A superhydrophobic composite coating having a multilayer self-similar anchoring structure and a method of making the same

Abstract

The application discloses a super-hydrophobic composite coating with a multi-layer self-similar anchoring structure, comprising a super-hydrophobic bottom layer with a self-similar anchoring structure and a super-hydrophobic surface layer, the super-hydrophobic bottom layer and the super-hydrophobic surface layer interact to form a micro-nano porous structure for bonding the upper and lower anchoring layers, the coating surface has a multi-scale micro-nano composite structure, and the super-hydrophobic bottom layer exercises the hydrophobic function when the super-hydrophobic surface layer is worn; the prepared coating has a multi-layer micro-nano anchoring wear-resistant structure, each layer has a similar structure, the layers are bonded and anchored into an integrated whole through interlayer interaction, has excellent super-hydrophobic performance and high mechanical durability, can effectively improve the wear resistance and impact resistance of the super-hydrophobic coating surface, the bottom layer can bear the main force when the surface layer is mechanically damaged, reduces the damage degree of the coating surface, and even if the coating surface is worn, the newly exposed coating surface can also show good hydrophobic performance.

Description

Technical Field

[0001] This invention relates to the field of hydrophobic materials, specifically to a superhydrophobic composite coating with a multilayer self-similar anchoring structure and its preparation method. Background Technology

[0002] Surfaces with a water contact angle greater than 150° and a water slip angle less than 10° are generally defined as superhydrophobic surfaces, inspired by natural lotus leaves. Although superhydrophobic surfaces possess excellent hydrophobicity, self-cleaning properties, anti-fouling, and anti-icing properties, their application is currently limited by poor durability. This is because the coating has poor mechanical wear resistance, and once the low surface energy material is depleted, it cannot be replenished. Damage to the surface easily leads to the loss of superhydrophobic properties and damage to the surface's micro-nano rough structure, causing a sharp decline in superhydrophobicity. Furthermore, the manufacturing methods are typically complex, expensive, and time-consuming. Existing patent CN118307213A discloses a superhydrophobic coated glass and its preparation method, comprising a glass substrate and a hydrophobic coating attached to the glass substrate. The hydrophobic coating is formed by applying a prepared coating composition to the glass surface and curing it. The components of the coating composition include silica particles, titanium dioxide, polyvinyl alcohol, deionized water, polyethylene glycol, fluorinated silane, and benzyltrimethoxysilane. The prepared glass has advantages such as good hydrophobicity and high light transmittance. However, the prepared coating has poor mechanical properties, and its superhydrophobic properties deteriorate due to mechanical damage. Patent CN118162346A discloses a superhydrophobic corrosion-resistant coating for aluminum alloy, its preparation method, and its application, including the following steps: immersing a pretreated aluminum alloy substrate in a corrosion-resistant coating liquid for immersion coating treatment, followed by curing to form a corrosion-resistant coating on the aluminum alloy surface; spraying a leveling transition coating liquid onto the aluminum alloy surface containing the corrosion-resistant layer, then applying an alternating rotating magnetic field accompanied by mechanical vibration to the aluminum alloy, followed by curing to form a leveling transition layer on the corrosion-resistant coating; spraying a superhydrophobic coating liquid onto the aluminum alloy surface containing the leveling transition layer, followed by curing to form a superhydrophobic coating on the leveling transition layer. The prepared aluminum alloy substrate has good corrosion protection for a relatively long time. However, its preparation method is cumbersome, the preparation process is complex, and its application fields are limited. Patent CN106119842A discloses a double-layer superhydrophobic material and its preparation method. The alloy substrate was immersed in a mixture of equal volumes of stearic acid ethanol solution and nickel sulfate aqueous solution, and hydrothermally heated at 140℃ for 7 hours. After cooling and drying, it was immersed in a mixture of equal volumes of stearic acid ethanol solution and cobalt sulfate aqueous solution, and hydrothermally heated at 130℃ for 8 hours; after cooling and drying, a bilayer superhydrophobic material was obtained. The prepared superhydrophobic material gives the alloy long-term corrosion resistance and antifouling properties. However, the interlayer bonding between the upper and lower layers is poor, resulting in poor overall mechanical stability.

[0003] Therefore, it is necessary to solve the technical problems of existing superhydrophobic coatings, such as rapid loss of superhydrophobic properties, poor mechanical properties, poor impact resistance, and insufficient adhesion between the coating and the substrate. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a superhydrophobic composite coating with a multilayer self-similar anchoring structure and its preparation method, so as to solve the technical problems of existing superhydrophobic coatings such as rapid loss of superhydrophobic properties, poor mechanical properties, poor impact resistance, and insufficient adhesion between the coating and the substrate.

[0005] The present invention provides a superhydrophobic composite coating with a multi-layer self-similar anchoring structure, comprising a superhydrophobic bottom layer and a superhydrophobic top layer with a self-similar anchoring structure. The superhydrophobic bottom layer and the superhydrophobic top layer interact to form a micro-nano porous structure for bonding and anchoring the upper and lower layers. The coating surface has a multi-scale micro-nano composite structure. When the superhydrophobic top layer is worn, the superhydrophobic bottom layer performs the hydrophobic function.

[0006] Furthermore, the superhydrophobic bottom layer material includes solvents, high-strength adhesives, toughening materials, highly inert nanoparticles, film-forming materials, plasticizers, filler granular rough materials, and curing materials; the superhydrophobic top layer material includes solvents, highly inert nanoparticles, low surface energy materials, and silicone elastomers.

[0007] Furthermore, by weight, the superhydrophobic bottom layer material contains 50-70 parts solvent, 10-30 parts high-strength adhesive, 8-25 parts toughening material, 1-3 parts highly inert nanoparticles, 5-20 parts film-forming material, 0.5-2 parts plasticizer, 1-3 parts filler, 8-12 parts partly rough material, and 0.2-0.6 parts curing material; the superhydrophobic top layer material contains 25-40 parts solvent, 1-3 parts highly inert nanoparticles, 1-3 parts low surface energy material, and 0.6-1.5 parts functional additives.

[0008] Further, the solvent is at least one of anhydrous ethanol, acetone, toluene, and tetrahydrofuran; the high-strength adhesive material is epoxy resin; the toughening material is at least one of polyester resin, acrylic resin, polyurethane resin, and alicyclic polyamine; and the highly inert nanoparticles are at least one of hydrophobic fumed nano-SiO2, namely R106, R202, R812, R812S, R972, R974, LA-R649, LA-R669, TS-530, TS-610, and TS-720.

[0009] Furthermore, the film-forming material is polysiloxane; the plasticizer is at least one of polymethyl methacrylate, phenolic resin, and polypropylene; the filler is at least one of quartz powder, talc powder, aluminum powder, or titanium dioxide; the granular coarse material is at least one of quartz sand, river sand, and manufactured sand; and the curing material is at least one of linear aliphatic polyamine, polyamide, and polythiol.

[0010] Furthermore, the low surface energy material is polydimethylsiloxane; the functional additive is at least one of octamethylcyclotetrasiloxane, tetramethyltetravinylcyclotetrasiloxane, tetravinylcyclotetrasiloxane, methylvinylcyclotrisiloxane, and methylvinylcyclopentasiloxane.

[0011] The present invention also discloses a method for preparing a superhydrophobic composite coating with a multi-layer self-similar anchoring structure, which adopts a layered coating method, first applying a superhydrophobic bottom layer solution to the substrate surface and curing it, and then applying a superhydrophobic top layer solution.

[0012] Furthermore, the preparation of the superhydrophobic bottom layer solution includes the following steps:

[0013] High-strength adhesive material, film-forming material, and plasticizer are dissolved in a solvent, stirred, and ultrasonically dispersed to obtain solution A; highly inert nanoparticles, toughening material, and filler are co-dissolved in a solvent, stirred, and ultrasonically dispersed to obtain solution B; solutions A, B, curing material, and particulate rough material are mixed.

[0014] Furthermore, the preparation method of the superhydrophobic surface layer solution includes the following steps:

[0015] Highly inert nanoparticles were dispersed in anhydrous ethanol to obtain a fumed nano-silica suspension. Then, a low surface energy substance was added and stirred. Finally, functional additives were added, stirred, and ultrasonically dispersed.

[0016] The beneficial effects of this invention are as follows: The method for preparing a superhydrophobic composite coating with a multi-layer self-similar anchoring structure produces a coating with a multi-layer micro-nano anchoring wear-resistant structure. Each layer has a similar structure, and the layers interact and bond together to form a single unit. The resulting double-layer coating exhibits excellent superhydrophobic properties and high mechanical durability. This multi-layer self-similar structure effectively improves the wear resistance and impact resistance of the superhydrophobic coating surface. The bottom layer can withstand the main force when the surface is subjected to mechanical damage, reducing the degree of wear and damage to the coating surface. Even if the coating surface is worn, the newly exposed coating surface can still exhibit good hydrophobic properties, ensuring the continued effectiveness of the supercomposite coating's hydrophobic properties. The prepared coating achieves a static water contact angle of 163°±0.8° and a roll-off angle of 3°±0.8°. After 150 cycles of sandpaper friction under 300g pressure, the coating still maintains its superhydrophobicity, with a maximum contact angle decrease of only 6.1%. After 16 hours of water droplet penetration testing and 12 hours of water flow impact testing, the contact angle of the coating remained above 153° and 151°, respectively. After immersion in acidic, alkaline, and salt solutions for 8 hours, the contact angle of the coating remained above 150°, and the roll-off angle remained below 10°, maintaining its superhydrophobicity and demonstrating good corrosion resistance. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0018] Figure 1 SEM image of the surface of the durable self-similar superhydrophobic composite coating;

[0019] Figure 2 FTIR spectra of different coated samples: a: superhydrophobic coating; b: hydrophobic adhesive coating;

[0020] Figure 3 The wettability of the coating after mechanical wear;

[0021] Figure 4 The wettability of the coating after the tape is peeled off;

[0022] Figure 5 The wettability of the coating after being impacted by water droplets;

[0023] Figure 6 The wettability of the coating after water flow impact. Detailed Implementation

[0024] This embodiment of a superhydrophobic composite coating with a multi-layer self-similar anchoring structure includes a superhydrophobic bottom layer and a superhydrophobic top layer, both with self-similar anchoring structures. The superhydrophobic bottom layer and the superhydrophobic top layer interact to form a micro / nano porous structure for bonding and anchoring the upper and lower layers. The coating surface has a multi-scale micro / nano composite structure. When the superhydrophobic top layer wears down, the superhydrophobic bottom layer takes over the hydrophobic function; preferably, a two-layer structure combining the bottom and top layers is used. The bottom layer not only bonds tightly to the substrate but also interacts effectively with the superhydrophobic coating of the top layer, promoting the formation and stability of the micro / nano structure within the coating. This allows the composite coating to maintain its structural and performance integrity even when subjected to external wear or impact. The coating surface has a multi-scale micro / nano composite structure, which not only provides the necessary roughness for a superhydrophobic coating but also significantly increases the air trapping capacity of the coating surface, forming an effective air isolation pad, thereby greatly improving the superhydrophobic performance of the coating. Importantly, this multi-scale micro / nano structure exhibits its advantages progressively during the wear process. Even if the top layer structure is damaged, the robust and durable hydrophobic film with a self-similar anchoring structure at the bottom layer can still maintain its complete hydrophobicity, ensuring the continued effectiveness of the hydrophobic properties of the supercomposite coating. This self-similar structural design greatly extends the service life of the durable superhydrophobic composite coating.

[0025] In this embodiment, the superhydrophobic underlayer material includes a solvent, a high-strength adhesive, a toughening material, highly inert nanoparticles, a film-forming material, a plasticizer, filler granular roughening material, and a curing material; the superhydrophobic toplayer material includes a solvent, highly inert nanoparticles, a low surface energy material, and an organosilicon elastomer; the epoxy resin in the underlayer has excellent adhesion and chemical stability, enabling the underlayer coating to adhere firmly to the substrate surface through strong adhesion, while also being firmly bonded to the highly inert nanoparticles. Its cross-linking structure allows the coating to form a robust matrix after curing, contributing to improved overall coating stability. The polysiloxane in the underlayer provides excellent weather resistance and water resistance, while the plasticizer enhances the coating's heat resistance and mechanical strength. Together, they form a strong protective layer in the underlayer coating. The filler in the underlayer fills the pores of the cross-linked structure to a certain extent, providing a certain degree of wear resistance and rheological properties, which can improve the coating's workability, making it easier to apply and dry. At the same time, the filler and granular roughening material together provide additional mechanical strength, enhancing the structural strength of the coating. The toughening material in the underlayer improves the mechanical strength and toughness of the coating, enhancing its wear resistance and impact resistance, thereby extending the coating's service life. By improving the coating's structure and physical properties, the toughening material effectively prevents cracking, peeling, and damage during daily use, ensuring the coating's long-term stability. The particulate rough material in the underlayer possesses excellent wear resistance and hardness, improving the coating's impact resistance and scratch resistance. Its rough structure, together with nano-SiO2, provides additional mechanical strength, enhancing the coating's strength and durability.

[0026] The low surface energy material in the surface layer is the main source of low surface energy in the superhydrophobic coating, effectively preventing the adhesion of moisture and dirt. The composite of polydimethylsiloxane and nano-SiO2 gives the coating extremely high hydrophobicity. This not only enhances the surface hardness and wear resistance but also gives the coating excellent self-cleaning ability.

[0027] In a preferred embodiment, by weight, the superhydrophobic bottom layer material comprises 50-70 parts solvent, 10-30 parts high-strength adhesive, 8-25 parts toughening material, 1-3 parts highly inert nanoparticles, 5-20 parts film-forming material, 0.5-2 parts plasticizer, 1-3 parts filler, 8-12 parts particulate roughening material, and 0.2-0.6 parts curing material; the superhydrophobic top layer material comprises 25-40 parts solvent, 1-3 parts highly inert nanoparticles, 1-3 parts low surface energy material, and 0.6-1.5 parts functional additives.

[0028] In this embodiment, the solvent is at least one of anhydrous ethanol, acetone, toluene, and tetrahydrofuran; the high-strength adhesive material is epoxy resin; the toughening material is at least one of polyester resin, acrylic resin, polyurethane resin, and alicyclic polyamine; the highly inert nanoparticles are at least one of hydrophobic fumed nano-SiO2, namely R106, R202, R812, R812S, R972, R974, LA-R649, LA-R669, TS-530, TS-610, and TS-720; the film-forming material is polysiloxane; the toughening agent is... The plastic material is at least one of polymethyl methacrylate, phenolic resin, and polypropylene; the filler is at least one of quartz powder, talc powder, aluminum powder, or titanium dioxide; the granular coarse material is at least one of quartz sand, river sand, and manufactured sand; the curing material is at least one of linear aliphatic polyamine, polyamide, and polythiol; the low surface energy substance is polydimethylsiloxane; and the functional additive is at least one of octamethylcyclotetrasiloxane, tetramethyltetravinylcyclotetrasiloxane, tetravinylcyclotetrasiloxane, methylvinylcyclotrisiloxane, and methylvinylcyclopentasiloxane. Polydimethylsiloxane in the surface layer, as an excellent low surface energy material, is the main source of low surface energy in superhydrophobic coatings, effectively preventing the adhesion of moisture and dirt. The composite of polydimethylsiloxane and nano-SiO2 gives the coating extremely high hydrophobicity. This not only enhances the surface hardness and wear resistance but also gives the coating excellent self-cleaning ability. The functional additives in the topcoat exhibit high reactivity, enabling them to form cross-linked networks with other silicon-based materials, further enhancing the surface roughness and hydrophobicity of the coating. The introduction of modified materials, combining nano-SiO2 and particulate roughening materials to provide roughness, and polydimethylsiloxane to provide low surface energy, collectively offer extremely high hydrophobicity, reducing dirt and dust adhesion and significantly enhancing self-cleaning capabilities. The hydrophobic fumed nano-SiO2 used in the bottom and top coatings possesses extremely small particle size and high specific surface area, significantly improving the coating's hardness, wear resistance, and surface smoothness. Furthermore, nano-SiO2 effectively enhances the coating's UV resistance, extending its service life. The nano-SiO2, particulate rough structure, and fillers in the bottom coating provide excellent wear resistance, while the particulate roughening materials further enhance the coating's abrasion resistance. This multi-layered wear-resistant design performs remarkably well in high-friction and high-impact environments. The abrasive particles in the base layer can replace most of the superhydrophobic topcoat when subjected to wear, protecting the superhydrophobicity of the topcoat and effectively improving its mechanical properties and impact resistance, achieving the excellent durability expected of superhydrophobic coatings. The application of composite resins and nanomaterials in both the base and topcoats enhances the coating's chemical resistance, enabling it to withstand the erosion of various chemicals and making it suitable for harsh environments such as the chemical industry. The combination of multiple resins and nanomaterials improves the coating's weather resistance, allowing it to resist the effects of ultraviolet radiation, moisture, and temperature changes, maintaining stable coating performance.The dual-layer, multi-level superhydrophobic coating can be applied to a variety of substrates. These substrates include both rough and smooth surfaces; rough surfaces include concrete and mortar, while smooth surfaces include metals.

[0029] This embodiment describes a method for preparing a superhydrophobic composite coating with a multi-layer self-similar anchoring structure. The method employs a layered coating approach: first, a superhydrophobic underlayer solution is applied to the substrate surface and cured, followed by the application of a superhydrophobic toplayer solution. The preparation of the superhydrophobic underlayer solution includes the following steps: dissolving a high-strength adhesive material, a film-forming material, and a plasticizer in a solvent, stirring, and ultrasonically dispersing to obtain solution A; co-dissolving highly inert nanoparticles, a toughening material, and a filler in a solvent, stirring, and ultrasonically dispersing to obtain solution B; and mixing solutions A, B, the curing material, and the particulate rough material. The preparation of the superhydrophobic toplayer solution includes the following steps: dispersing highly inert nanoparticles in anhydrous ethanol to obtain a fumed silica suspension, then adding a low surface energy substance and stirring, and finally adding a functional additive material, stirring, and ultrasonically dispersing. The hydrophobic film prepared by this invention uniformly and stably anchors the particulate rough material to the substrate surface, constructing a dense and tough wear-resistant underlayer. The high hardness, height difference formed on the substrate surface, and uniform distribution of the particulate rough material significantly improve the impact strength and wear resistance of the coating, thereby effectively extending its service life. The excellent adhesion strength exhibited by this hydrophobic film is mainly attributed to the synergistic effect of the epoxy resin and toughening material after curing. Furthermore, the addition of the film-forming material further enhances the tear resistance and wear resistance of the composite coating. The bottom layer not only bonds tightly to the substrate but also interacts effectively with the superhydrophobic coating on the top layer, promoting the formation and stability of the micro / nano structure within the coating. This allows the composite coating to maintain its structural and performance integrity even under external wear or impact. The coating surface is constructed from micron-sized particulate rough material and nano-sized SiO2 particles, forming a multi-scale micro / nano composite structure. This structure not only provides the necessary roughness for a superhydrophobic coating but also significantly increases the air trapping capacity of the coating surface, forming an effective air isolation pad, thus greatly improving the superhydrophobic performance of the coating. Crucially, this multi-scale micro / nano structure exhibits its advantages progressively during wear. Even if the top layer structure is damaged, the robust and durable hydrophobic film with a self-similar anchoring structure at the bottom layer can still maintain its complete hydrophobicity, ensuring the continued effectiveness of the hydrophobic properties of the supercomposite coating. This self-similar structural design greatly extends the service life of the durable superhydrophobic composite coating, demonstrating its great potential and advantages in practical applications.

[0030] This invention, building upon the traditional superhydrophobic coating formed by combining polydimethylsiloxane with nano-SiO2, introduces a highly active organosilicon monomer as a functional additive. After being composited with polymers such as polydimethylsiloxane, the highly active organosilicon monomer successfully constructs numerous micro / nanoplastic structures on the coating surface, significantly reducing the surface energy of the coating and thus optimizing the surface wettability of the composite coating, increasing the contact angle from 156° to 163°. Because the organosilicon monomer can chemically react with dimethylsiloxane and other silicon-based materials to form a stable cross-linked network, it not only enhances the bonding strength within the superhydrophobic surface layer but also promotes a tight bond between the surface layer and the underlying layer. Under impact or abrasion, this strong bonding effectively prevents coating delamination or peeling, thereby maintaining the integrity and superhydrophobic properties of the composite coating. Through the formation of the cross-linked network, the organosilicon monomer imparts a certain degree of elasticity and flexibility to the coating, enabling it to absorb and disperse impact energy through minute deformations, effectively preventing coating cracking or severe damage. Furthermore, the cross-linking effect of the organosilicon monomer significantly enhances the stability of the micro / nano structures on the coating surface. When subjected to impact or abrasion, the cross-linked network maintains the integrity and orderly arrangement of the micro / nano structure, preventing its destruction or recombination. Notably, the organosilicon monomer also exhibits excellent chemical stability, maintaining coating performance stability under various environmental conditions. When exposed to acids, alkalis, and other chemicals, the organosilicon monomer can synergistically work with other silicon-based materials to resist chemical attacks, preventing damage to the coating surface structure or performance degradation, thereby further enhancing the durability and practicality of the composite coating.

[0031] This invention presents a low-cost and simple preparation method, resulting in a coating with stable superhydrophobic properties, excellent adhesion, and good durability. Furthermore, the coating exhibits superior self-cleaning properties and eliminates the need for cumbersome pretreatment steps such as etching or modification of the substrate surface. This coating can be applied to a variety of substrate surfaces, including smooth and rough surfaces. Smooth surfaces include glass and metal surfaces such as steel, aluminum, and copper; rough surfaces include wood, concrete, and mortar. It can be applied to the outer shells or interior decorations of vehicles such as automobiles, ships, and aircraft, demonstrating a wide range of applications.

[0032] Example 1

[0033] The superhydrophobic composite coating with a multi-layer self-similar anchoring structure in this embodiment includes a base coating and a top coating. The base coating raw materials include, by weight, 50 parts solvent, 10 parts high-strength adhesive, 8 parts toughening material, 1 part highly inert nanoparticles, 5 parts film-forming material, 0.5 parts plasticizer, 1 part filler, 8 parts part granular roughening material, and 0.2 parts curing material. The top coating raw materials include, by weight, 25 parts solvent, 1 part highly inert nanoparticles, 1 part low surface energy material, and 0.6 parts functional additives.

[0034] In this embodiment, the solvent is anhydrous ethanol. Replacing anhydrous ethanol with acetone, toluene, or tetrahydrofuran, or with a mixture of anhydrous ethanol and acetone, toluene, or tetrahydrofuran, will achieve the objective of this invention. The high-strength adhesive material is epoxy resin. The toughening material is polyester resin. Replacing polyester resin with acrylic resin, polyurethane resin, or alicyclic polyamine, or with a mixture of polyester resin and acrylic resin, polyurethane resin, or alicyclic polyamine, will achieve the objective of this invention. The highly inert nanoparticles... The particles are hydrophobic vapor-phase nano-SiO2 containing R106. Replacing R106 with one of R202, R812, R812S, R972, R974, LA-R649, LA-R669, TS-530, TS-610, or TS-720, or with a mixture of R106 and R202, R812, R812S, R972, R974, LA-R649, LA-R669, TS-530, TS-610, or TS-720, can achieve the objective of this invention.

[0035] In this embodiment, the film-forming material is polysiloxane; the plasticizer is polymethyl methacrylate (PMMA), and replacing PMMA with phenolic resin or polypropylene, or a mixture of PMMA, phenolic resin, and polypropylene, can achieve the purpose of this invention; the filler is quartz powder, and replacing quartz powder with talc, aluminum powder, or titanium dioxide, or a mixture of quartz powder, talc, aluminum powder, and titanium dioxide, can achieve the purpose of this invention; the granular coarse material is quartz sand, and replacing quartz sand with river sand or manufactured sand, or a mixture of quartz sand, river sand, and manufactured sand, can achieve the purpose of this invention; the curing material is a linear aliphatic polyamine, and replacing the linear aliphatic polyamine with polyamide or polythiol, or a mixture of linear aliphatic polyamine, polyamide, and polythiol, can achieve the purpose of this invention.

[0036] In this embodiment, the low surface energy material is polydimethylsiloxane; the functional additive is octamethylcyclotetrasiloxane. Replacing octamethylcyclotetrasiloxane with one of tetramethyltetravinylcyclotetrasiloxane, tetravinylcyclotetrasiloxane, methylvinylcyclotrisiloxane, or methylvinylcyclopentasiloxane, or with a mixture of octamethylcyclotetrasiloxane and tetramethyltetravinylcyclotetrasiloxane, tetravinylcyclotetrasiloxane, methylvinylcyclotrisiloxane, or methylvinylcyclopentasiloxane, can achieve the purpose of this invention.

[0037] The preparation method of the bottom layer includes the following steps: First, epoxy resin, polysiloxane and plasticizing material are dissolved in ethanol solution and magnetically stirred at 2000 rpm for 3 hours, and then ultrasonically dispersed for 30 minutes to obtain solution A; hydrophobic vapor-phase nano-SiO2, toughening material and filler are mixed and dissolved in a second ethanol solution and magnetically stirred at 2000 rpm for 3 hours, and then ultrasonically dispersed for 30 minutes to obtain solution B; finally, the bottom layer solution is obtained by mixing solutions A and B, curing material and particulate rough material and magnetically stirring at 2000 rpm for 0.5 minutes.

[0038] The preparation method of the surface layer includes the following steps: First, hydrophobic fumed nano-SiO2 is dispersed in anhydrous ethanol to obtain a fumed nano-silica suspension; then, polydimethylsiloxane is added to the fumed nano-silica suspension and magnetically stirred at 500 rpm for 4 hours; then, functional additives are added and magnetically stirred at 2000 rpm for 3 hours, and ultrasonically dispersed for 2 hours to obtain the surface layer solution.

[0039] The coating, formed by combining the bottom layer solution and the top layer solution, is prepared by simple brushing to achieve a double-layer self-similar superhydrophobic composite coating on the substrate surface. After the bottom layer is applied to the substrate surface, it is left at room temperature for 24 hours to allow the solvent to evaporate and the coating to cure. The top layer is then compositely inlaid with the bottom layer, dried at 60°C for 50 minutes, and then cured at room temperature for 12 hours.

[0040] Example 2

[0041] The superhydrophobic composite coating with a multi-layer self-similar anchoring structure in this embodiment includes a base coating and a top coating. The base coating raw materials include, by weight, 70 parts solvent, 30 parts high-strength adhesive, 25 parts toughening material, 3 parts highly inert nanoparticles, 20 parts film-forming material, 2 parts plasticizer, 3 parts filler, 12 parts part particulate roughening material, and 0.2 parts curing material. The top coating raw materials include, by weight, 40 parts solvent, 3 parts highly inert nanoparticles, 3 parts low surface energy material, and 1.5 parts functional additives.

[0042] In this embodiment, the solvent is acetone. Replacing acetone with anhydrous ethanol, toluene, or tetrahydrofuran, or a mixture of acetone and anhydrous ethanol, toluene, or tetrahydrofuran, will achieve the objective of this invention. The high-strength adhesive material is epoxy resin. The toughening material is acrylic resin. Replacing acrylic resin with polyester resin, polyurethane resin, or alicyclic polyamine, or a mixture of acrylic resin and polyester resin, polyurethane resin, or alicyclic polyamine, will achieve the objective of this invention. The highly inert nanoparticles... The purpose of this invention can be achieved by replacing R202 in hydrophobic vapor-phase nano-SiO2 with one of R106, R812, R812S, R972, R974, LA-R649, LA-R669, TS-530, TS-610, or TS-720, or by replacing it with a mixture of R202 and R106, R812, R812S, R972, R974, LA-R649, LA-R669, TS-530, TS-610, or TS-720.

[0043] In this embodiment, the film-forming material is polysiloxane; the plasticizer is phenolic resin, and replacing the phenolic resin with polymethyl methacrylate or polypropylene, or a mixture of phenolic resin, polymethyl methacrylate, and polypropylene, can achieve the purpose of this invention; the filler is talc, and replacing the talc with quartz powder, aluminum powder, or titanium dioxide, or a mixture of talc with quartz powder, aluminum powder, and titanium dioxide, can achieve the purpose of this invention; the granular coarse material is river sand, and replacing the river sand with quartz sand or manufactured sand, or a mixture of river sand, quartz sand, and manufactured sand, can achieve the purpose of this invention; the curing material is polyamide, and replacing the polyamide with linear aliphatic polyamine or polythiol, or a mixture of polyamide with linear aliphatic polyamine and polythiol, can achieve the purpose of this invention.

[0044] In this embodiment, the low surface energy material is polydimethylsiloxane; the functional additive is tetramethyltetravinylcyclotetrasiloxane. Replacing tetramethyltetravinylcyclotetrasiloxane with one of octamethylcyclotetrasiloxane, tetravinylcyclotetrasiloxane, methylvinylcyclotrisiloxane, or methylvinylcyclopentasiloxane, or with a mixture of tetramethyltetravinylcyclotetrasiloxane and octamethylcyclotetrasiloxane, tetravinylcyclotetrasiloxane, methylvinylcyclotrisiloxane, or methylvinylcyclopentasiloxane, can achieve the objective of this invention.

[0045] The preparation method of the bottom layer includes the following steps: First, epoxy resin, polysiloxane and plasticizing material are dissolved in ethanol solution and magnetically stirred at 500 rpm for 5 hours, and then ultrasonically dispersed for 30-60 minutes to obtain solution A; hydrophobic gaseous nano-SiO2, toughening material and filler are mixed and dissolved in a second ethanol solution and magnetically stirred at 500 rpm for 5 hours, and then ultrasonically dispersed for 60 minutes to obtain solution B; finally, the bottom layer solution is obtained by mixing solutions A and B, curing material and particulate rough material and magnetically stirring at 500 rpm for 2 hours.

[0046] The preparation method of the surface layer includes the following steps: First, hydrophobic fumed nano-SiO2 is dispersed in anhydrous ethanol to obtain a fumed nano-silica suspension; then, polydimethylsiloxane is added to the fumed nano-silica suspension and magnetically stirred at 2000 rpm for 3 hours; then, functional additives are added, and magnetic stirring at 500 rpm is performed for 5 hours, followed by ultrasonic dispersion for 4 hours to obtain the surface layer solution.

[0047] In this example, the coating, composed of the bottom layer solution and the top layer solution, is prepared by simple brushing to achieve a double-layer, multi-level superhydrophobic coating on the substrate surface. After the bottom layer is applied to the substrate surface, it is left at room temperature for 36 hours to allow the solvent to evaporate and the coating to cure. The top layer is then compositely inlaid with the bottom layer, dried at 60°C for 60 minutes, and then cured at room temperature for 24 hours.

[0048] Example 3

[0049] The coating consists of two parts: a base coat and a top coat. The base coat consists of 60 parts by weight of solvent, 20 parts by weight of high-strength adhesive, 17 parts by weight of toughening material, 2 parts by weight of highly inert nanoparticles, 10 parts by weight of film-forming material, 1.5 parts by weight of plasticizer, 2 parts by weight of filler, 10 parts by weight of particulate roughening material, and 0.3 parts by weight of curing material. The top coat consists of 35 parts by weight of solvent, 2 parts by weight of highly inert nanoparticles, 2 parts by weight of low surface energy material, and 1 part by weight of functional additive material.

[0050] In this embodiment, the solvent is toluene. Replacing toluene with one of acetone, anhydrous ethanol, or tetrahydrofuran, or a mixture of toluene and acetone, anhydrous ethanol, or tetrahydrofuran, will achieve the objective of this invention. The high-strength adhesive material is epoxy resin. The toughening material is polyurethane resin. Replacing the polyurethane resin with one of acrylic resin, polyester resin, or alicyclic polyamine, or a mixture of polyurethane resin and acrylic resin, polyester resin, or alicyclic polyamine, will achieve the objective of this invention. The highly inert nanoparticles... The purpose of this invention can be achieved by replacing R812 in hydrophobic vapor-phase nano-SiO2 with one of R202, R106, R812S, R972, R974, LA-R649, LA-R669, TS-530, TS-610, or TS-720, or by replacing it with a mixture of R812 and R202, R106, R812S, R972, R974, LA-R649, LA-R669, TS-530, TS-610, or TS-720.

[0051] In this embodiment, the film-forming material is polysiloxane; the plasticizer is polypropylene, which can be replaced by phenolic resin, polymethyl methacrylate, or a mixture of polypropylene, phenolic resin, and polymethyl methacrylate to achieve the purpose of this invention; the filler is aluminum powder, which can be replaced by talc, quartz powder, or titanium dioxide, or a mixture of aluminum powder, talc, quartz powder, and titanium dioxide to achieve the purpose of this invention; the granular coarse material is quartz sand, which can be replaced by river sand, manufactured sand, or a mixture of quartz powder, quartz sand, river sand, and manufactured sand to achieve the purpose of this invention; the curing material is polythiol, which can be replaced by polyamide, linear aliphatic polyamine, or a mixture of polythiol, polyamide, and linear aliphatic polyamine to achieve the purpose of this invention.

[0052] In this embodiment, the low surface energy material is polydimethylsiloxane; the functional additive is methylvinylcyclotrisiloxane. Replacing methylvinylcyclotrisiloxane with one of tetramethyltetravinylcyclotetrasiloxane, tetravinylcyclotetrasiloxane, octamethylcyclotetrasiloxane, or methylvinylcyclopentasiloxane, or with a mixture of tetravinylcyclotetrasiloxane and tetramethyltetravinylcyclotetrasiloxane, octamethylcyclotetrasiloxane, methylvinylcyclotrisiloxane, or methylvinylcyclopentasiloxane, can achieve the objective of this invention.

[0053] The preparation method of the bottom layer includes the following steps: First, epoxy resin, polysiloxane and plasticizing material are dissolved in ethanol solution and magnetically stirred at 1000 rpm for 4 hours, and then ultrasonically dispersed for 40 minutes to obtain solution A; hydrophobic gaseous nano-SiO2, toughening material and filler are mixed and dissolved in a second ethanol solution and magnetically stirred at 1000 rpm for 4 hours, and then ultrasonically dispersed for 40 minutes to obtain solution B; finally, the bottom layer solution is obtained by mixing solutions A and B, curing material and particulate rough material and magnetically stirring at 1000 rpm for 1 hour.

[0054] The preparation method of the surface layer includes the following steps: First, hydrophobic fumed nano-SiO2 is dispersed in anhydrous ethanol to obtain a fumed nano-silica suspension; then, polydimethylsiloxane is added to the fumed nano-silica suspension and magnetically stirred at 1000 rpm for 3.5 h; then, functional additives are added, and magnetic stirring at 1000 rpm is performed for 4 h, followed by ultrasonic dispersion for 3 h to obtain the surface layer solution.

[0055] In this example, the coating, composed of the bottom layer solution and the top layer solution, is prepared by simple brushing to achieve a double-layer, multi-level superhydrophobic coating on the substrate surface. After the bottom layer is applied to the substrate surface, it is left at room temperature for 30 hours to allow the solvent to evaporate and the coating to cure. The top layer is then compositely inlaid with the bottom layer, dried at 60°C for 55 minutes, and then cured at room temperature for 18 hours.

[0056] Example 4

[0057] The coating consists of two parts: a base coat and a top coat. The base coat consists of 50 parts solvent, 10 parts high-strength adhesive, 8 parts toughening material, 1 part highly inert nanoparticles, 5 parts film-forming material, 0.5 parts plasticizer, 1 part filler, 8 parts part granular roughening material, and 0.45 parts curing material by weight. The top coat consists of 40 parts solvent, 3 parts highly inert nanoparticles, 3 parts low surface energy material, and 1.5 parts functional additives by weight.

[0058] In this embodiment, the solvent is tetrahydrofuran. Replacing tetrahydrofuran with acetone, toluene, or anhydrous ethanol, or with a mixture of tetrahydrofuran and acetone, toluene, or anhydrous ethanol, will achieve the objective of this invention. The high-strength adhesive material is epoxy resin. The toughening material is an alicyclic polyamine. Replacing the alicyclic polyamine with acrylic resin, polyurethane resin, or polyester resin, or with a mixture of alicyclic polyamine and acrylic resin, polyurethane resin, or polyester resin, will achieve the objective of this invention. The highly inert nanoparticles... The particles are R812S in hydrophobic vapor-phase nano-SiO2. Replacing R812S with one of R202, R812, R106, R972, R974, LA-R649, LA-R669, TS-530, TS-610, or TS-720, or with a mixture of R812S and R202, R812, R106, R972, R974, LA-R649, LA-R669, TS-530, TS-610, or TS-720, can achieve the purpose of this invention.

[0059] In this embodiment, the film-forming material is polysiloxane; the plasticizer is phenolic resin, and replacing the phenolic resin with polymethyl methacrylate or polypropylene, or a mixture of phenolic resin, polymethyl methacrylate, and polypropylene, can achieve the purpose of this invention; the filler is titanium dioxide, and replacing the titanium dioxide with talc, aluminum powder, or quartz powder, or a mixture of quartz sand, talc, aluminum powder, and titanium dioxide, can achieve the purpose of this invention; the granular coarse material is quartz sand, and replacing the quartz sand with river sand or manufactured sand, or a mixture of quartz powder, quartz sand, river sand, and manufactured sand, can achieve the purpose of this invention; the curing material is a linear aliphatic polyamine, and replacing the linear aliphatic polyamine with polyamide or polythiol, or a mixture of linear aliphatic polyamine, polyamide, and polythiol, can achieve the purpose of this invention.

[0060] In this embodiment, the low surface energy material is polydimethylsiloxane; the functional additive is methylvinylcyclopentasiloxane. The methylvinylcyclopentasiloxane can be one of tetramethyltetravinylcyclotetrasiloxane, tetravinylcyclotetrasiloxane, methylvinylcyclotrisiloxane, or octamethylcyclotetrasiloxane, or can be replaced with a mixture of methylvinylcyclopentasiloxane and tetramethyltetravinylcyclotetrasiloxane, tetravinylcyclotetrasiloxane, methylvinylcyclotrisiloxane, or octamethylcyclotetrasiloxane, all of which can achieve the objective of this invention.

[0061] The preparation method of the bottom layer includes the following steps: First, epoxy resin, polysiloxane and plasticizing material are dissolved in ethanol solution and magnetically stirred at 800 rpm for 3.5 h, and then ultrasonically dispersed for 55 min to obtain solution A; hydrophobic vapor-phase nano-SiO2, toughening material and filler are mixed and dissolved in a second ethanol solution and magnetically stirred at 800 rpm for 5 h, and then ultrasonically dispersed for 35 min to obtain solution B; finally, the bottom layer solution is obtained by mixing solutions A and B, curing material and particulate rough material and magnetically stirring at 800 rpm for 1.5 h.

[0062] The preparation method of the surface layer includes the following steps: First, hydrophobic fumed nano-SiO2 is dispersed in anhydrous ethanol to obtain a fumed nano-silica suspension; then, polydimethylsiloxane is added to the fumed nano-silica suspension and magnetically stirred at 800 rpm for 3 hours; then, functional additives are added, and magnetic stirring at 800 rpm is performed for 5 hours, followed by ultrasonic dispersion for 3 hours to obtain the surface layer solution.

[0063] In this example, the coating, composed of the bottom layer solution and the top layer solution, is prepared by simple brushing to achieve a double-layer, multi-level superhydrophobic coating on the substrate surface. After the bottom layer is applied to the substrate surface, it is left at room temperature for 24 hours to allow the solvent to evaporate and the coating to cure. The top layer is then compositely inlaid with the bottom layer, dried at 60°C for 50 minutes, and then cured at room temperature for 12 hours.

[0064] Example 5

[0065] The coating consists of two parts: a base coat and a top coat. The base coat consists of 70 parts solvent, 30 parts high-strength adhesive, 25 parts toughening material, 3 parts highly inert nanoparticles, 20 parts film-forming material, 2 parts plasticizer, 3 parts filler, 12 parts part particulate roughening material, and 0.6 parts curing material by weight. The top coat consists of 25 parts solvent, 1 part highly inert nanoparticles, 1 part low surface energy material, and 0.6 parts functional additives by weight.

[0066] In this embodiment, the solvent is anhydrous ethanol. Replacing anhydrous ethanol with acetone, toluene, or tetrahydrofuran, or with a mixture of anhydrous ethanol and acetone, toluene, or tetrahydrofuran, will achieve the objective of this invention. The high-strength adhesive material is epoxy resin. The toughening material is polyester resin. Replacing polyester resin with acrylic resin, polyurethane resin, or alicyclic polyamine, or with a mixture of polyester resin and acrylic resin, polyurethane resin, or alicyclic polyamine, will achieve the objective of this invention. The highly inert nanoparticles are... The purpose of this invention can be achieved by replacing LA-R649 in hydrophobic vapor-phase nano-SiO2 with one of R202, R812, R812S, R972, R974, R106, LA-R669, TS-530, TS-610, or TS-720, or by replacing it with a mixture of LA-R649 and R202, R812, R812S, R972, R974, R106, LA-R669, TS-530, TS-610, or TS-720.

[0067] In this embodiment, the film-forming material is polysiloxane; the plasticizer is polymethyl methacrylate (PMMA), which can be replaced with phenolic resin or polypropylene, or a mixture of PMMA, phenolic resin, and polypropylene, all of which achieve the purpose of this invention; the filler is quartz powder, which can be replaced with talc, aluminum powder, or titanium dioxide, or a mixture of quartz powder, talc, aluminum powder, and titanium dioxide, all of which achieve the purpose of this invention; the granular coarse material is quartz sand, which can be replaced with river sand or manufactured sand, or a mixture of quartz sand and river sand or manufactured sand, all of which achieve the purpose of this invention; the curing material is a linear aliphatic polyamine, which can be replaced with polyamide or polythiol, or a mixture of linear aliphatic polyamine, polyamide, and polythiol, all of which achieve the purpose of this invention.

[0068] In this embodiment, the low surface energy material is polydimethylsiloxane; the functional additive is octamethylcyclotetrasiloxane. Replacing octamethylcyclotetrasiloxane with one of tetramethyltetravinylcyclotetrasiloxane, tetravinylcyclotetrasiloxane, methylvinylcyclotrisiloxane, or methylvinylcyclopentasiloxane, or with a mixture of octamethylcyclotetrasiloxane and tetramethyltetravinylcyclotetrasiloxane, tetravinylcyclotetrasiloxane, methylvinylcyclotrisiloxane, or methylvinylcyclopentasiloxane, can achieve the purpose of this invention.

[0069] The preparation method of the bottom layer includes the following steps: First, epoxy resin, polysiloxane and plasticizing material are dissolved in ethanol solution and magnetically stirred at 1500 rpm for 4.5 h, and then ultrasonically dispersed for 55 min to obtain solution A; hydrophobic vapor-phase nano-SiO2, toughening material and filler are mixed and dissolved in a second ethanol solution and magnetically stirred at 1500 rpm for 3 h, and then ultrasonically dispersed for 55 min to obtain solution B; finally, the bottom layer solution is obtained by mixing solutions A and B, curing material and particulate rough material and magnetically stirring at 1500 rpm for 1.8 h.

[0070] The preparation method of the surface layer includes the following steps: First, hydrophobic fumed nano-SiO2 is dispersed in anhydrous ethanol to obtain a fumed nano-silica suspension; then, polydimethylsiloxane is added to the fumed nano-silica suspension and magnetically stirred at 1500 rpm for 3.3 h; then, functional additives are added, and the mixture is magnetically stirred at 1500 rpm for 3 hours and ultrasonically dispersed to obtain the surface layer solution.

[0071] In this example, the coating, composed of the bottom layer solution and the top layer solution, is prepared by simple brushing to achieve a double-layer, multi-level superhydrophobic coating on the substrate surface. After the bottom layer is applied to the substrate surface, it is left at room temperature for 36 hours to allow the solvent to evaporate and the coating to cure. The top layer is then compositely inlaid with the bottom layer, dried at 60°C for 60 minutes, and then cured at room temperature for 24 hours.

[0072] The coatings described in the above embodiments were tested, and the static water contact angle reached 163°±0.8°, while the roll-off angle was 3°±0.8°. After 150 cycles of sandpaper abrasion under 300g pressure, the coating maintained its superhydrophobicity, with a contact angle decrease of only 6.1%. After 16 hours of water droplet penetration testing and 12 hours of water flow impact testing, the contact angles of the coating remained above 153° and 151°, respectively. After immersion in acidic, alkaline, and salt solutions for 8 hours, the contact angle of the coating remained above 150°, and the roll-off angle remained below 10°, maintaining its superhydrophobicity and demonstrating excellent corrosion resistance.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A superhydrophobic composite coating with a multilayer self-similar anchoring structure, characterized in that: The coating comprises a superhydrophobic substrate and a superhydrophobic top layer with a self-similar anchoring structure. The superhydrophobic substrate and top layer interact to form a micro / nano porous structure for bonding and anchoring the two layers. The coating surface has a multi-scale micro / nano composite structure. When the superhydrophobic top layer wears down, the superhydrophobic substrate takes over the hydrophobic function. By weight, the superhydrophobic substrate comprises 50-70 parts solvent, 10-30 parts high-strength adhesive, 8-25 parts toughening material, 1-3 parts highly inert nanoparticles, 5-20 parts film-forming material, 0.5-2 parts plasticizer, 1-3 parts filler, 8-12 parts part granular roughening material, and 0.2-0.6 parts curing material. The superhydrophobic top layer comprises 25-40 parts solvent, 1-3 parts highly inert nanoparticles, and low surface area... The material comprises 1-3 parts of high-strength adhesive and 0.6-1.5 parts of functional additives; the high-strength adhesive is epoxy resin; the toughening material is at least one of polyester resin, acrylic resin, polyurethane resin, and alicyclic polyamine; the highly inert nanoparticles are at least one of hydrophobic fumed nano-SiO2, namely R106, R202, R812, R812S, R972, R974, LA-R649, LA-R669, TS-530, TS-610, and TS-720; the plasticizer is at least one of polymethyl methacrylate, phenolic resin, and polypropylene; the filler is at least one of quartz powder, talc powder, aluminum powder, or titanium dioxide; and the granular coarse material is at least one of quartz sand, river sand, and manufactured sand.

2. The superhydrophobic composite coating with a multi-layer self-similar anchoring structure according to claim 1, characterized in that: The solvent is at least one of anhydrous ethanol, acetone, toluene, and tetrahydrofuran.

3. The superhydrophobic composite coating with a multi-layer self-similar anchoring structure according to claim 1, characterized in that: The film-forming material is polysiloxane, and the curing material is at least one of linear aliphatic polyamine, polyamide, and polythiol.

4. The superhydrophobic composite coating with a multi-layer self-similar anchoring structure according to claim 1, characterized in that: The low surface energy material is polydimethylsiloxane; the functional additive material is at least one of octamethylcyclotetrasiloxane, tetramethyltetravinylcyclotetrasiloxane, tetravinylcyclotetrasiloxane, methylvinylcyclotrisiloxane, and methylvinylcyclopentasiloxane.

5. The method for preparing a superhydrophobic composite coating with a multilayer self-similar anchoring structure according to claim 1, characterized in that: A layered coating method is adopted, first applying the superhydrophobic bottom layer solution to the substrate surface and curing it, and then applying the superhydrophobic top layer solution.

6. The method for preparing a superhydrophobic composite coating with a multilayer self-similar anchoring structure according to claim 5, characterized in that: The preparation of the superhydrophobic bottom layer solution includes the following steps: High-strength adhesive material, film-forming material, and plasticizer are dissolved in a solvent, stirred, and ultrasonically dispersed to obtain solution A; highly inert nanoparticles, toughening material, and filler are mixed and dissolved in a solvent, stirred, and ultrasonically dispersed to obtain solution B; solutions A, B, curing material, and particulate rough material are mixed.

7. The method for preparing a superhydrophobic composite coating with a multilayer self-similar anchoring structure according to claim 6, characterized in that: The preparation method of the superhydrophobic surface layer solution includes the following steps: Highly inert nanoparticles were dispersed in anhydrous ethanol to obtain a fumed nano-silica suspension. Then, a low surface energy substance was added and stirred. Finally, functional additives were added, stirred, and ultrasonically dispersed.

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