Preparation method of anti-icing frost-resistant super-lubricating surface

Abstract

The invention provides a preparation method of an anti-icing and anti-frost super-lubricating surface, and belongs to the technical field of anti-icing and anti-frost of power transmission lines, and the preparation method comprises the following steps: preparing an alumina substrate of a porous structure with the pore diameter of 100-150 nm and the porosity of 60-70% by adopting an anodic oxidation method; immersing the alumina substrate into an ethanol solution of n-hexadecyl trimethoxysilane for modification to obtain a modified alumina substrate; the preparation method comprises the following steps: stirring and mixing silicone oil and n-hexadecyl trimethoxy silane to obtain modified silicone oil; the anti-icing frost-resistant super-lubricating surface is prepared from the modified silicone oil and the modified aluminum oxide substrate through a vacuum impregnation method. The preparation method of the anti-icing frost-resistant super-lubricating surface is simple, easy to implement, economical and effective, and the prepared super-lubricating surface has good anti-icing frost-resistant performance.

Description

Technical Field

[0001] This invention relates to the field of anti-icing and anti-frost technology for power transmission lines, and in particular to a method for preparing an anti-icing and anti-frost super-lubricating surface. Background Technology

[0002] Icing on transmission lines seriously threatens the safe and stable operation of the power grid. Currently, commonly used de-icing measures in engineering mainly rely on methods such as electric current melting and mechanical de-icing. While these methods can effectively remove existing ice, they cannot suppress ice accumulation in the early stages. When large-scale ice formation occurs, it often creates significant safety hazards or triggers accidents. Therefore, research on anti-icing technology for transmission lines is becoming increasingly crucial and urgent.

[0003] Since the widespread ice storm that struck the power grid in 2008, numerous researchers have conducted extensive and in-depth studies. Inspired by biomimetic techniques such as the "lotus effect," superhydrophobic coatings / surfaces have emerged. However, a key challenge with these methods is that in low-temperature, high-humidity environments, such as freezing rain, water vapor condenses and frosts within the micro / nanostructure of the material, leading to the failure of its anti-icing function. Furthermore, inspired by the biomimetic mechanism of pitcher plants, researchers have developed superlubricated surfaces (SLIPS) obtained by impregnating porous surfaces with lubricating fluid. SLIPS are a type of functional surface with unique properties. Their preparation principle involves injecting lubricating fluid into the interior of a porous substrate, forming a smooth and fluid lubricating film on the substrate surface. The presence of lubricating fluid in the substrate can delay or prevent water vapor from condensing into ice within the micro / nanopores, demonstrating great potential in anti-icing applications.

[0004] Superlubricating surfaces are a four-phase system consisting of a substrate, lubricant, water, and air. Their anti-icing performance and durability are affected by the substrate structure, lubricant properties, and the interaction between the two. To this end, researchers have conducted extensive performance optimization studies from these perspectives. (1) Substrate structure: A microporous dendritic porous structure substrate was designed. This substrate structure can suppress lubricant loss, improve the liquid storage capacity, and achieve lubricant self-replenishment. The lubricant-impregnated porous surface prepared based on this structure can still maintain an ultra-low ice adhesion strength of <20 kPa even after 190 freezing / thawing cycles. (2) Substrate-lubricant interaction: Before injecting the lubricant, the substrate is treated with a suitable modifier as a hydrophobic coating. This not only reduces the surface energy of the substrate but also improves the chemical compatibility between the substrate and the lubricant. Studies have shown that introducing a long-chain siloxane layer during the preparation of the lubricant-impregnated porous surface not only enhances the hydrophobicity of the substrate surface but also improves its chemical affinity with the lubricant phase, thereby reducing lubricant loss. (3) Lubricant properties: The properties of the lubricant are a key factor affecting the anti-icing performance of superlubricated surfaces, but this problem has not yet been fully solved. Researchers have conducted extensive studies on various lubricants, including perfluoropolyether oils, electronic fluorinated fluids, ionic liquids, mineral oils, and silicone oils, and each type of lubricant has shown unique advantages. Among them, silicone oil has received widespread attention due to its good environmental compatibility, high cost-effectiveness, and excellent functional performance.

[0005] The viscosity of silicone oil is negatively correlated with its droplet slip velocity on superlubricated surfaces, but positively correlated with its retention capacity. Studies have shown that silicone oil with a viscosity of 200 cSt is the optimal choice for anti-icing applications. However, compared to other reported lubricants, such as perfluoropolyether oils, which promote droplet condensation, aggregation, and growth and have delayed frosting properties, 200 cSt silicone oil accelerates frost spread in frosting environments, promoting the formation of loose, fine frost crystals, thereby impairing the long-term hydrophobicity and anti-icing performance of superlubricated surfaces. Furthermore, although low-viscosity oils can effectively inhibit frost spread by promoting droplet aggregation, this contradicts the high viscosity required to improve lubricant retention capacity on superlubricated surfaces.

[0006] Therefore, improving the anti-frost performance of high-viscosity lubricating silicone oil is an effective way to reconcile the above contradictions, and at the same time, it can also improve the durability of ultra-lubricating surfaces and the anti-icing and anti-frost performance. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a simple, easy, economical and effective method for preparing an anti-icing and anti-frost super-lubricating surface.

[0008] To address the aforementioned technical problems, this invention provides a method for preparing an anti-icing, anti-frost, and super-lubricating surface, comprising the following steps: preparing a porous alumina substrate with a pore size of 100-150 nm and a porosity of 60-70% using anodizing; modifying the alumina substrate by immersing it in an ethanol solution of hexadecyltrimethoxysilane to obtain a modified alumina substrate; mixing silicone oil with hexadecyltrimethoxysilane to obtain modified silicone oil; and preparing the anti-icing, anti-frost, and super-lubricating surface by vacuum impregnation of the modified silicone oil and the modified alumina substrate.

[0009] Furthermore, the method for preparing the alumina substrate includes: using aluminum as the anode and a stainless steel sheet as the cathode; connecting the anode and cathode wires to a DC power supply; electrolyzing in an oxalic acid electrolyte to obtain alumina; and immersing the alumina in a phosphoric acid solution at room temperature to expand the pores and obtain a porous alumina substrate.

[0010] Furthermore, the concentration of the oxalic acid electrolyte is 0.2-0.3 mol / L, and the electrolysis current intensity is 0.1-0.2 A / cm. 2 The electrolysis time is 10-15 min.

[0011] Furthermore, the phosphoric acid solution has a mass percentage concentration of 5-10 wt%.

[0012] Furthermore, the mass fraction of the ethanol solution of the alumina-modified hexadecyltrimethoxysilane is 2-5%, and the alumina-modification time is 30-60 min.

[0013] Furthermore, the modified alumina substrate obtained by modifying the alumina substrate in an ethanol solution of hexadecyltrimethoxysilane needs to be dried at 100-130 °C for 0.5-3 h.

[0014] Furthermore, the silicone oil and n-hexadecyltrimethoxysilane are mixed using magnetic stirring for 2-5 minutes.

[0015] Furthermore, the modified silicone oil contains 1-3% hexadecyltrimethoxysilane by mass.

[0016] Furthermore, the method for obtaining an anti-icing, anti-frost, and super-lubricating surface by vacuum impregnation of the modified silicone oil and the modified alumina substrate includes: placing the modified alumina substrate in a vacuum container to remove air from the modified alumina substrate; injecting modified silicone oil through the inlet of the vacuum container to immerse the air-removed modified alumina substrate, so that the modified silicone oil is impregnated into the porous structure of the modified alumina substrate surface; removing the modified alumina substrate impregnated with modified silicone oil from the vacuum container, and using atmospheric pressure to further press the modified silicone oil into the porous structure of the modified alumina substrate.

[0017] Furthermore, the modified alumina substrate is placed in a vacuum container for 4-6 hours, and the modified silicone oil is immersed in the air-removed modified alumina substrate for 6-18 hours.

[0018] This invention provides a method for preparing an anti-icing, anti-frost, and super-lubricating surface. The method involves adding 1-3% by mass of n-hexadecyltrimethoxysilane to silicone oil to modify it, resulting in a modified silicone oil. This is because one end of the n-hexadecyltrimethoxysilane molecule is a silicon atom bonded to three methoxy groups (-OCH3), while the other end is a long-chain n-hexadecyl (CH3(CH2)) group. 15 These three methoxy groups can be grafted onto the silicone oil molecular chain to form stable siloxane bonds (-Si-O-Si-), which is equivalent to introducing a large number of nonpolar long-chain alkyl functional groups into the silicone oil. According to the principle of "like dissolves like," the affinity between the nonpolar silicone oil surface and polar water molecules will be greatly reduced, making it difficult to form hydrogen bonds, thereby weakening the intermolecular forces between water and the lubricating surface.

[0019] Therefore, in a low-temperature and high-humidity environment, the super-lubricated surface formed by the porous alumina substrate impregnated with modified silicone oil is prone to a gas-liquid-solid phase change process, which causes a large number of condensed droplets to form on the surface. As time goes by, the condensed droplets continue to aggregate and grow. After a sufficient period of time, only a small number of droplets, mainly distributed in the edge area of ​​the super-lubricated surface, begin to freeze.

[0020] Therefore, the super-lubricated surface formed by impregnating a porous alumina substrate with modified silicone oil has excellent anti-frost properties.

[0021] Therefore, the present invention provides a method for preparing an anti-icing and anti-frost super-lubricating surface. The super-lubricating surface formed by the modified silicone oil impregnation of porous alumina substrate not only has good anti-icing performance and long-term hydrophobicity, but also has excellent anti-frost performance in harsh environments such as low temperature and high humidity.

[0022] Furthermore, the method for preparing an anti-icing and anti-frost super-lubricating surface provided by this invention uses few and inexpensive raw materials, and the method steps are simple. The obtained super-lubricating surface has good anti-icing and anti-frost properties and long-term hydrophobic properties. Therefore, the method is simple, feasible and effective, with low preparation cost and high economic benefits, and is worthy of application and promotion. Attached Figure Description

[0023] Figure 1 A flowchart illustrating a method for preparing an anti-icing, anti-frost, and super-lubricating surface according to an embodiment of the present invention;

[0024] Figure 2 The mechanism of silicone oil modification in the preparation method of an anti-icing and anti-frost super-lubricating surface provided in this embodiment of the invention is illustrated in the figure. Figure 3 The images show the changes in the macroscopic morphology of the superlubricated surfaces prepared by the superlubricated surface preparation methods provided in Example 1 and Comparative Examples 1-3 of this invention at 0.0h, 0.5h, 1.0h, and 1.5h. Figure 4 The images show the changes in the macroscopic morphology of the superlubricated surfaces prepared by the superlubricated surface preparation methods provided in Example 1 and Comparative Examples 4-6 of this invention at 0.0h, 0.5h, 1.0h, and 1.5h. Detailed Implementation

[0025] See Figure 1 The present invention provides a method for preparing an anti-icing, anti-frost, and super-lubricating surface, comprising the following steps: Step 1) Prepare a porous alumina substrate with a pore size of 100-150 nm and a porosity of 60-70% by anodizing.

[0026] The preparation method of the alumina substrate includes the following steps: 1) Use aluminum as the anode and stainless steel sheet as the cathode.

[0027] 2) Connect the anode and cathode wires to the DC power supply.

[0028] 3) Alumina is obtained by electrolysis in oxalic acid electrolyte.

[0029] 4) A porous alumina substrate is created by immersing alumina in a phosphoric acid solution at room temperature to expand its pores.

[0030] The concentration of the oxalic acid electrolyte is 0.2-0.3 mol / L, and the electrolysis current intensity is 0.1-0.2 A / cm. 2 The electrolysis time is 10-15 min.

[0031] The phosphoric acid solution has a mass percentage concentration of 5-10 wt%.

[0032] Step 2) The alumina substrate is modified by immersing it in an ethanol solution of hexadecyltrimethoxysilane to obtain a modified alumina substrate.

[0033] The mass fraction of the ethanol solution of hexadecyltrimethoxysilane immersed in the alumina substrate is 2-5%, and the immersion time is 30-60 min.

[0034] Furthermore, the modified alumina substrate obtained after being modified in an ethanol solution of hexadecyltrimethoxysilane needs to be dried in an oven after being removed from the ethanol solution of hexadecyltrimethoxysilane. The drying temperature is 100-130 °C and the drying time is 0.5-3 h.

[0035] Step 3) Mix silicone oil with n-hexadecyltrimethoxysilane to obtain modified silicone oil; When mixing silicone oil and n-hexadecyltrimethoxysilane, magnetic stirring is used for 2-5 minutes.

[0036] Furthermore, the modified silicone oil obtained by mixing silicone oil with n-hexadecyltrimethoxysilane has a mass fraction of 1-3% for n-hexadecyltrimethoxysilane.

[0037] Step 4) Modified silicone oil and modified alumina substrate are mixed by vacuum impregnation to obtain an anti-icing and anti-frost super-lubricating surface.

[0038] The method for preparing an anti-icing, anti-frost, and super-lubricating surface by vacuum impregnation of modified silicone oil and modified alumina substrate includes the following steps: 1) Place the modified alumina substrate in a vacuum container to remove air from the modified alumina substrate.

[0039] 2) The modified alumina substrate, which has been immersed in and de-aired, is injected through the inlet of a vacuum container, so that the modified silicone oil is impregnated into the porous structure on the surface of the modified alumina substrate.

[0040] 3) Remove the modified alumina substrate impregnated with modified silicone oil from the vacuum container and allow atmospheric pressure to further press the modified silicone oil into the porous structure of the modified alumina substrate.

[0041] The modified alumina substrate is placed in a vacuum container for 4-6 hours, and the modified silicone oil is immersed in the air-removed modified alumina substrate for 6-18 hours.

[0042] See Figure 2 This invention provides a method for preparing an anti-icing, anti-frost, and super-lubricating surface. The method involves adding 1-3% by mass of n-hexadecyltrimethoxysilane to silicone oil to modify it, resulting in a modified silicone oil. This is because one end of the n-hexadecyltrimethoxysilane molecule is a silicon atom bonded to three methoxy groups (-OCH3), while the other end is a long-chain n-hexadecyl (CH3(CH2)) group. 15 These three methoxy groups can be grafted onto the silicone oil molecular chain to form stable siloxane bonds (-Si-O-Si-), which is equivalent to introducing a large number of nonpolar long-chain alkyl functional groups into the silicone oil. According to the principle of "like dissolves like," the affinity between the nonpolar silicone oil surface and polar water molecules will be greatly reduced, making it difficult to form hydrogen bonds, thereby weakening the intermolecular forces between water and the lubricating surface.

[0043] The superlubricating surface formed by impregnating a porous alumina substrate with modified silicone oil can easily undergo a gas-liquid-solid phase change process under low temperature and high humidity conditions. A large number of condensed droplets are formed on the superlubricating surface, and they continue to aggregate and grow over time. After a sufficient period of time, only a small number of droplets, mainly distributed at the edge of the superlubricating surface, begin to freeze.

[0044] Therefore, the present invention provides a method for preparing an anti-icing and anti-frost super-lubricating surface by adding hexadecyltrimethoxysilane to silicone oil to modify the silicone oil to obtain modified silicone oil, and then impregnating a porous alumina substrate modified in an ethanol solution of hexadecyltrimethoxysilane with the modified silicone oil. The resulting super-lubricating surface not only maintains good anti-icing performance and long-term hydrophobicity, but also has excellent anti-frost performance in harsh environments such as low temperature and high humidity.

[0045] The following examples and comparative examples illustrate in detail the preparation method of the anti-icing and anti-frost super-lubricating surface provided by the present invention.

[0046] Example 1 Superlubricating surfaces were prepared using modified silicone oil with a viscosity of 200 cSt.

[0047] 1. Use aluminum as the anode and a stainless steel sheet as the cathode. Connect the cathode and anode to a DC power supply via wires, then place them in a 0.2-0.3 mol / L oxalic acid electrolyte solution at a current of 0.1-0.2 A / cm². 2 The anode aluminum is oxidized by an electric current for 10-15 minutes, and alumina is obtained by electrolysis. The alumina is then removed and immersed in a 5-10 wt% phosphoric acid solution at room temperature to expand the pores, thus obtaining a porous alumina substrate.

[0048] 2. Immerse the prepared porous alumina substrate in an ethanol solution of 2-5% n-hexadecyltrimethoxysilane for 30-60 minutes to complete the substrate modification; then take out the modified alumina substrate and dry it in an oven at 100-130℃ for 0.5-3 hours to obtain the modified alumina substrate.

[0049] 3. Add 1-3% of the total mass of hexadecyltrimethoxysilane to silicone oil (SO) with a viscosity of 200 cSt, and mix magnetically for 2-5 min. The resulting mixture is modified silicone oil, which is denoted as M-SO.

[0050] 4. Place the modified alumina substrate in a vacuum container and maintain it under vacuum for 5 hours to completely remove air. Inject modified silicone oil (M-SO) into the vacuum container through the inlet, completely immersing the modified alumina substrate. Maintain this for 6-18 hours to allow the modified silicone oil (M-SO) to slowly penetrate the porous structure of the modified alumina substrate surface. Then, remove the modified alumina substrate impregnated with modified silicone oil (M-SO) from the vacuum container and further press the modified silicone oil (M-SO) into the porous structure of the modified alumina substrate using atmospheric pressure, thereby completing the preparation of a superlubricating surface of modified silicone oil (M-SO) with a viscosity of 200 cSt.

[0051] The macroscopic morphology of frosting on a superlubricated surface (denoted as 200cSt M-SO SLIPS) prepared with modified silicone oil (M-SO) with a viscosity of 200 cSt in this embodiment of the invention is as follows: Figure 3 and Figure 4 As shown.

[0052] Comparative Example 1 Superlubricating surfaces were prepared using silicone oil with a viscosity of 20 cSt.

[0053] 1. Use aluminum as the anode and a stainless steel sheet as the cathode. Connect the cathode and anode to a DC power supply via wires, then place them in a 0.2-0.3 mol / L oxalic acid electrolyte solution at a current of 0.1-0.2 A / cm². 2 The anode aluminum is oxidized by an electric current for 10-15 minutes, and alumina is obtained by electrolysis. The alumina is then removed and immersed in a 5-10 wt% phosphoric acid solution at room temperature to expand the pores, thus obtaining a porous alumina substrate.

[0054] 2. Immerse the prepared porous alumina substrate in an ethanol solution of 2-5% n-hexadecyltrimethoxysilane for 30-60 minutes to complete the substrate modification; then take out the modified alumina substrate and dry it in an oven at 100-130℃ for 0.5-3 hours to obtain the modified alumina substrate.

[0055] 3. Place the modified alumina substrate in a vacuum container and maintain it under vacuum for 5 hours to completely remove air. Inject silicone oil (SO) with a viscosity of 20 cSt into the vacuum container through the inlet, completely immersing the modified alumina substrate. Maintain this for 6-18 hours to allow the silicone oil (SO) to slowly penetrate the porous structure of the modified alumina substrate surface. Then, remove the modified alumina substrate impregnated with the silicone oil (SO) with a viscosity of 20 cSt from the vacuum container and further press the silicone oil (SO) with a viscosity of 20 cSt into the porous structure of the modified alumina substrate using atmospheric pressure, thereby completing the preparation of the superlubricating surface of silicone oil (SO) with a viscosity of 20 cSt.

[0056] The macroscopic morphology of frosting on a superlubricated surface (denoted as 20cSt SOSLIPS) prepared with silicone oil (SO) with a viscosity of 20 cSt, as shown in the comparative example of this invention, is as follows. Figure 3 As shown.

[0057] Comparative Example 2 Superlubricated surfaces were prepared using silicone oil with a viscosity of 200 cSt.

[0058] 1. Use aluminum as the anode and a stainless steel sheet as the cathode. Connect the cathode and anode to a DC power supply via wires, then place them in a 0.2-0.3 mol / L oxalic acid electrolyte solution at a current of 0.1-0.2 A / cm². 2 The anode aluminum is oxidized by an electric current for 10-15 minutes, and alumina is obtained by electrolysis. The alumina is then removed and immersed in a 5-10 wt% phosphoric acid solution at room temperature to expand the pores, thus obtaining a porous alumina substrate.

[0059] 2. Immerse the prepared porous alumina substrate in an ethanol solution of 2-5% n-hexadecyltrimethoxysilane for 30-60 minutes to complete the substrate modification; then take out the modified alumina substrate and dry it in an oven at 100-130℃ for 0.5-3 hours to obtain the modified alumina substrate.

[0060] 3. Place the modified alumina substrate in a vacuum container and maintain it under vacuum for 5 hours to completely remove air. Inject silicone oil (SO) with a viscosity of 200 cSt into the vacuum container through the inlet, completely immersing the modified alumina substrate. Maintain this for 6-18 hours to allow the silicone oil (SO) to slowly penetrate into the porous structure of the modified alumina substrate surface. Then, remove the modified alumina substrate impregnated with the silicone oil (SO) with a viscosity of 200 cSt from the vacuum container and further press the silicone oil (SO) with a viscosity of 200 cSt into the porous structure of the modified alumina substrate using atmospheric pressure, thereby completing the preparation of the superlubricating surface of silicone oil (SO) with a viscosity of 200 cSt.

[0061] The macroscopic morphology of frosting on a superlubricated surface (denoted as 200 cSt SOSLIPS) prepared with silicone oil (SO) with a viscosity of 200 cSt, as shown in the comparative example of this invention, is as follows. Figure 3 As shown.

[0062] Comparative Example 3 Superlubricated surfaces were prepared using silicone oil with a viscosity of 1000 cSt.

[0063] 1. Use aluminum as the anode and a stainless steel sheet as the cathode. Connect the cathode and anode to a DC power supply via wires, then place them in a 0.2-0.3 mol / L oxalic acid electrolyte solution at a current of 0.1-0.2 A / cm². 2 The anode aluminum is oxidized by an electric current for 10-15 minutes, and alumina is obtained by electrolysis. The alumina is then removed and immersed in a 5-10 wt% phosphoric acid solution at room temperature to expand the pores, thus obtaining a porous alumina substrate.

[0064] 2. Immerse the prepared porous alumina substrate in an ethanol solution of 2-5% n-hexadecyltrimethoxysilane for 30-60 minutes to complete the substrate modification; then take out the modified alumina substrate and dry it in an oven at 100-130℃ for 0.5-3 hours to obtain the modified alumina substrate.

[0065] 3. Place the modified alumina substrate in a vacuum container and maintain it under vacuum for 5 hours to completely remove air. Inject 1000 cSt silicone oil (SO) into the vacuum container through the inlet, completely immersing the modified alumina substrate. Maintain this for 6-18 hours to allow the 1000 cSt silicone oil (SO) to slowly penetrate the porous structure of the modified alumina substrate surface. Then, remove the modified alumina substrate impregnated with 1000 cSt silicone oil (SO) from the vacuum container and further press the 1000 cSt silicone oil (SO) into the porous structure of the modified alumina substrate using atmospheric pressure, thus completing the preparation of the superlubricating surface of 1000 cSt silicone oil (SO).

[0066] The macroscopic morphology of frosting on a superlubricated surface (denoted as 1000 cSt SOSLIPS) prepared with silicone oil (SO) with a viscosity of 1000 cSt, as shown in the comparative example of this invention, is as follows. Figure 3 As shown.

[0067] Comparative Example 4 Superlubricated surfaces are prepared using perfluoropolyether oil (PFPE) as a lubricant.

[0068] 1. Use aluminum as the anode and a stainless steel sheet as the cathode. Connect the cathode and anode to a DC power supply via wires, then place them in a 0.2-0.3 mol / L oxalic acid electrolyte solution at a current of 0.1-0.2 A / cm². 2 The anode aluminum is oxidized by an electric current for 10-15 minutes, and alumina is obtained by electrolysis. The alumina is then removed and immersed in a 5-10 wt% phosphoric acid solution at room temperature to expand the pores, thus obtaining a porous alumina substrate.

[0069] 2. Modify the porous alumina substrate. Specific procedure: Immerse the alumina substrate in a 2-5% (w / w) perfluorodecyltriethoxysilane (FAS) ethanol solution for 30-60 minutes to complete the substrate modification; then remove the sample and dry it in an oven at 100-130 ℃ for 0.5-3 h.

[0070] 3. A vacuum impregnation method was used to inject perfluoropolyether oil (PFPE) into the modified anodized aluminum oxide substrate to prepare a super-lubricating and anti-icing surface of PFPE. The specific procedure was as follows: The modified substrate was placed in a vacuum chamber and kept under vacuum for 5 hours to completely remove air. Lubricant was injected into the chamber through the inlet valve, immersing the sample and maintaining this state for 6-18 hours to allow the perfluoropolyether oil (PFPE) to slowly penetrate into the porous structure of the sample surface. The sample was then removed from the vacuum chamber, and atmospheric pressure further propelled the lubricant into the nanopores.

[0071] The macroscopic morphology of frosting on the superlubricated surface (denoted as PFPE SLIPS) prepared using perfluoropolyether oil (PFPE) as a lubricant in this comparative example is as follows: Figure 4 As shown.

[0072] Comparative Example 5 Superlubricated surfaces were prepared using electronic fluorinated fluid (FC70).

[0073] 1. Use aluminum as the anode and a stainless steel sheet as the cathode. Connect the cathode and anode to a DC power supply via wires, then place them in a 0.2-0.3 mol / L oxalic acid electrolyte solution at a current of 0.1-0.2 A / cm². 2 The anode aluminum is oxidized by an electric current for 10-15 minutes, and alumina is obtained by electrolysis. The alumina is then removed and immersed in a 5-10 wt% phosphoric acid solution at room temperature to expand the pores, thus obtaining a porous alumina substrate.

[0074] 2. Modify the porous alumina substrate. Specific procedure: Immerse the alumina substrate in a 2-5% (w / w) perfluorodecyltriethoxysilane (FAS) ethanol solution for 30-60 minutes to complete the substrate modification; then remove the sample and dry it in an oven at 100-130 degrees Celsius for 0.5-3 hours.

[0075] 3. An electronic fluorinated liquid FC70 was injected into the modified anodized aluminum oxide substrate using a vacuum impregnation method to prepare the super-lubricating and anti-icing surface of FC70. The specific procedure was as follows: The modified substrate was placed in a vacuum chamber and kept under vacuum for 5 hours to completely remove air. The lubricant was injected into the chamber through the inlet valve, immersing the sample and maintaining this state for 6-18 hours to allow the lubricant (FC70) to slowly penetrate into the porous structure of the sample surface. The sample was then removed from the vacuum chamber, and atmospheric pressure further propelled the lubricant into the nanopores.

[0076] The macroscopic morphology of frosting on the superlubricated surface (denoted as FC70 SLIPS) prepared using electronic fluorinated liquid (FC70) as a lubricant in this comparative example is as follows: Figure 4 As shown.

[0077] Comparative Example 6 Superlubricated surfaces are prepared using mineral oil (MO).

[0078] 1. Use aluminum as the anode and a stainless steel sheet as the cathode. Connect the cathode and anode to a DC power supply via wires, then place them in a 0.2-0.3 mol / L oxalic acid electrolyte solution at a current of 0.1-0.2 A / cm². 2 The anode aluminum is oxidized by an electric current for 10-15 minutes, and alumina is obtained by electrolysis. The alumina is then removed and immersed in a 5-10 wt% phosphoric acid solution at room temperature to expand the pores, thus obtaining a porous alumina substrate.

[0079] 2. Modify the porous alumina substrate. Specific procedure: Immerse the alumina substrate in a 2-5% (w / w) hexadecyltrimethoxysilane (OTS) ethanol solution for 30-60 minutes to complete the substrate modification; then remove the sample and dry it in an oven at 100-130 degrees Celsius for 0.5-3 hours.

[0080] 3. A vacuum impregnation method was used to inject mineral oil (MO) into the modified anodic alumina substrate to prepare a superlubricating and anti-icing surface of MO. The specific procedure was as follows: The modified substrate was placed in a vacuum chamber and kept under vacuum for 5 hours to completely remove air. Lubricant was injected into the chamber through the inlet valve, immersing the sample and maintaining this state for 6-18 hours to allow the lubricant (MO) to slowly penetrate the porous structure of the sample surface. The sample was then removed from the vacuum chamber, and atmospheric pressure further propelled the lubricant into the nanopores.

[0081] The macroscopic morphology of frosting on the superlubricated surface (denoted as MO SLIPS) prepared using mineral oil (MO) as a lubricant in this comparative example is as follows: Figure 4 As shown.

[0082] Comparative Example 7 Superlubricated surfaces were prepared using ionic liquids (BMIm).

[0083] 1. Use aluminum as the anode and a stainless steel sheet as the cathode. Connect the cathode and anode to a DC power supply via wires, then place them in a 0.2-0.3 mol / L oxalic acid electrolyte solution at a current of 0.1-0.2 A / cm². 2 The anode aluminum is oxidized by an electric current for 10-15 minutes, and alumina is obtained by electrolysis. The alumina is then removed and immersed in a 5-10 wt% phosphoric acid solution at room temperature to expand the pores, thus obtaining a porous alumina substrate.

[0084] 2. Modify the porous alumina substrate. Specific procedure: Immerse the alumina substrate in a 2-5% (w / w) perfluorodecyltriethoxysilane (FAS) ethanol solution for 30-60 minutes to complete the substrate modification; then remove the sample and dry it in an oven at 100-130 degrees Celsius for 0.5-3 hours.

[0085] 3. An ionic liquid (BMIm) was injected into the modified anodic alumina substrate using a vacuum impregnation method to prepare a superlubricating and anti-icing surface for BMIm. The specific procedure was as follows: The modified substrate was placed in a vacuum chamber and kept under vacuum for 5 hours to completely remove air. The lubricant was then injected into the chamber through the inlet valve, immersing the sample. This process was maintained for 6-18 hours to allow the lubricant (BMIm) to slowly penetrate the porous structure of the sample surface. The sample was then removed from the vacuum chamber, and atmospheric pressure further propelled the lubricant into the nanopores.

[0086] The macroscopic morphology of frosting on the superlubricated surface (denoted as BMIm SLIPS) prepared using an ionic liquid (BMIm) as a lubricant in this comparative example is as follows: Figure 4 As shown.

[0087] See Figure 3 ,from Figure 3As can be seen, compared with the superlubricated surfaces (SLIPS) prepared using unmodified silicone oils of different viscosities in Comparative Examples 1-3, the superlubricated surface prepared with modified silicone oil of 200 cSt (denoted as 200 cSt M-SO SLIPS) in Example 1 of this invention exhibits a significant advantage in delaying frost formation. A clear gas-liquid-solid phase transition process was observed on the superlubricated surface (denoted as 200 cSt M-SO SLIPS) prepared in Example 1 of this invention, with a large number of condensed droplets forming on the surface, which continued to coalesce and grow over time. After 1.5 hours, only a small number of droplets (mainly distributed in the edge region) began to freeze. For unmodified silicone oil, an increase in lubricant viscosity significantly increased the frosting rate of the superlubricated surface. When the silicone oil viscosity was 20 cSt, water vapor first condensed into water droplets, which continuously coalesced and grew on the surface. As time increased, the condensed water droplets gradually froze, and at 1.5 h, nearly two-thirds of the water droplets on the surface had frozen. As the viscosity of the silicone oil continues to increase (≥200 cSt), frost crystals form directly on the surface without obvious liquid water droplets. The migration and growth of condensed micro-droplets on the high-viscosity silicone oil surface are difficult, the merging of water droplets is interrupted, and the distance between water droplets shortens, thus promoting frost propagation and ultimately forming a frost layer composed of fine frost crystals. Therefore, although the frost layer expansion rate of the superlubricating surface prepared with silicone oil increases with increasing silicone oil viscosity, the anti-frost performance of the superlubricating surface prepared with modified high-viscosity silicone oil is still superior to that prepared with low-viscosity silicone oil.

[0088] See Figure 4 ,from Figure 4As can be seen, compared with superlubricated surfaces (SLIPS) prepared using other types of lubricants, the superlubricated surface prepared with modified silicone oil with a viscosity of 200 cSt (denoted as 200 cSt M-SO SLIPS) in this embodiment of the invention exhibits a significant advantage in delaying frost formation. A clear gas-liquid-solid phase transition process was observed on the superlubricated surface (denoted as 200 cSt M-SO SLIPS) prepared in Example 1 of the invention, with a large number of condensed droplets forming on the surface, which continued to aggregate and grow over time. After 1.5 hours, only a small number of droplets (mainly distributed in the edge region) began to freeze. After 1.5 h, frost formation appeared on the surface of the perfluoropolyether oil (PFPE)-based superlubricating surface (SLIPS), with the frozen droplets showing a tendency to spread towards the center. Due to the larger surface droplet contact area of ​​the ionic liquid BMIm-based superlubricating surface (SLIPS), the freezing rate of the condensed droplets on its surface was the fastest. The surface of the electronic fluorinated liquid FC70-based superlubricating surface (SLIPS) had certain anti-frost properties, and the hydrophobic substrate surface could delay the freezing process of the condensed droplets. The condensed droplets on the surface of the mineral oil MO-based superlubricating surface (SLIPS) began to freeze at the edge of the sample after 1 h, and the frozen area further expanded after 1.5 h.

[0089] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing an anti-icing, anti-frost, super-lubricating surface, characterized in that, Includes the following steps: A porous alumina substrate with a pore size of 100-150 nm and a porosity of 60-70% was prepared by anodizing. Modified alumina substrate is obtained by immersing an alumina substrate in an ethanol solution of n-hexadecyltrimethoxysilane. Modified silicone oil is obtained by stirring and mixing silicone oil with n-hexadecyltrimethoxysilane; A super-lubricating, anti-icing, and anti-frost surface was prepared by vacuum impregnation of modified silicone oil and modified alumina substrate.

2. The method for preparing an anti-icing, anti-frost, and super-lubricating surface according to claim 1, characterized in that, The method for preparing the alumina substrate includes: Aluminum is used as the anode and stainless steel sheet is used as the cathode; Connect the anode and cathode leads to a DC power supply; Alumina is obtained by electrolysis in oxalic acid electrolyte; A porous alumina substrate is created by immersing alumina in a phosphoric acid solution at room temperature to expand its pores.

3. The method for preparing the anti-icing, anti-frost, and super-lubricating surface according to claim 2, characterized in that, The concentration of the oxalic acid electrolyte is 0.2-0.3 mol / L, and the electrolysis current intensity is 0.1-0.2 A / cm. 2 The electrolysis time is 10-15 min.

4. The method for preparing the anti-icing, anti-frost, and super-lubricating surface according to claim 3, characterized in that, The phosphoric acid solution has a mass percentage concentration of 5-10 wt%.

5. The method for preparing an anti-icing, anti-frost, and super-lubricating surface according to claim 1, characterized in that, The mass fraction of the ethanol solution of the alumina-based modified hexadecyltrimethoxysilane is 2-5%, and the alumina-based modification time is 30-60 min.

6. The method for preparing an anti-icing, anti-frost, and super-lubricating surface according to claim 5, characterized in that, The modified alumina substrate obtained by modifying the alumina substrate in an ethanol solution of hexadecyltrimethoxysilane needs to be dried at 100-130℃ for 0.5-3 h.

7. The method for preparing an anti-icing, anti-frost, and super-lubricating surface according to claim 1, characterized in that, The silicone oil and n-hexadecyltrimethoxysilane are mixed by magnetic stirring for 2-5 minutes.

8. The method for preparing an anti-icing, anti-frost, and super-lubricating surface according to claim 7, characterized in that, The modified silicone oil contains 1-3% hexadecyltrimethoxysilane by mass.

9. The method for preparing an anti-icing, anti-frost, and super-lubricating surface according to claim 1, characterized in that, The method for preparing an anti-icing, anti-frost, and super-lubricating surface by vacuum impregnation of modified silicone oil and modified alumina substrate includes: The modified alumina substrate was placed in a vacuum container to remove air from the modified alumina substrate; The modified alumina substrate, which has been immersed in and de-aired, is injected through the inlet of a vacuum container, allowing the modified silicone oil to penetrate into the porous structure on the surface of the modified alumina substrate. The modified alumina substrate impregnated with modified silicone oil is removed from the vacuum container, and atmospheric pressure is used to further press the modified silicone oil into the porous structure of the modified alumina substrate.

10. The method for preparing an anti-icing, anti-frost, and super-lubricating surface according to claim 9, characterized in that, The modified alumina substrate is placed in a vacuum container for 4-6 hours, and the modified silicone oil is immersed in the air-removed modified alumina substrate for 6-18 hours.

Images