to an ethanol-water solution, ultrasonically treated for 60 min under ice-water bath conditions, magnetically stirred at 80°C for 2 h, allowed to stand at room temperature, and vacuum dried at 60°C for 12 h to obtain dried powder. Then, the dried powder is added to a silk fibroin hydrolysate, ultrasonically treated for 30 min under ice-water bath conditions, heated to 80°C at a heating rate of 2°C / min, magnetically stirred at a nitrogen atmosphere for 4 h, allowed to stand at room temperature, centrifuged at 4000 rpm for 15 min, the precipitate is washed three times with ethanol, and vacuum dried at 60°C for 24 h to obtain silk fibroin modified TiO2.

[0024] The mass of TiO2 is 1.0-2.0 wt% of the total mass of the ethanol-water solution;

[0025] The volume ratio of ethanol to water in an ethanol-water solution is 3:1.

[0026] Preferably, the preparation method of silk fibroin hydrolysate includes the following steps: adding silk fibroin to an ethanol-water solution, then adding trypsin, heating in a water bath to 75°C, and magnetically stirring under reflux for 12 hours to obtain a pale yellow transparent liquid, cooling to room temperature, adjusting the pH to 8.0-8.5 with 1M NaOH solution, letting it stand at 4°C for 1 hour, centrifuging at 8000 rpm for 20 minutes to remove unhydrolyzed protein precipitate, collecting the supernatant to obtain a high-concentration silk fibroin hydrolysate;

[0027] The amount of silk fibroin protein is 3.0-5.0 wt% of the mass of the silk fibroin protein hydrolysate;

[0028] The mass of trypsin is 1.0-3.0 wt% of the silk fibroin protein.

[0029] The volume ratio of ethanol to water in an ethanol-water solution is 3:1.

[0030] Preferably, in step S2, the stirring time for one stirring session is 1-2 hours;

[0031] The second stirring time is 20-40 minutes;

[0032] The stirring time for the three stages is 10-30 minutes.

[0033] Preferably, in S3, the specific steps of gradient ultraviolet light irradiation are: first perform low-intensity ultraviolet irradiation and then perform high-intensity ultraviolet irradiation;

[0034] The wavelength of ultraviolet light is 360-370nm;

[0035] The power density of low-intensity ultraviolet irradiation is 5 mW / cm². 2 The time is 15 minutes;

[0036] The power density of high-intensity ultraviolet irradiation is 15 mW / cm². 2 The time is 15 minutes.

[0037] The present invention also provides an antifreeze and anti-fog hydrogel coating, which is prepared by the above-described method for preparing an antifreeze and anti-fog hydrogel coating.

[0038] The present invention also provides an application of an antifreeze and anti-fog hydrogel coating, wherein the above-described antifreeze and anti-fog hydrogel coating is applied to the surface of a wind turbine blade with an epoxy resin matrix.

[0039] Therefore, the present invention, employing the above-mentioned antifreeze and antifog hydrogel coating, its preparation method, and its application, has the following beneficial effects:

[0040] (1) By modifying CNC with aminated cage-type polysilsesquioxane, the hydrophilic groups and mechanical properties of CNC are enhanced. The hydrogel adsorbs water molecules into the cross-linked network. The hydroxyl groups of PVA and the carboxyl and amino groups in the modified cellulose nanocrystals are combined with water molecules through hydrogen bonds, reducing the mass of free water and reducing the hydrogen bond structure required for water molecules to form ice crystals, thereby preventing surface water vapor from freezing at low temperatures.

[0041] (2) Modified TiO2 and PVA are bonded by hydrogen bonds. The high hydrophilicity allows the condensate to spread into a continuous water film. The hydrophilic surface promotes the spread of water molecules, forming a uniform thin water film, avoiding the formation of discrete droplets and achieving the anti-fogging effect.

[0042] (3) Modified TiO2 forms ionic bonds with the hydroxyl groups of PVA through amino groups. At the same time, modified TiO2 is embedded in the micron-sized pores on the surface of the substrate during spin coating, so that the coating and the substrate form a physical interlock, which improves the adhesion of the hydrogel coating to the wind turbine blade.

[0043] The technical solution of the present invention will be further described in detail below through embodiments. Detailed Implementation

[0044] The technical solution of the present invention will be further described below through embodiments.

[0045] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0046] Example 1

[0047] An antifreeze and anti-fog hydrogel coating is prepared by the following steps:

[0048] S1. Add 0.0648g of modified cellulose nanocrystals to 50mL of glycerol-dimethyl sulfoxide-water solution (V 甘油 :V 二甲基亚砜 :V 水 In a mixture of 2:1:7, ultrasonic treatment was performed for 30 minutes to obtain a mixed solution.

[0049] The preparation method of modified cellulose nanocrystals includes the following steps: 0.8g of carboxylated cellulose nanocrystals are added to 80mL of citrate buffer, and ultrasonically treated (500W) for 15min under ice-water bath conditions. 0.2g of aminated cage-type polysilsesquioxane (POSS-NH2) is added, and the mixture is magnetically stirred at 40℃ for 2h. After centrifugation at 4℃ for 30min, the precipitate is freeze-dried at -50℃ and 10Pa for 24h to obtain 1g of aminated cage-type polysilsesquioxane modified cellulose nanocrystals.

[0050] The preparation method of aminated cage-type polysilsesquioxane includes the following steps: 0.455g of epoxy-based cage-type polysilsesquioxane is added to 472.1mL of toluene-ethanol solution, and the mixture is magnetically stirred at 40℃ for 1h. Then, 0.545g of 3-aminopropyltriethoxysilane is added, and the mixture is heated to 80℃ and refluxed under nitrogen for 24h. After centrifugation at high speed for 15min, the precipitate is washed with n-hexane and then vacuum dried at 60℃ for 24h to obtain 1g of aminated cage-type polysilsesquioxane.

[0051] Aminated cage-like polysilsesquioxane-modified cellulose is rich in hydrophilic groups, which bind to water molecules through hydrogen bonds, reducing the hydrogen bonds required for water molecules to form free ice crystals, thereby lowering the freezing point. The cage-like structure of polysilsesquioxane acts as a nano barrier, increasing the rigidity and steric hindrance of cellulose nanocrystals, disrupting the orderly arrangement of water molecules, and thus further preventing water molecules from crystallizing.

[0052] S2. Add 54 mL of polyvinyl alcohol (PVA) aqueous solution to the mixed solution prepared in S1, stir magnetically at 40 °C for 1 h, purge with nitrogen for 15 min to remove oxygen, add 0.00864 g of N,N'-methylenebisacrylamide (MBAA) and 0.0108 g of Irgacure 184 under nitrogen atmosphere, stir magnetically in the dark for 30 min, add 0.0378 g of modified TiO2, stir magnetically for 20 min to obtain a precursor solution containing PVA-modified CNC.

[0053] The preparation of the polyvinyl alcohol aqueous solution specifically includes the following steps: dissolve 5.4g of PVA in 48.6mL of deionized water and stir magnetically at 90℃ for 1h until the solution is clear.

[0054] The preparation method of modified TiO2 includes the following steps: adding 0.95g TiO2 to 75.27mL of ethanol-water solution (V 乙醇 :V 水 =3:1), after ultrasonic treatment for 60 min under ice-water bath conditions, magnetic stirring at 80℃ for 2 h, standing to room temperature, and vacuum drying at 60℃ for 12 h to obtain dried powder, the dried powder was then added to 1.2 mL of silk fibroin hydrolysate, ultrasonicated for 30 min under ice-water bath conditions, heated to 80℃ at a heating rate of 2℃ / min, magnetically stirred at nitrogen atmosphere for 4 h, standing to room temperature, centrifuged at 4000 rpm for 15 min, the precipitate was washed 3 times with ethanol, and vacuum dried at 60℃ for 24 h to obtain 1 g of silk fibroin modified TiO2.

[0055] The preparation method of silk fibroin hydrolysate includes the following steps: adding 0.4g of silk fibroin to an ethanol-water solution (V... 乙醇 :V 水 Add 8 mg of trypsin to the mixture (3:1), heat in a water bath to 75°C, and reflux with magnetic stirring for 12 h to obtain a pale yellow transparent liquid. Cool to room temperature, adjust the pH to 8.23 ​​with 1 M NaOH solution, let stand at 4°C for 1 h, and then centrifuge at 8000 rpm for 20 min to remove unhydrolyzed protein precipitate. Collect the supernatant to obtain 10 mL of high-concentration silk fibroin hydrolysate.

[0056] The contact angle of TiO2 modified with silk fibroin is reduced, and its hydrophilicity is significantly improved. The hydrophilic surface promotes the spread of water molecules, forming a uniform thin water film, avoiding the formation of discrete droplets, and achieving an anti-fogging effect.

[0057] S3. The precursor solution prepared in S2 is uniformly spin-coated onto the surface of the epoxy resin matrix of the wind turbine blade at a speed of 5000 rpm for 60 seconds. Then, the epoxy resin matrix of the wind turbine blade with the precursor solution spin-coated is placed in a nitrogen environment and irradiated with gradient ultraviolet light, i.e., first subjected to low-intensity ultraviolet light (5mW / cm²).2 Irradiate for 15 minutes, then subject to high-intensity ultraviolet (15mW / cm²) radiation. 2 After irradiation for 15 minutes, UV-initiated crosslinking agent MBAA undergoes a free radical polymerization reaction to obtain a hydrogel.

[0058] Modified titanium dioxide embeds itself into the micron-sized pores on the surface of the epoxy resin matrix during spin coating, creating a physical interlock between the coating and the matrix, thus improving the adhesion of the hydrogel coating to the wind turbine blade.

[0059] S4. Repeatedly wash the surface of the hydrogel prepared in S3 with deionized water to remove unreacted precursor solution and other impurities, and obtain the hydrogel coating.

[0060] Example 2

[0061] An antifreeze and anti-fog hydrogel coating is prepared by the following steps:

[0062] S1. Add 0.0772g of modified cellulose nanocrystals to 50mL of glycerol-dimethyl sulfoxide-water solution (V 甘油 :V 二甲基亚砜 :V 水 In a mixture of 2:1:7, ultrasonic treatment was performed for 30 minutes to obtain a mixed solution.

[0063] S2. Add 54 mL of polyvinyl alcohol (PVA) aqueous solution to the mixed solution prepared in S1, stir magnetically at 40 °C for 1 h, purge with nitrogen for 15 min to remove oxygen, add 0.0095 g N,N'-methylenebisacrylamide (MBAA) and 0.0119 g Irgacure184 under nitrogen atmosphere, stir magnetically in the dark for 30 min, add 0.0416 g modified TiO2, stir magnetically for 20 min to obtain the precursor solution containing PVA-modified CNC.

[0064] The preparation of the polyvinyl alcohol aqueous solution specifically includes the following steps: dissolve 5.94g of PVA in 48.06mL of deionized water and stir magnetically at 90℃ for 1h until the solution is clear.

[0065] S3. The precursor solution prepared in S2 is uniformly spin-coated onto the surface of the epoxy resin matrix of the wind turbine blade at a speed of 5000 rpm for 60 seconds. Then, the epoxy resin matrix of the wind turbine blade with the precursor solution spin-coated is placed in a nitrogen environment and irradiated with gradient ultraviolet light, i.e., first subjected to low-intensity ultraviolet light (5mW / cm²). 2 Irradiate for 15 minutes, then subject to high-intensity ultraviolet (15mW / cm²) radiation. 2 After irradiation for 15 minutes, UV-initiated crosslinking agent MBAA undergoes a free radical polymerization reaction to obtain a hydrogel.

[0066] S4. Repeatedly wash the surface of the hydrogel prepared in S3 with deionized water to remove unreacted precursor solution and other impurities, and obtain the hydrogel coating.

[0067] The preparation methods for modified cellulose nanocrystals, aminated cage-type polysilsesquioxane, modified TiO2, and silk fibroin hydrolysate are all the same as in Example 1.

[0068] Example 3

[0069] An antifreeze and anti-fog hydrogel coating is prepared by the following steps:

[0070] S1. Add 0.097g of modified cellulose nanocrystals to 50mL of glycerol-dimethyl sulfoxide-water solution (V 甘油 :V 二甲基亚砜 :V 水 In a mixture of 2:1:7, ultrasonic treatment was performed for 30 minutes to obtain a mixed solution.

[0071] S2. Add 54 mL of polyvinyl alcohol (PVA) aqueous solution to the mixed solution prepared in S1, stir magnetically at 40 °C for 1 h, purge with nitrogen for 15 min to remove oxygen, add 0.01037 g N,N'-methylenebisacrylamide (MBAA) and 0.0130 g Irgacure 184 under nitrogen atmosphere, stir magnetically in the dark for 30 min, add 0.0454 g modified TiO2, stir magnetically for 20 min to obtain the precursor solution containing PVA-modified CNC.

[0072] The preparation of the polyvinyl alcohol aqueous solution specifically includes the following steps: dissolve 6.48g of PVA in 47.52mL of deionized water and stir magnetically at 90℃ for 1h until the solution is clear.

[0073] S3. The precursor solution prepared in S2 is uniformly spin-coated onto the surface of the epoxy resin matrix of the wind turbine blade at a speed of 5000 rpm for 60 seconds. Then, the epoxy resin matrix of the wind turbine blade with the precursor solution spin-coated is placed in a nitrogen environment and irradiated with gradient ultraviolet light, i.e., first subjected to low-intensity ultraviolet light (5mW / cm²). 2 Irradiate for 15 minutes, then subject to high-intensity ultraviolet (15mW / cm²) radiation. 2 After irradiation for 15 minutes, UV-initiated crosslinking agent MBAA undergoes a free radical polymerization reaction to obtain a hydrogel.

[0074] S4. Repeatedly wash the surface of the hydrogel prepared in S3 with deionized water to remove unreacted precursor solution and other impurities, and obtain the hydrogel coating.

[0075] The preparation methods for modified cellulose nanocrystals, aminated cage-type polysilsesquioxane, modified TiO2, and silk fibroin hydrolysate are all the same as in Example 1.

[0076] Comparative Example 1

[0077] The difference between Comparative Example 1 and Example 3 is that the cellulose nanocrystals in Comparative Example 1 were not modified, while all other conditions were the same as in Example 3.

[0078] Comparative Example 2

[0079] The difference between Comparative Example 2 and Example 3 is that the silica was not modified in Comparative Example 2, while all other conditions were the same as in Example 3.

[0080] Test

[0081] The adhesion of the hydrogel coating to the epoxy resin matrix of the wind turbine blade was tested using the tensile test. In accordance with the standard ASTM D4541, a metal ingot (20 mm in diameter) was bonded to the surface of the hydrogel coating with epoxy adhesive. The coating was stretched vertically at a constant speed (displacement rate of 1 mm / min) using a tensile testing machine. The maximum tensile force (F) when the coating detached was recorded. The adhesion force (MPa) was calculated by dividing the maximum tensile force by the bottom area of ​​the ingot.

[0082] The salt spray resistance of the hydrogel coating was tested using the cyclic spray method. Following standard GJB 150.11A-2009, the sample was placed at a 15° angle inside the salt spray chamber; a 5% NaCl solution was continuously sprayed (temperature 35±2℃, sedimentation rate 1~3mL / (80cm²)). 2 •h); After a specified period of continuous testing, the sample is removed, the surface salt crystals are cleaned with deionized water and the corrosion level (%) is evaluated according to ISO 10289. The adhesion retention rate is calculated by dividing the adhesion after salt spray by the percentage of the initial adhesion.

[0083] The adhesion of ice to the hydrogel coating was tested according to ISO 17087 standard. The ice adhesion was measured by vertically peeling a 25mm diameter ice column (5mm thickness) at a rate of 5mm / min in an environment of -20℃.

[0084] The test results of the adhesion of the hydrogel coatings prepared in Examples 1-3 and Comparative Examples 1-2 to the epoxy resin matrix of wind turbine blades, the salt spray resistance of the hydrogel coatings, and the adhesion of ice to the hydrogel coatings are shown in Table 1.

[0085] Table 1. Performance test results of the hydrogel coatings prepared in Examples 1-3 and Comparative Examples 1-2

[0086]

[0087]

[0088] As can be seen from Table 1, the freezing point of the antifreeze and antifog hydrogel coating provided by the present invention can reach -41°C; the contact angle between the hydrogel coating and water is as low as 5°, indicating that the coating has good antifog performance; the adhesion between the hydrogel coating and the wind turbine blade is as high as 12MPa; the salt spray resistance of the coating is as high as 3000h; and the adhesion of ice to the hydrogel coating is as low as 39kPa.

[0089] Therefore, the present invention adopts the above-mentioned antifreeze and antifog hydrogel coating, its preparation method and application. The hydrogel coating has good antifreeze and antifog properties, and has high adhesion to the wind turbine blade substrate.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing an antifreeze and antifog hydrogel coating, characterized in that, Includes the following steps: S1. Modified cellulose nanocrystals are added to an aqueous solution of glycerol-dimethyl sulfoxide and ultrasonically treated to obtain a mixed solution; S2. Add polyvinyl alcohol aqueous solution to the mixed solution prepared in S1, stir once, add crosslinking agent and photoinitiator under nitrogen atmosphere, stir a second time in the dark, add modified TiO2, stir a third time to obtain precursor solution. S3. Spin-coat the precursor solution prepared in S2 onto the surface of the epoxy resin matrix of the wind turbine blade, and then place it in a nitrogen environment and irradiate it with gradient ultraviolet light to obtain a hydrogel. S4. Clean the surface of the hydrogel prepared in S3 to obtain a hydrogel coating.

2. The preparation method according to claim 1, characterized in that, In S1, the preparation method of modified cellulose nanocrystals includes the following steps: adding carboxylated cellulose nanocrystals to citrate buffer, sonicating under ice-water bath conditions, adding aminated cage-type polysilsesquioxane, stirring magnetically at 40°C for 2 hours, centrifuging at 4°C for 30 minutes, taking the precipitate and freeze-drying for 24 hours to obtain aminated cage-type polysilsesquioxane modified cellulose nanocrystals. The mass of carboxylated cellulose nanocrystals was 1.0 wt% of the mass of citrate buffer. The mass of the amino-cage-type polysilsesquioxane is 20-30 wt% of the mass of the carboxylated cellulose nanocrystals.

3. The preparation method according to claim 2, characterized in that, The preparation method of aminated cage-type polysilsesquioxane includes the following steps: adding epoxy-based cage-type polysilsesquioxane to toluene-ethanol solution, stirring magnetically at 40°C for 1 hour, adding 3-aminopropyltriethoxysilane, heating to 80°C, refluxing under nitrogen for 24 hours, centrifuging at high speed for 15 minutes, taking the precipitate, washing it with n-hexane, and then drying it under vacuum at 60°C for 24 hours to obtain aminated cage-type polysilsesquioxane; The mass of the epoxy-based cage-type polysilsesquioxane is 0.1 wt% of the mass of the toluene-ethanol solution; The mass of 3-aminopropyltriethoxysilane is 0.12 wt% of the mass of the toluene-ethanol solution.

4. The preparation method according to claim 1, characterized in that, In S1, the volume ratio of glycerol, dimethyl sulfoxide and water in the glycerol-dimethyl sulfoxide-water solution is (1-3):(1-1.5):(7-7.5).

5. The preparation method according to claim 1, characterized in that, In S2, the mass of polyvinyl alcohol in the aqueous solution is 6-12 wt%; The mass of modified cellulose nanocrystals in the mixed solution is 1.0-1.5 wt% of the mass of polyvinyl alcohol; The crosslinking agent is N,N'-methylenebisacrylamide, and the mass of N,N'-methylenebisacrylamide is 0.15-0.18 wt% of the mass of polyvinyl alcohol; The photoinitiator is Irgacure184, and the mass of Irgacure184 is 0.15-0.25 wt% of the mass of polyvinyl alcohol; The mass of modified TiO2 is 0.6-0.8 wt% of the mass of polyvinyl alcohol.

6. The preparation method according to claim 1, characterized in that, In S2, the preparation method of modified TiO2 includes the following steps: TiO2 is added to an ethanol-water solution, ultrasonically treated for 60 min under ice-water bath conditions, magnetically stirred at 80℃ for 2 h, allowed to stand at room temperature, and vacuum dried at 60℃ for 12 h to obtain dried powder. Then, the dried powder is added to a silk fibroin hydrolysate, ultrasonically treated for 30 min under ice-water bath conditions, heated to 80℃ at a heating rate of 2℃ / min, magnetically stirred at a nitrogen atmosphere for 4 h, allowed to stand at room temperature, centrifuged at 4000 rpm for 15 min, the precipitate is washed with ethanol 3 times, and vacuum dried at 60℃ for 24 h to obtain silk fibroin modified TiO2. The mass of TiO2 is 1.0-2.0 wt% of the total mass of the ethanol-water solution; The volume ratio of ethanol to water in an ethanol-water solution is 3:

1.

7. The preparation method according to claim 1, characterized in that, In S2, the stirring time is 1-2 hours. The second stirring time is 20-40 minutes; The stirring time for each of the three stages is 10-30 minutes.

8. The preparation method according to claim 1, characterized in that, In S3, the specific steps of gradient ultraviolet light irradiation are: first perform low-intensity ultraviolet irradiation, then perform high-intensity ultraviolet irradiation. The wavelength of ultraviolet light is 360-370nm; The power density of low-intensity ultraviolet irradiation is 5 mW / cm². 2 The time is 15 minutes; The power density of high-intensity ultraviolet irradiation is 15 mW / cm². 2 The time is 15 minutes.

9. An antifreeze and anti-fog hydrogel coating, characterized in that, The antifreeze and antifog hydrogel coating was prepared using the preparation method described in any one of claims 1-8.

10. The application of an antifreeze and antifog hydrogel coating, characterized in that, The antifreeze and antifog hydrogel coating of claim 9 is applied to the surface of wind turbine blades based on epoxy resin.

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