A solid bulk superhydrophobic material, its preparation method and application

Abstract

This application belongs to the field of materials preparation technology, and more specifically, relates to a solid bulk superhydrophobic material, its preparation method, and its application. The preparation method of the solid bulk superhydrophobic material provided in this application involves modifying silica with a low surface energy using a fluorinated alkyl compound, followed by evaporation. The resulting slurry is mixed with an organic resin solution and a silane coupling agent, and then subjected to degassing, curing, pressing, and post-curing treatments to prepare a solid bulk superhydrophobic material with excellent superhydrophobic properties on both the surface and interior, as well as high mechanical strength. The process for preparing the solid bulk superhydrophobic material in this application is simple, convenient to operate, requires low equipment specifications, and is suitable for large-scale production.

Description

Technical Field

[0001] This application belongs to the field of materials preparation technology, and more specifically, relates to a solid bulk superhydrophobic material, its preparation method and application. Background Technology

[0002] Moisture and dust accumulating on the surface of electrical equipment can reduce the insulation capacity of insulating materials, increase the risk of leakage and short circuits, hinder heat dissipation, and lead to overheating of the equipment, affecting its normal operation and lifespan. In addition, it may also cause rust and corrosion of metal parts of the equipment, weaken the structural strength of the equipment, and cause faults such as poor contact and open circuits, affecting the stability and reliability of the equipment.

[0003] Superhydrophobic materials are those where the contact angle of a water droplet on its surface is greater than 150°, exhibiting excellent self-cleaning, waterproofing, anti-fouling, and anti-icing properties. Currently, superhydrophobic materials are mainly applied to the surfaces of electrical equipment by spraying or brushing them onto the surface to form a superhydrophobic coating, thereby reducing the accumulation of moisture and dust and providing properties such as anti-flashover, anti-corrosion, and anti-icing. However, superhydrophobic coatings have relatively low mechanical strength, poor wear resistance, and poor durability. They are prone to degradation in harsh environments such as high humidity, ultraviolet radiation, and chemical corrosion. During use, impacts, scratches, abrasions, or repeated friction and wear from external objects can cause the superhydrophobic properties to be lost, and the weather resistance and service life of superhydrophobic coatings do not meet practical requirements.

[0004] Therefore, it is of great significance to prepare solid bulk superhydrophobic materials with superhydrophobic properties and high mechanical strength. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this application is to provide a solid bulk superhydrophobic material, its preparation method, and its application. The aim is to provide a solid bulk superhydrophobic material with excellent superhydrophobic properties on both the material surface and the interior of the matrix, as well as high mechanical strength, suitable for superhydrophobic shells of devices such as power equipment.

[0006] To achieve the above objectives, this application provides a method for preparing a solid bulk superhydrophobic material, comprising the following steps:

[0007] S1. The silica dispersion obtained by mixing silica particles and solvent is mixed and stirred with a fluorinated alkyl compound solution, so that the fluorine atoms in the fluorinated alkyl compound solution replace the hydroxyl groups on the surface of the silica particles, thereby performing low surface energy modification and obtaining a reaction solution containing modified silica particles.

[0008] S2. The slurry obtained by evaporating the reaction solution is mixed and stirred with the organic resin solution and silane coupling agent to form a suspension.

[0009] S3. The suspension is subjected to degassing, solidification, pressing and molding, and post-curing treatment to obtain a solid block superhydrophobic material.

[0010] Preferably, in step S1, the particle size of the silicon dioxide particles is 50 nm to 300 nm.

[0011] Preferably, the above-mentioned fluoroalkyl compound solution is prepared by mixing the fluoroalkyl compound with a solvent, wherein the fluoroalkyl compound is selected from one or more of perfluorooctyltriethoxysilane, triethoxyfluorosilane, perfluorooctane sulfonic acid, perfluorobutylethyltriethoxysilane, perfluoroethyl vinyl ether, and perfluorohexyl vinyl ether.

[0012] Preferably, the method for preparing the above-mentioned silica particles includes the following steps: under a protective atmosphere, mixing, stirring, centrifuging, washing and drying a silicon source compound, an alcohol solvent, an alkaline environment conditioner, deionized water and an auxiliary silicon source compound to obtain silica particles.

[0013] Preferably, the silicon source compound is a silanol compound selected from at least one of tetraethyl orthosilicate, propyl orthosilicate, and tetraethoxysilane; and / or,

[0014] The aforementioned auxiliary silicon source compound is selected from at least one of silane halides and trihalosilanes; and / or,

[0015] The volume ratio of the aforementioned silicon source compound to the aforementioned auxiliary silicon source compound is 1:(0.025–0.075); and / or,

[0016] The stirring temperature is 20℃~40℃, and the stirring time is 4h~6h.

[0017] Preferably, in step S2, the solid content of the modified silica particles in the slurry is 15% to 30%; and / or,

[0018] The above-mentioned organic resin solution is prepared by mixing an organic resin with an organic solvent, wherein the organic resin is selected from one or more of polyurethane resin, epoxy resin, methyl silicone resin, polymethyl methacrylate, and acrylic resin; and / or,

[0019] The aforementioned silane coupling agent is selected from one or more of 3-(methacryloyloxy)propyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and vinyltrimethoxysilane; and / or,

[0020] In the above suspension, the mass ratio of the modified silica particles to the organic resin is 1:(2.5 to 3.5), and the mass ratio of the silane coupling agent to the organic resin is 1:(80 to 120).

[0021] Preferably, in step S3, the specific operation of degassing is as follows: the suspension is placed in a mold with pores, and a vacuum is drawn to degas the air bubbles, wherein the vacuum degree is -0.09MPa to 0.01MPa, and the vacuuming time is 25min to 35min.

[0022] Preferably, in step S3, the curing temperature is 90℃~100℃, and the curing time is 16h~20h; and / or,

[0023] The pressure for the above-mentioned pressing and molding is 4MPa to 6MPa; and / or,

[0024] The post-curing temperature is 140℃~160℃, and the post-curing time is 3h~5h.

[0025] This application provides a solid bulk superhydrophobic material prepared according to the above preparation method.

[0026] This application also provides the application of the above-mentioned solid bulk superhydrophobic material in the fabrication of superhydrophobic shells for devices.

[0027] This application also provides a superhydrophobic shell comprising the above-mentioned solid bulk superhydrophobic material.

[0028] In summary, compared with the prior art, the technical solutions conceived in this application have the following main technical advantages:

[0029] (1) The method for preparing solid bulk superhydrophobic materials provided in this application involves modifying silica with a low surface energy using fluorinated alkyl compounds, followed by evaporation. The resulting slurry is then mixed with an organic resin solution and a silane coupling agent, and subjected to degassing, curing, pressing, and post-curing treatments to obtain a solid bulk superhydrophobic material with excellent superhydrophobic properties on both the surface and interior, as well as high mechanical strength. The process for preparing solid bulk superhydrophobic materials in this application is simple, easy to operate, requires low equipment specifications, and is suitable for large-scale production.

[0030] (2) Compared with the prior art, this application can control the particle size of silica particles and improve their dispersibility by adding an appropriate amount of auxiliary silicon source compound during the preparation of silica particles. No additional grinding or sieving is required, making the processing method simple and reducing production costs. Furthermore, the silica particles are modified with low surface energy and subjected to evaporation treatment. By reasonably adjusting the solid content of modified silica in the slurry, and simultaneously controlling the mass ratio, curing temperature, and time of modified silica, organic resin, and silane coupling agent in the suspension, a solid bulk superhydrophobic material can be prepared. This also improves the hydrophobic properties, interfacial strength, and mechanical stability of the solid bulk superhydrophobic material, making it suitable for superhydrophobic shells of devices such as power equipment.

[0031] (3) The solid bulk superhydrophobic material prepared in this application retains the advantages of superhydrophobic coatings while compensating for coating defects, thus improving the wear resistance and durability of the superhydrophobic material. In practical applications, when the surface of the aforementioned solid bulk superhydrophobic material is damaged, the inner layer material is exposed to the external environment, continuing to provide superhydrophobicity in place of the damaged part, greatly improving the weather resistance and service life of the superhydrophobic material. In addition, the solid bulk superhydrophobic material prepared in this application has high mechanical strength, can withstand greater mechanical loads, and reduces the decline in superhydrophobic performance caused by bumps, scratches, abrasions, wear, or impacts. Compared with existing superhydrophobic coatings, the solid bulk superhydrophobic material provided in this application has stronger durability, effectively reducing the frequency of maintenance and replacement, thereby significantly reducing long-term operating costs.

[0032] (4) The solid bulk superhydrophobic material provided in this application exhibits excellent mechanical properties and outstanding mechanical stability. The above solid bulk superhydrophobic material system can be pressed and molded into solid bulk superhydrophobic materials of different shapes, and has broad application prospects. Attached Figure Description

[0033] Figure 1 This is a flowchart of the preparation process of a solid bulk superhydrophobic material provided in this application;

[0034] Figure 2 This is the XPS spectrum of the modified silica nanoparticles prepared in Example 1 of this application;

[0035] Figure 3 It is a solid bulk superhydrophobic material prepared according to the embodiments of this application;

[0036] Figure 4 The contact angle measurement results are for the solid bulk superhydrophobic material prepared in Example 1 of this application. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0038] The purpose of this application is to prepare a solid bulk superhydrophobic material with excellent superhydrophobic properties on both the surface and interior, as well as high mechanical strength. The amount of modified silica in the material has a significant impact on its hydrophobic properties. Initially, attempts were made to improve the hydrophobic properties by increasing the amount of modified silica, followed by a drying method to prepare a solid bulk superhydrophobic material. However, the inventors of this application found that while increasing the amount of modified silica improved the superhydrophobic properties, it drastically increased the manufacturing difficulty. It became impossible to effectively mix the modified silica and organic resin, and the resulting hydrophobic material was a soft, clay-like material, requiring the addition of a large amount of curing agent to obtain a solid bulk material, while simultaneously reducing the hydrophobic properties. Furthermore, using a molding method resulted in a hydrophobic material with low interfacial strength, failing to achieve the desired hardness, and exhibiting uneven hydrophobic properties. The key problem this application aims to solve is how to improve the hydrophobic properties, interfacial strength, and mechanical stability of the prepared solid bulk hydrophobic material, making it suitable for superhydrophobic shells of devices such as power equipment. Based on this, this application provides a method for preparing a solid bulk superhydrophobic material, such as... Figure 1 As shown, it includes the following steps:

[0039] S1. The silica dispersion obtained by mixing silica particles and solvent is mixed and stirred with a fluorinated alkyl compound solution, so that the fluorine atoms in the fluorinated alkyl compound solution replace the hydroxyl groups on the surface of the silica particles, thereby performing low surface energy modification and obtaining a reaction solution containing modified silica particles.

[0040] S2. Mix and stir the slurry obtained by evaporating the above reaction solution with the organic resin solution and silane coupling agent to form a suspension.

[0041] S3. The above suspension is subjected to degassing, solidification, pressing and molding, and post-curing treatment to obtain a solid block superhydrophobic material.

[0042] In some embodiments, in step S1, the particle size of the silicon dioxide particles is 50 nm to 300 nm.

[0043] In a preferred embodiment, in step S1, the particle size of the silicon dioxide particles is 100nm to 200nm.

[0044] It is understood that the aforementioned silica particles can be purchased from commercially available products or prepared in the laboratory, as long as the particle size and particle size uniformity of the silica particles are consistent with those of this application.

[0045] In a preferred embodiment, the method for preparing the silica particles described above in this application includes the following steps:

[0046] Select precursor materials:

[0047] In some embodiments, the silicon source compound is a silanol compound, such as, but not limited to, tetraethyl orthosilicate (TEOS), propyl orthosilicate (TPS), and tetraethoxysilane (TEOSS). The auxiliary silicon source compound is a silane halide or trihalosilane, such as, but not limited to, silicon tetrachloride (STC) and trichloromethylsilane (MTMS). Both the silicon source compound and the auxiliary silicon source compound have a purity greater than 99.9% and are capable of hydrolysis under alkaline conditions, with the silicon source compound exhibiting superior hydrolysis performance compared to the auxiliary silicon source compound.

[0048] In a preferred embodiment, the volume ratio of the aforementioned silicon source compound to the aforementioned auxiliary silicon source compound is 1:(0.025~0.075). The inventors of this application have discovered through experiments that adding an appropriate amount of auxiliary silicon source compound can adjust the particle size of the prepared silica particles and improve their dispersibility, eliminating the need for additional grinding, sieving, or other treatments. In practical applications, this can effectively shorten production time and reduce production costs. Further experiments revealed that when the amount of auxiliary silicon source compound is too small, it cannot effectively improve the dispersibility of the silica particles; when the amount of auxiliary silicon source compound is too large, a large number of halogen groups are introduced into the reaction system. Excessive halogen groups may react with other components in the reaction system, producing side reactions, thus making the reaction system more complex and difficult to control. Simultaneously, halogen atoms have strong electronegativity, and excessive halogen groups can alter the surface properties of the silica particles, affecting the surface energy and hydrophilicity of the final product, leading to a deterioration in the superhydrophobic properties of the subsequently prepared hydrophobic material. This application experimentally discovered that auxiliary silicon source compounds have a significant impact on the microstructure of silica particles, which will further affect the mechanical stability and superhydrophobic stability of solid bulk superhydrophobic systems, thereby affecting their macroscopic hydrophobic properties.

[0049] Preparation of silica particles:

[0050] Under a protective atmosphere, the above-mentioned silicon source compound, alcohol solvent, alkaline environmental conditioner, deionized water and auxiliary silicon source compound are mixed and stirred to allow the silicon source compound to undergo hydrolysis and condensation reactions. After centrifugation, washing and drying, silicon dioxide particles are obtained.

[0051] This application does not limit the order of the above-mentioned "mixing and stirring". In some embodiments, it may be: mixing and stirring the above-mentioned silicon source compound, alcohol solvent, alkaline environment conditioner and deionized water, and adding auxiliary silicon source compound dropwise during the stirring process.

[0052] In some embodiments, the protective atmosphere includes one or more of nitrogen, argon, neon, helium, xenon, or krypton.

[0053] This application does not have any particular limitation on the types of alcohol solvents mentioned above. Any alcohol solvent reported in the prior art is acceptable, such as, but not limited to, anhydrous ethanol, methanol, and isopropanol.

[0054] In this application, the alkaline environment regulator is used to adjust the pH of the reaction system and create an alkaline environment. Any alkaline environment regulator reported in the prior art can be used, such as, but not limited to, ammonia and tetramethylammonium hydroxide. In a specific embodiment of this application, the pH value of the reaction system is controlled within the range of 7.2 to 8.0 by the alkaline environment regulator, thereby enabling the silicon source compound to undergo hydrolysis and condensation reactions in an alkaline environment to form silica particles with a certain particle size.

[0055] In some embodiments, the volume ratio of the silicon source compound, the alcohol solvent, the alkaline environment conditioner, and the deionized water is 1:(12-14):(1.75-2.25):(2.5-3.5).

[0056] In some embodiments, the mixing temperature is 20°C to 40°C, and the mixing time is 4 hours to 6 hours. It is understood that this application does not limit the method of "mixing and stirring" described above. Those skilled in the art can adapt the mixing time by extending or shortening it according to the mixing method, and all such extensions and shortens are within the scope of protection of this application.

[0057] In some embodiments, the centrifugation speed is 8000 rpm to 12000 rpm, and the centrifugation time is 10 min to 30 min.

[0058] In some embodiments, the precipitate obtained after centrifugation is washed with deionized water and the above-mentioned alcohol solvent, and the washing is repeated 2 to 5 times.

[0059] In some embodiments, the drying temperature is 50°C to 80°C, and the drying time is 12h to 48h.

[0060] In some embodiments, step S1 includes the following steps:

[0061] S1-1, Preparation of silica dispersion:

[0062] The silica particles obtained in step S1 are mixed with a solvent to obtain a silica dispersion.

[0063] In this application, the solvent described above enables the silica particles to be uniformly dispersed. This application does not limit the type of the solvent, such as but not limited to anhydrous ethanol, methanol, and isopropanol.

[0064] It should be noted that this application does not limit the mass ratio of the silica particles to the solvent, as long as the silica particles can be uniformly dispersed in the solvent.

[0065] This application does not limit the method of "mixing" described above, and may include, but is not limited to, ultrasound, stirring, etc. In some embodiments, the mixing method is ultrasound. In specific embodiments of this application, the ultrasound treatment time is 20 min to 60 min. In practical applications, shortening or extending the ultrasound treatment time according to the adaptability of the ultrasound equipment used is also within the scope of protection of this application.

[0066] Understandably, the above-mentioned silica dispersion can be obtained by mixing commercially available products with a solvent, or by mixing silica particles prepared by other experimental methods with a solvent.

[0067] S1-2, Low surface energy modification of silica particles:

[0068] The silica dispersion and the fluorinated alkyl compound solution were mixed and stirred, so that the fluorine atoms in the fluorinated alkyl compound solution replaced the hydroxyl groups on the surface of the silica particles, thereby performing low surface energy modification and obtaining a reaction solution containing modified silica particles.

[0069] In some embodiments, the above-mentioned fluoroalkyl compound solution is prepared by mixing the fluoroalkyl compound with a solvent, which may be, but is not limited to, ethanol, methanol, and ethyl acetate. This application does not limit the source of the above-mentioned fluoroalkyl compound solution; it may be purchased from commercially available products or prepared in a laboratory.

[0070] In a specific embodiment, a fluoroalkyl compound solution is prepared by mixing the fluoroalkyl compound with a solvent. This application does not limit the mass ratio of the fluoroalkyl compound to the solvent, as long as the fluoroalkyl compound can be uniformly dispersed in the solvent, which can be (0.5~1.5):1.

[0071] In some embodiments, the fluoroalkyl compounds mentioned above include one or more of perfluorooctyltriethoxysilane (HFOTES), triethoxyfluorosilane (TEFS), perfluorooctane sulfonic acid (PFOS), perfluorobutylethyltriethoxysilane, perfluoroethyl vinyl ether, and perfluorohexyl vinyl ether.

[0072] In this application, the mass ratio of the fluoroalkyl compound to the silica particles is not particularly limited and can be (0.1 to 1):1, to ensure that the fluorine atoms of the fluoroalkyl compound can fully replace the hydroxyl groups on the surface of the silica particles.

[0073] This application does not limit the method of "mixing and stirring the silica dispersion and the fluoroalkyl compound solution" as described above. In some embodiments, the fluoroalkyl compound solution is slowly added dropwise to the silica dispersion and mixed and stirred.

[0074] In some embodiments, the dropping rate is 3 mL / min to 10 mL / min, the mixing temperature is 40°C to 60°C, and the mixing time is 3 h to 5 h, to ensure that the fluoroalkyl compound and silica particles are in full contact and react fully, forming a stable low surface energy coating on the surface of the silica particles, thereby achieving low surface energy modification of the silica particles.

[0075] In some embodiments, step S2 includes the following steps:

[0076] S2-1. Evaporate the reaction liquid obtained in step S1 to obtain a slurry.

[0077] In some embodiments, the evaporation temperature is 48°C to 52°C, and the evaporation time is 2 hours to 3 hours.

[0078] In some embodiments, the solid content of the modified silica particles in the slurry is 15% to 30%.

[0079] In a preferred embodiment, the solid content of the modified silica particles in the slurry is 20% to 25%.

[0080] S2-2. Mix and stir the above slurry, organic resin solution and silane coupling agent to form a suspension.

[0081] In some embodiments, the above-mentioned organic resin solution is prepared by mixing organic resin with an organic solvent, which may be, but is not limited to, acetone, xylene, and ethyl acetate. This application does not limit the source of the above-mentioned organic resin solution; it may be purchased from commercially available products or prepared in a laboratory.

[0082] This application focuses on the main types and characteristics of functional groups on the surface of modified silica particles, and selects organic resins capable of forming strong bonds with them for mixing. In some embodiments, the organic resins are selected from one or more of polyurethane resins (PU resins), epoxy resins, methyl silicone resins, polymethyl methacrylate, and acrylic resins. It is understood that this application does not have specific requirements on the molecular weight of the organic resins, and any of the aforementioned organic resins disclosed in the prior art may be used.

[0083] In this application, the silane coupling agent acts as a surfactant, improving the dispersibility of modified silica particles in suspension and promoting better bonding between the modified silica particles and the organic resin. This application does not specifically limit the type of silane coupling agent; it can be one or more selected from 3-(methacryloyloxy)propyltrimethoxysilane (γ-MPS), 3-aminopropyltriethoxysilane (APTES), 3-aminopropyltrimethoxysilane (APTMS), and vinyltrimethoxysilane (VTMS).

[0084] In some embodiments, the mass ratio of modified silica particles to organic resin in the above suspension is 1:(2.5-3.5), and the mass ratio of silane coupling agent to organic resin is 1:(80-120).

[0085] The purpose of this application is to prepare a solid bulk superhydrophobic material with superhydrophobic properties and high mechanical strength. Experiments revealed that when the solid content of modified silica particles in the slurry is too low, a large amount of slurry needs to be added during the subsequent preparation of the suspension to ensure the material's superhydrophobic properties. This results in a soft, clay-like material, making it impossible to produce a solid bulk superhydrophobic material that meets the requirements for superhydrophobic shells in electrical equipment and other devices. Attempts were made to improve the superhydrophobic properties by increasing the amount of modified silica. However, the inventors of this application found that while increasing the solid content of modified silica in the slurry or increasing the mass fraction of modified silica in the suspension can improve the hydrophobic properties and produce a superhydrophobic material, it also increases the manufacturing difficulty. The modified silica and organic resin cannot be effectively mixed, resulting in low interfacial strength of the hydrophobic material and failure to achieve the desired hardness.

[0086] In some embodiments, step S3 includes the following steps:

[0087] The above suspension was subjected to degassing, solidification, pressing, and post-curing to obtain a solid block superhydrophobic material.

[0088] In some embodiments, the specific operation of degassing is as follows: the suspension is placed in a mold with pores, and a vacuum is drawn to remove the bubbles, wherein the vacuum degree is -0.09MPa to 0.01MPa, and the vacuuming time is 25min to 35min.

[0089] In some embodiments, the curing temperature is 90°C to 100°C, and the curing time is 16h to 20h. This is because when the curing temperature is low, the curing speed is slow, and the product obtained is a soft, putty-like material, which cannot produce a solid, blocky superhydrophobic material; when the curing temperature is high, the curing speed of the material is not significantly improved, and the superhydrophobic properties of the solid, blocky superhydrophobic material deteriorate.

[0090] In some embodiments, the pressure of the above-mentioned compression molding is 4MPa to 6MPa, the purpose of which is to form a bulk material and at the same time increase the interfacial bonding between the modified silica particles and the organic resin matrix.

[0091] In some embodiments, the post-curing temperature is 140°C to 160°C, and the post-curing time is 3 hours to 5 hours, with the aim of further enhancing the mechanical strength of the superhydrophobic material.

[0092] This application adjusts the solid content of modified silica in the slurry while synergistically controlling the mass ratio, curing temperature, and time of modified silica, organic resin, and silane coupling agent in the suspension, thereby preparing a solid bulk superhydrophobic material and improving its hydrophobic properties, interfacial strength, and mechanical stability, making it suitable for superhydrophobic shells of devices such as power equipment.

[0093] This application also provides solid bulk superhydrophobic materials prepared according to the above preparation method.

[0094] This application also provides the application of the aforementioned solid bulk superhydrophobic material in the fabrication of superhydrophobic shells for devices. The solid superhydrophobic material provided in this application can be applied to the surfaces of various devices, including but not limited to electrical equipment. This application does not limit the application method of the aforementioned solid bulk superhydrophobic material. For example, the solid bulk superhydrophobic material can be fixed to the device surface using an adhesive to form a superhydrophobic shell, or it can be fixed to the device surface using a clamp to form a superhydrophobic shell. This method is highly versatile and facilitates the wide application of products.

[0095] Based on this, this application also provides a superhydrophobic shell comprising the above-mentioned solid bulk superhydrophobic material.

[0096] It is understood that this application does not limit the shape and thickness of the superhydrophobic shell. In practical applications, those skilled in the art can choose a suitable shape and thickness according to actual needs.

[0097] In some embodiments, the thickness of the superhydrophobic shell is 5 mm to 30 mm.

[0098] In a preferred embodiment, the thickness of the superhydrophobic shell is 10 mm to 20 mm.

[0099] The above technical solutions are described in detail below with reference to specific embodiments. It should be understood that these are merely exemplary and not intended to limit this application. Materials of the same or similar type, model, quality, properties, or function as the reagents and instruments described below can be used to implement this application. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the materials and reagents used in the following embodiments are commercially available.

[0100] The following are examples and comparative examples:

[0101] Example 1

[0102] The method for preparing solid bulk superhydrophobic materials provided in this application includes the following steps:

[0103] Tetraethyl orthosilicate (TEOS) was selected as the main precursor material (silicon source compound), and silicon tetrachloride (STC) was selected as the auxiliary silicon source compound. The purity of the above reagents was 99.9%.

[0104] Under nitrogen protection, 100 mL of TEOS, 1.3 L of anhydrous ethanol, 200 mL of ammonia, and 300 mL of deionized water were mixed (pH 7.5 of the reaction system), and stirred at 35 °C for 2 h. Then, 5 mL of STC was slowly added dropwise, and stirring continued for 3 h to complete the hydrolysis and condensation reaction. The reaction solution was then centrifuged at 10,000 rpm for 20 min. The precipitate was washed three times with deionized water and anhydrous ethanol to remove unreacted raw materials and byproducts. Finally, the washed precipitate was dried at 65 °C for 24 h to obtain nano-silica particles with a particle size range of 130 nm to 170 nm and an average particle size of 150 nm.

[0105] S1. The above-mentioned nano-silica particles and anhydrous ethanol were mixed and ultrasonically treated for 40 min using an ultrasonic processor to enhance the dispersibility of the particles, thus obtaining a dispersion of silica particles. A fluoroalkyl compound (HFOTES) and ethanol were mixed at a mass ratio of 0.5:1 to form a homogeneous modifier solution, which was then slowly added dropwise to the silica particle dispersion at a rate of 5 mL / min. The mixture was stirred at 50 °C for 4 h to ensure sufficient contact and reaction between the modifier (fluoroalkyl compound) and the nano-silica particles, forming a stable low surface energy coating, resulting in a reaction solution containing modified silica particles. The modified silica particles were characterized using X-ray photoelectron spectroscopy (XPS). Figure 2 It can be seen that the surface of the modified silica particles showed the characteristic absorption peak of CF bond, indicating that HFOTES reacted with the surface of silica nanoparticles and formed low surface energy fluorinated alkyl groups on the surface of silica particles.

[0106] S2. The reaction solution obtained in step S1 was placed in a 50℃ water bath for evaporation and thickening treatment for 2.5 hours. The solid content of the evaporated slurry was measured by sampling and drying to constant weight. The results showed that the solid content of the modified silica particles in the slurry was 22%. PU resin (molecular weight 88, product model F0401, purchased from Shenzhen Yoshida Chemical Co., Ltd.) was dissolved in acetone to obtain a PU resin dispersion. Then, under stirring conditions, the above slurry, PU resin dispersion, and silane coupling agent (3-(methacryloyloxy)propyltrimethoxysilane) were mixed evenly at a mass ratio of modified silica particles to PU resin of 1:3 and a mass ratio of silane coupling agent to PU resin of 1:100 to obtain a suspension.

[0107] S3. Place the above suspension in a square mold with pores, and use a vacuum pump to remove air bubbles. The vacuum level is -0.09 MPa, and the vacuuming time is 30 minutes to ensure that the air bubbles in the suspension are completely removed. Then, place it in a 95°C vacuum oven for curing for 18 hours, followed by pressing under a pressure of 5 MPa to obtain a shaped block material with a Shore hardness of 70. Finally, place the above block material in a 150°C vacuum oven for post-curing treatment for 4 hours to obtain a solid block superhydrophobic material with a Shore hardness of 85. Figure 3 ).

[0108] Testing the superhydrophobic properties of the solid bulk superhydrophobic material provided in the embodiments of this application:

[0109] Solid bulk superhydrophobic materials were cut into appropriate sizes, cleaned with deionized water, and dried. The water contact angles on different surfaces were measured using a contact angle meter, and the roll-off angles were measured using a roll-off angle meter to evaluate the hydrophobic properties of the superhydrophobic materials. According to the Cassie-Baxter model, a material is considered superhydrophobic when the water contact angle is greater than 150° and the roll-off angle is less than 10°.

[0110] Test results show ( Figure 4 The solid bulk superhydrophobic material prepared in this application embodiment has a water contact angle of 151.113° and a roll-off angle of 3.0°, exhibiting excellent superhydrophobic properties.

[0111] Example 2

[0112] The method for preparing solid bulk superhydrophobic materials provided in this application includes the following steps:

[0113] Tetraethyl orthosilicate (TEOS) was selected as the main precursor material (silicon source compound), and trichloromethylsilane (MTMS) was selected as the auxiliary silicon source compound. The purity of the above reagents was 99.9%.

[0114] Under helium protection, 100 mL of TEOS, 1.4 L of anhydrous ethanol, 175 mL of ammonia, and 250 mL of deionized water (pH 8 of the reaction system) were mixed and stirred at 35 °C for 1.5 h. Then, 2.5 mL of MTMS was slowly added dropwise, and stirring continued for another 4.5 h to complete the hydrolysis and condensation reactions. The reaction mixture was then centrifuged at 8000 rpm for 30 min. The precipitate was washed five times with deionized water and anhydrous ethanol to remove unreacted raw materials and byproducts. Finally, the washed precipitate was dried at 50 °C for 48 h to obtain nano-silica particles with a particle size ranging from 140 nm to 180 nm and an average particle size of 160 nm.

[0115] S1. The above-mentioned nano-silica particles and anhydrous ethanol are mixed and ultrasonically treated for 30 min using an ultrasonic processor to enhance the dispersibility of the particles, thus obtaining a dispersion of silica particles. A fluoroalkyl compound (TEFS) and anhydrous ethanol are mixed at a mass ratio of 1:1 to form a homogeneous modifier solution. This solution is then slowly added dropwise to the silica particle dispersion at a rate of 10 mL / min. The mixture is stirred at 60 °C for 3 h to ensure sufficient contact and reaction between the modifier (fluoroalkyl compound) and the nano-silica particles, forming a stable low surface energy coating, thus obtaining a reaction solution containing modified silica particles.

[0116] S2. The reaction solution obtained in step S1 was placed in a 48℃ water bath for evaporation and thickening treatment for 3 hours. The solid content of the evaporated slurry was measured by sampling and drying to constant weight. The results showed that the solid content of the modified silica particles in the slurry was 25%. Epoxy resin (product model E44, purchased from Hunan Yuehua Chemical Co., Ltd.) was dissolved in acetone to obtain an epoxy resin dispersion. Then, under stirring conditions, the above slurry, epoxy resin dispersion, and silane coupling agent (3-aminopropyltriethoxysilane) were mixed evenly according to the mass ratio of modified silica particles to epoxy resin of 1:2.5 and the mass ratio of silane coupling agent to epoxy resin of 1:120 to obtain a suspension.

[0117] S3. Place the above suspension in a square mold with pores, and use a vacuum pump to remove air bubbles. The vacuum level is 0.01 MPa, and the vacuuming time is 25 minutes to ensure that the air bubbles in the suspension are completely removed. Then, place it in a 90°C vacuum oven for curing for 20 hours, followed by pressing under a pressure of 4 MPa to obtain a shaped block material with a Shore hardness of 65. Finally, place the above block material in a 160°C vacuum oven for post-curing treatment for 3 hours to obtain a solid block superhydrophobic material with a Shore hardness of 80. Figure 3 ).

[0118] The superhydrophobic performance test results of the solid bulk superhydrophobic material show that the solid bulk superhydrophobic material prepared in the embodiments of this application has a water contact angle of 151.0° and a roll-off angle of 3.5°, exhibiting excellent superhydrophobic performance.

[0119] Example 3

[0120] The method for preparing solid bulk superhydrophobic materials provided in this application includes the following steps:

[0121] Tetraethyl orthosilicate (TEOS) was selected as the main precursor material (silicon source compound), and silicon tetrachloride (STC) was selected as the auxiliary silicon source compound. The purity of the above reagents was 99.9%.

[0122] Under argon gas protection, 100 mL of TEOS, 1.2 L of anhydrous ethanol, 225 mL of ammonia, and 350 mL of deionized water were mixed (pH 7.5 of the reaction system). The mixture was stirred at 35°C for 2.5 h, followed by slow dropwise addition of 7.5 mL of STC, and stirring continued for another 1.5 h to complete the hydrolysis and condensation reactions. The reaction mixture was then centrifuged at 12000 rpm for 10 min. The precipitate was washed three times with deionized water and anhydrous ethanol to remove unreacted raw materials and byproducts. Finally, the washed precipitate was dried at 80°C for 12 h to obtain nano-silica particles with a particle size range of 120 nm to 160 nm and an average particle size of 140 nm.

[0123] S1. The above-mentioned nano-silica particles and anhydrous ethanol are mixed and ultrasonically treated for 50 min using an ultrasonic processor to enhance the dispersibility of the particles, thus obtaining a dispersion of silica particles. A fluoroalkyl compound (PFOS) and anhydrous ethanol are mixed at a mass ratio of 1.5:1 to form a homogeneous modifier solution. This solution is then slowly added dropwise to the silica particle dispersion at a rate of 3 mL / min. The mixture is stirred at 40 °C for 5 h to ensure sufficient contact and reaction between the modifier (fluoroalkyl compound) and the nano-silica particles, forming a stable low surface energy coating, thus obtaining a reaction solution containing modified silica particles.

[0124] S2. The reaction solution obtained in step S1 was placed in a 52℃ water bath for evaporation and thickening treatment for 2 hours. The solid content of the evaporated slurry was measured by sampling and drying to constant weight. The results showed that the solid content of the modified silica particles in the slurry was 20%. Methyl silicone resin (product model 077, purchased from Shandong Luderui New Material Co., Ltd.) was dissolved in acetone to obtain a methyl silicone resin dispersion. Then, under stirring conditions, the above slurry, methyl silicone resin dispersion and silane coupling agent (3-aminopropyltriethoxysilane) were mixed evenly according to the mass ratio of modified silica particles to methyl silicone resin of 1:3.5 and the mass ratio of silane coupling agent to methyl silicone resin of 1:80 to obtain a suspension.

[0125] S3. Place the above suspension in a square mold with pores, and use a vacuum pump to remove air bubbles. The vacuum level is -0.09 MPa, and the vacuuming time is 35 minutes to ensure that the air bubbles in the suspension are completely removed. Then, place it in a vacuum oven at 100℃ for curing for 16 hours, followed by pressing under a pressure of 6 MPa to obtain a shaped block material with a Shore hardness of 75. Finally, place the above block material in a vacuum oven at 140℃ for post-curing treatment for 5 hours to obtain a solid block superhydrophobic material with a Shore hardness of 85. Figure 3 ).

[0126] The superhydrophobic performance test results of the solid bulk superhydrophobic material show that the solid bulk superhydrophobic material prepared in the embodiments of this application has a water contact angle of 151.2° and a roll-off angle of 3.3°, exhibiting excellent superhydrophobic performance.

[0127] Comparative Example 1

[0128] In step S2, the evaporation time is 1 hour, the solid content of the modified silica particles in the slurry is 10%, and other operations are the same as in Example 1. The final hydrophobic material is a soft, clay-like material, and it is impossible to obtain a solid bulk superhydrophobic material.

[0129] Comparative Example 2

[0130] In step S2, the evaporation time is 1 hour, the solid content of the modified silica particles in the slurry is 40%, and other operations are the same as in Example 1. During the experiment, it was found that the slurry was difficult to disperse, which would lead to increased production difficulty and production costs in actual production. At the same time, the resulting hydrophobic material had low interfacial strength and a Shore hardness of 55.

[0131] Comparative Example 3

[0132] In step S2, the PU resin dispersion is mixed with the slurry at a mass ratio of 1:4 of modified silica particles to PU resin, and other operations are the same as in Example 1.

[0133] The superhydrophobic performance test results show that the contact angle between the prepared hydrophobic material and water is 110.0°, indicating poor hydrophobic performance.

[0134] Comparative Example 4

[0135] In step S2, the PU resin dispersion and slurry are mixed at a mass ratio of modified silica particles to PU resin of 1:2, and other operations are the same as in Example 1. The resulting hydrophobic material has low interfacial strength and a Shore hardness of 50, which fails to reach the predetermined hardness.

[0136] Comparative Example 5

[0137] In step S3, the curing temperature is 70°C, and other operations are the same as in Example 1. The final hydrophobic material is a soft, putty-like material.

[0138] Comparative Example 6

[0139] In step S3, the curing temperature is 150°C, and other operations are the same as in Example 1. The final hydrophobic material is dark in color, and the superhydrophobic performance test results show that the contact angle between the prepared hydrophobic material and water is 105°, indicating poor hydrophobic performance.

[0140] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a solid bulk superhydrophobic material, characterized in that, Includes the following steps: S1. The silica dispersion obtained by mixing silica particles and solvent is mixed and stirred with a fluorinated alkyl compound solution, so that the fluorine atoms in the fluorinated alkyl compound solution replace the hydroxyl groups on the surface of the silica particles, thereby performing low surface energy modification and obtaining a reaction solution containing modified silica particles. The silica particles have a particle size of 50 nm to 300 nm; the fluoroalkyl compound solution is prepared by mixing a fluoroalkyl compound with a solvent, wherein the fluoroalkyl compound is selected from one or more of perfluorooctyltriethoxysilane, triethoxyfluorosilane, perfluorooctane sulfonic acid, perfluorobutylethyltriethoxysilane, perfluoroethyl vinyl ether, and perfluorohexyl vinyl ether. S2. The slurry obtained by evaporating the reaction solution is mixed with the organic resin solution and silane coupling agent and stirred to form a suspension; the solid content of the modified silica particles in the slurry is 15%~30%; the mass ratio of modified silica particles to organic resin in the suspension is 1:(2.5~3.5). S3. The suspension is subjected to degassing, solidification, pressing and molding, and post-curing treatment to obtain a solid block superhydrophobic material; the curing temperature is 90℃~100℃, and the curing time is 16h~20h.

2. The preparation method according to claim 1, characterized in that, The method for preparing the silica particles includes the following steps: under a protective atmosphere, a silicon source compound, an alcohol solvent, an alkaline environment conditioner, deionized water, and an auxiliary silicon source compound are mixed, stirred, centrifuged, washed, and dried to obtain silica particles.

3. The preparation method according to claim 2, characterized in that, The silicon source compound is a silanol compound, selected from at least one of tetraethyl orthosilicate, propyl orthosilicate, and tetraethoxysilane; and / or, The auxiliary silicon source compound is selected from at least one of silane halides and trihalosilanes; and / or, The volume ratio of the silicon source compound to the auxiliary silicon source compound is 1:(0.025~0.075); and / or, The stirring temperature is 20℃~40℃, and the stirring time is 4h~6h.

4. The preparation method according to claim 1, characterized in that, In step S2, the organic resin solution is prepared by mixing an organic resin with an organic solvent, wherein the organic resin is selected from one or more of polyurethane resin, epoxy resin, methyl silicone resin, polymethyl methacrylate, and acrylic resin; and / or, The silane coupling agent is selected from one or more of 3-(methacryloyloxy)propyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and vinyltrimethoxysilane.

5. The preparation method according to claim 1, characterized in that, In step S3, the specific operation of removing air bubbles is as follows: the suspension is placed in a mold with air holes, and a vacuum is drawn to remove air bubbles, wherein the vacuum degree is -0.09MPa~0.01MPa, and the vacuuming time is 25min~35min.

6. The preparation method according to claim 1, characterized in that, In step S3, the pressing pressure is 4 MPa to 6 MPa; and / or, The post-curing temperature is 140℃~160℃, and the post-curing time is 3h~5h.

7. A solid bulk superhydrophobic material prepared by the preparation method according to any one of claims 1 to 6.

8. The application of the solid bulk superhydrophobic material of claim 7 in the fabrication of a superhydrophobic shell for a device.

9. A superhydrophobic shell comprising the solid bulk superhydrophobic material of claim 7.

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