CN117402555A - A superhydrophobic anti-icing surface based on super elliptical topology and its preparation method - Google Patents

Abstract

The invention discloses a super-hydrophobic anti-icing surface based on a super-elliptic topological structure and a preparation method thereof. The super-hydrophobic anti-icing surface comprises a super-elliptic topological structure substrate and a super-hydrophobic coating; the microstructure of the super-elliptic topological structure substrate has a protection function, and the inner super-hydrophobic coating is protected from failure caused by impact damage or friction and abrasion; the super-hydrophobic coating has an intrinsic super-hydrophobic nano structure, can reduce solid-liquid contact area and weaken solid-liquid heat transfer, thereby delaying icing, reducing ice adhesion and having anti-icing performance. The super-hydrophobic anti-icing surface has long-acting super-hydrophobicity with firm mechanical property, and the super-hydrophobic nano structure is protected by utilizing the super-elliptic topological microstructure, so that the problems of poor mechanical firmness and wear resistance of the super-hydrophobic surface are solved, the long-acting property and durability of the super-hydrophobic surface are enhanced, and the super-hydrophobic anti-icing surface can be applied to the fields of aerospace, energy sources, traffic and the like.

Description

A superhydrophobic anti-icing surface based on super elliptical topology and its preparation method

Technical field

The invention belongs to the field of superhydrophobic anti-icing and relates to a super-hydrophobic anti-icing surface based on a super-elliptical topological structure and a preparation method thereof.

Background technique

In low-temperature environments, the surface is prone to ice, causing safety hazards and energy efficiency losses in aerospace, energy, transportation and other fields. Traditional anti-icing methods are not environmentally friendly and consume high energy. Therefore, there is a need for a method to prepare a green, low-energy anti-icing surface to reduce ice formation and improve the anti-icing performance of the surface.

Learning from nature, biological surfaces such as lotus leaves, rice leaves, and butterfly wings have superhydrophobic phenomena. Their unique solid-gas-liquid contact interface guides the construction of new anti-icing surfaces. Bionic superhydrophobic surface anti-icing inspired by nature is a passive anti-icing technology. It mainly uses interface materials to reduce surface energy or construct micro-nano composite structures on the surface of the anti-icing area to reduce the impact of droplets on the solid surface. The contact area and contact time of the surface can be used to suppress ice formation on the surface, thereby significantly reducing the energy consumption required for anti-icing, which has great engineering application prospects.

However, a large number of research results show that the low solid-liquid contact area of superhydrophobic surfaces causes high local stress, resulting in poor mechanical stability and is susceptible to natural climate (sun, sand, wind and rain), external forces (impact, friction), icing -De-icing cycles and other damage will eventually lead to the failure of the superhydrophobic surface and the reduction of anti-icing efficiency, making mechanical stability a key bottleneck restricting the use of superhydrophobic surfaces in anti-icing applications. Therefore, it is necessary to protect mechanically fragile nano-hydrophobic structures by using super-elliptical topological microstructures, improve the mechanical stability of super-hydrophobic surfaces, and expand its anti-icing applications in aerospace, energy, transportation and other fields.

Contents of the invention

In order to solve the problems of poor mechanical robustness and poor durability of existing superhydrophobic anti-icing surfaces, the present invention adopts a strategy of protecting the nanostructure of superhydrophobic coatings by adopting a base superelliptical topological microstructure to regulate the composition and proportion of organic-inorganic hybrid superhydrophobic coatings. And filled it into the microstructure based on super elliptical topology, and prepared a superhydrophobic anti-icing surface based on super elliptical topology. The invention discloses a series of types, compositions and ingredient ratios of organic-inorganic hybrid super-hydrophobic coatings, and describes in detail different methods of filling super-hydrophobic coatings into super-elliptical microstructures.

The preparation technical scheme of the present invention is as follows:

A super-hydrophobic anti-icing surface based on a super-elliptical topological structure. The super-hydrophobic anti-icing surface includes a super-elliptical topological structure base (1) and a super-hydrophobic paint (2). The super-elliptical topological structure base (1) has a microstructure The structure has a protective function to protect the internal superhydrophobic coating (2) from failure due to impact damage or friction and wear; the superhydrophobic coating (2) has a superhydrophobic nanostructure, which can reduce the solid-liquid contact area and weaken the solid-liquid contact area. Heat transfer, thereby delaying icing, reducing ice adhesion, and having anti-icing properties.

The superhydrophobic anti-icing surface meets the following performance requirements: the water contact angle is greater than 150° and the rolling angle is less than 10°; its surface is still superhydrophobic after undergoing multiple friction and wear; and it can extend the bonding time compared to the original substrate surface. Ice time reduces ice adhesion; after experiencing repeated friction and wear, its surface is still anti-icing.

The material of the super-elliptical topological structure base (1) is one of plastics, ceramics, metals, and composite materials, and the topological structural unit is one of super-elliptical shapes, which are produced by laser processing. The shape curve of a hyperellipse is The semi-diameter a and b of the superellipse range from 60 to 500 μm, and the index parameter n ranges from 2 to 10. The value range of the distance between adjacent hyperellipses is 0-100 μm. The superhydrophobic coating (2) is an organic-inorganic hybrid material. The organic part is a kind of resin polymer, and the inorganic part is a kind of nanoparticle. The two are obtained by blending an organic solvent.

The super-elliptical topological structure substrate (1) and the super-hydrophobic coating (2) are prepared by dip coating, blade coating or spray coating, and then heated and solidified to form.

The preparation method of a superhydrophobic anti-icing surface as described in any one of the above includes the following steps:

Step 1, super elliptical topological structure substrate (1) processing is to process the substrate into a super elliptical shape through laser according to the design requirements;

Step 2, the superhydrophobic coating (2) is prepared by blending organic resin and inorganic nanoparticles in an organic solvent and stirring evenly;

Step 3: Apply the superhydrophobic coating (2) within the microstructure of the super-elliptical topological structure substrate (1) by dipping, scraping or spraying, and then heat and solidify it;

Step 4: Conduct a contact angle test on the prepared super-elliptical topological superhydrophobic anti-icing surface to evaluate its wettability. If it does not meet the superhydrophobic requirements, iterate the organic-inorganic hybrid ratio of the superhydrophobic coating (2) in step 2. , improve the mass ratio of nanoparticles.

Step 5: Test the anti-icing performance of the prepared super-elliptical topological superhydrophobic anti-icing surface, that is, when the surface temperature is -20°C, the freezing delay time of 10 μl supercooled droplets on it is compared with the original bare substrate.

Step 6: Conduct a friction test on the prepared super-elliptical topological superhydrophobic anti-icing surface. After repeatedly rubbing the surface 50 times with sandpaper loaded with a 500g weight, measure the surface contact angle to see if it still meets the superhydrophobic requirements; measure the surface icing delay time, compared to the original bare substrate.

The beneficial effect of the superhydrophobic anti-icing surface based on the superelliptical topological structure of the present invention is to have long-lasting, mechanically strong superhydrophobicity and anti-icing properties, and to protect the superhydrophobic nanostructure by utilizing the superelliptical topological microstructure. , which solves the problems of poor mechanical robustness and non-wear resistance of superhydrophobic surfaces, and enhances the long-term performance and durability of superhydrophobic surfaces. Specifically, it still has the superhydrophobicity and anti-icing performance of the original surface after repeated friction, which can Used in aerospace, energy, transportation and other fields.

Description of the drawings

Figure 1 is a schematic structural diagram of a superhydrophobic anti-icing surface based on a superelliptical topology in Examples 1, 2, and 3;

Figure 2 is a surface morphology diagram of a superhydrophobic anti-icing surface based on a superelliptical topology in Example 1;

Figure 3 is a characterization diagram of the wettability of a superhydrophobic anti-icing surface based on a superelliptical topology in Example 1 after repeated friction.

Among them: 1-Super elliptical topological structure substrate; 2-Super hydrophobic coating.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

Example 1

A super-hydrophobic anti-icing surface based on a super-elliptical topology, as shown in Figure 1. Its structure includes: (1) Super-elliptical topology substrate 1, with a length and width of 30mm×30mm, and the material is plexiglass acrylic. Its performance parameters It has a density of 1.19g/cm ³ , a Young's modulus of 3.6Gpa, a tensile strength of 60MPa, a flexural strength of 110MPa, a melting point of 130°C, and a Poisson's ratio of 0.4; (2) Superhydrophobic coating 2, the organic part is a siloxane polymer. Dimethylsiloxane and curing agent (Sylard 184, Dow Corning, USA), the inorganic part is silica nanoparticles (Degussa, R202), hydrophobic type, with an average particle size of 14nm. Figure 1 only illustrates the pattern design of four super-elliptical structures adjacent up, down, left, and right. In actual processing, the topological pattern can be repeated according to the size of the substrate and the size of the super-elliptical structure. The superhydrophobic coating 2 is filled in the super elliptical topological structure of the substrate. The surface morphology of the actually prepared super-elliptical topological superhydrophobic anti-icing surface was photographed by an electron scanning microscope, and its structure is shown in Figure 2.

Its preparation method is:

Step 1: Use laser to process a super elliptical shape on the organic glass acrylic substrate. The semi-diameters a and b of the super ellipse are 250 μm, the index n is 3, and the adjacent spacing d is 25 μm;

Step 2: Blend polydimethylsiloxane, curing agent and silica nanoparticles in n-hexane solvent in a mass ratio of 7:0.7:3, and stir evenly;

Step 3: Apply the superhydrophobic paint on the microstructure of the super elliptical topological structure base by scraping, and then place it in a vacuum tank for 10 minutes. Repeat this 2-3 times until the superhydrophobic paint fills the super elliptical topological microstructure, and then Cured at 80°C for 2 hours;

Step 4: Conduct a contact angle test on the prepared super-elliptical topological superhydrophobic surface. The water contact angle is 155° and the rolling angle is 5°, which meets the superhydrophobic requirements.

Step 5: Test the anti-icing performance of the prepared super-elliptical topological super-hydrophobic anti-icing surface. That is, when the surface temperature is -20°C, the freezing time of 10 μl supercooled droplets on it is delayed by more than 20 compared to the original bare acrylic surface. times.

Step 6: Use sandpaper loaded with a weight of 500g to repeatedly rub the super-elliptical superhydrophobic surface. The single rubbing distance is 2cm. After 50 times of rubbing, the water contact angle of the super-elliptical topological superhydrophobic surface is 151° and the rolling angle is 8°, as shown in the figure. As shown in 3, it still meets the superhydrophobic requirements. And the freezing time is more than 15 times delayed compared to the original bare acrylic surface.

Example 2

A super-hydrophobic anti-icing surface based on a super-elliptical topology, as shown in Figure 1. Its structure includes: (1) A super-elliptical topological structure base with a length and width of 30mm × 30mm, and the material is plexiglass acrylic. Its performance parameters are Density 1.19g/cm ³ , Young's modulus 3.6Gpa, tensile strength 60MPa, flexural strength 110MPa, melting point 130°C, Poisson's ratio 0.4; (2) Super hydrophobic coating, the organic part is siloxane polymer polydimethyl Based on siloxane (Dow Corning, USA, Sylard 184), the inorganic part is silica nanoparticles (Degussa, R202), hydrophobic type, with an average particle size of 14nm.

Its preparation method is:

Step 1: Use laser to process a super elliptical shape on the organic glass acrylic substrate. The semi-diameter a and b of the super ellipse are 250 μm, the index n is 3, and the adjacent spacing d is 75 μm;

Step 2: Blend the siloxane polymer polydimethylsiloxane and silica nanoparticles in n-hexane solvent in a mass ratio of 7:0.7:3, and stir evenly;

Step 3: Spray the superhydrophobic paint into the microstructure of the super elliptical topological structure substrate at a pressure of 0.1MPa. The distance between the substrate and the nozzle is 20cm during spraying. Spray twice, and then cure at 80°C for 2 hours;

Step 4: Conduct a contact angle test on the prepared super-elliptical topological superhydrophobic surface. The water contact angle is 145°, which does not meet the superhydrophobic requirements. Iterate the organic-inorganic hybrid ratio of superhydrophobic coating 2 in step 2 to improve the quality of nanoparticles. The ratio is 7:0.7:3.5, and then the contact angle test is performed. The water contact angle is 153° and the rolling angle is 5°, which meets the superhydrophobic requirements;

Step 5: Test the anti-icing performance of the prepared super-elliptical topological super-hydrophobic anti-icing surface. That is, when the surface temperature is -20°C, the freezing time of 10 μl supercooled droplets on it is delayed by more than 16 times compared with the original bare acrylic surface. times;

Step 6: Use sandpaper loaded with 500g weight to repeatedly rub the super-elliptical superhydrophobic surface. The single rubbing distance is 2cm. After 50 times of rubbing, the water contact angle of the super-elliptical topological superhydrophobic surface is 150° and the rolling angle is 10°, which still meets the requirements. Super hydrophobic requirements; freezing time is delayed more than 10 times compared to the original bare acrylic surface.

Example 3

A super-hydrophobic anti-icing surface based on a super-elliptical topology, as shown in Figure 1. Its structure includes: (1) A super-elliptical topological structure base with a length and width of 300mm×300mm, and the material is metal aluminum alloy. Its performance parameters are: : Density 2.81g/cm ³ , Young's modulus 71.7GPa, tensile strength 572MPa, flexural strength 385MPa, Poisson's ratio 0.33; (2) Super hydrophobic coating, the organic part is epoxy resin E-51 and curing agent T- 31 (Hangzhou Wuhuigang Adhesive Co., Ltd.), the inorganic part is carbon nanoparticles, with an average particle size of 20nm.

Its preparation method is:

Step 1: Use laser to process a super elliptical shape on an aluminum alloy substrate. The semi-diameter a and b of the super ellipse are 250 μm, the index n is 8, and the adjacent spacing d is 25 μm;

Step 2: Blend epoxy resin E-51, curing agent T-31 and carbon nanoparticles in acetone solvent in a ratio of 7:3.5:3, and stir evenly;

Step 3: Spray the superhydrophobic paint into the microstructure of the super elliptical topological substrate with a pressure of 0.1MPa. The distance between the substrate and the nozzle is 20cm during spraying. Spray twice, and then cure at 60°C for 2 hours;

Step 4: Conduct a contact angle test on the prepared super-elliptical topological superhydrophobic surface. The water contact angle is 156° and the rolling angle is 2°, which meets the superhydrophobic requirements.

Step 5: Test the anti-icing performance of the prepared super-elliptical topological super-hydrophobic anti-icing surface. That is, when the surface temperature is -20°C, the freezing time of 10 μl supercooled droplets on it is delayed by more than 22% compared to the original bare acrylic surface. times.

Step 6: Use sandpaper loaded with 500g weight to repeatedly rub the super-elliptical superhydrophobic surface. The single rubbing distance is 2cm. After 50 times of rubbing, the water contact angle of the super-elliptical topological superhydrophobic surface is 152° and the rolling angle is 7°, which still meets the requirements. Super hydrophobic requirements; freezing time is delayed more than 15 times compared to the original bare acrylic surface.

It should be noted that according to the above-mentioned embodiments of the present invention, those skilled in the art can fully realize the full scope of the independent claims and subordinate rights of the present invention. The implementation process and method are the same as the above-mentioned embodiments; and the present invention is not elaborated in detail. Some of them are well-known technologies in this field. The above are only some specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those familiar with the art within the technical scope disclosed in the present invention should be made. are covered by the protection scope of the present invention.

Claims (9)

1. The super-hydrophobic anti-icing surface based on the super-elliptic topological structure is characterized by comprising a super-elliptic topological structure substrate (1) and a super-hydrophobic coating (2), wherein the microstructure of the super-elliptic topological structure substrate (1) has a protection function, and the inner super-hydrophobic coating (2) is protected from failure caused by impact damage or friction and abrasion; the super-hydrophobic coating (2) has an intrinsic super-hydrophobic nano structure, can reduce solid-liquid contact area and weaken solid-liquid heat transfer, thereby delaying icing, reducing ice adhesion and having anti-icing performance.

2. The superhydrophobic anti-icing surface according to claim 1, wherein the superhydrophobic anti-icing surface meets the following superhydrophobic performance requirements: the water contact angle is greater than 150 deg. and the rolling angle is less than 10 deg..

3. The superhydrophobic anti-icing surface according to claim 1, wherein the superhydrophobic anti-icing surface has superhydrophobic surface after being subjected to a plurality of frictional wear.

4. The superhydrophobic anti-icing surface according to claim 1, wherein the superhydrophobic anti-icing surface is capable of extending icing time and reducing ice adhesion relative to an original substrate surface.

5. The superhydrophobic anti-icing surface according to claim 1, wherein the superhydrophobic anti-icing surface has anti-icing properties after being subjected to a plurality of frictional wear.

6. The superhydrophobic anti-icing surface according to claim 1, characterized in that the material of the superelliptical topological substrate (1) is one of plastic, ceramic, metal and composite material, and the topological unit is one of superelliptical shape, made by laser machining.

7. The superhydrophobic anti-icing surface according to claim 1, wherein said superhydrophobic coating (2) is an organic-inorganic hybrid material, the organic fraction is one of resin polymers, the inorganic fraction is one of nanoparticles, both obtained by blending with an organic solvent; preferably, the resin polymer is polydimethylsiloxane or epoxy resin; preferably, the nano-particles are nano-silica or carbon nano-particles; preferably, the particle size of the nano particles is 1-30 nm.

8. The super-hydrophobic anti-icing surface according to claim 1, characterized in that the super-elliptic topological structure substrate (1) and the super-hydrophobic coating (2) are prepared by dip coating, knife coating or spray coating, and then are formed by heating and curing.

9. A method of preparing a superhydrophobic anti-icing surface according to any of claims 1-8 comprising the steps of:

step 1, processing a super-elliptic topological structure substrate (1), namely processing the super-elliptic shape of the substrate by laser according to design requirements, and then cleaning the surface;

step 2, preparing the super-hydrophobic coating (2), namely blending organic resin and inorganic nano particles in an organic solvent, and uniformly stirring;

step 3, coating the super-hydrophobic coating (2) in the microstructure of the super-elliptic topological structure substrate (1) in a dip coating, blade coating or spray coating mode, and then heating and curing;

step 4, performing contact angle test on the prepared super-elliptic topological structure super-hydrophobic anti-icing surface, evaluating wettability of the super-elliptic topological structure super-hydrophobic anti-icing surface, and if the super-elliptic topological structure super-hydrophobic requirement is not met, iterating the organic-inorganic hybridization ratio of the super-hydrophobic coating (2) in the step 2;

step 5, carrying out an anti-icing performance test on the prepared super-elliptic topological structure super-hydrophobic anti-icing surface, namely comparing the icing delay time of 10 mu l supercooled liquid drops on the super-elliptic topological structure super-hydrophobic anti-icing surface with that of an original bare substrate at the surface temperature of minus 20 ℃;

step 6, friction test is carried out on the super-hydrophobic anti-icing surface of the prepared super-elliptic topological structure, after the surface is repeatedly rubbed for 100 times by using sand paper loaded with a weight of 500g, the contact angle of the surface is measured, and whether the super-hydrophobic requirement is still met or not; the surface icing delay time is measured and compared to the original bare substrate.