Transparent super-hydrophobic coating, preparation method and application
The preparation of transparent superhydrophobic coating by dip coating of silica nanoparticles and PMMA solves the problem of complex and high cost in the prior art, and achieves a combination of high transparency and good hydrophobicity, which is suitable for applications in multiple fields.
Patent Information
- Application Number
- CN202510508164.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-22
- Publication Date
- 2025-07-08
AI Technical Summary
The existing methods for preparing transparent superhydrophobic coatings are complex and costly, which limits their large-scale application, and it is difficult to take into account both transparency and hydrophobicity.
Silica nanoparticles and polymethyl methacrylate (PMMA) are used as raw materials to prepare a transparent superhydrophobic coating by dip coating to form a micro-nano fractal structure, simplifying the process and improving transparency and hydrophobicity.
The water contact angle of the transparent superhydrophobic coating prepared is greater than 160°, has good self-cleaning capacity, and the visible light transmittance in the range of 400~700nm is higher than 89%, which is suitable for large-scale production.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of coating materials, and particularly to a transparent superhydrophobic coating, a preparation method and an application thereof. Background Art
[0002] Disclosing the information of this background art section is only intended to enhance the overall understanding of the present invention, and is not necessarily regarded as an admission or any form of implication that this information constitutes the prior art already known to those of ordinary skill in the art.
[0003] Superhydrophobic materials refer to materials that make water droplets spherical on the surface of such materials, with a contact angle greater than 150° and a rolling angle less than 10°. Superhydrophobic materials are widely used due to their self-cleaning properties, and can be used in medical antibacterial, oil-water separation, anti-icing and other fields: covering a layer of superhydrophobic materials on the fan blades of wind turbines and the surfaces of solar panels can effectively prevent icing on their surfaces, saving manpower and material resources required for cleaning, and also timely ensuring the normal operation of equipment in extreme weather; covering superhydrophobic materials on the surface of metal products can reduce the contact time between droplets and the substrate, thereby achieving the effect of anti-corrosion. However, the application of ordinary superhydrophobic materials is relatively limited. For optical instruments and equipment, harsh outdoor conditions often cause dust to adsorb on the surfaces of these devices, affecting their performance. For example, the power generation efficiency of solar photovoltaics decreases after being blocked, the clarity of lenses decreases after being blocked, and the line of sight is affected after the automotive windshield is blocked, etc. Therefore, improving ordinary superhydrophobic materials to enhance transparency while ensuring hydrophobicity has great development prospects.
[0004] In the prior art, the preparation methods of transparent superhydrophobic coatings mainly include laser ablation method, chemical vapor deposition method, self-assembly method, sol-gel method, composite coating method, etc. However, the transparent superhydrophobic coatings prepared by existing methods still have the defects of high preparation cost and process complexity: for example, the sol-gel method requires precise control of reaction temperature, time and material ratio, so it requires precision equipment (such as ultrasonic spraying) and complex processes (such as multi-step sol reactions), resulting in limited large-scale application.
[0005] In view of the problems existing in the above prior art, the inventor believes that providing a transparent superhydrophobic coating with simple process, good hydrophobicity and transparency is of great significance for realizing the large-scale production of superhydrophobic materials, extending the service life of precision instruments and reducing maintenance costs. Summary of the Invention
[0006] In order to make up for the deficiencies of the prior art, the present invention provides a transparent superhydrophobic coating. This coating takes into account both hydrophobicity and transparency. The raw materials do not contain fluorine components, and the prepared coating is environmentally friendly and pollution-free. Moreover, the coating preparation process is simpler and is very suitable for large-scale production.
[0007] Based on the above-mentioned technical effects achieved, the present invention provides the following technical solutions: In a first aspect, a method for preparing a transparent superhydrophobic coating is provided, comprising the following steps: adding silica nanoparticles and poly(methyl methacrylate) (abbreviated as PMMA) to an organic solvent for dissolution to obtain a dipping solution; immersing the substrate to be treated in the dipping solution for more than 2 seconds, extracting and drying to obtain the coating.
[0008] Further, the particle size of the silica nanoparticles is 12 - 16 nm.
[0009] Further, the organic solvent is preferably an organic reagent having a good dissolution effect on PMMA, such as dichloromethane.
[0010] Further, the dosage ratio of the silica nanoparticles, poly(methyl methacrylate) and the organic solvent is 0.15 - 0.4 g: 0.1 - 0.3 g: 40 mL, preferably 0.25 - 0.3 g: 0.1 - 0.3 g: 40 mL, and more preferably 0.25 - 0.3 g: 0.2 g: 40 mL. Verified by the present invention, the concentration of silica nanoparticles in the dipping solution is correlated with the hydrophobicity of the coating surface. When the concentration of silica nanoparticles reaches 6.25 g / L or more, the hydrophobic angle of the coating also increases to more than 160°, belonging to the superhydrophobic materials recognized in the art.
[0011] After adding the above-mentioned silica nanoparticles and poly(methyl methacrylate) to the organic solvent, dissolution can be accelerated by stirring. There is no limitation on the stirring time, and it can be stirred in a manner well-known to those skilled in the art until the solid components are completely dissolved and the solution is transparent and homogeneous.
[0012] The substrate to be treated includes but is not limited to glass, wood products, metal products, ceramic products, textiles, photovoltaic materials, battery electrodes, building facades, etc.
[0013] In the drying process, those skilled in the art can conventionally select the drying temperature and time until the organic solvent is completely volatilized and the surface is dry.
[0014] In a second aspect, a superhydrophobic coating prepared by the method in the first aspect.
[0015] By electrolytic observation of the coating prepared by the method in the first aspect, it is shown that PMMA serves as an adhesion layer, carrying the protruding structure of silica nanoparticles, tightly adhering to the surface of other materials; among them, the larger-sized (greater than 100 nm) agglomerates formed by the aggregation of nanoparticles constitute the microstructures, and the overall forms a micro-nano fractal structure.
[0016] In a third aspect, a product coated with the superhydrophobic coating described in the second aspect.
[0017] In a fourth aspect, the application of the superhydrophobic coating described in the second aspect, and the preferred application fields are such as cultural relic restoration, medical devices, photovoltaic power generation, construction industry, aerospace, ocean engineering, automobile manufacturing, etc.
[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a preparation method and application of a simple transparent superhydrophobic coating. The present invention uses silica nanoparticles and PMMA (polymethyl methacrylate) as raw materials to prepare a transparent superhydrophobic coating dipping solution, and obtains a transparent superhydrophobic coating by the dipping method. The water contact angle of the transparent superhydrophobic coating prepared by the present invention is greater than 160°, and it has good self-cleaning ability, and the visible light transmittance in the range of 400-700 nm is higher than 89%. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The attached drawings forming a part of the description of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention.
[0020] Figure 1 is a flowchart of the preparation method of the transparent superhydrophobic coating described in the present invention; Figure 2 is a schematic structural diagram of the transparent superhydrophobic coating described in the present invention; Among them, 1 represents the nanoparticles on the coating surface, 2 is the substrate, and 3 is the PMMA adhesion layer.
[0021] Figure 3 are the transparency display effect and hydrophobic effect diagram of the glass substrate and the coated glass in Example 3; Figure 3 where a is the transparency display effect in Figure 3 and b is the hydrophobic effect diagram in Figure 4 are the contact angle test results of the coatings prepared in Examples 1-5; Figure 5 are the light transmittance test results of the glass substrate and the coatings prepared in Examples 1-5; Figure 6 is the scanning electron micrograph of the coating prepared in Example 3; Figure 7 are the self-cleaning ability test effect diagrams of the glass substrate and the coating prepared in Example 3; Figure 7 where a is the glass substrate in Figure 7 and b is the glass with the coating in Example 3; Figure 8The wetting conditions of different liquids on the surface of ordinary glass and the coated glass prepared in Example 3; Figure 8 In a, it is the wetting condition of tomato ketchup on the surface of the glass substrate, Figure 8 In b, it is the wetting condition of artificial plasma on the surface of the glass substrate, Figure 8 In c, it is the wetting condition of tomato ketchup on the surface of the coating in Example 3, Figure 8 In d, it is the wetting condition of artificial plasma on the surface of the coating prepared in Example 3. Detailed implementation manners
[0022] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanations of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.
[0023] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary implementation manners according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0024] In order to enable those skilled in the art to more clearly understand the technical solutions of the present invention, the technical solutions of the present invention will be described in detail below in conjunction with specific embodiments.
[0025] The specific models of the silica nanoparticles used in the following examples are: 14 nm particle size, Evonik Corporation; the specific model of PMMA is: analytical pure, Aladdin Reagent (Shanghai) Co., Ltd.
[0026] Example 1 In this example, a method for preparing a transparent superhydrophobic coating is provided, including the following steps: (1) Weigh 0.15 g of silica nanoparticles, add them to 40 mL of dichloromethane, and then add 0.2 g of PMMA powder. After adding the materials, stir magnetically until the colloidal PMMA is fully dissolved in dichloromethane to obtain a dip coating solution.
[0027] (2) Immerse a glass slide as the substrate to be treated into the dip coating solution in step (1). After about 2 s of gelation, take out the glass slide from the dip coating solution and dry it by natural evaporation in the air to form a film, thus obtaining the transparent superhydrophobic coating.
[0028] Example 2 In this embodiment, another method for preparing a transparent superhydrophobic coating is provided. The difference from Embodiment 1 is that in step (1), the dosage of silica nanoparticles is 0.2 g.
[0029] Embodiment 3 In this embodiment, another method for preparing a transparent superhydrophobic coating is provided. The difference from Embodiment 1 is that in step (1), the dosage of silica nanoparticles is 0.25 g.
[0030] Embodiment 4 In this embodiment, another method for preparing a transparent superhydrophobic coating is provided. The difference from Embodiment 1 is that in step (1), the dosage of silica nanoparticles is 0.3 g.
[0031] Embodiment 5 In this embodiment, another method for preparing a transparent superhydrophobic coating is provided. The difference from Embodiment 1 is that in step (1), the dosage of silica nanoparticles is 0.4 g.
[0032] Performance verification 1. Display effect of the superhydrophobic coating Figure 3 In Figure a, it is a photo of the display effect of the transparent superhydrophobic coating in Embodiment 3. The glass substrate is on the top, and the glass with the coating is at the bottom. There is little difference in transparency between the two.
[0033] Figure 3 In Figure b, it is a photo of the hydrophobic effect of the transparent superhydrophobic coating in Embodiment 3. The glass substrate is on the top, and the glass with the coating is at the bottom. It can be seen that the water droplets on the coated glass below are closer to spheres, proving that the coating has good hydrophobic effect.
[0034] 2. Contact angle test The contact angle test results of the transparent superhydrophobic coatings in Embodiments 1 - 5 are shown in Figure 4 , and it can be known from Figure 4 that: as the concentration of silica nanoparticles increases, the contact angle of water droplets continuously increases. When the concentration of silica nanoparticles is 3.75 g / L, the water contact angle of the coating is 120.1°; when the concentration of silica nanoparticles increases to 10.00 g / L, the water contact angle rises to 170.2°.
[0035] 3. Transmittance test Using a holographic ultraviolet-visible-near-infrared spectrophotometer, the transmittance of the glass with the transparent superhydrophobic coating and the glass substrate in Embodiments 1 - 5 was measured. The experimental selected detection wavelength range was from 350 nm to 800 nm. The test results are as shown in Figure 5As shown in the figure: As the concentration of silica nanoparticles increases, the light transmittance of the coating gradually decreases. This is because the superhydrophobic surface with a higher concentration of nanoparticles has a larger roughness, and the light scattering on the material surface becomes stronger. This reduces the transmitted light and lowers the surface transparency.
[0036] 4. Characterization of Material Surface Properties The transparent superhydrophobic coating prepared in Example 3 was subjected to scanning electron microscopy (SEM) testing. The test results are shown in Figure 6 . As Figure 6 shown, when the concentration of silica nanoparticles is 6.25 g / L, the material surface has a micro-nano composite structure: larger-sized (greater than 100 nm) agglomerates formed by the aggregation of nanoparticles constitute the micro-structure; while the nanoparticles adhering to the surface of the agglomerates and exposed outside form the nano-protrusion structure of the micro-scale agglomerates.
[0037] 5. Self-Cleaning Ability Test Taking the glass substrate and the glass with the coating in Example 3 as the objects of investigation, the self-cleaning performance of the coating was tested: Dust was used as a pollutant and spread on the surface of the sample. Then the sample was placed obliquely, and water droplets were dropped from above to observe the self-cleaning performance of the test sample. The test results are shown in Figure 7 . Figure 7 In Figure 7 , a is the glass substrate, and
[0038] In Figure 7 , b is the glass with the coating prepared in Example 3. Figure 7 The test results of the glass substrate are shown in
[0039] In a. After adding water droplets, due to the large adhesion of water to the glass substrate, the water droplets adhere to its surface and cannot effectively carry away the surface pollutants; the test results of the coating prepared in Example 3 are shown in Figure 8 In
[0040] Figure 8 b. After adding water droplets, due to the ultra-low adhesion of water to the superhydrophobic surface, the water droplets roll rapidly on the coating surface and carry away the surface pollutants, keeping the surface clean, indicating that the coating prepared in Example 3 has good self-cleaning ability. Figure 8 In Figure 8 c, a is the wetting situation of ketchup on the glass substrate surface, Figure 8d represents the wetting situation of the artificial plasma on the coating surface prepared in Example 3. From Figure 8 It can be seen from c and d above that the above two liquids show a spherical shape on the coating surface, indicating that the coating has good repellency to these liquids and excellent hydrophobic effect.
[0041] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A method for preparing a transparent superhydrophobic coating, characterized in that, It includes the following steps: Dissolve silica nanoparticles and PMMA in an organic solvent to obtain a dip-coating solution; Immerse the substrate to be treated in the dip-coating solution for more than 2 seconds, take it out and dry it to obtain the product.
2. The preparation method of the transparent superhydrophobic coating according to claim 1, characterized in that, The organic solvent is dichloromethane.
3. The preparation method of the transparent superhydrophobic coating according to claim 1, characterized in that, The dosage ratio of the silica nanoparticles, polymethyl methacrylate and the organic solvent is 0.15 - 0.4 g: 0.1 - 0.3 g: 40 mL, preferably 0.25 - 0.3 g: 0.1 - 0.3 g: 40 mL, and more preferably 0.25 - 0.3 g: 0.2 g: 40 mL.
4. The preparation method of the transparent superhydrophobic coating according to claim 1, characterized in that, The substrate to be treated includes but is not limited to glass, wood products, metal products, ceramic products, textiles, photovoltaic materials, battery electrodes or building facades.
5. A superhydrophobic coating prepared by the method according to any one of claims 1 - 4.
6. A product coated with the superhydrophobic coating according to claim 5.
7. Use of the superhydrophobic coating according to claim 5, characterized in that, The application field is selected from cultural relics restoration, medical devices, photovoltaic power generation, construction, aerospace, ocean engineering or automobile manufacturing.