A super-hydrophobic anti-icing coating with surface microstructure and preparation method and application thereof

Abstract

The present invention provides a super-hydrophobic anti-icing coating with a surface microstructure, and a preparation method and application thereof. It belongs to the technical field of anti-icing of material surfaces. The present invention provides a super-hydrophobic anti-icing coating with a surface microstructure, on the surface of a super-hydrophobic substrate, a nano-scale dot-shaped particle structure composed of a hemisphere and a cylinder with the same diameter combined by a circular section is modified, and the particle diameter is 10-20nm. The super-hydrophobic anti-icing coating can effectively solve the problem of ice formation in rainy and snowy weather, as well as the problem of ice formation of nano-scale droplets in the air under low temperature conditions without rainy and snowy weather, and ensure that the nano-scale droplets will bounce off the surface of the object in the form of a ring-shaped rebound when hitting the surface of the particle. Compared with hitting a flat surface, the contact time is reduced by 40%, which solves various ice formation problems on the surface of the object from the root.

Description

Technical Field

[0001] The present invention relates to the technical field of material surface anti-icing, and more specifically to a super-hydrophobic anti-icing coating with a surface microstructure, and a preparation method and application thereof. Background Art

[0002] Icing refers to the phenomenon of ice gathering on the surface of equipment under specific meteorological conditions. Icing may occur as long as high humidity and low temperature conditions are encountered. The freezing process of droplets on the surface of an object is a liquid-solid phase change process based on heat and mass transfer, which is specifically manifested in the supercooling of droplets on the surface and the nucleation and growth of ice crystals. Compared with the deposited droplets on the surface of an object, more ice crystal nucleation points will be generated after the droplets hit the surface of the object, making it easier for the impacting droplets to freeze on the surface.

[0003] There are two ways to deal with icing. One is to remove the ice after it forms; the other is to directly prevent the formation of ice, that is, de-icing and anti-icing. Any mechanical means to break the ice from the surface or a periodic working design is a de-icing system. The de-icing system is highly efficient, but it is difficult to predict the impact of icing on the equipment during the non-cycle period. It is a passive working method. Compared with the de-icing system, the anti-icing system is relatively proactive and can monitor and prevent equipment during the non-cycle period. However, the traditional anti-icing system has problems such as high energy consumption, limited anti-icing time, and incomplete anti-icing. On the other hand, it also requires high equipment and material costs. Therefore, seeking new methods that are economical, efficient, and can inhibit icing from the source is an important research direction in the field of anti-icing.

[0004] In recent years, domestic and foreign scholars have carried out a lot of work on the research of anti-icing surface design methods, providing a good reference and guidance for the design of anti-icing systems. With the rapid development of surface anti-icing technology, the application field of anti-icing surfaces is becoming more and more extensive. At present, the most widely used anti-icing methods are liquid anti-icing, electric heating anti-icing, hot air anti-icing, and coating anti-icing. However, there are certain disadvantages in anti-icing effect, stability, durability, energy consumption and application scope. In summary, there are the following points:

[0005] 1. Liquid anti-icing has very high requirements for the liquid used for anti-icing and requires a large amount of liquid. It is also easy to get clogged at low temperatures. Therefore, liquid anti-icing is currently mainly used for equipment with a small area to be protected.

[0006] 2. Due to the high power consumption and insufficient thermal power of electric heating anti-icing, it is currently generally used in areas with strict anti-icing indicators and small anti-icing scale.

[0007] 3. Hot air anti-icing is limited by the equipment itself. Equipment that does not generate hot air during operation or has a very low hot air flow rate cannot use this anti-icing method without adding additional devices.

[0008] 4. The coating has good anti-icing effect and can also be used in large anti-icing areas. However, the technology is not mature enough and the lack of durability is the main problem that needs to be solved urgently.

[0009] Although domestic and foreign scholars have achieved a lot of research results in the field of anti-icing technology, most of the existing technologies are aimed at the research on macro-scale droplet freezing, and there are few studies on the anti-icing of micro-scale droplets. Moreover, most of the prevention and control is the freezing of rain and snow. The research on the freezing problem of small droplets in the air in low temperature environment without rain and snow is even rarer. The diameter of small droplets in the air is generally 10-100nm, and the impact of scale effect makes the related research work more challenging.

[0010] Inspired by the hydrophobicity of lotus leaf surfaces, more and more researchers at home and abroad have begun to pay attention to the application of hydrophobic surfaces in anti-icing fields such as regulating droplet movement, delaying or weakening wall ice formation. The mechanism of the currently commonly used hydrophobic surface anti-icing method is to use hydrophobic surfaces to increase the ice crystal nucleation barrier and prolong the ice crystal nucleation time; or reduce the adhesion of ice crystals to the surface. However, the above methods only increase the freezing time or make ice easier to remove, and do not inhibit ice formation from the source.

[0011] Therefore, how to provide a coating that can fundamentally prevent small droplets in the air from freezing on the surface of objects under low temperature conditions without rain or snow is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0012] In view of this, the present invention provides a super-hydrophobic anti-icing coating with a surface microstructure, a preparation method and an application thereof, which can effectively deal with the icing problem at the microscopic scale, and starting from the root, based on the theory of reducing the contact time between the impacting droplets and the particle surface, effectively deal with the icing problem of small droplets in the air from the root.

[0013] In order to achieve the above object, the present invention adopts the following technical solution:

[0014] A super-hydrophobic anti-icing coating with a surface microstructure is provided. A nanometer-scale dot-shaped particle structure is modified on the surface of a super-hydrophobic substrate. The dot-shaped particle structure is composed of hemispheres and cylinders with the same diameter combined through circular sections, and the diameter is 10-20 nm.

[0015] The beneficial effects of the above operation are: the surface microstructure setting of the hydrophobic anti-icing coating can effectively solve the ice formation in rainy and snowy weather and the freezing of small droplets in the air on the surface of objects in low temperature environment without rainy and snowy weather, and the structure is constructed based on the anti-icing theory of reducing the contact time of droplets impacting the point microstructure surface, which solves various icing problems on the surface of objects from the root.

[0016] Preferably, the spacing between the dot-shaped particle structures is less than 0.5 times the maximum spreading diameter.

[0017] The beneficial effects of the above operation are: ensuring that when the droplet hits the surface of the super-hydrophobic substrate, it will contact the point-like particle structure, and ensuring that the contact time when the droplet hits the particle surface is reduced.

[0018] Another object of the present invention is to provide: application of the above-mentioned super-hydrophobic anti-icing coating in preventing ice from forming on the surface of an object.

[0019] Another object of the present invention is to provide: application of the above-mentioned super-hydrophobic anti-icing coating in preventing nano-scale droplets in the air from freezing on the surface of objects in rainy, snowy and / or low-temperature weather.

[0020] Preferably, the diameter of the nanoscale droplets is 10-100 nm.

[0021] Another object of the present invention is to provide: a method for preparing the above-mentioned super-hydrophobic anti-icing coating, comprising the following steps:

[0022] (1) Constructing an initial simulation system with nanoscale droplets and an anti-icing coating with nanoscale spherical particles on the surface;

[0023] (2) Simulate the impact process of nanodroplets on the surface of spherical particles at different Weber numbers We;

[0024] (3) Changing the diameter of the spherical particles, measuring the ratio of particle diameter to droplet diameter λ, and simulating the impact process under different λ conditions;

[0025] (4) Based on the simulation results under different initial conditions, the We~λ phase diagram was drawn, and the impact results were divided into top rebound, standard rebound, ring deposition, ring rebound and splash rebound according to the rebound mode of the droplet;

[0026] (5) Changing the particle structure, simulating the impact process of droplets under different Weber numbers We and different λ conditions, and drawing the We~λ phase diagram to eliminate the ring-shaped deposited particle structure as the point-shaped particle structure modified on the surface of the superhydrophobic substrate;

[0027] (6) Simulating the process of nanoscale droplet impacting the point-like particle structure in step (5), analyzing the dynamic behavior at different λ values, and comparing the contact time with the droplet impacting a flat surface;

[0028] (7) Analyze the difference in contact time and determine the diameter of the point-like particle structure by the λ value corresponding to the occurrence of the ring rebound; determine the spacing of the point-like particle structure by the maximum spreading diameter when the nano-scale droplet hits the flat surface, so that the spacing between the point-like particles is less than 0.5 times the maximum spreading diameter;

[0029] (8) Based on the results of molecular dynamics simulation and theoretical analysis, a superhydrophobic anti-icing coating with surface microstructure is produced.

[0030] Preferably, when a ring-shaped rebound occurs in step (7), 0.1<λ<2; the diameter of the corresponding point-shaped particle structure is 10-20 nm.

[0031] The beneficial effect of the above operation is that the diameter setting of the point-like particle structure can effectively deal with 10-100nm nano-sized droplets in the air, so that when they hit the point-like particle structure, they can bounce off the particle surface in a ring-shaped rebound mode, reducing the contact time and preventing ice from the source.

[0032] Another object of the present invention is to provide application of the above preparation method in preparing anti-icing coating.

[0033] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention provides a super-hydrophobic anti-icing coating with a surface microstructure. A nanometer-scale dot-shaped particle structure is modified on the surface of a super-hydrophobic substrate. The dot-shaped particle structure is composed of a hemisphere and a cylinder with the same diameter combined through a circular section, and the diameter of the dot-shaped particle structure is 10-20nm. The super-hydrophobic anti-icing coating can effectively deal with the icing problem caused by nanometer-scale droplets in the air hitting the surface of an object in a low-temperature environment without rain or snow. It ensures that the nanometer-scale droplets will bounce off the surface of the object in the form of a ring rebound when hitting the particle surface. Compared with hitting a flat surface, the contact time is reduced by 40%, thereby solving various icing problems on the surface of the object from the root. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0036] Figure 1 The super-hydrophobic anti-icing coating and surface microstructure of the present invention, wherein D s is the diameter of the point-like particle structure;

[0037] Figure 2 The initial simulation system constructed in Example 2, D s is the particle diameter, D is the droplet diameter, and λ is the ratio of particle to droplet diameter;

[0038] Figure 3 : five rebound modes corresponding to Example 2 are illustrated;

[0039] Figure 4 is: We-λ phase diagram of all simulation results before particle structure changes;

[0040] Figure 5 is: We-λ phase diagram of all simulation results after particle structure changes;

[0041] Figure 6 Snapshots of the dynamic spreading process and contact time comparison of a droplet impacting a flat surface and a particle surface; (a) flat surface; (b) particle surface;

[0042] Figure 7 : A comparison of the contact time when a droplet hits a flat surface and a particle surface with different λ values;

[0043] Figure 8 : Schematic diagram of the crushing rebound when the λ value is 2;

[0044] Fig. 9 : Surface effect diagram of super hydrophobic anti-icing coating with surface microstructure based on molecular dynamics simulation analysis results, where d is the particle distance. DETAILED DESCRIPTION

[0045] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0046] Example 1

[0047] A super-hydrophobic anti-icing coating with a surface microstructure, wherein a nanometer-scale dot-shaped particle structure is modified on the surface of a super-hydrophobic substrate, wherein the dot-shaped particle structure is composed of a hemisphere and a cylinder with the same diameter combined through a circular section, and the diameter is 10-20nm, and the spacing between the dot-shaped particle structures is less than 0.5 times the maximum spreading diameter; Figure 1 As shown, Figure 1 Ds corresponds to the diameter of the point-like particles.

[0048] Example 2

[0049] A method for preparing a super-hydrophobic anti-icing coating with a surface microstructure comprises the following steps:

[0050] (1) Using LAMMPS software, an initial simulation system was constructed with nanoscale droplets and an anti-icing coating with nanoscale spherical particles on the surface. Figure 2The initial simulation system of a nanodroplet impacting a spherical particle surface is demonstrated, where the simulated droplet diameter is 12nm, the particle diameter is 1.2-2.4nm, and the box size is 60×60×40nm 3 ;

[0051] (2) Simulate the impact of nanodroplets on the surface of spherical particles at different Weber numbers We and analyze their rebound patterns ( Figure 3 );

[0052] (3) Changing the diameter of the spherical particles, simulating the impact process under different λ (particle diameter / droplet diameter), and analyzing the influence of different λ conditions on the rebound results;

[0053] (4) Based on the simulation results under different initial conditions, the We~λ phase diagram was drawn, and the impact results were divided into top rebound, standard rebound, ring deposition, ring rebound and splash rebound according to the droplet rebound mode. Figure 4 );

[0054] (5) Change the particle structure, simulate the impact process of droplets under different Weber numbers We and different λ conditions, and draw the We~λ phase diagram ( Figure 5 ), to eliminate the ring-shaped deposited particle structure as the point-shaped particle structure modified on the surface of the super-hydrophobic substrate ( Figure 1 ) to achieve the rebound of droplets under full Weber number and full λ conditions;

[0055] (6) Simulate the process of nanoscale droplet impacting the point-like particle structure in step (5), analyze the dynamic behavior under different λ values, and compare the contact time ( Figure 6 );

[0056] (7) Analyze the difference in contact time and determine the diameter of the point-like particle structure by using the λ value corresponding to the ring rebound. Figure 7 and Figure 8 ); the spacing of the point-like particle structure is determined by the maximum spreading diameter when the nano-scale droplet hits the flat surface, so that the spacing of the point-like particles is less than 0.5 times the maximum spreading diameter;

[0057] (8) Based on the results of molecular dynamics simulation and theoretical analysis, a super-hydrophobic anti-icing coating with surface microstructure was prepared ( Fig. 9 ).

[0058] Result analysis:

[0059] Figure 3The classification snapshots of droplets impacting the surface of spherical particles at different Weber numbers are shown, including (a) top rebound when We = 16.3, (b) standard rebound when We = 29.1, (c) ring deposition when We = 65.3, (d) ring rebound when We = 116.1, and (e) splash rebound when We = 181.3. The contact time of top rebound and standard rebound does not change significantly when the droplet hits a flat surface. Ring deposition will not cause the droplet to rebound from the surface of the particle, but will deposit on the solid surface; the two rebound modes of ring rebound and splash rebound are the key discoveries in reducing the contact time in the present invention, and the reduction rate of the contact time is as high as more than 40%. In this state, the freezing time of the droplet can be effectively reduced, thereby effectively inhibiting the freezing of nanodroplets on the solid surface or reducing the extreme freezing temperature of the solid surface. However, after the splash rebound, the droplet splits into multiple sub-droplets, and it is impossible to control all the sub-droplets to complete the rebound, so the anti-icing effect is not as good as the ring rebound.

[0060] Depend on Figure 4 and Figure 5 It can be seen that the ring-shaped deposition area is obvious in the We-λ phase diagram before changing the particle structure. This phenomenon will seriously increase the probability of droplets freezing on the solid surface. For this reason, we redesigned the structure of the nanoparticles and changed the lower hemisphere of the particles into a cylinder, which prevented some water molecules from depositing at the bottom of the particles so that the droplets can still rebound from the solid surface at low Weber numbers or large particle diameters. This design effectively avoids the occurrence of ring-shaped deposition and transforms it into top rebound and standard rebound, realizing the rebound of droplets under the conditions of full Weber coefficient and full diameter ratio.

[0061] Next, we analyzed the reasons why the ring rebound reduces the contact time, such as Figure 6 As shown in the figure, we used the same Weber number to collide with a flat surface and a point-shaped particle surface, and compared their rebound processes. We observed that the droplet would undergo a retraction process when it hits a flat surface, and the retraction process time is significantly longer than the spreading process. When the droplet hits the particle surface, the diameter rebounds in a ring shape without undergoing a retraction process. This is why the contact time of the ring rebound is greatly reduced. This is because the particle pierces the center of the droplet when the droplet spreads to its maximum diameter, causing the inner contact line of the ring droplet to quickly diffuse outward and approach the outer contact line. The surface energy is quickly converted into upward kinetic energy, causing the droplet to bounce in a ring shape on the solid surface, resulting in a significant reduction in the contact time.

[0062] Figure 7The comparison of contact time when a droplet hits a flat surface and a particle surface with different λ values ​​is shown. As the Weber number increases, the contact time of the flat surface reaches a limit of about 120ps. When λ=0.1, the limit of the contact time is about 130ps. This is because the particle diameter in this case is small, and the center is not punctured when the droplet hits the maximum spread, and a ring-shaped droplet cannot be formed, so the contact time does not decrease. When λ=0.2 and the Weber number is close to 75, a ring-shaped rebound occurs, and the contact time is greatly reduced and enters the second limit of nearly 80ps, a decrease of more than 40%. The emergence of this phenomenon greatly reduces the probability of droplet freezing. As λ continues to increase, this phenomenon becomes more obvious. When λ≥2, droplet breakage will occur, and some small droplets will continue to stay on the surface. At this time, the contact time can be understood as infinite ( Figure 8 ).

[0063] Finally, it is determined that when λ(λ=D s / D) is greater than 0.1 and less than 2, the droplet will bounce off the contact surface in the form of a ring. The diameter (D) of the small droplets in the air is between 10-100nm. In order to achieve the full range of small droplet rebound, the diameter (D) of the point-like particle structure is determined. s ) is 10-20nm, and the anti-icing effect can be adjusted according to the air humidity of the environment in which the equipment is located, that is, when the humidity is low, a particle diameter closer to 10nm is selected, and when the humidity is high, a particle diameter closer to 20nm is selected.

[0064] Fig. 9 , the scaling relationship of the maximum spreading diameter of a droplet impacting a solid surface fitted by molecular dynamics simulation results βmax (maximum spreading factor) ~ We 1 / 2 Re 1 / 5 , Weber number (We=ρD0V0 2 / γ), Reynolds number (Re=ρD0V0 / μ), we can predict the maximum spreading diameter of the droplet when it hits the flat surface. In order to ensure that the droplet will contact the particle when it hits the particle surface, we must ensure that the particle spacing d<0.5D max , where d is the distance between particles, D is the droplet diameter, and D max The maximum spreading diameter of the droplets. This ensures that the contact time of the droplets will be reduced to varying degrees when they hit the particle surface.

[0065] Scaling relation of the maximum spreading diameter of nano-sized droplets βmax~We 1 / 2 Re 1 / 5 , the applicant has verified the scaling relationship in the previously applied patent 202310715553.4, the specific contents are as follows:

[0066] The impact of a droplet on a solid surface is one of the most studied phenomena in interface science. Different dynamic processes occur after a droplet impacts a solid surface, mainly manifested as spreading, retraction, deposition, splashing, and even rebounding on superhydrophobic surfaces. All of these remarkable phenomena are due to several competitive forces involved in the impact process, including inertial, capillary, and viscous forces. In addition, the physical properties of the impacting droplet (density, viscosity, surface tension, etc.) together with the competitive forces determine the various outcomes of the impacting droplet.

[0067] In order to simplify the collision situation studied, several dimensionless parameters are proposed to characterize the relationship between competitiveness and physical performance. These dimensionless parameters include the Weber number (We = ρD0V0 2 / γ) and Reynolds number (Re=ρD0V0 / μ). The physical meaning of We is the ratio of inertial force to capillary force, and Re represents the ratio of inertial force to viscous force. Among them, ρ, γ, and μ are the density, surface tension, and viscosity of the impact droplet, respectively; V0 and D0 are the impact velocity and diameter of the droplet, respectively. Through molecular dynamics simulation, the dynamic characteristics of nanodroplets impacting point-like particles on solid surfaces are studied in a large Weber number range. The minimum contact time of the nanodroplet system is mainly studied.

[0068] During the simulation, it was found that the normalized spreading factor is insensitive to the intrinsic wettability at high We, which indicates that the maximum spreading factor βmax can be theoretically predicted by the scaling law. First, we tried to use the well-known βmax~We 1 / 4 We can test whether this scaling law on the macroscopic scale also applies to our microscopic system by using the scaling relation of . To this end, we plot βmax as a function of We 1 / 4 (16.3 to 181.3). The results show that the theoretical model underestimates βmax, especially in the high We range. At the macroscale, the initial kinetic energy of the impacting droplet is not only converted into surface energy stored when the droplet is deformed, but also forms a vortex motion at the edge of the droplet to store part of the energy in the form of internal kinetic energy. At the nanoscale, the velocity gradient exists in the entire impact droplet, and the velocity boundary layer disappears. This indicates that violent internal disturbances may destroy the vortex motion inside the droplet at the macroscale, thereby reducing energy consumption. Based on the law of conservation of energy, the impact kinetic energy is completely converted into surface energy, and γ is obtained. lv D 2 ~V 2 , so the maximum spreading factor can be derived as βmax~We 1 / 2 Due to the non-negligible scale effect, the increasing viscosity at the nanoscale is also an important factor in the current system, which destroys the kinetic energy in the form of viscous dissipation, with a scale of Re 1 / 5 Therefore, we assume that βmax should follow We 1 / 2 and Re 1 / 5Combination rules to obtain βmax~We 1 / 2 Re 1 / 5 Then we plotted the data of βmax on the solid surface versus We 1 / 2 Re 1 / 5 (16.3 < We < 181.3), indicating that the rule of βmax~We 1 / 2 Re 1 / 5 is in excellent agreement with the molecular dynamics simulation data in the We range from 16.3 to 181.3. Therefore, we use this rule to predict the maximum spreading diameter of a nano-droplet impacting a flat surface.

[0069] In summary, the technical solution of the present invention, from a brand-new perspective, based on the molecular dynamics simulation results of nano-droplets, through the analysis and discussion of the simulation results of nano-droplets impacting a super-hydrophobic surface modified with a dot-like particle structure, reveals the mechanism of reducing the droplet impact contact time on the dot-like micro-structure surface, and proposes an anti-icing technology theory based on reducing the droplet impact contact time on the dot-like micro-structure surface. It explains the mechanism of the nano-micro-structure surface for reducing the droplet impact contact time and thus promoting the droplet rebound. With the idea of reducing the droplet impact contact time and promoting the droplet rebound as the anti-icing approach, and taking the method of reducing the droplet impact contact time to be lower than the droplet nucleation re-illumination time, combined with the simulation data and research results, a design idea for an efficient anti-icing coating is proposed, and its effect is verified by molecular dynamics simulation. Furthermore, a brand-new anti-icing technology based on surface micro-structure design is proposed, and it provides theoretical support and a brand-new design idea for designing a surface micro-structure more suitable for anti-icing technology.

[0070] The various embodiments in the specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0071] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a super-hydrophobic anti-icing coating, characterized in that: The steps include: (1) Construct an initial simulation system using nano-sized droplets and an anti-icing coating with nano-sized spherical particles on the surface; (2) Simulate the impact of nanodroplets on the surface of spherical particles at different Weber numbers We; (3) Changing the diameter of the spherical particles, measuring the ratio of particle diameter to droplet diameter λ, and simulating the impact process under different λ conditions; (4) Based on the simulation results under different initial conditions, the We~λ phase diagram was drawn, and the impact results were divided into top rebound, standard rebound, ring deposition, ring rebound and splash rebound according to the rebound mode of the droplet; (5) Changing the particle structure, simulating the impact process of droplets under different Weber numbers We and different λ conditions, and drawing the We~λ phase diagram to eliminate the ring-shaped deposited particle structure as the point-shaped particle structure modified on the surface of the superhydrophobic substrate; (6) Simulate the process of nanoscale droplet impacting the point-like particle structure in step (5), analyze the dynamic behavior under different λ values, and compare the contact time with the droplet impacting the flat surface; (7) Analyze the difference in contact time and determine the diameter of the point-like particle structure based on the λ value corresponding to the occurrence of a ring-like rebound; determine the spacing of the point-like particle structure based on the maximum spreading diameter when the nano-scale droplet hits the flat surface, so that the spacing between the point-like particles is less than 0.5 times the maximum spreading diameter; (8) Based on the results of molecular dynamics simulation and theoretical analysis, a super-hydrophobic anti-icing coating with surface microstructure is prepared; The structure of the super-hydrophobic anti-icing coating is as follows: a nano-scale dot-shaped particle structure is modified on the surface of a super-hydrophobic substrate, wherein the dot-shaped particle structure is composed of hemispheres and cylinders with the same diameter combined through circular sections, and the diameter is 10-20 nm.

2. The preparation method according to claim 1, characterized in that: When a ring rebound occurs in step (7), 0.1<λ<2.

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