A super-hydrophobic surface with hierarchical re-entrant-honeycomb coupling structure and its preparation method and application

Abstract

The application relates to a super-hydrophobic surface with a hierarchical fold-back-honeycomb coupling structure and a preparation method and application thereof, the structure of the super-hydrophobic surface comprises a regular hexagonal honeycomb frame structure and a fold-back structure connected with the vertexes of the regular hexagonal honeycomb frame structure; the structure of the fold-back structure comprises a cylinder and a circular chamfered triangular prism connected with the surface of the cylinder. The hierarchical fold-back-honeycomb coupling structure can present excellent super-hydrophobic characteristics; the structure can achieve a physical antibacterial and antifouling function by maximally reducing the actual contact area between liquid drops, microorganisms and the surface. The construction strategy can provide a new design path for the super-hydrophobic surface with antibioadhesion in a marine environment, realizes efficient antifouling, guarantees long-term functional reliability of the surface, and prolongs the service life of marine facilities.

Description

Technical Field

[0001] This invention relates to the field of biomimetic superhydrophobic micro / nano structure antibacterial technology, and in particular to a superhydrophobic surface with a hierarchical fold-back-honeycomb coupling structure and its preparation method. Background Technology

[0002] In today's marine environment, the adhesion of microorganisms such as bacteria and fungi not only seriously affects the normal operation of marine facilities such as buoys and sensing equipment, but also increases navigation drag. Solving marine biofouling has become a major international challenge. Superhydrophobic surfaces have attracted widespread attention from academia and industry due to their enormous application potential in self-cleaning, anti-icing, drag reduction, oil-water separation, microfluidic control, and biofouling prevention. Their realization essentially relies on two core elements: low surface energy chemical modification of the material surface and patterned micron / nanoscale rough structures. While chemically active substances can effectively control microbial contamination, they also cause irreversible water pollution problems.

[0003] Current biomimetic superhydrophobic surface structure design strategies mainly include the integrated design of micro / nano morphologies, reasonable ranges of low surface energy, and responsive components. Common microstructure designs mainly include needle-like, porous, mesh-like, and simple composite morphologies. Single-scale micropillar / microneedle arrays are the most classic and widely studied model, composed of regularly arranged cylindrical, square, or conical protrusions. This model is simple and easy to fabricate precisely using techniques such as photolithography and etching, but it suffers from extremely poor mechanical stability. A typical example of multi-level composite structures is that by adjusting the micro / nano structure of the substrate surface, liquid adhesion can be reduced. However, due to the randomness of the surface structure, it is difficult to quantitatively assess surface wettability and free energy. Particles are only bound by weak physical adsorption or a small amount of binder, making them extremely prone to large-scale detachment under mechanical action.

[0004] Faced with the challenge of resisting the infiltration and adhesion of droplets and microorganisms of different sizes, while chemically active substances can effectively control microbial contamination, bactericides such as... , Surfactants may also cause irreversible water pollution problems. The anti-adhesion properties of superhydrophobic surfaces show unique environmental advantages in combating marine microbial pollution. However, it is difficult to achieve long-lasting antibacterial properties on the surface by chemical modification alone. Moreover, existing surface design strategies usually only involve the adhesion of pollutants and their derivatives at a single scale, with weak interfacial bonding, which is not conducive to the overall performance of composite materials.

[0005] Therefore, there is an urgent need to design a superhydrophobic surface and optimize its structure, which is expected to achieve a mechanical sterilization strategy without inducing antibiotic resistance. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a superhydrophobic surface with a hierarchical foldback-honeycomb coupling structure, its preparation method, and its application. The hierarchical foldback-honeycomb coupling structure constructed by this invention exhibits stable superhydrophobic functionality. Simultaneously, by utilizing the unique "inverted" geometry of the foldback structure, an energy barrier is physically constructed to prevent the liquid-gas interface from shifting downwards. Even under high external pressure, it can effectively lock the air cushion and maintain a stable Cassie state.

[0007] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a superhydrophobic surface with a hierarchical fold-back-honeycomb coupling structure, wherein the structure of the superhydrophobic surface includes a regular hexagonal honeycomb frame structure and a fold-back structure with vertex connections; The structure of the folding structure includes a cylinder and a rounded-beveled triangular prism connected to its surface.

[0008] The primary honeycomb structure base frame and the secondary folded protrusions constructed in this invention are integrated into a single structure. The honeycomb structure is arranged in a close-packed hexagonal plane, and the secondary folded structure is a mushroom-shaped structure composed of cylinders and rounded-corner triangular prisms. This folded structure exhibits superhydrophobicity, while also having an extremely low roll-off angle and anti-adhesion properties, thus resisting the adhesion of droplets and microorganisms. Through the encapsulation and anti-permeation process of droplets and bacteria by the honeycomb structure and folded structure, a physical antibacterial function is achieved.

[0009] Preferably, the formula for determining the hydrophobicity of the superhydrophobic surface is: ; in, θ critical The critical intrinsic contact angle, a The length of the base side of the chamfered triangular prism with a folded-back structure. D The distance between the outer walls of the honeycomb structure is the edge distance. d This represents the distance between the inner walls and the edges of the honeycomb frame. k It is a dimensionless proportionality coefficient. h 1 represents the height of the honeycomb frame. h 2 represents the height of the folded-back cylinder. h 3 represents the height of the chamfered triangular prism with a folded-back structure. d c The diameter of the base of the folded-back cylindrical structure. k The chamfering factor is the ratio of the effective side length of the chamfered triangular prism to the original side length. when θ critical If the angle is ≥150°, the surface is superhydrophobic; When 90° < θ critical If the angle is less than 150°, the surface is hydrophobic. when θ critical If the angle is less than 90°, the surface is hydrophilic.

[0010] The θ critical ≥150°, for example, it can be 150°, 155°, 160°, 165°, 170°, 175° or 179°. θ critical <150°, for example, it can be 90°, 100°, 110°, 120°, 130°, 140° or 149°. θ critical <90°, for example, can be any one or a combination of at least two of 89°, 80°, 70°, 60°, 50°, 40°, 30°, 20° or 10°.

[0011] In this invention, the design features of the folded honeycomb structure are incorporated into the aforementioned functional relationship to calculate the theoretical value of the normalized free energy of the superhydrophobic surface under different wetting states. The superhydrophobicity is determined by comparing the normalized free energy of the Cassie and Wenzel states, thus achieving controllable design of the superhydrophobic surface. Furthermore, the rounded chamfered folded structure design and the air layer formed by the honeycomb cavity can inhibit the adhesion of microorganisms. The folded structure also exerts a physical bactericidal effect by piercing the bacterial cell membrane. Therefore, the designed superhydrophobic surface enables buoys, sensing devices, and other marine facilities to have green antibacterial and antifouling functions while maintaining superhydrophobicity.

[0012] Preferably, the distance between opposite sides of the outer wall of the regular hexagonal honeycomb frame is 300-500 μm. The 300-500 μm can be, for example, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm.

[0013] Preferably, the distance between opposite sides of the inner wall of the regular hexagonal honeycomb frame is 200-400 μm. This 200-400 μm can be, for example, 200 μm, 250 μm, 300 μm, 350 μm, or 400 μm.

[0014] Preferably, the height of the regular hexagonal honeycomb frame is 100-300 μm. The 100-300 μm can be, for example, 100 μm, 150 μm, 200 μm, 250 μm, or 300 μm.

[0015] The folded-back honeycomb coupling structure of this invention has micron-level structural characteristic parameters. The honeycomb cavity and folded-back angle formed can trap air. When water droplets are immersed, a liquid-gas-solid contact interface can be formed, thereby exhibiting superhydrophobic function. When bacteria, algae, barnacles, or other microorganisms adhere to the surface using water as a medium, the extremely low surface energy of the superhydrophobic surface and the high contact angle of the water droplets make it difficult for microorganisms to stably attach to the surface or "hover" on the air pad of the folded-back structure. This greatly reduces the actual contact area between microorganisms and the solid surface, making it difficult for them to secrete adhesive substances and inhibiting the formation of biofilms.

[0016] Preferably, the height of the cylinder is 80-200 μm. The 80-200 μm can be, for example, 80 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, or 200 μm.

[0017] Preferably, the diameter of the bottom surface of the cylinder is 30-60 μm. The 30-60 μm can be, for example, 30 μm, 40 μm, 50 μm, or 60 μm.

[0018] Preferably, the height of the rounded-bevel triangular prism is 20-50 μm. This 20-50 μm can be, for example, 20 μm, 30 μm, 40 μm, or 50 μm.

[0019] Preferably, the base side length of the rounded chamfered triangular prism is 80-120 μm. The 80-120 μm can be, for example, 80 μm, 90 μm, 100 μm, 110 μm, or 120 μm.

[0020] Preferably, the chamfer factor is 0-1. For example, it can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.6, 0.7, 0.8 or 0.9, etc.

[0021] In this invention, k The "degree of cutting" that affects the chamfer. k The smaller the radius, the shorter the effective side length of the chamfered triangular prism, and the larger the radius of the arc, meaning the chamfer at the vertex of the triangular prism is "deeper" and the arc is smoother. k When =0, the upper plane of the folded structure is the side length of a The area of ​​the incircle of an equilateral triangle; when k When =1, there is no chamfer, and the upper plane of the folded structure is the side length of... a The area of ​​an equilateral triangle.

[0022] Preferably, the superhydrophobic surface of the hierarchical foldback-honeycomb coupling structure further includes a coating.

[0023] Preferably, the material of the coating includes any one or a combination of two of the following: perfluoroalkyl silanes, perfluoroalkyl phosphonic acids / carboxylic acids, fluoropolymers, or fluorinated siloxanes.

[0024] Preferably, the perfluoroalkylsilanes include any one or a combination of at least two of 1H,1H,2H,2H-perfluorodecyltriethoxysilane, 1H,1H,2H,2H-perfluorododecyltriethoxysilane, or 3-(perfluorohexyl)propyltrimethoxysilane.

[0025] In a second aspect, the present invention provides a method for preparing a superhydrophobic surface with a hierarchical fold-back-honeycomb coupling structure according to the first aspect, the method comprising using 3D printing to prepare the superhydrophobic surface with a hierarchical fold-back-honeycomb coupling structure as described in the first aspect.

[0026] Preferably, the 3D printing material includes a high-temperature liquid resin.

[0027] Preferably, the preparation method further includes the preparation of a coating.

[0028] Preferably, the preparation of the coating includes: immersing a superhydrophobic surface with a hierarchical folded-honeycomb coupling structure in a coating solution, and then drying it.

[0029] Preferably, the solute in the coating solution includes any one or a combination of at least two of the following: perfluoroalkylsilanes, perfluoroalkylphosphonic acids / carboxylic acids, fluoropolymers, or fluorinated siloxanes.

[0030] Preferably, the perfluoroalkylsilanes include any one or a combination of at least two of 1H,1H,2H,2H-perfluorodecyltriethoxysilane, 1H,1H,2H,2H-perfluorododecyltriethoxysilane, or 3-(perfluorohexyl)propyltrimethoxysilane.

[0031] Preferably, the concentration of the solute in the coating solution is 1%-5%. This 1%-5% can be, for example, 1%, 2%, 3%, 4%, or 5%.

[0032] Preferably, the solvent of the coating solution includes any one of anhydrous ethanol, isopropanol, or toluene.

[0033] Preferably, the soaking time is 4-8 hours. The 4-8 hours can be, for example, 4 hours, 5 hours, 6 hours, 7 hours, or 8 hours.

[0034] Preferably, the drying temperature is 55℃-65℃ and the drying time is 40-50 min. The 55℃-65℃ can be, for example, 55℃, 57℃, 59℃, 61℃, 63℃, or 65℃.

[0035] Thirdly, the present invention provides an application of the method for preparing a superhydrophobic surface with a hierarchical fold-back-honeycomb coupling structure according to the first aspect or the method for preparing a superhydrophobic surface with a hierarchical fold-back-honeycomb coupling structure according to the second aspect in the preparation of marine facilities.

[0036] Compared with the prior art, the present invention has at least the following beneficial effects: 1. This invention is a design method for superhydrophobic surfaces using a hierarchical folded-honeycomb coupling structure. The microstructure that achieves superhydrophobicity is an integrated hierarchical array composed of a honeycomb frame and folded protrusions. Based on the geometric features of this structure, a transient function expression equation is established using the Gibbs free energy and the Cassie-Baxter wetting model as a judgment formula, revealing the numerical relationship between structural parameters and droplet contact angle. By adjusting the characteristic parameters, the precise design of superhydrophobicity can be achieved.

[0037] 2. The surface designed in this invention not only achieves superhydrophobicity, but also significantly improves compressive stability by locking the air pad through a folded structure, and imparts excellent mechanical durability and impact resistance to the surface by dispersing stress with the help of a rigid honeycomb frame, thus providing a non-chemical release, environmentally friendly, long-lasting physical antibacterial solution for marine antifouling. Attached Figure Description

[0038] Figure 1 This is a diagram of a superhydrophobic surface structure with a hierarchical foldback-honeycomb coupling structure.

[0039] Figure 2 The dimensions of key structural parameters and cross-sectional diagrams are provided.

[0040] Figure 3 The diagrams show three wetting states of a graded foldback-cell coupling structure. Figure a shows the Cassie state, figure b shows the Cassie wetting state, and figure c shows the Wenzel state.

[0041] Figure 4 This is a scanning electron microscope (SEM) image of a sample printed using projection micro-stereolithography (PμSL) 3D printing technology.

[0042] Figure 5 The figures show the static contact angle of the droplets measured on the sample after microstructure parameter optimization. Figure a is the surface characterization of the smooth resin, Figure b is the surface characterization of the microstructure with only the folded-back structure, and Figure c is the surface characterization of the superhydrophobic surface of the folded-back honeycomb coupling structure.

[0043] Figure 6 This is a design flowchart for a superhydrophobic surface with a hierarchical foldback-honeycomb coupling structure.

[0044] Figure 7The result diagram is used to verify the antifouling and anticorrosion properties.

[0045] in, a The length of the base side of the chamfered triangular prism with a folded-back structure. D The distance between the outer walls of the honeycomb structure is the edge distance. d This represents the distance between the inner walls and the edges of the honeycomb frame. h 1 represents the height of the honeycomb frame. h 2 represents the height of the folded-back cylinder. h 3 represents the height of the chamfered triangular prism with a folded-back structure. d c The diameter of the base of the folded-back cylinder. Detailed Implementation

[0046] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0047] Example 1 This embodiment involves three-dimensional modeling and structural design of a superhydrophobic surface. Using 3D modeling software (SketchUp), construct as follows: Figure 1 The hierarchical foldback-honeycomb coupling structure model shown depicts a superhydrophobic functional surface with a micron-scale structure designed as a rigid honeycomb framework densely packed with regular hexagonal planes. Mushroom-shaped micron-foldback protrusions are integrally constructed at each vertex of this framework, thus forming a hierarchical composite structure with secondary topological features. The design also includes... Figure 2 The key structural parameters and cross-sectional diagrams are shown.

[0048] Primary honeycomb structure: A densely tessellated hexagonal honeycomb grid is established as the base framework. The distance between opposite sides of the outer wall of the hexagon (diameter of the inscribed circle) is set to... D The distance between opposite sides of the honeycomb inner wall (diameter of the inscribed circle) d The height of the honeycomb structure is h 1.

[0049] Secondary foldback structure: At the vertex of each regular hexagon, a mushroom-shaped foldback structure is constructed. This foldback structure consists of a cylindrical root and a rounded-beveled triangular prism with a flat top. The diameter of the root is set to... d c The height is h 2. The side length of the triangular prism is... a The three vertices of the triangular prism are rounded, with a chamfer factor of . k The height is h 3, and h 3 should be the total height of the entire turnaround structure ( h 2+h 3) One-fifth of that.

[0050] Key Dimension Settings: Set the height of the primary honeycomb structure h Total height of Level 1 and Level 2 turnaround structures ( h 2+ h 3) It is 150 μm. Therefore, h 2 = 120 μm, h 3 = 30 μm.

[0051] Example 2 This embodiment performs parameter optimization and free energy analysis of the superhydrophobic surface. Based on the classical theoretical model of surface wettability and the thermodynamic analysis method of Gibbs free energy, the geometric model parameters established in Example 1 were used to establish transient functional equations relating free energy, free energy barrier, and apparent contact angle through theoretical calculation and analysis. By deriving the normalized free energy equation, the quantitative numerical relationship between structural characteristic parameters and the superhydrophobic properties characterizing the droplet's apparent contact angle was clarified. The geometric characteristic parameters include: the side-to-side distance of the honeycomb cells. d and D Bottom diameter of the foldback structure d c , top side length of the foldback a and structural height ratio λ = h 1 / ( h 2+ h 3). This invention can improve the accuracy of the model by systematically classifying the infiltration state into three types based on the different penetration depths of the hierarchical structure, such as... Figure 3 As shown, these represent the composite state (Cassie state), the transition state (Cassie-Impregnating state), and the non-composite state (Wenzel state).

[0052] The classical theoretical model of surface wettability was first proposed by Thomas Young in 1805, with the most typical expression being Young's equation for the static contact angle: ; In the formula, For solid-gas interfacial tension, For solid-liquid interfacial tension, For liquid-gas interfacial tension, θ Y This represents the contact angle in the equilibrium state in Young's model. Since the solid surface has no physical roughness structure, this value is determined only by the chemical composition of the solid surface and the external environment, and is also called the intrinsic contact angle.

[0053] The change in the system's free energy is as follows: ; Based on the second law of thermodynamics, this equation satisfies When this happens, the solid surface will spontaneously undergo a wetting process, that is, when... ,0°< θ Y When <90°, it is defined as a hydrophilic surface; when 90° < θ Y When the angle is less than 180°, it is defined as a hydrophobic surface. To overcome the limitations of the Young's equation for ideally smooth surfaces, Wenzel first proposed the relationship between roughness and wettability in 1936. Wenzel's theory describes the non-composite state when the actual contact area between a droplet and a solid surface is greater than the apparent contact area. The Wenzel equation is: ; in, θ w The apparent contact angle in the Wenzel state; r Defined as the roughness factor, it is a dimensionless parameter introduced by Wenzel to describe the morphology of solid surfaces. It is defined as the ratio of the actual surface area to the projected area. Typically, r ≥1. The Wenzel equation shows that when Then, The presence of a rough structure promotes the hydrophilicity of the solid surface; conversely, Then, The presence of rough structures promotes the hydrophobicity of solid surfaces. Therefore, the original wetting properties of the solid surface are amplified in the Wenzel model. The Wenzel equation cannot be applied to calculate the free energy barrier that droplets need to overcome in the wetting behavior of chemically heterogeneous or porous surfaces. If the additional vibrational energy provided by the external environment cannot offset the required free energy barrier, the Wenzel model will no longer be applicable to droplets in a metastable wetting state. To overcome the limitations of heterogeneous solid surfaces, in 1944, Cassie and Baxter proposed a new model to explain the concept of a "composite surface" between a solid surface with microscopic roughness and a droplet. The droplet can trap gas inside the grooves of the microstructure. For the solid-liquid-gas three-phase wetting model, the correlation expression between the apparent contact angle and the solid area fraction in the Cassie state is as follows: ; In the formula, Solid phase fraction (area fraction of solid protrusions and rough structures) f s ≤1), The intrinsic contact angle of the material.

[0054] Depend on Figure 1 and Figure 2 As can be seen, the superhydrophobic surface in this design is a periodic arrangement structure. In the honeycomb grid, each hexagon has 6 vertices, and each vertex is shared by 3 hexagons. Therefore, each hexagon has 2 vertices, that is, each honeycomb cell has 2 folded structures. Figure 1 Area of ​​repeated independent unit structures A cell for: ; Surface solid fraction f 1. Expression: ; ; ; ; ; in, a The side length of the rounded chamfered triangular prism with a folded-back structure. D This refers to the edge distance of the outer wall of the honeycomb structure. d This is the distance between the edges of the inner wall of the honeycomb. A 1 represents the projected area of ​​the honeycomb structure within a single unit. f 1 represents the surface solid fraction of the primary honeycomb structure. A 2 represents the projected area of ​​the secondary foldback structure within a single unit. k The chamfer factor is... f 2 represents the surface solid fraction of the secondary foldback structure. f s The solid fraction on the surface of the hierarchical foldback-honeycomb coupled structure.

[0055] ; ; ; ; ; in, h 1 represents the height of the honeycomb structure. h 2 represents the height of the cylindrical root of the folded-back structure. h 3 represents the height of the chamfered triangular prism with a folded-back structure. d c The diameter at the root of the cylinder in the folded-back structure. S 1 represents the outer surface area of ​​the primary honeycomb structure. r1 represents the surface roughness of the first-order honeycomb structure. P top The top perimeter of the secondary foldback structure. S 2 represents the outer surface area of ​​the secondary foldback structure. r 2 represents the surface roughness of the secondary foldback structure. r The surface roughness is for the graded foldback-honeycomb coupling structure.

[0056] Based on the Wenzel and Cassie-Baxter models, an expression for the contact angle balancing the two states can be derived. This expression describes the critical condition for a droplet to transition from the Cassie-Baxter state to the Wenzel state on a rough surface. When the intrinsic contact angle of the material... θ > θ critical When the intrinsic contact angle of the material is high, the droplet tends to remain in the Cassie-Baxter state (superhydrophobic). θ < θ critical When, the droplet tends to transform into the Wenzel state (fully wetted), when θ = θ critical At this point, the two states may coexist or transform into each other. The critical intrinsic contact angle value in equilibrium state is: ; ; In the formula, θ critical This is the critical intrinsic contact angle.

[0057] In the designed superhydrophobic surface, the diameter of the inscribed circle of the outer wall of the primary honeycomb structure is... D for μm, diameter of the inscribed circle of the inner wall d for μm, side length of the top surface of a rounded-beveled triangular prism with a secondary folded-back structure a The radius is 100 μm. The three vertices of the triangular prism are rounded. The rounding factor is... k The diameter of the cylindrical structure is 0.79. d c For a It is the incircle of a triangle with equilateral sides. h 1. h 2. h The heights of the three are 150 μm, 120 μm, and 30 μm, respectively.

[0058] Subsequently, the designed structural geometric parameters were substituted into the above numerical relationship to calculate the contact angle of the water droplet on the theoretical model. By systematically adjusting key parameters and optimizing the structural configuration, the theoretical value of the water droplet contact angle was calculated to be 150.2° (the judgment is greater than 150°), thereby ensuring that the surface meets the judgment criteria for superhydrophobic function, and simultaneously achieving the pressure stability formed by the air pad locked by the folded part and the mechanical durability provided by the honeycomb frame.

[0059] Example 3 This embodiment explores the hydrophobicity of superhydrophobic surfaces. (1) Preparation of superhydrophobic surfaces with hierarchical foldback-honeycomb coupling structure Using the hierarchical foldback-honeycomb coupled superhydrophobic surface constructed in Example 2, light yellow HTL resin with a curing band of 405 nm was selected as the 3D printing matrix material. Based on the Mofang nanoArch S130 high-precision printing system, optical precision of 2 μm and 10 μm was used to intelligently identify feature details and automatically switch between interlayer and intralayer precision to complete the processing of the hierarchical foldback-honeycomb coupled superhydrophobic surface composite structure.

[0060] A 2% anhydrous ethanol solution of 1H,1H,2H,2H-perfluorodecyltriethoxysilane was prepared. The superhydrophobic sample with the folded-back honeycomb coupling structure was immersed in the prepared solution for 6 h and then dried at 60 °C for 45 min to obtain a fluorinated superhydrophobic surface with the folded-back honeycomb coupling structure.

[0061] (2) Hydrophobicity test To investigate the hydrophobicity of the hierarchical folded-honeycomb coupled superhydrophobic surface prepared in Example 2, wettability characterization tests were performed on the superhydrophobic surface. The contact angle of water droplets on the superhydrophobic surface was measured multiple times to obtain the morphology and three-dimensional structure of the superhydrophobic surface.

[0062] The superhydrophobic surface morphology of the hierarchical foldback-honeycomb coupling structure of the photocurable resin material was characterized by scanning electron microscopy (SEM, SU 8600, Carl Zeiss AG, Germany). Figure 4 As shown, the periodic arrangement hierarchical fold-back-honeycomb coupling structure obtained by the photopolymer resin 3D printing method can be clearly seen under scanning electron microscope images at different magnifications.

[0063] The contact angle of the droplets on the superhydrophobic surface was measured using a contact angle meter (SL200KS, Solon Corporation, USA). Figure 5As shown. The specific testing method is as follows: The contact angle of water droplets on the superhydrophobic surface is measured using a contact angle meter. The superhydrophobic sample is placed on the measurement platform, and 2 μL water droplets are dropped onto a smooth resin surface, a microstructure surface with only a folded-back structure, and a superhydrophobic surface with a folded-back-honeycomb coupling structure, respectively. The contact angles obtained are 78.7°, 135°, and 150.2°, respectively, which are no different from the contact angles calculated by the numerical equation.

[0064] The construction process of the above-mentioned hierarchical foldback-honeycomb coupling structure superhydrophobic surface is as follows: Figure 6 As shown, Figure 6 The flowchart illustrates the design and fabrication process of a hierarchical folded-back honeycomb coupled superhydrophobic surface. First, a three-dimensional wetting mechanics model of the superhydrophobic surface is established, i.e., a hierarchical folded-back honeycomb coupled structure is constructed. Based on Gibbs free energy, a theoretical judgment of the transition between the Cassie-Baxter and Wenzel states is established, and the numerical relationship between the geometric characteristics of the folded-back honeycomb coupled structure and the wetting state transition is derived. According to the theoretically preset structural geometric characteristic parameters, the transient free energy is calculated, and it is determined whether the minimum energy requirement is met. The microstructure of the superhydrophobic surface is optimized by adjusting the structural geometric characteristic parameters until the transient free energy meets the minimum energy requirement. Then, the microstructure surface is fabricated by 3D printing using HTL resin with a curing band of 405 nm, and a low surface energy modification fluorination treatment is performed. It is then determined whether the superhydrophobic performance requirements are met. If not, the structural parameters are optimized, ultimately achieving controllable fabrication of the superhydrophobic surface.

[0065] Example 4 This embodiment verifies the antifouling and anticorrosion properties and analyzes the mechanism. To verify the comprehensive antifouling and anticorrosion performance of the superhydrophobic surface prepared in Example 3, contact angle tests were conducted on six typical reagent aqueous solutions with different pH values, viscosity coefficients, and chemical activities. The results showed that the apparent contact angles of all six droplets on the surface were greater than 150°, demonstrating its excellent broad-spectrum antifouling and anticorrosion capabilities. Specific test results for the six solutions are as follows: Figure 7 As shown.

[0066] 1. Sodium chloride aqueous solution (pH 6.5, viscosity 1.05 mPa·s): As a simulated solution for marine environments (3.5% NaCl), its contact angle reaches 152.3°. The mechanism lies in the hierarchical structure locking air cushion forming a "physical barrier," allowing Cl to... - It cannot directly contact the substrate surface, thus avoiding the anodic dissolution process of electrochemical corrosion; at the same time, the low surface energy fluorinated layer (surface energy ≤20mN / m) inhibits the capillary penetration of salt solution.

[0067] 2. Milk (pH 6.6, viscosity 4.0 mPa·s): As a high-protein, viscous liquid, its contact angle reaches 151.7°, verifying its resistance to organic fouling. The key mechanism is that the gravitational potential energy of the droplet is insufficient to overcome the energy barrier at the liquid-gas interface, and protein molecules are difficult to adsorb and cross-link on low surface energy surfaces; at the same time, the extremely low roll-off angle (<8°) makes the droplet easy to roll off, avoiding the deposition of biofilm precursors.

[0068] 3. Anhydrous ferric chloride aqueous solution (pH 1.5, viscosity 1.10 mPa·s): The contact angle with strongly acidic corrosive liquids reaches 150.9°, demonstrating its resistance to acid corrosion. The core mechanism is: the composite structure air cushion allows H... + The contact area with the substrate is reduced to less than 1%, significantly decreasing the corrosion reaction kinetic rate; at the same time, the chemical inertness of the fluorinated layer can resist Fe 3+ The catalytic oxidation effect avoids the degradation of hydrophobicity caused by the increase of surface energy.

[0069] 4. Alizarin Green aqueous solution (pH 9.5, viscosity 1.08 mPa·s): The contact angle of the strongly alkaline dye solution reaches 151.2°. The anti-corrosion mechanism includes: in an alkaline environment, the air pads in the honeycomb cavity can buffer OH... - Erosion of the surface; dye molecules cannot undergo chemical adsorption due to low surface energy, and the high contact angle causes the droplets to form a "spherical encapsulation" state, carrying away trace amounts of contaminants attached to the surface.

[0070] 5. Copper sulfate pentahydrate aqueous solution (pH 4.5, viscosity 1.06 mPa·s): The contact angle of the heavy metal ion corrosion solution reached 150.5°, demonstrating the synergistic effect of chemical corrosion resistance and biofouling prevention. 2+ As a common antibacterial agent, its low adhesion to surfaces indicates that its structure can inhibit the non-specific adsorption of heavy metal ions, avoiding secondary pollution; at the same time, the presence of the liquid-gas interface blocks Cu 2+ The contact pathway with the microbial cell membrane enhances the physical antibacterial effect.

[0071] 6. Carbon nanotube dispersion solution (pH 6.5, viscosity 1.20 mPa·s): The contact angle of the nanoparticle suspension reached 152.0°, verifying its resistance to nanoscale fouling. The high specific surface area of ​​carbon nanotubes makes them easy to aggregate and adsorb on conventional surfaces, while the multi-level roughness of the structure of this invention allows the nanoparticles to be "suspended" on the surface of the air cushion. The solid-phase contact area is less than 5%, which cannot form a stable adsorption layer, demonstrating broad-spectrum antifouling properties against pollutants of different scales.

[0072] The test results for the above six solutions demonstrate that this surface achieves superhydrophobic stability across acidity and viscosity ranges through a synergistic mechanism of air cushion locking via a folded-back structure and a honeycomb structure, combined with low surface energy chemical modification. Its core thermodynamic basis is that the hierarchical structure increases the solid-liquid contact fraction in each solution. f s With an apparent contact angle of ≥150° calculated according to the Cassie equation, it is sufficient to resist the Cassie-Wenzel transformation under external force, thereby achieving long-term anti-fouling and anti-corrosion function.

[0073] In summary, the present invention provides a design and preparation method for a hierarchical folded-honeycomb coupled superhydrophobic surface, which can provide an innovative research and development approach for high-performance superhydrophobic surfaces, and can achieve functions such as self-cleaning, antibacterial and anti-corrosion, thus helping to improve the performance of equipment and materials in related fields in the long term.

[0074] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A superhydrophobic surface with a hierarchical folded-honeycomb coupling structure, characterized in that, The structure of the superhydrophobic surface includes a regular hexagonal honeycomb frame structure and a folded-back structure connecting its vertices; The structure of the folding structure includes a cylinder and a rounded-beveled triangular prism connected to its surface.

2. The superhydrophobic surface with a hierarchical foldback-honeycomb coupling structure according to claim 1, characterized in that, The formula for determining the hydrophobicity of the superhydrophobic surface is as follows: ； in, θ critical The critical intrinsic contact angle, a The length of the base side of the chamfered triangular prism with a folded-back structure. D The distance between the outer walls of the honeycomb structure is the edge distance. d This represents the distance between the inner walls and the edges of the honeycomb frame. h 1 represents the height of the honeycomb frame. h 2 represents the height of the folded-back cylinder. h 3 represents the height of the chamfered triangular prism with a folded-back structure. d c The diameter of the base of the folded-back cylindrical structure. k The chamfering factor is the ratio of the chamfer distance to the side length of the base of the triangular prism. when θ critical If the angle is ≥150°, the surface is superhydrophobic; When 90° < θ critical If the angle is less than 150°, the surface is hydrophobic. when θ critical If the angle is less than 90°, the surface is hydrophilic.

3. The superhydrophobic surface with a hierarchical foldback-honeycomb coupling structure according to claim 1 or 2, characterized in that, The side-to-side distance of the outer wall of the regular hexagonal honeycomb frame is 300-500 μm; Preferably, the distance between opposite sides of the inner wall of the regular hexagonal honeycomb frame is 200-400 μm; Preferably, the height of the regular hexagonal honeycomb frame is 100-300 μm.

4. The superhydrophobic surface with a hierarchical foldback-honeycomb coupling structure according to any one of claims 1-3, characterized in that, The height of the cylinder is 80-200 μm; Preferably, the diameter of the bottom surface of the cylinder is 30-60 μm.

5. The superhydrophobic surface with a hierarchical foldback-honeycomb coupling structure according to any one of claims 1-4, characterized in that, The height of the rounded chamfered triangular prism is 20-50 μm; Preferably, the base side length of the rounded chamfered triangular prism is 80-120 μm; Preferably, the chamfer factor is 0-0.

8.

6. The superhydrophobic surface with a hierarchical foldback-honeycomb coupling structure according to any one of claims 1-5, characterized in that, The superhydrophobic surface of the hierarchical foldback-honeycomb coupling structure also includes a coating. Preferably, the material of the coating includes any one or a combination of at least two of the following: perfluoroalkyl silanes, perfluoroalkyl phosphonic acids / carboxylic acids, fluoropolymers, or fluorinated siloxanes. Preferably, the perfluoroalkylsilanes include any one or a combination of at least two of 1H,1H,2H,2H-perfluorodecyltriethoxysilane, 1H,1H,2H,2H-perfluorododecyltriethoxysilane, or 3-(perfluorohexyl)propyltrimethoxysilane.

7. A method for preparing a superhydrophobic surface with a hierarchical fold-back-honeycomb coupling structure according to any one of claims 1-6, characterized in that, The preparation method includes using 3D printing to prepare a superhydrophobic surface with a hierarchical foldback-honeycomb coupling structure as described in any one of claims 1-6.

8. The method for preparing a superhydrophobic surface with a hierarchical fold-back-honeycomb coupling structure according to claim 7, characterized in that, The 3D printing material includes high-temperature liquid resin.

9. The method for preparing a superhydrophobic surface with a hierarchical fold-back-honeycomb coupling structure according to claim 7 or 8, characterized in that, The preparation method further includes the preparation of a coating; Preferably, the preparation of the coating includes: immersing a superhydrophobic surface with a hierarchical folded-honeycomb coupling structure in a coating solution, and then drying it to obtain the coating. Preferably, the solute in the coating solution includes any one or a combination of at least two of the following: perfluoroalkylsilanes, perfluoroalkylphosphonic acids / carboxylic acids, fluoropolymers, or fluorinated siloxanes. Preferably, the perfluoroalkylsilanes include any one or a combination of at least two of 1H,1H,2H,2H-perfluorodecyltriethoxysilane, 1H,1H,2H,2H-perfluorododecyltriethoxysilane, or 3-(perfluorohexyl)propyltrimethoxysilane. Preferably, the concentration of the solute in the coating solution is 1%-5%; Preferably, the solvent of the coating solution includes any one of anhydrous ethanol, isopropanol, or toluene; Preferably, the soaking time is 4-8 hours; Preferably, the drying temperature is 55℃-65℃ and the drying time is 40-50 min.

10. The application of the superhydrophobic surface with a hierarchical foldback-honeycomb coupling structure according to any one of claims 1-5 or the method for preparing the superhydrophobic surface with a hierarchical foldback-honeycomb coupling structure according to any one of claims 6-9 in the preparation of marine facilities.

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