Firm and wear-resistant micro-nano composite super-hydrophobic coating as well as preparation process and application thereof

Abstract

The invention belongs to the technical field of functional coatings, and relates to a firm and wear-resistant micro-nano composite super-hydrophobic coating as well as a preparation process and application thereof. According to the firm and wear-resistant micro-nano composite super-hydrophobic coating, super-hydrophobic composite silicon dioxide particles are adopted, and the super-hydrophobic composite silicon dioxide particles are formed by connecting modified nano silicon dioxide particles and modified micron silicon dioxide particles through chemical bonds; the modified nano silicon dioxide particles are nano silicon dioxide particles of which the surfaces are modified with C6-C20 straight-chain alkyl or fluorine-substituted C6-C20 straight-chain alkyl, and the modified micron silicon dioxide particles are micron silicon dioxide particles of which the surfaces contain groups capable of being simultaneously bonded with the coating matrix and the modified nano silicon dioxide particles. The contact angle between the coating and water can exceed 175 degrees, and meanwhile, the super-hydrophobic structure in the coating is also formed by the structure of the super-hydrophobic composite silicon dioxide particles, so that the super-hydrophobic composite silicon dioxide particles have high mechanical stability and have wide application prospects in the fields of resistance reduction, pollution prevention, ice prevention and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional coatings and relates to a strong and wear-resistant micro-nano composite super-hydrophobic coating and a preparation process and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] Non-wetting interfaces, due to their unique liquid-repelling properties, have shown important application value in anti-icing, drag reduction, anti-fouling and other fields. The super-hydrophobic surface is the most widely studied non-wetting surface. It is a special surface with extremely low surface energy and a contact angle with water greater than 150°. This surface enables water droplets to form a nearly perfect sphere on it and roll off quickly, showing excellent water repellency. The super-hydrophobic surface is the most widely studied non-wetting surface. It is a special surface with extremely low surface energy and a contact angle with water greater than 150°. This surface enables water droplets to form a nearly perfect sphere on it and roll off quickly, showing excellent water repellency.

[0004] In the preparation process of super-hydrophobic surfaces, constructing micro-nano composite structures is a crucial step. At present, the preparation methods of traditional microstructures mainly include photolithography, deposition, template method, laser processing method and 3D printing method. However, these methods have many limitations in practical applications. On the one hand, they are difficult to achieve large-scale and efficient preparation of microstructured surfaces, and are usually only applicable to substrates with small areas or specific shapes; on the other hand, these methods have extremely stringent requirements on the shape and material of the substrate, which to a large extent limits the wide application of super-hydrophobic surfaces in practical engineering fields. The spraying method has attracted much attention due to its significant advantages such as simple operation, wide range of applications and ability to meet large-scale preparation. However, the super-hydrophobic properties of the materials used in the spraying method need to be further improved, and in actual use, the coating after spraying is easily damaged by external mechanical effects, thereby affecting the performance and service life of the super-hydrophobic surface. Summary of the Invention

[0005] In order to address the deficiencies in the prior art, the purpose of the present invention is to provide a strong and wear-resistant micro-nano composite super-hydrophobic coating and its preparation process and application. The strong and wear-resistant micro-nano composite super-hydrophobic coating provided by the present invention uses super-hydrophobic composite silica particles, so that the contact angle of the coating with water can exceed 175°. At the same time, the super-hydrophobic structure in the coating is also formed by the structure of the super-hydrophobic composite silica particles themselves, so it has high mechanical stability and has broad application prospects in the fields of drag reduction, anti-fouling, anti-icing, etc.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] In a first aspect, a super-hydrophobic composite silica particle is formed by chemically connecting modified nano-silica particles and modified micron-silica particles, wherein the modified nano-silica particles are nano-silica particles whose surfaces are modified with C6-C20 straight-chain alkyl groups or fluorine-substituted C6-C20 straight-chain alkyl groups, and the modified micron-silica particles are micron-silica particles whose surfaces contain groups that can simultaneously bond (form chemical bonds) with the coating matrix and the modified nano-silica particles.

[0008] In the composite silica particles provided by the present invention, the surfaces of the modified nano-silica particles are modified with C6-C20 straight-chain alkyl groups or fluorine-substituted C6-C20 straight-chain alkyl groups, so that the nano-silica particles have low surface energy characteristics. At the same time, the modified nano-silica particles and modified micron-silica particles are connected by chemical bonds to form a micro-nano composite structure in which small spheres wrap around large spheres. This structure not only gives the coating a unique microscopic morphology, but also further optimizes the super-hydrophobic properties of the coating.

[0009] In addition, the modified micron silica particles contain groups on their surface that can form chemical bonds with the coating matrix. When they are compounded with the coating matrix to form a coating, the modified micron silica particles can be connected to the coating matrix through chemical bonds, which not only ensures the superhydrophobic properties of the coating, but also improves the mechanical stability of the superhydrophobic coating.

[0010] On the other hand, a method for preparing the above-mentioned super-hydrophobic composite silica particles comprises the following steps:

[0011] The nano-silica particles are first modified by using a low-surface-energy silane and a first silane coupling agent to obtain modified nano-silica particles; the low-surface-energy silane is a silane containing a C6-C20 straight-chain alkyl group or a fluorine-substituted C6-C20 straight-chain alkyl group;

[0012] performing a second modification on the micron silica particles using a second silane coupling agent to obtain modified micron silica particles;

[0013] The modified nano-silica particles and the modified micro-silica particles are subjected to a catalytic reaction, so that chemical bonds are formed between the modified nano-silica particles and the modified micro-silica particles.

[0014] During the preparation process, the present invention not only achieves low surface energy modification of nano-silica particles through the silane coupling agent, but also retains groups that can bond to each other and groups that can bond to the coating matrix on the surfaces of the modified nano-silica particles and the modified micron-silica particles, so that the modified nano-silica particles and the modified micron-silica particles can be connected by chemical bonds.

[0015] In a third aspect, a strong and wear-resistant micro-nano composite super-hydrophobic coating comprises a coating substrate and a super-hydrophobic modified material attached to the surface of the coating substrate, wherein the super-hydrophobic modified material is the above-mentioned super-hydrophobic composite silica particles.

[0016] In a fourth aspect, a process for preparing the above-mentioned strong and wear-resistant micro-nano composite super-hydrophobic coating comprises the following steps:

[0017] Providing the above-mentioned super-hydrophobic composite silica particles;

[0018] Adding the super-hydrophobic composite silica particles to a solution of a coating substrate and mixing them uniformly to obtain a coating solution;

[0019] The coating liquid is sprayed on the surface of the substrate, solidified and dried to obtain the coating.

[0020] In a fifth aspect, a use of the above-mentioned super-hydrophobic composite silica particles or the strong and wear-resistant micro-nano composite super-hydrophobic coating in marine equipment or medical devices.

[0021] The beneficial effects of the present invention are:

[0022] 1. The super-hydrophobic composite silica particles provided by the present invention have a well-defined and controllable composite structure. The super-hydrophobic surface prepared based on these particles exhibits extremely excellent super-hydrophobic properties, with a water contact angle of over 175°, significantly superior to related products in the prior art.

[0023] 2. The surface of the super-hydrophobic composite silica particles provided by the present invention is rich in active sites and can be cross-linked with the polymer in the coating matrix material through covalent bonds. These particles are tightly wrapped by the polymer network and show excellent structural retention. In addition, the micro-nano composite silica particles, as a reinforcement of the coating matrix material, form a double cross-linked structure in the coating, significantly improving the wear resistance and mechanical stability of the entire coating, thereby significantly extending the service life of the coating.

[0024] 3. The strong and wear-resistant micro-nano composite super-hydrophobic coating provided by the present invention can be prepared by a spraying method, eliminating the reliance on traditional complex processes such as laser processing, photolithography, and template method, and can be quickly constructed on any substrate surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] Figure 1 SEM (left) and TEM (right) images of the super-hydrophobic composite silica particles prepared in Example 1 of the present invention;

[0027] Figure 2 This is a graph showing the water contact angle test results of the strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in Example 1 of the present invention;

[0028] Figure 3 This is a diagram showing the drag reduction effect of the strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in Example 1 of the present invention;

[0029] Figure 4 This is an antifouling effect diagram of the strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in Example 1 of the present invention;

[0030] Figure 5 This is a wear-resistant effect diagram of the strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0031] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0032] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0033] In view of the fact that the super-hydrophobic properties of the materials used in the spraying method need to be further improved and the mechanical stability of the formed coating is poor, the present invention proposes a strong and wear-resistant micro-nano composite super-hydrophobic coating and its preparation process and application.

[0034] A typical embodiment of the present invention provides a super-hydrophobic composite silica particle, which is formed by modifying nano-silica particles and modified micron-silica particles connected by chemical bonds, wherein the modified nano-silica particles are nano-silica particles whose surfaces are modified with C6-C20 straight-chain alkyl groups or fluorine-substituted C6-C20 straight-chain alkyl groups, and the modified micron-silica particles are micron-silica particles whose surfaces contain groups that can simultaneously bond (form chemical bonds) with the coating matrix and the modified silica particles.

[0035] The C6-C20 straight-chain alkyl group of the present invention may be n-hexyl, n-octyl, n-decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, or the like.

[0036] The fluorine-substituted C6-C20 straight-chain alkyl group described in the present invention is a C6-C20 straight-chain alkyl group in which at least one hydrogen atom, or even all hydrogen atoms, are substituted with fluorine. The straight-chain alkyl group may be n-hexyl, n-octyl, n-decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, or the like. The fluorine-substituted C6-C20 straight-chain alkyl group may be 1H, 1H, 2H, or 2H-perfluorooctyl.

[0037] In some embodiments, the modified nano-silica particles have a particle size of 50 to 800 nm.

[0038] In some embodiments, the modified micronized silica particles have a particle size of 1 to 100 μm.

[0039] In some embodiments, the mass ratio of the modified nano-silica particles to the modified micro-silica particles is 2 to 6:1.

[0040] Another embodiment of the present invention provides a method for preparing the above-mentioned super-hydrophobic composite silica particles, comprising the following steps:

[0041] The nano-silica particles are first modified by using a low-surface-energy silane and a first silane coupling agent to obtain modified nano-silica particles; the low-surface-energy silane is a silane containing a C6-C20 straight-chain alkyl group or a fluorine-substituted C6-C20 straight-chain alkyl group;

[0042] performing a second modification on the micron silica particles using a second silane coupling agent to obtain modified micron silica particles;

[0043] The modified nano-silica particles and the modified micro-silica particles are subjected to a catalytic reaction, so that chemical bonds are formed between the modified nano-silica particles and the modified micro-silica particles.

[0044] The present invention performs a first modification on nano-silica particles by using low-surface-energy silane and a first silane coupling agent, so that the nano-silica particles not only have low-surface-energy properties but also have active sites that can participate in subsequent reactions, thus providing a basis for subsequent composite structure construction.

[0045] The second silane coupling agent is used to perform a second modification on the micron silica particles, ensuring that the micron silica spheres can bond with the nano silica spheres and form a stable bond with the matrix material in the subsequent coating system, thereby enhancing the overall performance of the coating.

[0046] Finally, a catalytic reaction promotes the reaction between the modified nano-silica particles and the surface sites of the modified micro-silica particles. Through chemical bonding, silica spheres of varying sizes are interconnected, forming a micro-nano composite structure where larger spheres are encapsulated by smaller spheres. This structure not only imparts a unique microscopic morphology to the coating but also further optimizes its superhydrophobic properties.

[0047] The low surface energy silane described in the present invention can be a trimethoxysilane containing a C6-C20 straight-chain alkyl group or a fluorine-substituted C6-C20 straight-chain alkyl group, and can be n-hexyltrimethoxysilane, n-octyltrimethoxysilane, n-decyltrimethoxysilane, dodecyltrimethoxysilane, tetradecyltrimethoxysilane, hexadecyltrimethoxysilane, octadecyltrimethoxysilane, eicosyltrimethoxysilane, 1H,1H,2H,2H-perfluorooctyl, etc.

[0048] In some embodiments, the first silane coupling agent is KH550 silane coupling agent or KH560 silane coupling agent.

[0049] In some embodiments, the mass ratio of the nano-silica particles to the first silane coupling agent is 1:0.8-1.2.

[0050] In some embodiments, the temperature of the first modification is 70-80°C.

[0051] In some embodiments, the catalyst used in the first modification process is ammonia.

[0052] In some embodiments, the first modification process comprises: adding the nano-silica particles and the first silane coupling agent to an alcohol-water solution, mixing them uniformly, adding a catalyst, heating to 70-80°C for a pre-reaction, and then adding the low-surface-energy silane. The reaction is complete to obtain the product. Specifically, the pre-reaction time is 0.5-2 hours. Specifically, the reaction time after adding the low-surface-energy silane is 4-8 hours.

[0053] In some embodiments, the second silane coupling agent is KH550 silane coupling agent or KH560 silane coupling agent.

[0054] In some embodiments, the mass ratio of the micronized silica particles to the first silane coupling agent is 1:1.8-2.2.

[0055] In some embodiments, the temperature of the second modification is 70-80°C.

[0056] In some embodiments, the catalyst used in the second modification process is ammonia.

[0057] In some embodiments, the second modification process is as follows: adding micronized silica particles and the second silane coupling agent to an alcohol-water solution, mixing them uniformly, adding a catalyst, heating to 70-80° C., and reacting until the reaction is complete. Specifically, the reaction time is 4-10 hours.

[0058] In some embodiments, the mass ratio of the modified nano-silica particles to the modified micro-silica particles is 2 to 6:1.

[0059] In some embodiments, modified nano-silica particles and modified micro-silica particles are added to an alcohol-water solution and uniformly dispersed, and after adding a catalyst, the solution is heated to 60-70° C. for reaction. Specifically, the reaction time is 4-10 hours.

[0060] A third embodiment of the present invention provides a strong and wear-resistant micro-nano composite super-hydrophobic coating, comprising a coating substrate and a super-hydrophobic modified material attached to the surface of the coating substrate, wherein the super-hydrophobic modified material is the above-mentioned super-hydrophobic composite silica particles.

[0061] In some embodiments, the coating matrix includes, but is not limited to, epoxy resin, polyurethane, polydimethylsiloxane, and the like.

[0062] In some embodiments, the mass ratio of the coating substrate to the superhydrophobic modifying material is 1:0.8-1.2.

[0063] A fourth embodiment of the present invention provides a process for preparing the above-mentioned strong and wear-resistant micro-nano composite super-hydrophobic coating, comprising the following steps:

[0064] Providing the above-mentioned super-hydrophobic composite silica particles;

[0065] Adding the super-hydrophobic composite silica particles to a solution of a coating substrate and mixing them uniformly to obtain a coating solution;

[0066] The coating liquid is sprayed on the surface of the substrate, solidified and dried to obtain the coating.

[0067] The purpose of preparing the coating substrate into a coating substrate solution is to dilute the coating substrate to a sprayable concentration. The solvent used includes but is not limited to volatile organic solvents such as methanol, ethanol, toluene, n-hexane, and dichloromethane.

[0068] In some embodiments, the coating liquid is sprayed onto the surface of a preheated substrate. Preheating the substrate is more conducive to the curing and drying of the coating liquid. Specifically, the preheating temperature is 60-80°C.

[0069] A fifth embodiment of the present invention provides an application of the above-mentioned super-hydrophobic composite silica particles or the strong and wear-resistant micro-nano composite super-hydrophobic coating in marine equipment or medical devices.

[0070] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments and comparative examples.

[0071] Example 1

[0072] 1. Preparation of modified nano-silica particles:

[0073] 3g of silica particles with a particle size of 100nm were dispersed in 90mL of 90% ethanol aqueous solution, followed by the addition of 3mL of KH560 silane coupling agent and 8mL of 25% w / w ammonia as a catalyst. After reacting at 75°C for 1 hour, 3mL of octadecyltrimethoxysilane was added to the reaction system and stirred for 5 hours. After the reaction was complete, the nano-silica particles were collected by centrifugation, then washed with ethanol several times, and dried to obtain modified nano-silica particles.

[0074] 2. Preparation of modified micronized silica particles:

[0075] 3g of 2μm silica particles were dispersed in 90mL of 90% ethanol-water solution. 6mL of KH550 silane coupling agent and 8mL of 25% w / w ammonia were added as a catalyst. The mixture was reacted at 75°C for 6 hours. After the reaction was complete, the micronized silica particles were collected by centrifugation, washed with ethanol several times, and dried to obtain modified micronized silica particles.

[0076] 3. Preparation of super-hydrophobic composite silica particles:

[0077] 1g of the modified micronized silica particles obtained in step 2 and 4g of the modified nano-silica particles obtained in step 1 were dispersed in 90mL of an ethanol aqueous solution having a mass fraction of 90%, and 8mL of ammonia water (25% w / w) was added as a catalyst. The reaction was carried out at a temperature of 65°C for 6 hours to achieve bonding between micronized silica particles and nano-silica particles. After the reaction was complete, the silica particles were collected by centrifugation, subsequently washed with ethanol several times, and dried to obtain super-hydrophobic composite silica particles.

[0078] 4. Preparation of spray coating liquid:

[0079] A mixture of 10 g of bisphenol A epoxy resin and amine curing agent was added to 90 mL of toluene for dilution, and then 10 g of the super-hydrophobic composite silica particles prepared in step 4 was added to the diluted epoxy resin to obtain a spray coating liquid.

[0080] 5. Preparation of strong and wear-resistant micro-nano composite super-hydrophobic coating:

[0081] The copper alloy substrate was ultrasonically cleaned in deionized water and anhydrous ethanol for 10 minutes each, then removed and dried. The cleaned and dried copper alloy substrate was heated to 70°C, and the spray coating prepared in step 4 was sprayed onto the copper alloy surface. The coating was cured and dried.

[0082] The microscopic morphology of the super-hydrophobic composite silica particles prepared in this embodiment is as follows: Figure 1 shown.

[0083] The water contact angle test results of the strong and wear-resistant micro-nano composite super hydrophobic coating prepared in this embodiment are as follows: Figure 2 As shown, the water contact angle on the left is 175.52°, the water contact angle on the right is 178.10°, and the average contact angle is 176.81°.

[0084] Taking an uncoated copper alloy substrate as a comparison, the drag reduction and anti-fouling effects of the strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in this embodiment were tested.

[0085] The drag reduction effect of super-hydrophobic coating is tested using a high-precision rheometer. Specific testing method is as follows: the substrate with a firm, wear-resistant micro-nano composite super-hydrophobic coating prepared by the blank substrate of the uncoated coating and the present embodiment is attached to the bottom of the container facing the rheometer turntable, ensuring that the distance between the sample and the rheometer turntable is accurately 2mm. Subsequently, the rotating speed of the turntable is gradually increased, increased from 0 to 300 rev / min, and maintained at a rotating speed of 300 rev / min for a period of time to measure the torque suffered by the turntable in the process. By contrasting the torque values ​​of the blank substrate of the uncoated coating and the substrate coated with super-hydrophobic coating under the same conditions, drag reduction is calculated.

[0086] The results are as follows Figure 3 As shown in FIG, the copper alloy with a strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in this embodiment is subjected to significantly less torque during rotation than the blank copper alloy.

[0087] The antifouling properties of different surfaces were tested using an antimicrobial adhesion test. The specific method involved immersing an uncoated blank copper alloy and a copper alloy coated with the durable, wear-resistant micro-nano composite superhydrophobic coating prepared in this example into a microbial culture medium. After incubation, the sample surface was rinsed with deionized water to remove loosely adsorbed microorganisms. The sample was then ultrasonically rinsed with deionized water to remove adsorbed microorganisms. The desorbed microorganisms were then applied to an agar plate and incubated for 12 hours. Finally, the antifouling properties of the different samples were evaluated by counting the number of microbial colonies on the corresponding agar plates.

[0088] The results are as follows Figure 4 As shown, the amount of microorganisms adhering to the copper alloy surface with the strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in this embodiment is much less than that on the blank copper alloy surface.

[0089] The super-hydrophobic coating prepared in this embodiment was polished using 2000-grit sandpaper at a pressure of 250 Pa, and the wear resistance of the coating was evaluated by measuring the change in the contact angle of the super-hydrophobic coating after different polishing times using a contact angle meter.

[0090] The results are as follows Figure 5 As shown in FIG. 3 , after 3000 polishing cycles, the durable and wear-resistant micro-nano composite super-hydrophobic coating prepared in this embodiment still has an excellent super-hydrophobic effect, and the water contact angle remains above 170°.

[0091] Example 2

[0092] 1. Preparation of modified nano-silica particles:

[0093] 3g of silica particles with a particle size of 100nm were dispersed in 90mL of a 90% ethanol aqueous solution. 3mL of KH560 silane coupling agent was then added to the solution, followed by 8mL of 25% w / w ammonia as a catalyst. After reacting at 70°C for 1 hour, 3mL of octadecyltrimethoxysilane was added to the reaction system and stirred for 5 hours. After the reaction was complete, the nano-silica particles were collected by centrifugation, then washed with ethanol several times, and dried to obtain modified nano-silica particles.

[0094] 2. Preparation of modified micronized silica particles:

[0095] 3g of 2μm silica particles were dispersed in 90mL of 90% ethanol-water solution. 6mL of KH550 silane coupling agent and 8mL of 25% w / w ammonia were added as a catalyst. The mixture was reacted at 70°C for 6 hours. After the reaction was complete, the micronized silica particles were collected by centrifugation, washed with ethanol several times, and dried to obtain modified micronized silica particles.

[0096] 3. Preparation of super-hydrophobic composite silica particles:

[0097] 1g of the modified micronized silica particles obtained in step 2 and 4g of the modified nano-silica particles obtained in step 1 were dispersed in 90mL of an ethanol aqueous solution having a mass fraction of 90%, and 8mL of ammonia water (25% w / w) was added as a catalyst. The reaction was carried out at a temperature of 60°C for 6 hours to achieve bonding between micronized silica particles and nano-silica particles. After the reaction was complete, the silica particles were collected by centrifugation, subsequently washed with ethanol several times, and dried to obtain super-hydrophobic composite silica particles.

[0098] 4. Preparation of spray coating liquid:

[0099] A mixture of 10 g of bisphenol A epoxy resin and amine curing agent was added to 90 mL of toluene for dilution, and then 10 g of the super-hydrophobic composite silica particles prepared in step 4 was added to the diluted epoxy resin to obtain a spray coating liquid.

[0100] 5. Preparation of strong and wear-resistant micro-nano composite super-hydrophobic coating:

[0101] The copper alloy substrate was ultrasonically cleaned in deionized water and anhydrous ethanol for 10 minutes each, then removed and dried. The cleaned and dried copper alloy substrate was heated to 70°C, and the spray coating prepared in step 4 was sprayed onto the copper alloy surface. The coating was cured and dried.

[0102] The average water contact angle of the strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in this embodiment is 176.22°.

[0103] Example 3

[0104] 1. Preparation of modified nano-silica particles:

[0105] 3g of silica particles with a particle size of 100nm were dispersed in 90mL of 90% ethanol aqueous solution, followed by the addition of 3mL of KH560 silane coupling agent and 8mL of 25% w / w ammonia as a catalyst. After reacting at 80°C for 1 hour, 3mL of octadecyltrimethoxysilane was added to the reaction system and stirred for 5 hours. After the reaction was complete, the nano-silica particles were collected by centrifugation, then washed with ethanol several times, and dried to obtain modified nano-silica particles.

[0106] 2. Preparation of modified micronized silica particles:

[0107] 3g of 2μm silica particles were dispersed in 90mL of 90% ethanol-water solution. 6mL of KH550 silane coupling agent and 8mL of 25% w / w ammonia were added as a catalyst. The mixture was reacted at 80°C for 6 hours. After the reaction was complete, the micronized silica particles were collected by centrifugation, washed with ethanol several times, and dried to obtain modified micronized silica particles.

[0108] 3. Preparation of super-hydrophobic composite silica particles:

[0109] 1g of the modified micronized silica particles obtained in step 2 and 4g of the modified nano-silica particles obtained in step 1 were dispersed in 90mL of an ethanol aqueous solution having a mass fraction of 90%, and 8mL of ammonia water (25% w / w) was added as a catalyst. The reaction was carried out at a temperature of 70°C for 6 hours to achieve bonding between micronized silica particles and nano-silica particles. After the reaction was complete, the silica particles were collected by centrifugation, subsequently washed with ethanol several times, and dried to obtain super-hydrophobic composite silica particles.

[0110] 4. Preparation of spray coating liquid:

[0111] A mixture of 10 g of bisphenol A epoxy resin and amine curing agent was added to 90 mL of toluene for dilution, and then 10 g of the super-hydrophobic composite silica particles prepared in step 4 was added to the diluted epoxy resin to obtain a spray coating liquid.

[0112] 5. Preparation of strong and wear-resistant micro-nano composite super-hydrophobic coating:

[0113] The copper alloy substrate was ultrasonically cleaned in deionized water and anhydrous ethanol for 10 minutes each, then removed and dried. The cleaned and dried copper alloy substrate was heated to 70°C, and the spray coating prepared in step 4 was sprayed onto the copper alloy surface. The coating was cured and dried.

[0114] The average water contact angle of the strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in this embodiment is 176.56°.

[0115] Example 4

[0116] 1. Preparation of modified nano-silica particles:

[0117] 3g of silica particles with a particle size of 100nm were dispersed in 90mL of a 90% ethanol aqueous solution. 3mL of KH560 silane coupling agent was then added to the solution, followed by 8mL of 25% w / w ammonia as a catalyst. After reacting at 75°C for 1 hour, 3mL of hexadecyltrimethoxysilane was added to the reaction system and stirred for 5 hours. After the reaction was complete, the nano-silica particles were collected by centrifugation, then washed with ethanol several times, and dried to obtain modified nano-silica particles.

[0118] 2. Preparation of modified micronized silica particles:

[0119] 3g of 2μm silica particles were dispersed in 90mL of 90% ethanol-water solution. 6mL of KH550 silane coupling agent and 8mL of 25% w / w ammonia were added as a catalyst. The mixture was reacted at 75°C for 6 hours. After the reaction was complete, the micronized silica particles were collected by centrifugation, washed with ethanol several times, and dried to obtain modified micronized silica particles.

[0120] 3. Preparation of super-hydrophobic composite silica particles:

[0121] 1g of the modified micronized silica particles obtained in step 2 and 4g of the modified nano-silica particles obtained in step 1 were dispersed in 90mL of an ethanol aqueous solution having a mass fraction of 90%, and 8mL of ammonia water (25% w / w) was added as a catalyst. The reaction was carried out at a temperature of 65°C for 6 hours to achieve bonding between micronized silica particles and nano-silica particles. After the reaction was complete, the silica particles were collected by centrifugation, subsequently washed with ethanol several times, and dried to obtain super-hydrophobic composite silica particles.

[0122] 4. Preparation of spray coating liquid:

[0123] A mixture of 10 g of bisphenol A epoxy resin and amine curing agent was added to 90 mL of toluene for dilution, and then 10 g of the super-hydrophobic composite silica particles prepared in step 4 was added to the diluted epoxy resin to obtain a spray coating liquid.

[0124] 5. Preparation of strong and wear-resistant micro-nano composite super-hydrophobic coating:

[0125] The copper alloy substrate was ultrasonically cleaned in deionized water and anhydrous ethanol for 10 minutes each, then removed and dried. The cleaned and dried copper alloy substrate was heated to 70°C, and the spray coating prepared in step 4 was sprayed onto the copper alloy surface. The coating was cured and dried.

[0126] The average water contact angle of the strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in this embodiment is 175.43°.

[0127] Example 5

[0128] 1. Preparation of modified nano-silica particles:

[0129] 3g of silica particles with a particle size of 100nm were dispersed in 90mL of a 90% ethanol aqueous solution. 3mL of KH560 silane coupling agent was then added to the solution, followed by 8mL of 25% w / w ammonia as a catalyst. After reacting at 75°C for 1 hour, 3mL of tetradecyltrimethoxysilane was added to the reaction system and stirred for 5 hours. After the reaction was complete, the nano-silica particles were collected by centrifugation, then washed with ethanol several times, and dried to obtain modified nano-silica particles.

[0130] 2. Preparation of modified micronized silica particles:

[0131] 3g of 2μm silica particles were dispersed in 90mL of 90% ethanol-water solution. 6mL of KH550 silane coupling agent and 8mL of 25% w / w ammonia were added as a catalyst. The mixture was reacted at 75°C for 6 hours. After the reaction was complete, the micronized silica particles were collected by centrifugation, washed with ethanol several times, and dried to obtain modified micronized silica particles.

[0132] 3. Preparation of super-hydrophobic composite silica particles:

[0133] 1g of the modified micronized silica particles obtained in step 2 and 4g of the modified nano-silica particles obtained in step 1 were dispersed in 90mL of an ethanol aqueous solution having a mass fraction of 90%, and 8mL of ammonia water (25% w / w) was added as a catalyst. The reaction was carried out at a temperature of 65°C for 6 hours to achieve bonding between micronized silica particles and nano-silica particles. After the reaction was complete, the silica particles were collected by centrifugation, subsequently washed with ethanol several times, and dried to obtain super-hydrophobic composite silica particles.

[0134] 4. Preparation of spray coating liquid:

[0135] A mixture of 10 g of bisphenol A epoxy resin and amine curing agent was added to 90 mL of toluene for dilution, and then 10 g of the super-hydrophobic composite silica particles prepared in step 4 was added to the diluted epoxy resin to obtain a spray coating liquid.

[0136] 5. Preparation of strong and wear-resistant micro-nano composite super-hydrophobic coating:

[0137] The copper alloy substrate was ultrasonically cleaned in deionized water and anhydrous ethanol for 10 minutes each, then removed and dried. The cleaned and dried copper alloy substrate was heated to 70°C, and the spray coating prepared in step 4 was sprayed onto the copper alloy surface. The coating was cured and dried.

[0138] The average water contact angle of the strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in this embodiment is 174.28°.

[0139] Example 6

[0140] 1. Preparation of modified nano-silica particles:

[0141] 3g of silica particles with a particle size of 100nm were dispersed in 90mL of 90% ethanol aqueous solution, followed by the addition of 3mL of KH560 silane coupling agent and 8mL of 25% w / w ammonia as a catalyst. After reacting at 75°C for 1 hour, 3mL of dodecyltrimethoxysilane was added to the reaction system and stirred for 5 hours. After the reaction was complete, the nano-silica particles were collected by centrifugation, then washed with ethanol several times and dried to obtain modified nano-silica particles.

[0142] 2. Preparation of modified micronized silica particles:

[0143] 3g of 2μm silica particles were dispersed in 90mL of 90% ethanol-water solution. 6mL of KH550 silane coupling agent and 8mL of 25% w / w ammonia were added as a catalyst. The mixture was reacted at 75°C for 6 hours. After the reaction was complete, the micronized silica particles were collected by centrifugation, washed with ethanol several times, and dried to obtain modified micronized silica particles.

[0144] 3. Preparation of super-hydrophobic composite silica particles:

[0145] 1g of the modified micronized silica particles obtained in step 2 and 4g of the modified nano-silica particles obtained in step 1 were dispersed in 90mL of an ethanol aqueous solution having a mass fraction of 90%, and 8mL of ammonia water (25% w / w) was added as a catalyst. The reaction was carried out at a temperature of 65°C for 6 hours to achieve bonding between micronized silica particles and nano-silica particles. After the reaction was complete, the silica particles were collected by centrifugation, subsequently washed with ethanol several times, and dried to obtain super-hydrophobic composite silica particles.

[0146] 4. Preparation of spray coating liquid:

[0147] A mixture of 10 g of bisphenol A epoxy resin and amine curing agent was added to 90 mL of toluene for dilution, and then 10 g of the super-hydrophobic composite silica particles prepared in step 4 was added to the diluted epoxy resin to obtain a spray coating liquid.

[0148] 5. Preparation of strong and wear-resistant micro-nano composite super-hydrophobic coating:

[0149] The copper alloy substrate was ultrasonically cleaned in deionized water and anhydrous ethanol for 10 minutes each, then removed and dried. The cleaned and dried copper alloy substrate was heated to 70°C, and the spray coating prepared in step 4 was sprayed onto the copper alloy surface. The coating was cured and dried.

[0150] Example 7

[0151] 1. Preparation of modified nano-silica particles:

[0152] 3g of silica particles with a particle size of 100nm were dispersed in 90mL of 90% ethanol aqueous solution, followed by the addition of 3mL of KH560 silane coupling agent and 8mL of 25% w / w ammonia as a catalyst. After reacting at 75°C for 1 hour, 3mL of n-decyltrimethoxysilane was added to the reaction system and stirred for 5 hours. After the reaction was complete, the nano-silica particles were collected by centrifugation, then washed with ethanol several times, and dried to obtain modified nano-silica particles.

[0153] 2. Preparation of modified micronized silica particles:

[0154] 3g of 2μm silica particles were dispersed in 90mL of 90% ethanol-water solution. 6mL of KH550 silane coupling agent and 8mL of 25% w / w ammonia were added as a catalyst. The mixture was reacted at 75°C for 6 hours. After the reaction was complete, the micronized silica particles were collected by centrifugation, washed with ethanol several times, and dried to obtain modified micronized silica particles.

[0155] 3. Preparation of super-hydrophobic composite silica particles:

[0156] 1g of the modified micronized silica particles obtained in step 2 and 4g of the modified nano-silica particles obtained in step 1 were dispersed in 90mL of an ethanol aqueous solution having a mass fraction of 90%, and 8mL of ammonia water (25% w / w) was added as a catalyst. The reaction was carried out at a temperature of 65°C for 6 hours to achieve bonding between micronized silica particles and nano-silica particles. After the reaction was complete, the silica particles were collected by centrifugation, subsequently washed with ethanol several times, and dried to obtain super-hydrophobic composite silica particles.

[0157] 4. Preparation of spray coating liquid:

[0158] A mixture of 10 g of bisphenol A epoxy resin and amine curing agent was added to 90 mL of toluene for dilution, and then 10 g of the super-hydrophobic composite silica particles prepared in step 4 was added to the diluted epoxy resin to obtain a spray coating liquid.

[0159] 5. Preparation of strong and wear-resistant micro-nano composite super-hydrophobic coating:

[0160] The copper alloy substrate was ultrasonically cleaned in deionized water and anhydrous ethanol for 10 minutes each, then removed and dried. The cleaned and dried copper alloy substrate was heated to 70°C, and the spray coating prepared in step 4 was sprayed onto the copper alloy surface. The coating was cured and dried.

[0161] The average water contact angle of the strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in this embodiment is 173.64°.

[0162] Example 8

[0163] 1. Preparation of modified nano-silica particles:

[0164] 3g of silica particles with a particle size of 100nm were dispersed in 90mL of 90% ethanol aqueous solution, followed by the addition of 3mL of KH560 silane coupling agent and 8mL of 25% w / w ammonia as a catalyst. After reacting at 75°C for 1 hour, 3mL of n-octyltrimethoxysilane was added to the reaction system and stirred for 5 hours. After the reaction was complete, the nano-silica particles were collected by centrifugation, then washed with ethanol several times, and dried to obtain modified nano-silica particles.

[0165] 2. Preparation of modified micronized silica particles:

[0166] 3g of 2μm silica particles were dispersed in 90mL of 90% ethanol-water solution. 6mL of KH550 silane coupling agent and 8mL of 25% w / w ammonia were added as a catalyst. The mixture was reacted at 75°C for 6 hours. After the reaction was complete, the micronized silica particles were collected by centrifugation, washed with ethanol several times, and dried to obtain modified micronized silica particles.

[0167] 3. Preparation of super-hydrophobic composite silica particles:

[0168] 1g of the modified micronized silica particles obtained in step 2 and 4g of the modified nano-silica particles obtained in step 1 were dispersed in 90mL of an ethanol aqueous solution having a mass fraction of 90%, and 8mL of ammonia water (25% w / w) was added as a catalyst. The reaction was carried out at a temperature of 65°C for 6 hours to achieve bonding between micronized silica particles and nano-silica particles. After the reaction was complete, the silica particles were collected by centrifugation, subsequently washed with ethanol several times, and dried to obtain super-hydrophobic composite silica particles.

[0169] 4. Preparation of spray coating liquid:

[0170] A mixture of 10 g of bisphenol A epoxy resin and amine curing agent was added to 90 mL of toluene for dilution, and then 10 g of the super-hydrophobic composite silica particles prepared in step 4 was added to the diluted epoxy resin to obtain a spray coating liquid.

[0171] 5. Preparation of strong and wear-resistant micro-nano composite super-hydrophobic coating:

[0172] The copper alloy substrate was ultrasonically cleaned in deionized water and anhydrous ethanol for 10 minutes each, then removed and dried. The cleaned and dried copper alloy substrate was heated to 70°C, and the spray coating prepared in step 4 was sprayed onto the copper alloy surface. The coating was cured and dried.

[0173] The average water contact angle of the strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in this embodiment is 169.75°.

[0174] Example 9

[0175] 1. Preparation of modified nano-silica particles:

[0176] 3g of silica particles with a particle size of 100nm were dispersed in 90mL of a 90% ethanol aqueous solution. 3mL of KH560 silane coupling agent and 8mL of 25% w / w ammonia were then added to the solution as a catalyst. After reacting at 75°C for 1 hour, 3mL of 1H,1H,2H,2H-perfluorooctyltrimethoxysilane was added to the reaction system and stirred for 5 hours. After the reaction was complete, the nano-silica particles were collected by centrifugation, washed with ethanol several times, and dried to obtain modified nano-silica particles.

[0177] 2. Preparation of modified micronized silica particles:

[0178] 3g of 2μm silica particles were dispersed in 90mL of 90% ethanol-water solution. 6mL of KH550 silane coupling agent and 8mL of 25% w / w ammonia were added as a catalyst. The mixture was reacted at 75°C for 6 hours. After the reaction was complete, the micronized silica particles were collected by centrifugation, washed with ethanol several times, and dried to obtain modified micronized silica particles.

[0179] 3. Preparation of super-hydrophobic composite silica particles:

[0180] 1g of the modified micronized silica particles obtained in step 2 and 4g of the modified nano-silica particles obtained in step 1 were dispersed in 90mL of an ethanol aqueous solution having a mass fraction of 90%, and 8mL of ammonia water (25% w / w) was added as a catalyst. The reaction was carried out at a temperature of 65°C for 6 hours to achieve bonding between micronized silica particles and nano-silica particles. After the reaction was complete, the silica particles were collected by centrifugation, subsequently washed with ethanol several times, and dried to obtain super-hydrophobic composite silica particles.

[0181] 4. Preparation of spray coating liquid:

[0182] A mixture of 10 g of bisphenol A epoxy resin and amine curing agent was added to 90 mL of toluene for dilution, and then 10 g of the super-hydrophobic composite silica particles prepared in step 4 was added to the diluted epoxy resin to obtain a spray coating liquid.

[0183] 5. Preparation of strong and wear-resistant micro-nano composite super-hydrophobic coating:

[0184] The copper alloy substrate was ultrasonically cleaned in deionized water and anhydrous ethanol for 10 minutes each, then removed and dried. The cleaned and dried copper alloy substrate was heated to 70°C, and the spray coating prepared in step 4 was sprayed onto the copper alloy surface. The coating was cured and dried.

[0185] The average water contact angle of the strong and wear-resistant micro-nano composite super-hydrophobic coating prepared in this embodiment is 174.36°.

[0186] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A super-hydrophobic composite silica particle, characterized in that: The modified nano-silica particles and modified micro-silica particles are connected by chemical bonds. The modified nano-silica particles are nano-silica particles whose surfaces are modified with C6-C20 straight-chain alkyl groups or fluorine-substituted C6-C20 straight-chain alkyl groups. The modified micro-silica particles are micro-silica particles whose surfaces contain groups that can simultaneously bond to the coating matrix and the modified silica particles.

2. The super-hydrophobic composite silica particles according to claim 1, wherein The particle size of the modified nano-silica particles is 50-800 nm; Alternatively, the particle size of the modified micronized silica particles is 1 to 100 μm.

3. The super-hydrophobic composite silica particles according to claim 1, wherein The mass ratio of the modified nano-silica particles to the modified micro-silica particles is 2-6:

1.

4. A method for preparing super-hydrophobic composite silica particles according to claim 1, characterized in that: The steps include: The nano-silica particles are first modified by using a low-surface-energy silane and a first silane coupling agent to obtain modified nano-silica particles; the low-surface-energy silane is a silane containing a C6-C20 straight-chain alkyl group or a fluorine-substituted C6-C20 straight-chain alkyl group; performing a second modification on the micron silica particles using a second silane coupling agent to obtain modified micron silica particles; The modified nano-silica particles and the modified micro-silica particles are subjected to a catalytic reaction, so that chemical bonds are formed between the modified nano-silica particles and the modified micro-silica particles.

5. The preparation method according to claim 4, characterized in that: The first silane coupling agent is KH550 silane coupling agent and / or KH560 silane coupling agent; Alternatively, the mass ratio of the nano-silica particles to the first silane coupling agent is 1:0.8-1.2; Alternatively, the temperature of the first modification is 70-80°C; Alternatively, the catalyst used in the first modification process is aqueous ammonia; Alternatively, the first modification process is: adding the nano-silica particles and the first silane coupling agent to an alcohol-water solution and mixing them evenly, adding a catalyst, heating to 70-80° C. for pre-reaction, and then adding the low surface energy silane, and obtaining the product after the reaction is complete; Or, the second silane coupling agent is KH550 silane coupling agent and / or KH560 silane coupling agent; Alternatively, the mass ratio of the micronized silica particles to the first silane coupling agent is 1:1.8-2.2; Alternatively, the temperature of the second modification is 70-80°C; Alternatively, the catalyst used in the second modification process is aqueous ammonia; Alternatively, the second modification process is: adding micron silica particles and the second silane coupling agent to an alcohol-water solution, mixing them evenly, adding a catalyst, heating to 70-80° C., and obtaining the product after the reaction is complete; Or, the mass ratio of the modified nano-silica particles to the modified micro-silica particles is 2 to 6:1; Alternatively, the modified nano-silica particles and modified micro-silica particles are added to an alcohol-water solution and dispersed evenly, and after adding a catalyst, the solution is heated to 60-70° C. for reaction.

6. A strong and wear-resistant micro-nano composite super-hydrophobic coating, characterized by: It comprises a coating substrate and a super-hydrophobic modified material attached to the surface of the coating substrate, wherein the super-hydrophobic modified material is the super-hydrophobic composite silica particles.

7. The strong and wear-resistant micro-nano composite super-hydrophobic coating according to claim 6, characterized in that: The mass ratio of coating substrate to superhydrophobic modified material is 1:0.8~1.

2.

8. A process for preparing the strong and wear-resistant micro-nano composite super-hydrophobic coating according to claim 6, characterized in that: The steps include: Providing the above-mentioned super-hydrophobic composite silica particles; Adding the super-hydrophobic composite silica particles to a solution of a coating substrate and mixing them uniformly to obtain a coating solution; The coating liquid is sprayed on the surface of the substrate, solidified and dried to obtain the coating.

9. The preparation process according to claim 8, characterized in that: The coating liquid is sprayed on the surface of the preheated substrate.

10. Use of the super-hydrophobic composite silica particles according to any one of claims 1 to 3 or the strong and wear-resistant micro-nano composite super-hydrophobic coating according to claim 6 or 7 in marine equipment or medical devices.

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