Preparation method of stable and efficient super-hydrophobic anti-icing coating

Abstract

The invention discloses a preparation method of a stable and efficient super-hydrophobic anti-icing coating, and aims to solve the technical bottlenecks that an existing super-hydrophobic anti-icing coating is narrow in base material adaptability, easy to fall off, poor in hydrophobic-anti-icing performance stability, high in industrial production difficulty and the like. The method is carried out through four core process links in sequence: firstly, substrate pretreatment is carried out, surface impurities are removed through ultrasonic cleaning, then, femtosecond laser is adopted for substrate surface machining, a micro-nano composite rough structure is constructed on the surface of the substrate, and a high-hydrophilicity substrate is prepared; secondly, the substrate subjected to laser processing is placed in acid liquor to be soaked, surface oxides and impurities are removed, and the coating performance of the coating is prevented from being affected; dispersing the carbon-based functional material into a polydimethylsiloxane (PDMS) matrix, adding a curing agent after the carbon-based functional material is uniformly dispersed, and coating the surface of a substrate with the curing agent to complete coating curing; and finally, femtosecond laser is adopted to process the cured sample, a coating surface microstructure is constructed, and finally the super-hydrophobic anti-icing material is obtained. The preparation method is simple and efficient, the substrate adaptability is wide, the process parameter controllability is high, and the large-scale production requirements of anti-icing components in the fields of traffic, electric power, aerospace and the like can be met.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a stable and efficient super-hydrophobic anti-icing coating, and belongs to the technical field of multi-substrate adaptive functional coating. BACKGROUND

[0002] With the improvement of the reliability requirements of equipment in extreme environments in the fields of transportation, power transmission and aerospace, the super-hydrophobic anti-icing coating has become a research hotspot in the field of functional coating in recent years because it can achieve passive anti-icing by reducing the adhesion of liquid drops and the adhesion strength of ice. The technical core of the super-hydrophobic anti-icing coating is to achieve the anti-icing effect through the synergistic effect of "structure regulation + component optimization": on the one hand, by constructing a micro-nano multi-level structure combining micron-level protrusions and nano-level fluff, the actual contact area of water drops with the surface of the coating is greatly reduced, the water contact angle is stably greater than 150 degrees, the rolling angle is less than 10 degrees, the water drops are quickly rolled off on the surface, and the formation and growth of ice nuclei are inhibited from the source; on the other hand, by introducing polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE) and other low surface energy substances, the adhesion of water molecules to the surface of the coating is reduced, and even if the environmental temperature is too low to cause a small amount of icing, the ice layer can be removed under the action of slight external forces such as wind and vibration, realizing the dual functions of "anti-icing + deicing". However, the current mainstream preparation methods in the industry, such as sol-gel method, chemical vapor deposition method, template method and traditional laser processing method, still have many technical bottlenecks (poor substrate adaptability, easy delamination of light metal surface, difficult uniformity of composite material surface, easy damage of substrate by pretreatment, insufficient stability of coating, imbalance between preparation efficiency and cost, etc.).

[0003] In view of the above problems, the patent proposes a femtosecond laser processing and PDMS-carbon-based material composite coating process, which prepares a low-damage and high-wetting substrate surface structure by femtosecond laser, and enhances the combination of the substrate and the coating by chemical treatment, effectively solving the problem of anti-icing coating falling off. At the same time, by efficiently processing the PDMS-carbon-based material composite coating, a primary, secondary or even multi-level microstructure is formed, which significantly enhances the hydrophilic property and anti-icing property of the material; the carbon-based material can further reduce the surface energy of the coating through synergistic action with PDMS to enhance the passive anti-icing ability, form a heat conduction network to assist active ice melting, strengthen the mechanical property of the coating to avoid structure collapse, and optimize the dispersion uniformity and improve the environmental tolerance. The patent can provide a stable and low-cost anti-icing solution for multiple fields, and has important innovation value and application prospect. SUMMARY

[0004] In view of the deficiencies of the prior art, in order to improve the preparation efficiency of the super-hydrophobic anti-icing material and improve the overall performance of the sample, the application provides a preparation method of a stable and efficient super-hydrophobic anti-icing coating.

[0005] The application discloses a preparation method of a stable and efficient super-hydrophobic anti-icing coating.

[0006] (1) First, the substrate is polished by using 400, 600, 800 and 1200 mesh crystal phase sandpaper, and then is ultrasonically cleaned for 10 minutes, and after being taken out, is repeatedly cleaned by using acetone, anhydrous ethanol and deionized water to remove surface grease and dust, and is dried by using high-purity argon. Then, the substrate is surface processed by using a femtosecond laser, and appropriate processing parameters are adjusted, so that a high-hydrophilic substrate is obtained;

[0007] (2) The processed substrate is placed in acid liquor, is soaked for a period of time, and then is repeatedly cleaned by using deionized water until neutral, and is dried in a vacuum drying box;

[0008] (3) A certain amount of carbon-based material is added into PDMS, and is uniformly dispersed by magnetic stirring. Then, a curing agent is added in a proportion of 10:1, and the mixture is continuously stirred until uniform, so that a coating is obtained. The coating is uniformly applied to the surface of the substrate after the surface oxide is removed, and is heated in a vacuum drying box at 80 DEG C for 2 hours, so that the curing of the coating is completed;

[0009] (4) The sample after curing is placed on a laser processing platform, the height and position of the platform are adjusted, so that the surface of the sample is located at the designed position. The surface microstructure of the PDMS is prepared by setting appropriate laser processing parameters, and then, the sample is cleaned and dried by using ultra-pure argon, so that the preparation of the stable and efficient super-hydrophobic anti-icing material is completed.

[0010] Further, the oxide of the substrate material in step (1) is one of low-carbon steel, aluminum alloy, magnesium alloy, titanium alloy and composite material;

[0011] Further, the femtosecond laser processing parameters in step (1) are as follows: the center wavelength is 200-1200 nm, the pulse width is 10-300 fs, the repetition frequency is 50-200 kHz, the average power is 1-30 W, the scanning speed is 50-500 mm / s, and the single-pulse energy is 50-200 muJ;

[0012] Further, the acid liquor in step (2) is one of hydrochloric acid, phosphoric acid, sulfuric acid and nitric acid with a mass fraction of 3%-8%, the acid liquor soaking time is 0.5-3 hours, the vacuum drying temperature is 60-120 DEG C, and the drying time is 0.5-3 hours;

[0013] Further, the carbon-based material in step (3) is one of graphite, carbon nanotube and graphene;

[0014] Further, the thickness of the coating on the surface of the substrate in step (3) is 100-1000 mu m.

[0015] Further, the laser processing parameters in the step (4) are set as: central wavelength 200-600 nm, pulse width 10-300 fs, repetition frequency 1-100 kHz, average power 0.01-5 W, scanning speed 1-1000 mm / s, and single pulse energy 1-50 muJ.

[0016] With respect to others, the preparation method of the stable and efficient super-hydrophobic anti-icing coating has the advantages that:

[0017] (1) In the present application, by designing the surface microstructure, the substrate and the PDMS coating are combined more firmly, effectively solving the problem of easy peeling of the anti-icing coating; (2) In the present application, the substrate is more adaptable and the pretreatment is non-damaging, breaking through the material limitations and greatly widening the application substrate range of the super-hydrophobic anti-icing coating

[0018] At the same time, the material cost is low, and the femtosecond laser processing does not need to customize the template and the amount of chemical reagent is small, so the overall preparation cost is lower than that of the chemical vapor deposition method, and the coating has a long service life;

[0019] (3) The present application uses a hydrophobic coating combined with femtosecond laser processing (high precision, no need for complex post-processing), which not only shortens the processing period, but also realizes efficient processing of large-area and irregular substrates, has higher preparation efficiency, and avoids the "low efficiency and high consumption" problem of traditional processes;

[0020] (4) The material prepared by the present application has better comprehensive performance and can resist wear, cold and hot cycles and other harsh environments, significantly improving the stability and service life, solving

[0021] the "weak anti-icing and easy failure" pain points;

[0022] (5) In the present application, the whole process optimization of "substrate pretreatment-coating preparation-coating modification" is formed, and the multiple pain points of "poor substrate adaptation, coating easy to fail, and unbalanced efficiency and cost" in the prior art are systematically solved, realizing the integrated anti-icing solution of "stability, efficiency and low cost". BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a flowchart of the preparation of the super-hydrophobic anti-icing material by laser processing technology in the present application;

[0024] Figure 2 is a contact angle diagram of the super-hydrophobic anti-icing surface obtained in Example 1. DETAILED DESCRIPTION

[0025] To make the purpose, technical scheme and advantages of the present application clearer and more explicit, the present application will be further described in detail below with reference to the specific embodiments and the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application.

[0026] Example 1:

[0027] (1) The magnesium alloy substrate purchased was polished using 400, 600, 800 and 1200 mesh crystal phase sandpaper to reduce the surface roughness. The processed surface was cleaned with acetone, anhydrous ethanol and deionized water to remove surface debris and dried with argon gas for use;

[0028] (2) The substrate was placed on the laser processing platform, and the platform height was adjusted so that the laser was focused on the sample surface. An infrared femtosecond laser with a central wavelength of 1030 nm, a pulse width of 209 fs, a repetition frequency of 100 kHz, an average power of 5 W and a scanning speed of 50 mm / s was used for processing to obtain a substrate with a microgroove surface structure;

[0029] (3) The substrate was ultrasonically cleaned for 10 min and immersed in a 5% hydrochloric acid solution for 40 min. After removal, it was repeatedly cleaned with deionized water and dried in a vacuum drying oven at 80°C for standby use;

[0030] (4) 1 g of graphene was dispersed in 10 mL of toluene solution, and magnetic stirring and ultrasonic treatment were used to disperse it uniformly. 3 g of PDMS was measured and 1 mL of graphene solution was added, and the two were thoroughly mixed by magnetic stirring. 0.3 g of curing agent was added, and after thorough stirring, the solution was evenly coated on the surface of the substrate and placed in a vacuum drying oven for curing at 80°C under vacuum conditions for 2 h. After curing, it was removed, repeatedly cleaned with deionized water and dried with argon gas for standby use;

[0031] (5) The PDMS-coated substrate was placed on the femtosecond laser processing platform, and the platform height was adjusted so that the laser was in a positive defocusing state. The material was processed using an ultraviolet femtosecond laser with a central wavelength of 342 nm, a pulse width of 209 fs, a repetition frequency of 1 kHz, an average power of 100 mW and a scanning speed of 3 mm / s to obtain a surface microstructure with a combination of nanoparticles and nanocolumns. The processed surface was repeatedly cleaned with acetone, anhydrous ethanol and deionized water to remove surface residues, and the preparation of the superhydrophobic anti-icing material was completed after drying with argon gas.

[0032] It should be understood that the above specific embodiments of the present application are only used for illustrative or explanatory purposes of the principles of the present application, and do not constitute a limitation on the present application. Therefore, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present application shall be included within the protection scope of the present application. In addition, the appended claims of the present application are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A method for preparing a stable and efficient superhydrophobic anti-icing coating, characterized in that... ， A method for preparing a stable and efficient superhydrophobic anti-icing coating, characterized by comprising the following steps: (1) First, the substrate is polished with 400, 600, 800 and 1200 grit crystal phase sandpaper, followed by 10 minutes of ultrasonic cleaning. After removal, the substrate is repeatedly cleaned with acetone, anhydrous ethanol and deionized water to remove surface grease and dust, and then dried with high-purity argon gas. Next, a femtosecond laser is used to adjust the appropriate processing parameters to perform surface processing on the substrate, resulting in a highly hydrophilic substrate. (2) Place the processed substrate into the acid solution and soak it for a period of time to remove the oxide layer on the surface. Then wash it repeatedly with deionized water until it is neutral and place it in a vacuum drying oven to dry. (3) Weigh a certain amount of carbon-based material and add it to PDMS. Stir it magnetically to disperse it evenly. Then, add the curing agent at a ratio of 10:1 and continue stirring until the mixture is uniform to obtain the coating. Apply the coating evenly to the substrate surface after surface oxide removal and place it in a vacuum drying oven at 80℃ for 2 hours to complete the curing of the coating. (4) Place the cured sample on the laser processing platform, and adjust the platform height and position to position the sample surface in the designed location. By setting appropriate laser processing parameters, the microstructure of the PDMS surface is prepared. Subsequently, the sample is cleaned and dried with ultrapure argon gas to complete the preparation of a stable and efficient hydrophobic anti-icing material.

2. The method for preparing a stable and efficient superhydrophobic anti-icing coating according to claim 1, characterized in that, In step (1), the matrix material is one of the following: low carbon steel, aluminum alloy, magnesium alloy, titanium alloy, and composite material.

3. The method for preparing a stable and efficient superhydrophobic anti-icing coating according to claim 1, characterized in that, The femtosecond laser processing parameters in step (1) are: center wavelength 200-1200nm, pulse width 10-300fs, repetition frequency 50-200kHz, average power 1-30W, scanning speed 50-500mm / s, and single pulse energy 50-200μJ.

4. The method for preparing a stable and efficient superhydrophobic anti-icing coating according to claim 1, characterized in that, In step (2), the acid solution is one of hydrochloric acid, phosphoric acid, sulfuric acid, or nitric acid with a mass fraction of 3%-8%. The acid solution soaking time is 0.5-3 hours, the vacuum drying temperature is 60-120℃, and the drying time is 0.5-3 hours.

5. The method for preparing a stable and efficient superhydrophobic anti-icing coating according to claim 1, characterized in that, In step (3), the carbon-based material is one of graphite, carbon nanotubes, or graphene.

6. The method for preparing a stable and efficient superhydrophobic anti-icing coating according to claim 1, characterized in that, In step (3), the thickness of the coating on the substrate surface is 100-1000 μm.

7. The method for preparing a stable and efficient superhydrophobic anti-icing coating according to claim 1, characterized in that, In step (4), the laser processing parameters are set as follows: center wavelength 200-600nm, pulse width 10-300fs, repetition frequency 1-100kHz, average power 0.01-5W, scanning speed 1-1000mm / s, and single pulse energy 1-50μJ.

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