Micro-nano hot-embossing method of super-hydrophobic material, super-hydrophobic material and application thereof

Abstract

This invention discloses a micro / nano hot-pressing method for superhydrophobic materials, as well as the superhydrophobic materials and their applications, relating to the field of superhydrophobic materials technology. The micro / nano hot-pressing method for superhydrophobic materials of this invention includes: processing a hydrophobic inorganic material onto the surface of a polymer material via hot pressing, thereby forming a micro / nano composite structure on the polymer surface. Compared to existing methods for processing superhydrophobic surfaces using single micro / nano structure molds, this method is more flexible and adaptable, applicable to most non-metallic film and sheet surfaces. The surface micro / nano structure is not solely derived from the mold, but is obtained in a single step through the combined action of a micrometer-scale mold structure and nanometer-scale hydrophobic particles. Micrometer-scale molds are more readily available and have lower processing costs than nanometer-scale molds. Furthermore, due to the short processing time and the availability and low cost of the mold, this method enables highly continuous fabrication.

Description

Technical Field

[0001] This invention relates to the field of superhydrophobic materials technology, and more specifically, to a micro-nano hot embossing method for superhydrophobic materials, as well as superhydrophobic materials and their applications. Background Technology

[0002] The technology for preparing superhydrophobic surfaces is based on the observation and understanding of superhydrophobic phenomena in nature, commonly found on the surfaces of organisms such as lotus leaves and water striders. These surfaces can remain dry when water droplets fall on them because the droplets do not wet the surface but form near-perfect spheres and easily roll off. This phenomenon, known as the "lotus effect," is the foundation of superhydrophobic surface research. In recent years, due to the rapid development of nanomaterials, a wide variety of nanomaterials have emerged based on the synthesis of nanotechnology. Their application prospects are broad, and one of their main uses is as a novel type of superhydrophobic material. More than 60 years of research has been conducted on superhydrophobic materials both domestically and internationally. Research has found that under ideal surface energy conditions, the water contact angle can only reach a minimum of 120°. Based on surface wetting theory, the superhydrophobic properties of solid surfaces depend not only on the low surface energy material of the surface but also on the surface roughness structure. Therefore, the study of superhydrophobic properties must be carried out from the following two aspects: (1) by reducing the surface energy of materials with rough surface structures; (2) by constructing a specific structure on the surface of low surface energy materials.

[0003] Superhydrophobic surfaces have a wide range of applications in production and daily life due to their superior properties. In industrial applications, such as aerospace, wind turbine blades, and ships, these components operate in cold environments and require good wear resistance to resist ice adhesion and abrasion. Wear resistance is a key indicator of a material's surface durability, especially in outdoor applications such as outdoor glass, solar panels, and packaging bags, where materials are frequently exposed to harsh environments and are easily subjected to friction and wear. Although there are many methods for preparing superhydrophobic surfaces, such as the template method (which has poor durability and wear resistance); chemical vapor deposition and electrochemical deposition methods (which may cause air pollution, are difficult to operate, produce uneven surface coatings, and have poor wear resistance); and laser etching and chemical etching methods (which are costly, have limited application range, and have poor strength and wear resistance), most of these methods are expensive, time-consuming, and labor-intensive, making it difficult to control costs and ensure product stability during mass production. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a micro / nano thermoimprinting method for superhydrophobic materials, as well as the superhydrophobic materials and their applications. This invention embeds superhydrophobic materials onto the surface of a polymer through thermoimprinting, combining this with the transfer of micro / nano structures to create a complex superhydrophobic micro / nano structure. The superhydrophobic material is processed onto the surface of a polymer sample via thermoimprinting. Under pressure, hydrophobic particles are partially or mostly embedded into the processed sheet, forming a superhydrophobic micro / nano structure where most of the hydrophobic particles are embedded in the surface. Because the bonding force with the surface increases after embedding, this structure can improve the hydrophobicity of the product while ensuring its weather resistance and wear resistance. Compared to other existing superhydrophobic surface processing methods, this method is simpler, more efficient, and produces more stable results. The products obtained by this method have strong wear resistance and weather resistance, making them more suitable for production applications. They also maintain good hydrophobic properties even under friction and extrusion.

[0005] One of the objectives of this invention is to provide a micro / nano hot embossing method for superhydrophobic materials.

[0006] The micro / nano hot embossing method for superhydrophobic materials of the present invention includes: Hydrophobic inorganic materials are processed onto the surface of polymer materials by hot embossing, forming micro-nano composite structures on the polymer surface.

[0007] In a preferred embodiment of the present invention, the method includes: (1) Hydrophobic particles are dispersed in an organic solvent to prepare a hydrophobic particle dispersion; (2) The hydrophobic particle dispersion is coated onto a micron-structured mold; (3) The micron structure mold is covered on the polymer material to be processed and hot-pressed to form a micro-nano composite structure on the polymer surface, thus obtaining a superhydrophobic material.

[0008] This invention transfers hydrophobic particles to the surface of a mold with micron-sized structures, and then molds a micro / nano composite structure onto a polymer material surface in a single step using a thermoforming process. The micron-sized structure is achieved by thermoforming the micron-sized structure on the mold surface onto the polymer material surface; the nano-structure is formed by transferring nanoparticles coated on the mold to the polymer material surface. This invention achieves highly durable superhydrophobic properties through the combination of "imprinted micron-sized structures + embedded nanoparticles".

[0009] In a preferred embodiment of the present invention: In step (1): The concentration of the hydrophobic particle dispersion is 0.5wt%-10wt%, preferably 3wt%-7wt%, which can balance dispersion stability and hydrophobic effect; and / or, The hydrophobic particles are a mixture of hydrophobic hydrotalcite and hydrophobic silica. Preferably, the weight ratio of the hydrophobic hydrotalcite to the hydrophobic silica is 1:(1-3), more preferably 1:(1-2); and / or, The hydrophobic particles are nanoparticles and / or microparticles. Preferably, the nanoparticles have a particle size range of ≤50 nm, more preferably 20-50 nm, and / or, the microparticles have a particle size range of 10-30 μm, more preferably 10-20 μm. This ensures that the particles can be uniformly dispersed in organic solvents and form effective nanoscale protrusion structures after hot pressing. This, combined with the microstructure fabricated using a microstructure mold, achieves superhydrophobic properties; and / or, For example, hydrophobic particles can be formulated as follows: Formula A: Nano hydrotalcite: Nano silica in a 1:1 ratio; Formula B: Nano-hydrotalcite: Micron-sized silica in a 1:1 ratio; Formula C: Micron-sized hydrotalcite: nano-sized silica in a 1:1 ratio; Formula D: Nano hydrotalcite: micron silica: nano silica in a ratio of 1:1:1; Formula E: Micron-sized hydrotalcite: Micron-sized silica: Nano-sized silica in a ratio of 1:1:1.

[0010] The combination of hydrophobic hydrotalcite and hydrophobic silica used in this invention has the following significant effects: (1) More stable hydrophobic properties: The two types of particles work together. The hydrophobic hydrotalcite has a layered structure and can be used as a dispersion carrier for hydrophobic silica, avoiding the aggregation of silica particles and ensuring that they are evenly distributed on the mold surface and inside the polymer material. This results in a denser and more uniform micro-nano composite hydrophobic structure on the surface of the product, and the water contact angle is stably maintained above 150° (the single silica system is prone to contact angle fluctuations due to aggregation, usually between 140° and 148°).

[0011] (2) Improved wear resistance and durability: The layered structure of hydrophobic hydrotalcite has a certain toughness. When combined with rigid hydrophobic silica, it can enhance the bonding force between hydrophobic particles and polymer material substrate. Compared with a single hydrophobic particle system, the new surface exposed after wear can still maintain a continuous hydrophobic layer. After 50 friction tests, the contact angle can still reach more than 134° (the contact angle of a single silica system usually drops to below 120° after friction).

[0012] (3) Multifunctional integration advantages: Hydrophobic hydrotalcite itself has excellent UV blocking properties. When combined with hydrophobic silica, no additional functional particles are needed to enable the product to simultaneously achieve superhydrophobicity, UV aging resistance and high barrier (water vapor, oxygen) functions. In contrast, single hydrophobic materials can usually only achieve hydrophobic functions. If UV resistance or barrier properties are required, other functional materials need to be compounded, which makes the process more complicated and the cost higher.

[0013] (4) Wider compatibility: It has good compatibility with various thermoplastic polymers (PP / PE / PPS / PAR, etc.) and can be uniformly dispersed in the polymer material matrix through melt blending. However, single hydrophobic particles (such as hydrophobic titanium dioxide) are prone to uneven dispersion and poor compatibility in some polymers (such as PPS), which affects the overall performance of the product.

[0014] The organic solvent is a low-boiling-point organic solvent. Preferably, the boiling point of the organic solvent is ≤80℃. More preferably, the organic solvent is at least one of ethanol, isopropanol, ethyl acetate, and acetone. It can be naturally air-dried or dried at low temperature before hot stamping, and will not remain on the surface of the micron-structured mold or polymer material, thus not affecting product performance; and / or, The dispersion is ultrasonic dispersion. Preferably, the ultrasonic dispersion rotation speed is 1800-2200 r / min, and / or the dispersion time is 60-120 seconds. The high-frequency ultrasonic vibration breaks the van der Waals forces between particles, thus preventing agglomeration.

[0015] In a preferred embodiment of the present invention: Adding a dispersant to the hydrophobic particle dispersion can further improve the dispersion stability of the nanoparticles; preferably, The concentration of the dispersant added is 0.1wt%-0.3wt%; and / or The dispersant is polyethylene glycol octylphenyl ether and / or sodium polyacrylate (NaPAA); and / or After dispersion and standing, the average particle size of the particles tested (dynamic light scattering method) is ≤100nm. More preferably, the standing time is 12-24 hours.

[0016] In a preferred embodiment of the present invention: In step (2): The coating is applied by spraying and / or brushing, and / or the coating thickness is 5-50 μm, preferably 10-20 μm. In actual operation, the coating thickness can be adaptively adjusted by controlling the amount of spraying or the number of brushings. If the thickness is too thin (<5 μm, less than 5 sprays), the hydrophobic particles will not be adequately covered, and a continuous nanostructure cannot be formed; if the thickness is too thick (>8 sprays), the hydrophobic particles will accumulate, and the excess hydrophobic particles will easily fall off after hot stamping, affecting the hydrophobic stability; and / or The aperture of the micron-structured mold is 5-20μm, preferably 10-20μm stainless steel mesh. Commonly used metal molds with micron structures in the art, such as stainless steel mesh, can be selected.

[0017] In a preferred embodiment of the present invention: In step (3): The polymer material is a thermoplastic polymer, preferably at least one selected from polyethylene, polypropylene, polyvinyl chloride, polystyrene (PS), polybutylene terephthalate (PBT), polyarylate (PAR), and polyphenylene sulfide (PPS); and / or, The pressure of the hot stamping is 2-10 MPa, preferably 3-5 MPa. If the pressure is too low, the hydrophobic particles cannot be effectively embedded in the surface of the polymer material. If the pressure is too high, the polymer material will be easily deformed. And / or, the temperature is higher than the glass transition temperature of the polymer material and lower than the melting point of the polymer material, preferably 60-120℃, more preferably 80-95℃, to ensure that the polymer material has a certain fluidity, which facilitates the transfer of the micron structure of the micron structure mold and the embedding of the hydrophobic particles. And / or, the holding time is 20-60 seconds, preferably 30-40 seconds. If the holding time is too short, the structure transfer will be incomplete. If it is too long, the production efficiency will be reduced.

[0018] In a preferred embodiment of the present invention: The polymer material described in step (3) is pre-melted with functional particles and / or hydrophobic particles; preferably, The mass ratio of the polymer material to the functional particles and hydrophobic particles is 100:(1-5):(1-5), more preferably 100:(1-3):(1-3. This maintains the mechanical properties of the polymer matrix and ensures that the internally dispersed particles are promptly exposed after surface wear, thus maintaining the hydrophobic and barrier functions; and / or, The functional particles are functional hydrotalcites, such as UV-resistant hydrotalcites; and / or, The hydrophobic particles are a mixture of hydrophobic hydrotalcite and hydrophobic silica. Preferably, the weight ratio of the hydrophobic hydrotalcite to the hydrophobic silica is 1:(1-3), more preferably 1:(1-2); and / or, The blending temperature for melt blending is 160-300℃. In actual operation, it can be adjusted according to the type of polymer material, such as 160-180℃ for PP, 280-300℃ for PPS, and / or, the screw speed is 200-300 r / min, and / or, the blending time is 5-10 minutes, to ensure that the particles are uniformly dispersed in the polymer material matrix.

[0019] In a preferred embodiment of the present invention: Step (3) involves rolling before hot stamping, preferably, The rotational speed of the roller is 0.5-5.0 m / min, preferably 1.0-4.0 m / min, and more preferably 2.5-3.0 m / min, which allows the polymer material to be fully heated and the micron-structured mold structure to be completely transferred, while realizing continuous production. And / or, the temperature is 80-110℃, preferably 90-95℃. This temperature needs to match the temperature of hot pressing to ensure the fluidity of the polymer material and the structural transfer effect. And / or, the pressure is 5-15 MPa, preferably 10-12 MPa. This pressure needs to be higher than that of flatbed hot pressing to adapt to the rapid prototyping requirements of continuous processing.

[0020] Specifically, the present invention can adopt the following solution: Option 1: A process for applying hydrophobic inorganic materials to the surface of polymer sheets via hot stamping, which ensures rapid formation of the polymer surface microstructure during hot stamping, includes the following steps: (1) Prepare hydrophobic particle dispersion by forming the material to be processed into sheets of appropriate size; (2) The nano-sized hydrophobic particle dispersion is evenly coated onto the micron-structured mold; (3) A micron-structured mold is placed over the sheet being processed, with pads placed on top and bottom; (4) Place the whole assembly into a flatbed hot press; (5) Set the pressure, holding time and temperature, and perform hot pressing. By applying pressure, the hydrophobic particles are embedded into the surface of the product, and a micro-nano structure is formed at one time. (6) Remove the sample after the pressure holding is completed.

[0021] Option 2: By improving the flatbed hot stamping process of Scheme 1 above, a spray gun is used to more uniformly coat hydrophobic particles onto the surface of the micron-structured mold, and continuous processing is achieved through roller pressing, which is more efficient and closer to production. The method steps are as follows: (1) The material to be processed is rolled up in the bottom layer to prepare a hydrophobic particle dispersion; (2) Load the hydrophobic particle dispersion into the spray gun, fix the spray gun above the mold roll, and turn on the spray gun to spray evenly onto the micron structure mold. (3) A micron-structured mold screen roll is placed over the sheet being processed, with pads placed on top and bottom; (4) Feed the roll and start the continuous roll pressing device, and set parameters such as speed and temperature; (5) The whole material is conveyed to the roller pressing position where the preset temperature and speed have been reached and the roller is rotating at a uniform speed for embedded hot pressing. The hydrophobic particles are embedded into the surface of the sheet by pressure. (6) When the entire film passes through the rollers, demold quickly before it cools down, complete the processing, take out the sample, and obtain the product.

[0022] Option 3: (1) Functional particles and hydrophobic particles are melt-blended with the surface material to be processed to form a film; (2) Prepare a hydrophobic particle dispersion and load it into a spray gun, then spray it evenly onto a micron-structured mold; (3) Place it in a flatbed hot press, set the pressure, holding time and temperature, and then heat press the hydrophobic particles to embed them into the surface of the product. (4) After the pressure holding is completed, the sample is taken out and a membrane with hydrophobic particles and functional particles inside and a superhydrophobic membrane with hydrophobic particles embedded on the surface can be obtained.

[0023] The advantages of this invention lie in two aspects: firstly, during the hot-pressing process, the mold can transfer its inherent micron-sized structure to the surface of the processed material; secondly, the uniform micron-sized template structure helps to evenly disperse and embed hydrophobic particles. This invention embeds hydrophobic particles into the surface and interior of the polymer material, thus achieving a more robust superhydrophobic surface. Compared to traditional template methods, chemical vapor deposition, and electrochemical deposition methods, which often result in insufficient adhesion between the hydrophobic coating and the substrate, making it prone to detachment during friction and wear, leading to a decline in hydrophobic properties, this invention embeds hydrophobic particles into the polymer surface and interior through hot pressing, enhancing the adhesion between the hydrophobic particles and the substrate, thereby improving wear resistance. Other processing methods may form a uniform coating on the surface, but long-term exposure to harsh weather conditions can lead to coating degradation and detachment, affecting hydrophobic properties. This method, however, creates a complex surface structure, and the embedded hydrophobic particles, melt-blended hydrophobic particles, and multifunctional particles can greatly ensure sustained long-term hydrophobic performance and meet the functional requirements of more application scenarios. In addition, compared with laser etching and chemical etching methods, this method has higher efficiency in continuous roll forming, reduces pollution, is simple and convenient to operate, and avoids hydrophobic instability caused by changes in operation of traditional methods.

[0024] A second objective of this invention is to provide a superhydrophobic material prepared by a micro-nano hot embossing method as described in one objective of this invention.

[0025] A third objective of this invention is to provide a micro / nano hot-pressing method for superhydrophobic materials as described in one objective of this invention, or the application of superhydrophobic materials in the fields of self-cleaning and / or anti-icing as described in another objective of this invention; preferably, The self-cleaning field includes at least one of outdoor glass, solar panels, and packaging bags; and / or, The anti-icing field includes at least one of aviation, wind turbine blades, and ships.

[0026] This invention processes hydrophobic particles onto the surface of a polymer material using a thermoforming method. Under pressure, the hydrophobic particles are partially or mostly embedded into the processed sheet, forming a superhydrophobic micro / nano structure where most of the hydrophobic particles are embedded in the surface. Due to the increased bonding force after embedding, this structure enhances the hydrophobicity of the product while maintaining its weather resistance and abrasion resistance. Compared to other existing superhydrophobic surface processing methods, this method is simpler, more efficient, and produces more stable results. In particular, compared to products obtained through other methods where the hydrophobic particles adhere to the surface of the processed material, products obtained using this method exhibit strong abrasion resistance and weather resistance, making them more suitable for production applications. They also maintain good hydrophobic properties even under friction and pressure. The hydrophobic angle of the superhydrophobic surface processed by this method can reach 151°.

[0027] Furthermore, this invention forms a complex micro / nano structure on the surface of the product using a hot-pressing method. Hydrophobic particles are embedded into the surface and even inside the processed material through hot pressing. In addition, the processed material and hydrophobic particles are blended together to form a film. Therefore, this invention achieves triple hydrophobicity protection through the complexity of the surface structure, the embedding of hydrophobic particles, and the blending of hydrophobic particles with the processed material.

[0028] Furthermore, since flatbed hot embossing lacks the characteristic of continuous production, its application in large areas is greatly limited. This invention, through a combination of roll pressing and hot embossing, enables continuous operation, producing films with excellent hydrophobic properties, as well as good mechanical stability and chemical durability.

[0029] The method of this invention is more flexible and versatile than existing methods for fabricating superhydrophobic surfaces using a single micro / nano structure mold, and can be applied to the vast majority of non-metallic film and sheet surfaces. The surface micro / nano structure is not solely derived from the mold, but is achieved through the combined action of a micrometer-scale mold structure and nanometer-scale hydrophobic particles to obtain the micro / nano structure in a single process. Micrometer-scale molds are more readily available and have lower processing costs than nanometer-scale molds. Furthermore, due to the short processing time and the availability and low cost of the mold, this method enables highly continuous fabrication. Compared to other complex methods that involve preparing molds and then performing lengthy processing, this method is more suitable for production applications.

[0030] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships, such as A and / or B. Specifically, it can mean that A and B can be included at the same time, A can exist alone, or B can exist alone, and any of the above three situations can be met. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the flatbed hot stamping process of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the rolling process of Embodiment 2 of the present invention; Figure 3 The results of the water contact angle test of the material prepared in Example 1 of this invention; Figure 4 This is a graph showing the relationship between the roller speed and the contact angle in Embodiment 2 of the present invention; Figure 5 These are images of the material surface morphology at different rolling speeds in Embodiment 2 of the present invention. Among them, (a) is the surface morphology of the material at a rolling speed of 1.0 m / min; (b) is the surface morphology of the material at a rolling speed of 2.5 m / min; and (c) is the surface morphology of the material at a rolling speed of 4 m / min. Figure 6 This is a schematic diagram of a friction experiment; Figure 7 The surface contact angle test results of the material in Example 3 of the present invention after a friction test; Figure 8 The surface contact angle test results are shown for the material in Example 3 of this invention after an adhesion test. Figure 9 This is a schematic diagram of the cross-sectional structure of the material obtained by the method of the present invention; Figure 10 The water contact angle test results are for the material prepared in Example 3 of this invention. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0033] All raw materials used in the embodiments of this invention are commercially available products.

[0034]

Example 1

[0035]

Example 2

[0036]

Example 3

[0037] Embodiment 1 of this invention achieves a simple process to easily and simultaneously obtain micron- and nano-scale structures in one step, significantly improving hydrophobic properties. The hydrophobic properties of the samples processed according to GB / T 30693-2014 were tested, and the water droplet contact angle of the samples was obtained as follows: Figure 3 The angle reached 150°.

[0038] Tests revealed that changes in roller speed in Example 2 affected the contact angle. After processing the test data, a curve showing the relationship between roller speed and contact angle was plotted, as shown below. Figure 4 As shown in the figure, the contact angle increases with increasing speed, reaching its maximum value of 152° when the rotational speed reaches 2.5–3.0 m / min. With increasing roller speed, the contact angle gradually decreases and stabilizes around 120°. SEM images of samples at roller speeds of 1.0 m / min, 2.5 m / min, and 4.0 m / min are shown below. Figure 5 As shown, under the same temperature and pressure, the film formed at a rotation speed of 2.5~3.0 m / min exhibits superior microstructure height and surface replication compared to samples formed under other conditions. At low speeds, the longer the sample is in contact with the rollers, the higher the sample temperature becomes, leading to melting wrinkles on the sample surface. When the rotation speed reaches 2.5 m / min, the temperature and pressure during hot pressing are within a suitable range, resulting in a sample with good microstructure and micro-organism. When the rotation speed is further increased to 4.0 m / min, the sample detaches from the rollers before forming a near-solid state, resulting in insufficient heating and an inability to completely replicate the sieve structure on the sample surface, leading to poor hydrophobicity. Based on the above experimental results and scanning electron microscopy analysis, the optimal rolling speed is considered to be 2.5~3.0 m / min. Example 2 of this invention demonstrates the continuous production capability of the preparation method of this invention through rolling, which is simpler, more stable, and closer to large-scale production applications compared to other methods.

[0039] The durability of the film samples prepared in Example 3 was tested using three methods: friction method, high-adhesion tape bonding method, and water immersion method.

[0040] like Figure 6 As shown, in the friction test, a sample piece of 20×20cm size was taken, a weight that can provide a pressure of about 2800Pa was pressed on the sample surface, and then the sample was placed on a 1000-grit sandpaper surface and rubbed back and forth at a certain speed 50 times.

[0041] After wiping, it can be seen that although a few particles have peeled off the surface of the sandpaper, the contact angle with water was measured, and the test results are as follows. Figure 7The results showed that the contact angle of the film surface decreased after friction, but the hydrophobic effect remained good. When water droplets were applied to the sample surface using a dropper, the droplets immediately slid off, indicating that the sample had excellent wear resistance.

[0042] In the high-tack tape adhesion test, the high-tack tape (8915, 3M) was adhered to the sample surface 50 times, and then the contact angle between the sample and water was measured. like Figure 8 As shown, although the water contact angle of the sample decreased after being repeatedly adhered with high-adhesion tape, it still exhibited hydrophobicity. When a drop of water was placed on the sample surface, the hydrophobicity remained, and the water droplet slid off immediately upon contact.

[0043] The thin film sample prepared in Example 3 was placed in clean water. After seven days, the thin film sample was taken out and observed. It was noted that the sample in the water was not wetted, which means that water immersion does not have a significant impact on the contact angle.

[0044] Therefore, the above tests demonstrate that the samples obtained by the processing method of the present invention have strong weather resistance. The reasons for this are as follows: Figure 9 As shown, because the hydrophobic particles are partially or completely embedded in the surface, a large amount of hydrophobic particles will not be lost after immersion in water, and the surface structure will not be damaged, so it can still maintain good hydrophobic properties. In Example 3, hydrotalcite and hydrophobic particles with barrier properties were added to the sheet, which improved wear resistance and service life.

Claims

1. A method of micro- and nano- hot embossing of superhydrophobic materials, characterized in that The method includes: Hydrophobic inorganic materials are processed onto the surface of polymer materials by hot embossing, forming micro-nano composite structures on the polymer surface.

2. The method of claim 1, wherein The method includes: (1) Hydrophobic particles are dispersed in an organic solvent to prepare a hydrophobic particle dispersion; (2) The hydrophobic particle dispersion is coated onto a micron-structured mold; (3) The micron structure mold is covered on the polymer material to be processed and hot-pressed to form a micro-nano composite structure on the polymer surface, thus obtaining a superhydrophobic material.

3. The method according to claim 2, characterized in that: In step (1): The concentration of the hydrophobic particle dispersion is 0.5wt%-10wt%, preferably 3wt%-7wt%; and / or, The hydrophobic particles are a mixture of hydrophobic hydrotalcite and hydrophobic silica. Preferably, the weight ratio of the hydrophobic hydrotalcite to the hydrophobic silica is 1:(1-3), more preferably 1:(1-2); and / or, The hydrophobic particles are nanoparticles and / or microparticles. Preferably, the particle size of the nanoparticles is ≤50 nm, more preferably 20-50 nm, and / or, the particle size of the microparticles is 10-30 μm, more preferably 10-20 μm; and / or, The organic solvent is a low-boiling-point organic solvent, preferably with a boiling point ≤80°C, more preferably, the organic solvent is at least one selected from ethanol, isopropanol, ethyl acetate, and acetone; and / or, The dispersion is ultrasonic dispersion, preferably, the ultrasonic dispersion rotation speed is 1800-2200 r / min, and / or the dispersion time is 60-120 seconds.

4. The method according to claim 3, characterized in that: A dispersant is added to the hydrophobic particle dispersion; preferably, a dispersant is added to the dispersion. The concentration of the dispersant added is 0.1wt%-0.3wt%; and / or The dispersant is polyethylene glycol octylphenyl ether and / or sodium polyacrylate; and / or After dispersion and standing, the average particle size of the particles tested is ≤100nm. More preferably, the standing time is 12-24 hours.

5. The method according to claim 2, characterized in that: In step (2): The coating is applied by spraying and / or brushing, and / or the coating thickness is 5-50 μm, preferably 10-20 μm; and / or The aperture of the micron-structured mold is 5-20 μm, preferably a stainless steel screen with an aperture of 10-20 μm.

6. The method according to claim 2, characterized in that: In step (3): The polymer material is a thermoplastic polymer, preferably at least one of polyethylene, polypropylene, polyvinyl chloride, polystyrene, polybutylene terephthalate, polyarylate, and polyphenylene sulfide; and / or, The pressure of the hot stamping is 2-10 MPa, preferably 3-5 MPa, and / or the temperature is higher than the glass transition temperature of the polymer material and lower than the melting point of the polymer material, preferably 60-120°C, more preferably 80-95°C, and / or the holding time is 20-60 seconds, preferably 30-40 seconds.

7. The method according to claim 2, characterized in that: The polymer material described in step (3) is pre-melted with functional particles and / or hydrophobic particles; preferably, The mass ratio of the polymer material to the functional particles and hydrophobic particles is 100:(1-5):(1-5), more preferably 100:(1-3):(1-3); and / or, The functional particles are functional hydrotalcite; and / or, The hydrophobic particles are a mixture of hydrophobic hydrotalcite and hydrophobic silica. Preferably, the weight ratio of the hydrophobic hydrotalcite to the hydrophobic silica is 1:(1-3), more preferably 1:(1-2); and / or, The blending temperature of the melt blend is 160-300℃, and / or the screw speed is 200-300 r / min, and / or the blending time is 5-10 minutes.

8. The method according to claim 2, characterized in that: Step (3) involves rolling before hot stamping, preferably, The rotational speed of the roller is 0.5-5 m / min, preferably 1.0-4.0 m / min, more preferably 2.5-3.0 m / min, and / or the temperature is 80-110℃, preferably 90-95℃, and / or the pressure is 5-15 MPa, preferably 10-12 MPa.

9. A superhydrophobic material prepared by a micro-nano hot embossing method according to any one of claims 1-8.

10. A micro-nano hot embossing method for a superhydrophobic material as described in any one of claims 1-8, or the application of a superhydrophobic material as described in claim 9 in the fields of self-cleaning and / or anti-icing.

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