Self-cleaning hydrosol capable of preventing corrosion and ice as well as preparation method and application of self-cleaning hydrosol

Abstract

The invention provides a self-cleaning hydrosol capable of preventing corrosion and ice as well as a preparation method and application of the self-cleaning hydrosol. The preparation method of the self-cleaning hydrosol capable of preventing corrosion and ice comprises the following steps: adding TiO2 nano powder into a solvent, and uniformly stirring to obtain a transparent TiO2 solution; dropwise adding orthosilicate into the obtained TiO2 solution, and uniformly stirring to obtain a white colloidal solution; dropwise adding amino silane into the obtained white colloidal solution, and uniformly stirring to obtain a milk white colloidal solution; and dropwise adding a silane coupling agent into the milk white colloidal solution, and uniformly stirring to obtain the product. According to the invention, a stable micro-nano coarse structure constructed by TiO2 / SiO2 is used as a'skeleton ', and is modified by low-surface-energy fluorosilane, so that a super-hydrophobic interface capable of stably locking air is formed on various substrates, and meanwhile, the super-hydrophobic coating has the effects of corrosion isolation prevention and freezing delay prevention, thereby achieving a multi-energy, efficient and lasting protection effect.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of self-cleaning water-based sol of anti-corrosion and anti-icing and its preparation method and application, belong to functional coating material technical field. BACKGROUND

[0002] The performance degradation and safety accidents caused by the adhesion of water, ice, corrosive medium (such as Cl − ) on the surface of materials are serious challenges faced by aerospace, marine engineering, power transportation, modern architecture and other fields for a long time. Inspired by the phenomenon of lotus leaf "out of sludge and not stained" in nature, superhydrophobic surface (usually defined as the static contact angle with water is greater than 150°) has become a frontier research direction to solve the above problems due to its excellent water repellency and significant self-cleaning, anti-corrosion and anti-icing potential derived from high contact angle. The self-cleaning performance of superhydrophobic surface is due to its micro-nano structure and low surface energy, so that the water droplets can easily roll on the surface and remove dust and pollutants, thereby realizing efficient self-cleaning. Specifically, water droplets under superhydrophobic state are easy to roll on the surface, thereby "carrying away" the pollutants particles attached in their path. This physical cleaning mechanism does not depend on chemical reagents or external energy input, and is an ideal way to achieve long-lasting and green self-cleaning. Therefore, building a stable superhydrophobic surface is one of the most effective strategies to endow materials with self-cleaning function.

[0003] The realization of superhydrophobic performance mainly depends on two key factors: one is the appropriate surface micro-nano hierarchical rough structure, which is used to trap air to form a stable "air cushion"; the second is the low surface free energy, which is used to maximize the reduction of the adhesion between water droplets and solid surface. This structure makes water droplets on the surface show high contact angle and low rolling angle, so as to easily roll and remove pollutants, and realize self-cleaning function. At present, there are various techniques for constructing superhydrophobic coating, including but not limited to sol-gel method, chemical vapor deposition, electrochemical deposition, etching method, template method, electrospinning and the like. However, these methods have obvious limitations in practical application. For example, chemical vapor deposition and template method usually require complex equipment, strict vacuum or high temperature conditions, which are high in cost and difficult to handle large area or complex shape substrates; etching method may be not environmentally friendly, and may damage the performance of the substrate body; and many coating systems based on organic solvents have safety and environmental problems such as volatile organic compounds emission, flammability and explosion.

[0004] In existing research, nanoparticles (such as SiO2, TiO2 or ZnO) are used as reinforcing phases to construct roughness and improve coating hardness. For example, a hard corrosion-resistant coating with good biological activity is reported in the literature (Applied Surface Science, 2019, 484, 975-980.) by depositing two layers, first depositing a dense layer, and then depositing a porous titanium dioxide layer. TiO2 nanoparticles not only have high refractive index, good chemical stability, non-toxicity and other advantages, but also have photocatalytic self-cleaning properties, which are expected to endow the coating with more functions. However, how to achieve stable dispersion of TiO2 nanoparticles in aqueous solution, and make it firmly combined with the silane hydrolysis network, while precisely controlling the micro-nano structure to obtain persistent and stable super-hydrophobic properties and self-cleaning function, is still a current technical difficulty. Chinese patent document CN111405778A discloses a preparation method of a super-hydrophobic coating waterproof circuit board, comprising the following steps: S1: adding deionized water and anhydrous ethanol into oxide nanoparticles respectively to form an oxide nanoparticle solution; S2: adding silane coupling agent and ammonia water into the oxide nanoparticle solution respectively, stirring at 60-80°C to obtain a modified oxide nanoparticle solution; S3: precipitating and filtering the modified oxide nanoparticle solution to obtain solid particles; drying the solid particles to obtain modified oxide nanoparticles; S4: mixing silane coupling agent and anhydrous ethanol to prepare a coupling agent anhydrous ethanol solution; S5: mixing crosslinking agent, the coupling agent anhydrous ethanol solution and alkaline silica sol to obtain a modified silica sol; S6: adding the modified oxide nanoparticles into the modified silica sol and performing ultrasonic treatment to obtain a super-hydrophobic coating solution; S7: applying the super-hydrophobic coating solution on the circuit board and drying to obtain a super-hydrophobic coating waterproof circuit board. However, the complex process and heating conditions of this method limit its efficiency and cost in large-scale industrial application; the use of ammonia water may cause environmental and safety problems; and the coating may lack the microstructure basis for long-term corrosion and ice prevention and self-cleaning, and the performance durability needs to be verified. Chinese patent document CN119121614A discloses a titanium dioxide hybrid silica sol, which is prepared by the following steps: mixing ethanol, tetraethyl orthosilicate, long-chain alkyl silane, vanillin modified silane and water, stirring at a speed of 500 rpm for 25 min, adding hydrochloric acid to adjust the pH value to 3, continuing to stir for 2 h, then adding tetrabutyl titanate dropwise, stirring at a speed of 400 rpm for 48 h, and standing for 72-80 h to obtain a titanium dioxide hybrid silica sol. The long-chain alkyl silane is one of octyl triethoxysilane, dodecyl triethoxysilane and hexadecyl trimethoxysilane, and the vanillin modified silane is vanillin modified amino silane coupling agent.However, the long reaction and standing requirements of the method make it difficult to meet the high efficiency requirements of industrial production; the use of organic solvents and special modifiers increases the environmental burden and cost; and the stability of the sol, the adhesion of the coating, and the multifunctionality (such as corrosion and ice prevention and self-cleaning) may be insufficient.

[0005] In existing reports, many methods still require complex pretreatment steps, expensive equipment or special process conditions, making it difficult to meet the needs of industrial large-scale production and application. Therefore, it has extremely important theoretical significance and great market application value to develop a preparation method of water-based sol which is simple in process, easy to obtain raw materials, environmentally friendly, good in stability, and capable of forming a coating with strong adhesion, wear resistance, corrosion resistance, excellent and durable super-hydrophobicity on various substrates. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides a self-cleaning water-based sol capable of preventing corrosion and ice and a preparation method and application thereof.

[0007] Explanation of terms: Room temperature: has the meaning known in the art, refers to 25±5℃.

[0008] The present application is realized by the following technical solutions: A preparation method of a self-cleaning water-based sol capable of preventing corrosion and ice, comprising the following steps: (1) adding TiO2 nano powder into a solvent and stirring uniformly to obtain a transparent TiO2 solution; (2) adding tetraethyl orthosilicate dropwise into the TiO2 solution obtained in step (1) and stirring uniformly to obtain a white colloidal solution; (3) adding amino silane dropwise into the white colloidal solution obtained in step (2) and stirring uniformly to obtain a milky white colloidal solution; (4) adding silane coupling agent dropwise into the milky white colloidal solution obtained in step (3) and stirring uniformly to obtain a self-cleaning water-based sol capable of preventing corrosion and ice.

[0009] According to the present application, preferably, the solvent in step (1) is deionized water or a mixed solution of deionized water and anhydrous ethanol, and the volume ratio of deionized water to anhydrous ethanol in the mixed solution is 1-5:1.

[0010] According to the present application, preferably, the particle size of the TiO2 nano powder in step (1) is 5-10 nm; and the mass of the TiO2 nano powder to the volume of the solvent is (0.25-0.5) g:(25-50) mL.

[0011] According to the present application, preferably, the tetraethyl orthosilicate in step (2) is tetraethyl orthosilicate.

[0012] According to the application, preferably, the mass of the orthosilicate to the volume of the TiO2 solution in step (2) is (0.15-0.5) g:25 mL, and more preferably (0.15-0.3) g:25 mL.

[0013] According to the application, preferably, the amino silane in step (3) is 3-aminopropyl triethoxysilane.

[0014] According to the application, preferably, the mass of the amino silane to the volume of the white colloidal solution in step (3) is (0.1-0.2) g:(27-30) mL, and more preferably (0.1-0.15) g:(27-30) mL.

[0015] According to the application, preferably, the silane coupling agent in step (4) is perfluorodecyltrimethoxysilane or dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride.

[0016] According to the application, preferably, the mass of the silane coupling agent to the volume of the milky white colloidal solution in step (4) is (0.15-0.5) g:(30-32) mL, and more preferably (0.15-0.3) g:(30-32) mL.

[0017] According to the application, preferably, the stirring time in step (4) is 10-60 min, and more preferably 30 min.

[0018] A self-cleaning hydrocolloid capable of corrosion and ice prevention is prepared by the above method.

[0019] According to the application, the self-cleaning hydrocolloid capable of corrosion and ice prevention is used to construct a super-hydrophobic self-cleaning protective coating on the surface of various substrates such as metals, glasses and fabrics, and is particularly used for corrosion protection of metal components, ice prevention / delay of surface in low-temperature environment, and self-cleaning and antifouling treatment of material surface.

[0020] The technical features and advantages of the application are as follows: 1. The micro-morphology of the self-cleaning hydrocolloid is composed of fine particles with substantially the same shape and narrow size distribution, and the size of the particles is 5-10 nm, which is within the range of colloidal particles. The sol can form a dense and uniform nanometer film, effectively blocking the penetration of water, oxygen and corrosion medium, which is the microstructure basis for realizing long-term corrosion and ice prevention.

[0021] 2. The self-cleaning hydrosol has an ingeniously designed composition that achieves synergistic effects. It uses TiO2 nanoparticles as the core to construct a nanoscale rough framework; it enhances structural stability by forming a silica network through the hydrolysis of tetraethyl silicate (TEOS); it introduces 3-aminopropyltriethoxysilane as a "molecular bridge" to improve compatibility and binding force; and it uses low surface energy materials such as perfluorodecyltrimethoxysilane for surface modification, achieving a perfect combination of micro-nano rough structure and low surface energy, thereby simultaneously obtaining superhydrophobicity and self-cleaning properties.

[0022] 3. Green preparation process: The entire preparation process uses deionized water as the main solvent, avoiding the environmental and safety problems caused by the use of toxic organic solvents in traditional methods. The process is green and environmentally friendly.

[0023] 4. Simple process and mild conditions: All steps can be completed at room temperature by simple solution mixing and stirring, without the need for complex equipment, high temperature or vacuum and other harsh conditions, making it very suitable for large-scale industrial production.

[0024] 5. Universal hydrophobic and self-cleaning effects on substrate materials: The obtained hydrosol can be applied to various substrates such as tinplate, glass, and cotton fabrics through simple methods such as coating and soaking, exhibiting excellent universal hydrophobic and self-cleaning effects.

[0025] 6. The application of the corrosion-resistant and anti-icing self-cleaning hydrosol of the present invention is based on using a stable micro-nano rough structure constructed from TiO2 / SiO2 as a "skeleton," which is then modified with low surface energy fluorosilanes to ultimately form a superhydrophobic interface on various substrates that can stably lock in air. This interface simultaneously plays the dual role of "corrosion-resistant isolation layer" and "anti-icing delay layer," thereby achieving a multi-functional, highly efficient, and long-lasting protective effect.

[0026] 7. Green economy with broad application prospects: The raw materials of this invention are readily available, the cost is low, the process is simple and safe, and the prepared products have excellent performance and are suitable for various material surfaces. It has huge market application potential in aerospace, marine engineering, power transportation, building materials and other fields. Attached Figure Description

[0027] Figure 1 The image shows the XRD patterns of the self-cleaning hydrosol and TiO2 material prepared in Example 1.

[0028] Figure 2 The image shows the infrared spectrum of the self-cleaning hydrosol prepared in Example 1.

[0029] Figure 3(a) water contact angle test pattern on glass substrate coated with the self-cleaning hydrosol prepared in Example 1, (b) water contact angle test pattern on glass substrate coated with the self-cleaning hydrosol prepared in Example 2, (c) water contact angle test pattern on glass substrate coated with the self-cleaning hydrosol prepared in Example 3, (d) water contact angle test pattern on glass substrate coated with the self-cleaning hydrosol prepared in Example 4.

[0030] Figure 4 (a) water contact angle test pattern on glass substrate coated with the hydrosol prepared in Comparative Example 1, (b) water contact angle test pattern on glass substrate coated with the hydrosol prepared in Comparative Example 2, (c) water contact angle test pattern on glass substrate coated with the hydrosol prepared in Comparative Example 3, (d) water contact angle test pattern on glass substrate coated with the hydrosol prepared in Comparative Example 4, (e) water contact angle test pattern on glass substrate coated with the hydrosol prepared in Comparative Example 5, (f) water contact angle test pattern on glass substrate coated with the hydrosol prepared in Comparative Example 6, (g) water contact angle test pattern on glass substrate coated with the hydrosol prepared in Comparative Example 7.

[0031] Figure 5 (a) water contact angle test pattern on glass substrate coated with the self-cleaning hydrosol prepared in Example 1, (b) water contact angle test pattern on glass substrate coated with the self-cleaning hydrosol prepared in Example 1 after 48 h standing.

[0032] Figure 6 (a) and (b) are low and high magnification SEM images of the film material obtained by coating TiO2hydrosol on glass substrate, (c) and (d) are low and high magnification SEM images of the film material obtained by coating the self-cleaning hydrosol prepared in Example 1 on glass substrate.

[0033] Figure 7 (a) and (f) are drop imaging front view and top view of Rhodamine B solution on cotton fabric soaked with the self-cleaning hydrosol prepared in Example 1, (b) and (g) are drop imaging front view and top view of Rhodamine B solution on cotton fabric soaked with the self-cleaning hydrosol prepared in Example 2, (c) and (h) are drop imaging front view and top view of Rhodamine B solution on cotton fabric soaked with the self-cleaning hydrosol prepared in Example 3, (d) and (i) are drop imaging front view and top view of Rhodamine B solution on cotton fabric soaked with the self-cleaning hydrosol prepared in Example 4, (e) and (j) are drop imaging front view and top view of Rhodamine B solution on cotton fabric of the blank group.

[0034] Figure 8 Raw photos of tinplate pieces coated with the self-cleaning hydrosol prepared in Example 1, Example 2, Example 3, Example 4 and tinplate pieces of the blank group.

[0035] Figure 9 Corrosion photos of tinplate coated with self-cleaning hydrosol prepared in Example 1, Example 2, Example 3, Example 4 and blank tinplate after immersion in 3.5wt% NaCl aqueous solution for 1 day.

[0036] Figure 10 Corrosion photos of tinplate coated with self-cleaning hydrosol prepared in Example 1, Example 2, Example 3, Example 4 and blank tinplate after immersion in 3.5wt% NaCl aqueous solution for 3 days.

[0037] Figure 11 Corrosion photos of tinplate coated with self-cleaning hydrosol prepared in Example 1, Example 2, Example 3, Example 4 and blank tinplate after immersion in 3.5wt% NaCl aqueous solution for 5 days.

[0038] Figure 12 Corrosion photos of tinplate coated with self-cleaning hydrosol prepared in Example 1, Example 2, Example 3, Example 4 and blank tinplate after immersion in 3.5wt% NaCl aqueous solution for 7 days.

[0039] Figure 13 Corrosion photos of tinplate coated with self-cleaning hydrosol prepared in Example 1, Example 2, Example 3, Example 4 and blank tinplate after immersion in 3.5wt% NaCl aqueous solution for 10 days.

[0040] Figure 14 Imaging photos of tinplate under polarizing microscope at 20 times (a) and 50 times (b), imaging photos of tinplate coated with self-cleaning hydrosol prepared in Example 1 under polarizing microscope at 20 times (c) and 50 times (d).

[0041] Figure 15Image of the droplets on the glass substrate coated with the self-cleaning hydrosol prepared in Example 1 (a), the image of the droplets frozen after 220 s at -18°C (f); Image of the droplets on the glass substrate coated with the self-cleaning hydrosol prepared in Example 2 (b), the image of the droplets frozen after 220 s at -18°C (g); Image of the droplets on the glass substrate coated with the self-cleaning hydrosol prepared in Example 3 (c), the image of the droplets frozen after 100 s at -18°C (h); Image of the droplets on the glass substrate coated with the self-cleaning hydrosol prepared in Example 4 (d), the image of the droplets frozen after 80 s at -18°C (i); Image of the droplets on the blank glass substrate (e), the image of the droplets frozen after 50 s at -18°C (j). DETAILED DESCRIPTION

[0042] Hereinafter, the present application will be described in detail. Before undertaking the DETAILED DESCRIPTION below, it should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. It will be understood that where the application is

[0043] The following examples are presented merely as representative examples of embodiments of the application and are not intended to limit the application of the present application. It will be understood by those skilled in the art that modifications can be made in the embodiments without departing from the spirit and scope of the application. The experimental methods described in the following examples are routine methods unless otherwise specified. The reagents and materials described in the following examples are commercially available unless otherwise specified. The equipment used in the following examples is routine equipment.

[0044] Example 1 A method for preparing a self-cleaning hydrosol capable of preventing corrosion and ice, comprising the following steps: (1) TiO2nanopowder (particle size of 5-10 nm) is added to deionized water and stirred to obtain a TiO2solution; the ratio of the mass of TiO2nanopowder to the volume of deionized water is 0.25 g:25 mL; (2) Tetraethyl orthosilicate is slowly added (addition rate of 0.05 mL / s) to the TiO2solution obtained in step (1) and stirred to obtain a white colloidal solution; the ratio of the mass of tetraethyl orthosilicate to the volume of the TiO2solution is 0.3 g:25 mL; (3) Weigh 3-aminopropyltriethoxysilane and slowly add it dropwise (dropping rate 0.05 mL / s) to the white colloidal solution obtained in step (2), stir evenly to obtain a milky white colloidal solution; the mass ratio of 3-aminopropyltriethoxysilane to the volume of the white colloidal solution is 0.15 g: 27 mL; (4) Weigh perfluorodecyltrimethoxysilane and slowly add it dropwise (dropping rate 0.05 mL / s) to the milky white colloidal solution obtained in step (3), stir for 30 min, and obtain a self-cleaning hydrosol that can prevent corrosion and ice; the mass ratio of perfluorodecyltrimethoxysilane to the volume of the milky white colloidal solution is 0.3 g: 30 mL.

[0045] Figure 1 The images show the XRD patterns of the self-cleaning hydrosol and TiO2 material prepared in Example 1. The XRD patterns indicate that the crystal structure of the self-cleaning hydrosol prepared in Example 1 is consistent with that of anatase TiO2, and no other diffraction peaks were detected. However, the peaks of the self-cleaning hydrosol prepared in Example 1 show a certain blue shift compared to the TiO2 peaks. This phenomenon indicates that the interplanar spacing of TiO2 in the sol has increased. During the preparation process, tetraethyl silicate undergoes a hydrolysis reaction to produce Si-OH, and simultaneously, Ti-OH undergoes a condensation reaction to produce a portion of Si... 4+ Possibly replacing Ti 4+ This provides strong structural evidence for the successful substitution doping of the material.

[0046] Figure 2 The infrared spectrum of the self-cleaning hydrosol prepared in Example 1 is shown. The formation of Ti-O-Ti bonds proves that TiO2 nanoparticles can construct a rough nanoscale structure on the surface. When hydrophobic fluorosilanes cover the surface of these nanoparticles, a rough hydrophobic surface similar to the "lotus effect" is formed, which significantly enhances the hydrophobic properties (even reaching superhydrophobicity) and improves the stability and self-cleaning ability of the coating. The stretching vibration of the CF bond of perfluorodecyltrimethoxysilane is the most direct evidence that PFAS was successfully introduced into the coating. The stretching vibration of the Si-O-Si bond proves that TEOS was successfully hydrolyzed and condensed to form a silica network. The bending vibration of the CH bond reflects the functional group characteristics of the silane coupling agent. The infrared spectrum further proves the successful preparation of the self-cleaning sol and reveals the structural root of its hydrophobic and self-cleaning properties.

[0047] Example 2 A method for preparing a self-cleaning hydrosol with anti-corrosion and anti-icing properties includes the following steps: (1) Add TiO2 nanopowder (particle size of 5-10 nm) to deionized water and stir until homogeneous to obtain TiO2 solution; the mass ratio of TiO2 nanopowder to deionized water is 0.25 g: 25 mL. (2) Weigh out tetraethyl silicate and slowly add it dropwise (dropping rate 0.05 mL / s) to the TiO2 solution obtained in step (1), stir until homogeneous, and obtain a white colloidal solution; the mass ratio of tetraethyl silicate to the volume of TiO2 solution is 0.15 g: 25 mL; (3) Weigh 3-aminopropyltriethoxysilane and slowly add it dropwise (dropping rate 0.05 mL / s) to the white colloidal solution obtained in step (2), stir evenly to obtain a milky white colloidal solution; the mass ratio of 3-aminopropyltriethoxysilane to the volume of the white colloidal solution is 0.1 g: 27 mL; (4) Weigh perfluorodecyltrimethoxysilane and slowly add it dropwise (dropping rate 0.05 mL / s) to the milky white colloidal solution obtained in step (3), stir for 30 min, and obtain a self-cleaning hydrosol that can prevent corrosion and ice; the mass ratio of perfluorodecyltrimethoxysilane to the volume of milky white colloidal solution is 0.15 g: 30 mL.

[0048] Example 3 A method for preparing a self-cleaning hydrosol that can prevent corrosion and ice is as described in Example 1, except that: in step (4), dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride is used instead of perfluorodecyltrimethoxysilane.

[0049] Example 4 A method for preparing a self-cleaning hydrosol that can prevent corrosion and ice is described in Example 1, except that: in step (1), a mixed solution of deionized water and anhydrous ethanol is used instead of deionized water, and the volume ratio of deionized water to anhydrous ethanol in the mixed solution is 3:2.

[0050] Comparative Example 1 A method for preparing a hydrosol includes the following steps: (1) Add TiO2 nanopowder (particle size of 5-10 nm) to deionized water and stir until homogeneous to obtain TiO2 solution; the mass ratio of TiO2 nanopowder to deionized water is 0.25 g: 25 mL. (2) Weigh 3-aminopropyltriethoxysilane and slowly add it dropwise (dropping rate 0.05 mL / s) to the TiO2 solution obtained in step (1), stir until uniform, and obtain a milky white colloidal solution; the mass ratio of 3-aminopropyltriethoxysilane to the volume of TiO2 solution is 0.15 g: 27 mL; (3) Weigh perfluorodecyltrimethoxysilane and slowly add it dropwise (dropping rate 0.05 mL / s) to the milky white colloidal solution obtained in step (2), stir for 30 min to obtain a hydrosol; the mass ratio of perfluorodecyltrimethoxysilane to the volume of the milky white colloidal solution is 0.3 g: 30 mL.

[0051] Tetraethyl silicate was not added in this comparative example.

[0052] Comparative Example 2 A method for preparing a hydrosol is described in Example 1, except that the mass ratio of tetraethyl silicate to TiO2 solution in step (2) is 0.6 g: 25 mL.

[0053] In this comparative example, too much tetraethyl silicate was added.

[0054] Comparative Example 3 A method for preparing a hydrosol includes the following steps: (1) Add TiO2 nanopowder (particle size of 5-10 nm) to deionized water and stir until homogeneous to obtain TiO2 solution; the mass ratio of TiO2 nanopowder to deionized water is 0.25 g: 25 mL. (2) Weigh out tetraethyl silicate and slowly add it dropwise (dropping rate 0.05 mL / s) to the TiO2 solution obtained in step (1), stir until homogeneous, and obtain a white colloidal solution; the mass ratio of tetraethyl silicate to the volume of TiO2 solution is 0.3 g: 25 mL; (3) Weigh perfluorodecyltrimethoxysilane and slowly add it dropwise (dropping rate 0.05 mL / s) to the white colloidal solution obtained in step (2), stir for 30 min to obtain a hydrosol; the mass ratio of perfluorodecyltrimethoxysilane to the volume of the white colloidal solution is 0.3 g: 30 mL.

[0055] 3-Aminopropyltriethoxysilane was not added in this comparative example.

[0056] Comparative Example 4 A method for preparing a hydrosol is described in Example 1, except that the mass ratio of 3-aminopropyltriethoxysilane to the volume of the white colloidal solution in step (3) is 0.3 g: 27 mL.

[0057] In this comparative example, the amount of 3-aminopropyltriethoxysilane added was excessive.

[0058] Comparative Example 5 A method for preparing a hydrosol includes the following steps: (1) Add TiO2 nanopowder (particle size of 5-10 nm) to deionized water and stir until homogeneous to obtain TiO2 solution; the mass ratio of TiO2 nanopowder to deionized water is 0.25 g: 25 mL. (2) Weigh out tetraethyl silicate and slowly add it dropwise (dropping rate 0.05 mL / s) to the TiO2 solution obtained in step (1), stir until homogeneous, and obtain a white colloidal solution; the mass ratio of tetraethyl silicate to the volume of TiO2 solution is 0.3 g: 25 mL; (3) Weigh 3-aminopropyltriethoxysilane and slowly add it dropwise (dropping rate 0.05 mL / s) to the white colloidal solution obtained in step (2), stir evenly to obtain a hydrosol; the mass ratio of 3-aminopropyltriethoxysilane to the volume of the white colloidal solution is 0.15 g: 27 mL.

[0059] No perfluorodecyltrimethoxysilane was added in this comparative example.

[0060] Comparative Example 6 A method for preparing a hydrosol is described in Example 1, except that in step (4), the mass ratio of perfluorodecyltrimethoxysilane to the volume of the milky white colloidal solution is 0.6 g: 30 mL.

[0061] In this comparative example, the amount of perfluorodecyltrimethoxysilane added was excessive.

[0062] Comparative Example 7 A method for preparing a hydrosol is described in Example 1, except that in step (4), hexadecyltrimethoxysilane is used instead of perfluorodecyltrimethoxysilane.

[0063] Experimental Example 1 Contact angle test The aqueous sols prepared in Examples 1-4 and Comparative Examples 1-7 were coated onto glass substrates to obtain film materials, with a coating amount of 1 mL / cm². 2 After drying at room temperature, the contact angle of water on a glass substrate coated with hydrosol was measured.

[0064] Figure 3 The images show the contact angle test results of water on a glass substrate coated with the self-cleaning hydrosol prepared in Example 1 (a), water on a glass substrate coated with the self-cleaning hydrosol prepared in Example 2 (b), water on a glass substrate coated with the self-cleaning hydrosol prepared in Example 3 (c), and water on a glass substrate coated with the self-cleaning hydrosol prepared in Example 4 (d).

[0065] Figure 4The following are contact angle test diagrams for water on glass substrates coated with the hydrosol prepared in Comparative Example 1 (a), water on glass substrates coated with the hydrosol prepared in Comparative Example 2 (b), water on glass substrates coated with the hydrosol prepared in Comparative Example 3 (c), water on glass substrates coated with the hydrosol prepared in Comparative Example 4 (d), water on glass substrates coated with the hydrosol prepared in Comparative Example 5 (e), water on glass substrates coated with the hydrosol prepared in Comparative Example 6 (f), and water on glass substrates coated with the hydrosol prepared in Comparative Example 7 (g).

[0066] from Figure 3 and Figure 4 As can be seen from the contact angle test results, the hydrosols prepared in Examples 1-4 all exhibit excellent hydrophobic properties. The most outstanding is the hydrosol prepared in Example 1, which demonstrates superhydrophobicity with a contact angle of 161.07°. This excellent hydrophobicity lays a solid foundation for application experiments and is directly related to its self-cleaning ability. In contrast, all Comparative Examples 1-7 show poor hydrophobicity, with contact angles significantly lower than those in the examples. In Comparative Example 3, the contact angle without 3-aminopropyltriethoxysilane is 100.61°. In Comparative Example 4, the excessive amount of 3-aminopropyltriethoxysilane significantly reduces the contact angle to 52.64°. This is because the excess 3-aminopropyltriethoxysilane molecules cannot all be stably bonded to the substrate or the previous silane layer through chemical bonds; instead, they physically accumulate, and due to intermolecular hydrogen bonding, a large amount of hydrophilic amino groups (-NH2) are exposed on the outermost layer. The reason why the contact angle decreased in Comparative Example 6 due to the excess of perfluorodecyltrimethoxysilane was that the excess perfluorodecyltrimethoxysilane molecules preferentially underwent hydrolysis and condensation in the solution to form oligomers or particles, instead of being uniformly bonded to the substrate. The film layer became cracked or peeled due to excessive accumulation, exposing the underlying layer or substrate with relatively high surface energy, thereby reducing the overall hydrophobicity and self-cleaning effect.

[0067] Furthermore, the stability of the self-cleaning hydrosol prepared in Example 1 was tested. Figure 5 A water droplet was placed on a glass substrate coated with the self-cleaning hydrosol prepared in Example 1. After 48 hours, the contact angle was tested again, and the result was 155.21°, which proved the stability of the hydrophobic properties of the hydrosol.

[0068] Experimental Example 2 The TiO2 solution and the self-cleaning hydrosol prepared in Example 1 were coated onto a 1cm×1cm glass substrate to obtain a membrane material (coating amount of 1mL). After drying at room temperature, the membrane material was subjected to SEM testing. Figure 6Low-magnification SEM images (a) and high-magnification SEM images (b) of the film material obtained by coating TiO2 hydrosol onto a glass substrate, and low-magnification SEM images (c) and high-magnification SEM images (d) of the film material obtained by coating the self-cleaning hydrosol prepared in Example 1 onto a glass substrate. Figure 6 As can be seen, both are composed of 5-10nm nanoparticles coated on the glass substrate. Compared with TiO2 solution, the self-cleaning hydrosol forms a denser and more uniform nanofilm. This optimization of microstructure is crucial, as it is directly related to the improvement of its macroscopic performance: on the one hand, the dense film can more effectively block the penetration of water, oxygen and corrosive media, thereby enhancing the corrosion resistance; on the other hand, the uniform and flat nanostructure is the basis for building a stable superhydrophobic surface, which is essential for maintaining long-term anti-icing performance.

[0069] To verify the universality of the hydrosol on different substrates, cotton fabrics were immersed in the self-cleaning hydrosols of Examples 1-4, dried at room temperature, and untreated cotton fabrics were used as blank controls. Figure 7 When Rhodamine B solution was added, the cotton fabric in the blank group rapidly absorbed the droplets, while stable droplets formed on the surface of the fabrics treated in each example. This phenomenon directly demonstrates that this series of self-cleaning hydrosols can successfully impart excellent hydrophobic and self-cleaning properties to cotton fabrics.

[0070] Application Experiment Example 1 Self-cleaning hydrosol coating enhances the corrosion resistance of tinplate sheets. To evaluate the anti-corrosion performance of self-cleaning hydrosols, accelerated corrosion experiments were conducted on tinplate sheets coated with different hydrosols. Samples prepared in Examples 1-4 were coated onto 12cm × 2.5cm tinplate sheets (coating amount 10mL) and dried at room temperature. A blank control group without coating was also included. All tinplate sheets were immersed in a 3.5wt% NaCl aqueous solution and periodically (on days 1, 3, 5, 7, and 10) for optical photography and macroscopic morphology analysis. The results are as follows: Figures 8-13 As shown.

[0071] After immersion in a 3.5 wt% NaCl aqueous solution for 10 days, only the sample group in Example 1 maintained its surface integrity without significant corrosion. However, in Examples 2-4, corrosion gradually intensified with prolonged immersion time; the blank control group suffered the most severe damage, with its surface covered in corrosion products. These comparative results clearly establish that the self-cleaning hydrosol of Example 1 has the best anti-corrosion effect among all prepared samples.

[0072] Based on this, images of the blank tinplate and the tinplate coated with the self-cleaning hydrosol prepared in Example 1 were acquired using a polarizing microscope. The microscope magnification was set to 20x and 50x, respectively. The results are as follows:Figure 14 As shown, from Figure 14 As can be seen, the blank group of tinplate sheets has obvious rolling stripes, while the surface of the tinplate sheet coated with the self-cleaning hydrosol prepared in Example 1 is more uniformly and densely covered by the hydrosol film material. Therefore, the test results lay the foundation for the material to have excellent anti-corrosion performance.

[0073] Application Experiment Example 2 Self-cleaning hydrosol coating enhances antifreeze performance. The samples prepared in Examples 1-4 were coated onto a 6cm × 8cm glass substrate (coating volume 5mL) and dried at room temperature to form a film. An uncoated substrate was used as a control group. Equal amounts of water droplets were added to each substrate, and the initial morphology was recorded. The substrates were then uniformly transferred to a -18℃ environment, and timing was started. The freezing time was recorded and the morphology was photographed again when the droplets completely solidified. The freezing resistance was analyzed by comparing the freezing times of each experimental group with the control group.

[0074] The results are as follows Figure 15 As shown, the freezing time for Example 1 was 220 seconds, significantly longer than the other groups (Example 2: 120 seconds; Example 3: 100 seconds; Example 4: 80 seconds; Control group: 50 seconds). Furthermore, the droplets in Example 1 maintained a good spherical morphology after solidification. Compared to the control group, Example 1 extended the freezing time by more than three times, demonstrating its superior anti-freezing ability.

Claims

1. A method for preparing a self-cleaning hydrosol that is corrosion-resistant and anti-icing, characterized in that, The steps include the following: (1) Add TiO2 nanopowder to a solvent and stir until homogeneous to obtain a transparent TiO2 solution; (2) Add orthosilicate to the TiO2 solution obtained in step (1) and stir until homogeneous to obtain a white colloidal solution; (3) Add aminosilane dropwise to the white colloidal solution obtained in step (2), stir evenly, and obtain a milky white colloidal solution; (4) Add the silane coupling agent dropwise to the milky white colloidal solution obtained in step (3), stir evenly, and obtain a self-cleaning hydrosol that can prevent corrosion and ice.

2. The method for preparing the corrosion-resistant and anti-icing self-cleaning hydrosol according to claim 1, characterized in that, The solvent mentioned in step (1) is deionized water, or a mixed solution of deionized water and anhydrous ethanol, wherein the volume ratio of deionized water to anhydrous ethanol in the mixed solution is 1-5:

1.

3. The method for preparing the corrosion-resistant and anti-icing self-cleaning hydrosol according to claim 1, characterized in that, The TiO2 nanopowder in step (1) has a particle size of 5-10 nm; the mass ratio of the TiO2 nanopowder to the volume of the solvent is (0.25-0.5) g: (25-50) mL.

4. The method for preparing the corrosion-resistant and anti-icing self-cleaning hydrosol according to claim 1, characterized in that, The orthosilicate in step (2) is tetraethyl orthosilicate; the mass ratio of the orthosilicate to the volume of the TiO2 solution is (0.15-0.5) g: 25 mL, preferably (0.15-0.3) g: 25 mL.

5. The method for preparing the corrosion-resistant and anti-icing self-cleaning hydrosol according to claim 1, characterized in that, The aminosilane mentioned in step (3) is 3-aminopropyltriethoxysilane.

6. The method for preparing the corrosion-resistant and anti-icing self-cleaning hydrosol according to claim 1, characterized in that, The mass ratio of aminosilane to the volume of white colloidal solution in step (3) is (0.1-0.2)g:(27-30)mL, preferably (0.1-0.15)g:(27-30)mL.

7. The method for preparing the corrosion-resistant and anti-icing self-cleaning hydrosol according to claim 1, characterized in that, The silane coupling agent mentioned in step (4) is perfluorodecyltrimethoxysilane or dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride; the mass ratio of the silane coupling agent to the volume of the milky white colloidal solution is (0.15-0.5)g:(30-32)mL, preferably (0.15-0.3)g:(30-32)mL.

8. The method for preparing the corrosion-resistant and anti-icing self-cleaning hydrosol according to claim 1, characterized in that, The stirring time in step (4) is 10-60 min, preferably 30 min.

9. A self-cleaning hydrosol with anti-corrosion and anti-icing properties, characterized in that, It is prepared by the preparation method described in any one of claims 1-8.

10. The application of the corrosion-resistant and anti-icing self-cleaning hydrosol according to claim 9, characterized in that, Used to construct superhydrophobic protective coatings on the surfaces of metal, glass, and fabric substrates.

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