High-reflection super-amphiphobic powder coating and preparation method thereof

Abstract

According to the high-reflection super-amphiphobic powder coating and the preparation method, the preparation process is simple and easy to control, no extra equipment needs to be used, and the problems that in the prior art, the sunlight reflectivity is not high enough, the surface is prone to contamination, and preparation is complex are effectively solved. The high-reflection super-amphiphobic powder coating comprises a long-chain fluorine-containing silane coupling agent with low surface energy, ethanol and pigment nanoparticles. The long-chain fluorine-containing silane coupling agent is perfluorooctyltrichlorosilane, perfluorooctyltrichlorosilane, perfluorooctyltriethoxysilane, polydimethylsiloxane, dimethyl diethoxy silane, methyl triethoxy silane or hexadecyl trichlorosilane, and the fluorine-containing silane coupling agent can be a fluorine-containing silane coupling agent, a fluorine-containing silane coupling agent, a fluorine-containing silane coupling agent, a fluorine-containing silane coupling agent, a fluorine-containing silane coupling agent, a fluorine-containing silane coupling agent, a fluorine-containing silane coupling agent and a fluorine-containing silane coupling agent. The pigment and filler nanoparticles are titanium dioxide, barium sulfate, aluminum oxide, barium sulfate, calcium carbonate, silicon dioxide or zinc oxide with the diameter of 10nm-5mu m. The volume ratio of the pigment nanoparticles to the ethanol solution to the long-chain fluorine-containing silane coupling agent is (1-5): (5-10): (0.1-0.3).

Description

Technical Field

[0001] The present invention relates to the technical field of self-cleaning materials, and particularly to a highly reflective superhydrophobic and oleophobic powder coating and a preparation method thereof. Background Art

[0002] With the rapid development of fields such as optics, electronics, solar energy, and building energy conservation, traditional materials have become difficult to meet the requirements of modern technologies in terms of light reflection efficiency, durability, and environmental adaptability. Therefore, developing new high-reflection coatings with high reflectivity, good stability, and environmental friendliness is an urgent task currently faced by the scientific research and industrial communities.

[0003] High-reflection coatings are usually made of high-refractive-index materials, which have special electronic structures and energy band structures and can effectively reflect light back. For example, metal films with high reflectivity such as silver and aluminum, inorganic dielectric coatings with high refractive index and stability such as titanium dioxide and silicon dioxide, and some composite reflective coatings. In addition, higher reflectivity can be achieved by designing the micro-nano structure of the coating. Currently, researchers have achieved many excellent research results. However, during outdoor use, these high-reflection coatings are vulnerable to damage from the natural environment. When dust, rain, and oil adhere to the coating surface, the reflectivity of the coating will decrease. This requires the coating to have superhydrophobic and oleophobic properties. Through the combined action of special surface microstructures and low-surface-energy substances, water droplets and oil droplets are difficult to stay on the coating surface, and self-cleaning can also be achieved through rain and morning fog in nature.

[0004] In this regard, researchers at home and abroad have conducted a large number of studies, attempting to combine high-reflection performance with superhydrophobic and oleophobic performance to develop a new type of coating material. However, the research in this field still faces many challenges. One is material selection. High-reflection materials often differ from superhydrophobic and oleophobic materials in chemical properties and physical structures, and how to achieve their organic combination is a difficult problem. The second is the preparation process. The preparation of a highly reflective superhydrophobic and oleophobic powder coating requires precise control of the surface microstructure and chemical composition of the coating, which poses high requirements for the preparation process. The third is performance optimization. How to balance the high-reflection performance and self-cleaning performance of a highly reflective superhydrophobic and oleophobic powder coating is an important research direction currently. Therefore, it is crucial to develop a coating with both high reflectivity and superhydrophobic and oleophobic properties. Summary of the Invention

[0005] Aiming at the above problems in the prior art, the present invention provides a highly reflective superhydrophobic and oleophobic powder coating and a preparation method thereof. This coating not only has the reflection performance of traditional high-reflection coatings but also has the waterproof and oil-proof properties of superhydrophobic and oleophobic coatings. The preparation process is simple and easy to control, and no additional processing equipment is required. It effectively solves the problems in the prior art such as insufficient reflectivity, easy contamination, and complex preparation methods.

[0006] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0007] The present invention provides a highly reflective superhydrophobic and oleophobic powder coating, comprising a long-chain fluorosilane coupling agent with low surface energy, ethanol, and pigment nanoparticles.

[0008] Preferably, the long-chain fluorosilane coupling agent is perfluorooctyltrichlorosilane, perfluorodecyltrichlorosilane, perfluorooctyltriethoxysilane, polydimethylsiloxane, dimethyldiethoxysilane, methyltriethoxysilane, or hexadecyltrichlorosilane.

[0009] Preferably, the diameter of the pigment and filler nanoparticles is 10 nm - 5 μm.

[0010] Preferably, the pigment nanoparticles are titanium dioxide, silicon dioxide, aluminum oxide, barium sulfate, calcium carbonate, or zinc oxide.

[0011] Preferably, the volume ratio of the pigment nanoparticles, ethanol solution, and long-chain fluorosilane coupling agent is 1 - 5:5 - 10:0.1 - 0.3.

[0012] A method for preparing a highly reflective superhydrophobic and oleophobic powder coating includes the following steps:

[0013] S1 Suspend and disperse the pigment nanoparticles in an ethanol solution and stir well;

[0014] S2 Add a long-chain fluorosilane coupling agent with low surface energy to the suspension solution and mix evenly;

[0015] S3 Coat the suspension on the surface of the required substrate, and a highly reflective superhydrophobic and oleophobic powder coating is formed after the solvent evaporates.

[0016] Preferably, step S1 is further specifically implemented as adding the pigment nanoparticles to the ethanol solution and magnetically stirring for 1 - 3 hours to form a uniform white solution.

[0017] Preferably, step S2 is further specifically implemented as adding the long-chain fluorosilane coupling agent to the solution obtained in step S1 and magnetically stirring for 1 - 5 hours to graft the fluorinated long chain onto the surface of the pigment nanoparticles.

[0018] Preferably, step S3 is further specifically implemented as coating the suspension solution obtained in step S2 on the required substrate by various methods such as spraying, roll coating, and knife coating, and a highly reflective superhydrophobic and oleophobic powder coating is formed after the solvent evaporates.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1. The preparation process of the present invention is simple and easy to control, and has universality. The prepared coating can adhere to various surfaces, such as metals, plastics, glasses, and woods, etc. Without the need for additional high-cost equipment and complex preparation conditions. The obtained high-reflection superhydrophobic and oleophobic powder coating has a self-cleaning effect, effectively solving the problems of low production efficiency, poor material durability, and easy contamination in the prior art.

[0021] 2. When preparing the coating, the cost of the preparation raw materials is low, the raw materials are easy to obtain, and there is no need for a polymer matrix. By regulating the pigment and filler nanoparticles with different particle sizes and types, excellent properties of high reflectivity and superliquid repellency can be obtained.

[0022] 3. The suspension in the present invention can be coated on the surface of any object by various simple methods such as spraying and brushing. After natural evaporation, a coating with a porous hierarchical structure is formed. Due to the large refractive index difference between the (solid-phase) nanoparticles and the gas phase (air), a high reflectivity can be achieved by using the optical backward porous scattering mechanism.

[0023] 4. The coating formed by coating the suspension in the present invention on the surface has an ultra-low surface energy. After pollutants land on the surface, the adhesion force between the pollutants and the coating is extremely low. Therefore, it can effectively utilize natural conditions such as rainwater, morning fog, and wind in nature to clean the pollutants, without any additional cleaning and wiping. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the coating formed by the superhydrophobic and oleophobic powder with high reflectivity of the present invention;

[0025] Figure 2 are scanning electron microscope photos of the coating formed by the superhydrophobic and oleophobic powder with high reflectivity of the present invention magnified 10,000 times and 30,000 times microscopically;

[0026] Figure 3 is the reflectivity of the coating formed by the superhydrophobic and oleophobic powder with high reflectivity of the present invention in the solar light band. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the following further describes the present invention in detail with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Those not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not specified by the manufacturer can be obtained as conventional products through commercial purchase.

[0028] Figure 1It is a schematic diagram of a coating formed by superhydrophobic and oleophobic powder with high reflectivity in this embodiment. First, pigment nanoparticles are uniformly dispersed in absolute ethanol, and then a long-chain fluorosilane coupling agent is added to the dispersion solution. After magnetic stirring, a pigment nanoparticle / ethanol / fluoropolymer dispersion suspension is prepared. Then, the prepared paint-like solution is sprayed, dropped, or impregnated onto various substrates, and a high-reflection superhydrophobic and oleophobic powder coating is obtained after the ethanol solvent naturally evaporates.

[0029] The preparation method of the present invention will be described in detail below in conjunction with specific embodiments.

[0030] Example 1

[0031] A high-reflection superhydrophobic and oleophobic powder coating, and its preparation method includes the following steps:

[0032] (1) Titanium dioxide nanoparticles with a particle size of 20 nm - 1 μm are added to absolute ethanol, and magnetic stirring is carried out for 3 h to prepare a uniform white solution;

[0033] (2) Perfluorooctyltrichlorosilane is added to the white solution, and magnetic stirring is carried out at 25°C for 5 h to prepare a dispersion suspension solution of perfluorooctyltrichlorosilane / titanium dioxide / ethanol (mass ratio of 1:15:100).

[0034] (3) The paint-like solution prepared in (2) is added dropwise (0.3 ml / cm2) to the exposed sticky side of the double-sided tape prepared in (1), and a coating with a thickness of about 150 μm is obtained after the solvent evaporates for 3 h.

[0035] Example 2

[0036] A high-reflection superhydrophobic and oleophobic coating, and its preparation method includes the following steps:

[0037] (1) Barium sulfate nanoparticles with a particle size of 50 nm - 2 μm are added to absolute ethanol, and magnetic stirring is carried out for 3 h to prepare a uniform white solution;

[0038] (2) Perfluoroquintyltrichlorosilane is added to the white solution, and magnetic stirring is carried out at 25°C for 5 h to prepare a dispersion suspension solution of perfluoroquintyltrichlorosilane / barium sulfate / ethanol (mass ratio of 1:20:100).

[0039] (3) The paint-like solution prepared in (2) is added dropwise (0.2 ml / cm2) to the exposed sticky side of the spray glue prepared in (1), and a coating with a thickness of about 100 μm is obtained after the solvent evaporates for 5 h.

[0040] Example 3

[0041] A high-reflection superhydrophobic and oleophobic powder coating, and its preparation method includes the following steps:

[0042] (1) Alumina nanoparticles with a particle size of 10 nm - 50 nm are added to absolute ethanol and magnetically stirred for 3 h to prepare a uniform white solution;

[0043] (2) Perfluorooctyltriethoxysilane is added to the white solution and magnetically stirred at 25 °C for 5 h to prepare a dispersion suspension solution of perfluorooctyltriethoxysilane / alumina / ethanol (mass ratio of 1:30:100).

[0044] (3) The paint-like solution prepared in (2) is added dropwise (0.15 ml / cm2) to one side of the exposed sticky surface of the AB glue prepared in (1), and a coating with a thickness of about 80 μm is obtained after the solvent evaporates for 5 h.

[0045] Example 4

[0046] A highly reflective superhydrophobic and oleophobic powder coating, and its preparation method includes the following steps:

[0047] (1) Calcium carbonate nanoparticles with a particle size of 100 nm - 1000 nm are added to absolute ethanol and magnetically stirred for 3 h to prepare a uniform white solution;

[0048] (2) Polydimethylsiloxane is added to the white solution and magnetically stirred at 25 °C for 5 h to prepare a dispersion suspension solution of polydimethylsiloxane / calcium carbonate / ethanol (mass ratio of 1:15:100).

[0049] (3) The paint-like solution prepared in (2) is added dropwise (0.2 ml / cm2) to one side of the exposed sticky surface of the double-sided tape prepared in (1), and a coating with a thickness of about 100 μm is obtained after the solvent evaporates for 5 h.

[0050] Example 5

[0051] A highly reflective superhydrophobic and oleophobic powder coating, and its preparation method includes the following steps:

[0052] (1) Zinc oxide nanoparticles with a particle size of 10 nm - 500 nm are added to absolute ethanol and magnetically stirred for 3 h to prepare a uniform white solution;

[0053] (2) Hexadecyltrichlorosilane is added to the white solution and magnetically stirred at 25 °C for 5 h to prepare a dispersion suspension solution of hexadecyltrichlorosilane / zinc oxide / ethanol (mass ratio of 1:20:100).

[0054] (3) The paint-like solution prepared in (2) is added dropwise (0.2 ml / cm2) to one side of the exposed sticky surface of the spray adhesive prepared in (1), and a coating with a thickness of about 100 μm is obtained after the solvent evaporates for 5 h.

[0055] Example 6

[0056] A highly reflective superhydrophobic and oleophobic powder coating, and a preparation method thereof comprises the following steps:

[0057] (1) Adding silicon dioxide nanoparticles with a particle size of 10 nm to 5 μm into absolute ethanol, and magnetically stirring for 3 h to prepare a uniform white solution;

[0058] (2) Adding perfluorooctyltrichlorosilane into the white solution, and magnetically stirring at 25 °C for 5 h to prepare a dispersed suspension solution of perfluorooctyltrichlorosilane / silicon dioxide / ethanol (mass ratio of 1:10:100).

[0059] (3) Adding the paint-like solution prepared in (2) dropwise (0.2 ml / cm2) onto one side of the sticky surface of the spray glue prepared in (1), and after the solvent evaporates for 5 h, a coating with a thickness of about 100 μm is obtained.

[0060] The structure and performance of the highly reflective superhydrophobic and oleophobic powder coating according to the embodiments of the present invention will be described below with reference to the accompanying drawings. Figure 2 They are respectively the scanning electron microscope photos of the highly reflective superhydrophobic and oleophobic powder coating according to the embodiments of the present invention magnified 10,000 times and 30,000 times microscopically. It can be seen from the figure that the primary nanoparticles with a particle size of 20 nm - 1 μm are self-assembled into a micro-nano composite porous structure with a multi-scale distribution. Each nanoparticle is fully grafted and wrapped with fluorosilane. The reflectivity of the solar spectrum of the embodiments of the present invention is as Figure 3 shown. The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. Due to the adoption of the above technical solutions, the present invention has the following advantages:

[0061] 1. It does not contain a polymer matrix material, the refractive index difference between the inorganic nanoparticle phase and the air phase is larger, and it has a higher scattering efficiency for sunlight, and the solar spectrum reflectivity is high;

[0062] 2. After the surface of the nanoparticles is grafted with a long-chain silane coupling agent, the surface of the coating has an extremely low surface energy, which can reduce the adhesion force of various substances such as water and oil on the surface, and the superhydrophobic and oleophobic performance is strong;

[0063] 3. It has strong self-cleaning ability and can effectively utilize rainwater, morning fog and wind force in the natural environment to achieve the self-cleaning function.

Claims

1. A highly reflective super-hydrophobic and super-oleophobic powder coating, characterized in that: It contains a long-chain fluorosilane coupling agent with a low surface energy, ethanol, and pigment nanoparticles.

2. The highly reflective super-hydrophobic and oleophobic powder coating according to claim 1, wherein: The long-chain fluorosilane coupling agent is at least one of perfluorooctyltrichlorosilane, perfluorodecyltrichlorosilane, perfluorooctyltriethoxysilane, polydimethylsiloxane, dimethyldiethoxysilane, methyltriethoxysilane, or cetyltrichlorosilane.

3. The highly reflective super-hydrophobic and oleophobic powder coating according to claim 1, wherein: The diameter of the pigment nanoparticles is 10 nm - 5 μm.

4. The highly reflective super-hydrophobic and super-oleophobic powder coating according to claim 1, wherein: The pigment nanoparticles are at least one of titanium dioxide, silicon dioxide, aluminum oxide, barium sulfate, calcium carbonate, or zinc oxide.

5. The highly reflective super-hydrophobic and oleophobic powder coating according to claim 1, characterized in that: The volume ratio of the pigment nanoparticles, ethanol solution, and long-chain fluorosilane coupling agent is 1 - 5:5 - 10:0.1 - 0.

3.

6. The preparation method of the highly reflective superhydrophobic and oleophobic powder coating according to any one of claims 1 to 5, characterized in that, It includes the following steps: S1 Suspend and disperse the pigment nanoparticles in an ethanol solution and stir well. S2 Add a long-chain fluorosilane coupling agent with a low surface energy to the suspension solution and mix evenly. S3 Coat the suspension on the surface of the substrate, and after the solvent evaporates, a highly reflective superhydrophobic and oleophobic powder coating is formed.

7. The preparation method of the highly reflective super-hydrophobic and oleophobic powder coating according to claim 6, characterized in that: Step S1 is further specifically described as adding the pigment nanoparticles to the ethanol solution and magnetically stirring for 1 - 3 hours to form a uniform white solution.

8. The preparation method of the highly reflective super-oleophobic and super-hydrophobic powder coating according to claim 6, wherein: Step S2 is further specifically described as adding the long-chain fluorosilane coupling agent to the solution obtained in step S1 and magnetically stirring for 1 - 5 hours to graft the fluorinated long chain onto the surface of the pigment nanoparticles.

9. The preparation method of the highly reflective super-hydrophobic and oleophobic powder coating according to claim 6, characterized in that: Step S3 is further specifically described as coating the suspension solution obtained in step S2 on the substrate by spraying, roll coating, and knife coating, and after the solvent evaporates, a highly reflective superhydrophobic and oleophobic powder coating is formed.

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