Preparation method of fluoride-free firm photo-thermal super-hydrophobic anti-icing coating

Abstract

The invention discloses a preparation method of a fluoride-free firm photo-thermal super-hydrophobic anti-icing coating, which comprises the following steps: S1, cleaning the surface of a base material: cleaning the surface of the base material by adopting one or more treatments such as abrasive paper polishing, alcohol and the like; s2, preparing a coating, namely mixing 100 parts of epoxy resin A and epoxy resin B, 6.2-36 parts of a PDMS prepolymer, 0.5-2 parts of a PDMS curing agent, 1-5 parts of carbon nanotubes, 40-50 parts of silicon dioxide and 250-300 parts of alcohol, stirring the mixed solution on a magnetic stirrer at a high speed for 20-50 minutes at room temperature, spraying a uniform suspension obtained by magnetic stirring onto a pre-treated base material, curing for 20-10 hours at room temperature to 110 DEG C, and drying to obtain the coating. The components of the prepared coating are fluoride-free components, the coating has a multi-stage micro-nano structure and a compact nano structure, the contact angle of the coating is larger than 150 degrees, meanwhile, the coating has mechanical and chemical stability, excellent liquid drop bounce performance and high-speed water flow puncture resistance, and the coating has the advantages of being green, environmentally friendly and suitable for large-area preparation; the method has remarkable progress in the field of preparation of super-hydrophobic coatings.

Description

Technical Field

[0001] The invention belongs to the technical field of material surface treatment, and in particular relates to a method for preparing a fluorine-free strong super hydrophobic coating which can be prepared on a large area and has excellent droplet bouncing performance and resistance to high-speed water flow puncture. Background Art

[0002] The research on super-hydrophobicity has been and has been in rapid development for a long time, and the existing research and development of super-hydrophobic coating technology have indeed solved many bottleneck problems that hinder its application, such as poor mechanochemical stability, low efficiency, complex process, use of potentially harmful fluorine-containing low surface energy materials, poor resistance to high-speed water flow puncture, poor water droplet bouncing performance, etc. Excellent super-hydrophobic properties, including droplet bouncing performance and resistance to high-speed water flow impact, play an important role in the self-cleaning, corrosion resistance, and ice prevention of super-hydrophobic coatings outdoors. However, most of the super-hydrophobic coatings with excellent mechanochemical stability, droplet bouncing performance, and resistance to high-speed water flow puncture performance currently use fluorine-containing materials to reduce the surface energy of the coating system or complex preparation processes. Fluorine-containing materials have long-term potential hazards to the environment and humans. Complex preparation processes are difficult to apply on a large scale. The development of photothermal super-hydrophobic coatings with excellent mechanochemical stability, droplet bouncing performance, and resistance to high-speed water flow impact through fluorine-free components is of great significance for ice prevention. Super-hydrophobic coatings usually use epoxy resins, polyurethanes, etc. as film-forming materials to achieve excellent mechanical properties. These film-forming materials are often hydrophilic, so some hydrophobic substances are needed to reduce the surface energy of the system. However, in order to obtain excellent bouncing performance and high-speed water flow puncture resistance, this type of coating is often added by adding fluorine-containing curing agents, components or fluorine-modified low surface energy micro-nanoparticles. This is mainly because fluorine-containing materials often have lower surface energy than fluorine-free components, and can better reduce the surface energy of the coating. Fluorine-free super-hydrophobic coatings with excellent mechanochemical stability are often difficult to obtain excellent bouncing performance and water flow puncture resistance. Fluorine-containing materials have potential environmental and human hazards. A large number of studies have shown that fluorine-containing materials are closely related to some human diseases. From an environmental protection perspective, it is extremely important to avoid the use of fluorine-containing materials in production and application. At the same time, the composition is only part of the coating performance. To achieve a high-performance super-hydrophobic coating, it is also necessary to imitate the high-density nanostructure on the surface of the lotus leaf. Therefore, how to use large-scale spraying technology to prepare a fluorine-free strong photothermal super-hydrophobic coating with excellent droplet bouncing performance and high-speed water flow puncture resistance is a problem that needs to be solved urgently. Photothermal anti-icing coatings make full use of clean and widespread solar energy. By combining photothermal properties with the low ice adhesion characteristics of superhydrophobic properties, surface ice can be quickly removed to achieve excellent active and passive anti-icing performance. Therefore, this paper proposes a method for preparing a fluorine-free, strong photothermal superhydrophobic coating with droplet bouncing performance and resistance to high-speed water puncture, which can be widely used in many fields. Summary of the invention

[0003] This study uses epoxy resin, PDMS prepolymer (polydimethylsiloxane), fluorine-free hydrophobic modified nano-silica, and a uniform suspension prepared by multi-walled carbon nanotubes to prepare a super-hydrophobic coating on a variety of materials by spraying, thereby achieving the surface super-hydrophobicity of the material. The designed super-hydrophobic coating is that the film-forming material is epoxy resin, which can provide strong adhesion and mechanical properties for the super-hydrophobic coating. The core of this patent is that the surface energy of the system is reduced by the synergistic effect of high content of hydrophobic nano-silica and polydimethylsiloxane. At the same time, the high volume fraction of SiO 2 The synergistic effect of nanoparticles and carbon nanotubes can form a multi-level micro-nano composite structure. In particular, its surface has a dense nanostructure. This is the key to achieving excellent super-hydrophobic performance, bouncing performance and impact resistance. At the same time, the coating has good photothermal performance and photothermal deicing performance. The coating can still maintain good bouncing ability in an environment of -30°C, avoid water droplet icing, and has excellent passive anti-icing ability; the coating also has excellent photothermal anti-icing performance, which can achieve rapid melting of surface ice. This super-hydrophobic coating with excellent active and passive anti-icing performance has a good application prospect in the field of anti-icing. The preparation method of this new fluorine-free photothermal super-hydrophobic anti-icing coating can be prepared on a large surface only by mechanical stirring and one-step spraying, and the raw material cost used is low, so it can be widely promoted and applied. The coating uses ethanol as a solvent and has good environmental protection. This simple, low-cost, green and high-performance super-hydrophobic coating has broad application prospects in different fields. The purpose of the present invention is achieved through the following technical solutions:

[0004] A method for preparing a fluorine-free strong photothermal super-hydrophobic anti-icing coating comprises the following steps:

[0005] S1: Cleaning the substrate surface: Use one or more methods such as sandpaper polishing and alcohol to treat and clean the substrate surface. If the substrate surface is clean or some clean surfaces are not required to be treated;

[0006] S2: Prepare the coating: 100 parts of epoxy resin A and B, 6.2-36 parts of PDMS prepolymer, 0.5-2 parts of PDMS curing agent, 1-5 parts of carbon nanotubes, 40-50 parts of silica, and 250-300 parts of alcohol. Stir the mixed solution at high speed on a magnetic stirrer for 20-50 minutes at room temperature. Spray the uniform suspension obtained by magnetic stirring onto the pre-treated substrate and cure it at room temperature to 110°C for 20 minutes to 10 hours.

[0007] The silicon dioxide is fluorine-free hydrophobically modified nano silicon dioxide.

[0008] Compared with the prior art, the present invention has the following beneficial effects:

[0009] The present invention provides a method for preparing a fluorine-free, strong photothermal super hydrophobic anti-icing coating with excellent droplet bouncing performance and resistance to high-speed water flow puncture. The coating is composed of fluorine-free components, and the coating has a multi-level micro-nano structure and a dense nanostructure. Its contact angle is greater than 150°. It also has mechanochemical stability, excellent droplet bouncing performance and resistance to high-speed water flow puncture. It is green, environmentally friendly, and suitable for large-area preparation. The invention has made significant progress in the field of super hydrophobic coating preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Contact angle and surface morphology of super hydrophobic coating;

[0011] Figure 2 This is a graph showing the water flow puncture resistance performance of the superhydrophobic coating;

[0012] Figure 3 This is a diagram showing the excellent bouncing performance of the super-hydrophobic coating;

[0013] Figure 4 This is the contact angle effect diagram of the super hydrophobic coating after acid and alkali immersion;

[0014] Figure 5 This is the contact angle effect diagram of Taber wear load 250g test for 100 cycles;

[0015] Figure 6 This is a picture of the effect of supercooled water droplets bouncing off the surface of the superhydrophobic coating in an environment of -30℃;

[0016] Figure 7 This is a photothermal performance effect diagram of the super-hydrophobic coating;

[0017] Figure 8 This is a photothermal deicing performance effect diagram of the super-hydrophobic coating;

[0018] Fig. 9 The effect diagram of super hydrophobic coating being suitable for different substrates. DETAILED DESCRIPTION

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0020] Embodiment 1:

[0021] A method for preparing a fluorine-free strong photothermal super-hydrophobic anti-icing coating comprises the following steps:

[0022] S1: Cleaning the substrate surface: Use one or more methods such as sandpaper polishing and alcohol to treat and clean the substrate surface. If the substrate surface is clean or some clean surfaces are not required to be treated;

[0023] S2: Prepare the coating: mix 100 parts of epoxy resin A and B, 22 parts of PDMS prepolymer, 2 parts of PDMS curing agent, 4 parts of multi-walled carbon nanotubes, 40 parts of silica, and 250 parts of alcohol. Stir the mixed solution at high speed on a magnetic stirrer for 50 minutes at room temperature. Spray the uniform suspension obtained by magnetic stirring onto the pre-treated substrate and cure it at 90°C for 30 minutes.

[0024] The prepared super-hydrophobic coating has a multi-level micro-nano structure and a dense nanostructure, with a contact angle of 164.8° ( Figure 1 ), the rolling angle is about 1°, the coating has excellent resistance to high-speed water flow impact, and there is no obvious water puncture phenomenon on the surface after about 4 seconds of water flow impact at a speed of 12m / s and a diameter of about 5mm ( Figure 2 A water drop falling from 12cm can bounce 17 times, which has excellent bouncing performance ( Figure 3 ). After the coating was immersed in a strong acid with pH = 0 for 24 hours, the contact angle of the coating was 161.9° ( Figure 4 ), the rolling angle is still 1°, and after immersion in a strong base of pH = 13 for 24 hours, the contact angle of the coating is 160.9° ( Figure 4 ), the rolling angle is still 1°, proving that the coating has excellent chemical stability. After 100 cycles of Taber wear load 250g test, the contact angle of the coating is 154.8° and the rolling angle is 10° ( Figure 5 Even at -30℃, supercooled water droplets can still bounce off the surface well, proving that it has good anti-icing properties ( Figure 6 The coating has excellent photothermal properties. Under one sun, the temperature of the coating can be raised from room temperature to about 70°C ( Figure 7 ). In an environment of -30℃, the frozen droplets can melt quickly in just 223s under 1 light intensity, showing excellent photothermal deicing performance ( Figure 8 The coating is suitable for different substrates and complex curved surfaces, such as copper mesh, PVC board, wood, power lines, etc. ( Fig. 9 ). The prepared superhydrophobic coating has excellent mechanical, chemical, high-speed water flow puncture resistance, droplet bouncing and excellent anti-icing properties.

[0025] Embodiment 2:

[0026] A method for preparing a fluorine-free strong photothermal super-hydrophobic anti-icing coating comprises the following steps:

[0027] S1: Cleaning the substrate surface: Use one or more methods such as sandpaper polishing and alcohol to treat and clean the substrate surface. If the substrate surface is clean or some clean surfaces are not required to be treated;

[0028] S2: Prepare the coating: mix 100 parts of epoxy resin A and B, 22 parts of PDMS prepolymer, 2 parts of PDMS curing agent, 1 part of multi-walled carbon nanotubes, 40 parts of silica, and 250 parts of alcohol. Stir the mixed solution at high speed on a magnetic stirrer for 50 minutes at room temperature. Spray the uniform suspension obtained by magnetic stirring onto the pre-treated substrate and cure it at 90°C for 30 minutes.

[0029] The prepared super-hydrophobic coating has a multi-level micro-nano structure and a dense nanostructure, with a contact angle of 162.4° and a rolling angle of about 1°. The coating has excellent resistance to high-speed water flow impact. There is no obvious water droplet puncture phenomenon on the surface after about 4s of water flow impact with a diameter of about 5mm and a speed of 5m / s. At the same time, a water drop dripping from 12cm can bounce 12 times, with excellent bouncing performance. After the coating was soaked in a strong acid with pH = 0 for 24h, the contact angle of the coating was 159.8° and the rolling angle was 2°. After soaking in a strong base with pH = 13 for 24h, the contact angle of the coating was 159.5°, and the rolling angle was still 2°, proving that the coating has excellent chemical stability. After 100 cycles of Taber wear load 250g test, the contact angle of the coating was 153.6° and the rolling angle was 12°. At the same time, even at -30℃, supercooled water droplets can still bounce off the surface well, proving that it has good anti-icing performance. The coating has excellent photothermal properties. Under 1 sun, the temperature of the coating can be raised from room temperature to about 68°C. In an environment of -30°C, ice can be quickly melted in only 238s under 1 light intensity, showing excellent photothermal deicing performance. The prepared coating is suitable for different substrates. The prepared superhydrophobic coating has excellent mechanical, chemical, high-speed water flow puncture resistance, droplet bouncing and excellent anti-icing properties.

[0030] Embodiment 3:

[0031] A method for preparing a fluorine-free strong photothermal super-hydrophobic anti-icing coating comprises the following steps:

[0032] S1: Cleaning the substrate surface: Use one or more methods such as sandpaper polishing and alcohol to treat and clean the substrate surface. If the substrate surface is clean or some clean surfaces are not required to be treated;

[0033] S2: Prepare the coating: mix 100 parts of epoxy resin A and B, 33 parts of PDMS prepolymer, 3 parts of PDMS curing agent, 5 parts of multi-walled carbon nanotubes, 50 parts of silica, and 300 parts of alcohol. Stir the mixed solution at high speed on a magnetic stirrer for 20 minutes at room temperature. Spray the uniform suspension obtained by magnetic stirring onto the pre-treated substrate and cure it at 110°C for 20 minutes.

[0034] The prepared superhydrophobic coating has a multi-level micro-nano structure and a dense nanostructure, with a contact angle of 161.4° and a rolling angle of about 1°. The coating has excellent resistance to high-speed water flow impact. There is no obvious water droplet puncture phenomenon on the surface after about 4s of water flow impact with a diameter of about 5mm and a speed of 5m / s. At the same time, water drops dripping from 12cm can bounce 15 times, with excellent bouncing performance. After the coating was soaked in a strong acid with pH = 0 for 24h, the contact angle of the coating was 160.0°, and the rolling angle was still 1°. After soaking in a strong base with pH = 13 for 24h, the contact angle of the coating was 158.3°, and the rolling angle was still 1°, proving that the coating has excellent chemical stability. After 100 cycles of Taber wear load 250g test, the contact angle of the coating was 152.2° and the rolling angle was 13°. At the same time, even at -30℃, supercooled water droplets can still bounce off the surface well, proving that it has good anti-icing performance. The coating has excellent photothermal properties. Under 1 sun, the temperature of the coating can be raised from room temperature to 72°C. In an environment of -30°C, ice can be quickly melted under 1 light intensity in just 212s, showing excellent photothermal deicing performance. The prepared superhydrophobic coating has excellent mechanical, chemical, high-speed water flow puncture resistance, droplet bouncing and excellent anti-icing properties.

[0035] Embodiment 4:

[0036] A method for preparing a fluorine-free strong photothermal super-hydrophobic anti-icing coating comprises the following steps:

[0037] S1: Cleaning the substrate surface: Use one or more methods such as sandpaper polishing and alcohol to treat and clean the substrate surface. If the substrate surface is clean or some clean surfaces are not required to be treated;

[0038] S2: Prepare the coating: mix 100 parts of epoxy resin A and B, 5.7 parts of PDMS prepolymer, 0.5 parts of PDMS curing agent, 4 parts of multi-walled carbon nanotubes, 50 parts of silica, and 300 parts of alcohol. Stir the mixed solution at high speed on a magnetic stirrer for 50 minutes at room temperature. Spray the uniform suspension obtained by magnetic stirring onto the pre-treated substrate and cure it at room temperature for 10 hours.

[0039] The prepared super-hydrophobic coating has a multi-level micro-nano structure and a dense nanostructure, with a contact angle of 164.2° and a rolling angle of about 1°. The coating has excellent resistance to high-speed water flow impact. There is no obvious water droplet puncture phenomenon on the surface after about 4s of water flow impact with a diameter of about 5mm and a speed of 5m / s. At the same time, a water drop dripping from 12cm can bounce 13 times, with excellent bouncing performance. At the same time, after the coating is immersed in a strong acid with pH = 0 for 24h, the contact angle of the coating is 159.5°, and the rolling angle is still 1°. After soaking in a strong base with pH = 13 for 24h, the contact angle of the coating is 158°, and the rolling angle is still 1°, which proves that the coating has excellent chemical stability. After 100 cycles of Taber wear load 250g test, the contact angle of the coating is 154.8° and the rolling angle is 13°. At the same time, even at -30℃, supercooled water droplets can still bounce off the surface well, proving that it has good anti-icing performance. The coating has excellent photothermal properties. Under 1 sun, the temperature of the coating can be raised from room temperature to 72°C. In an environment of -30°C, ice can be quickly melted in only 219s under 1 light intensity, showing excellent photothermal deicing performance. The prepared coating is suitable for different substrates. The prepared superhydrophobic coating has excellent mechanical, chemical, high-speed water flow puncture resistance, droplet bouncing and excellent anti-icing properties.

Claims

1. A method for preparing a fluorine-free, strong, photothermal, super-hydrophobic, anti-icing coating, characterized in that: The following steps are involved: S1: Cleaning the substrate surface: Use one or more methods such as sandpaper polishing and alcohol to treat and clean the substrate surface; S2: Prepare the coating: 100 parts of epoxy resin A and B, 6.2-36 parts of PDMS prepolymer, 0.5-2 parts of PDMS curing agent, 1-5 parts of carbon nanotubes, 40-50 parts of silica, and 250-300 parts of alcohol. Stir the mixed solution at high speed on a magnetic stirrer for 20-50 minutes at room temperature. Spray the uniform suspension obtained by magnetic stirring onto the pre-treated substrate and cure it at room temperature to 110°C for 20 minutes to 10 hours.

2. The method for preparing the fluorine-free strong photothermal super-hydrophobic anti-icing coating according to claim 1, characterized in that: The silicon dioxide is fluorine-free hydrophobically modified nano silicon dioxide.

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