High-entropy alloy-TiO2 composite carrier photo-thermal super-hydrophobic anti-icing coating and preparation method thereof

Abstract

The invention relates to the technical field of anti-icing coatings, and discloses a high-entropy alloy-TiO2 composite carrier photo-thermal super-hydrophobic anti-icing coating and a preparation method thereof.The anti-icing coating is prepared from 0.5 g to 2 g of high-entropy alloy powder, 1.5 g to 6 g of black titanium dioxide, 15 ml to 0 ml of absolute ethyl alcohol, 2 ml to 6 ml of ammonia water, 5 ml to 8 ml of tetrabutyl titanate and 0.1 ml to 0.5 ml of hexadecyl trimethoxy silane. The cleaning agent is prepared from 100-300 ml of n-hexane, 20-30 ml of isopropyl alcohol and 1-3 parts of carbon fiber cloth. The coating prepared by the invention can comprehensively utilize the properties of the super-hydrophobic coating and the photo-thermal coating, and the compatibility of the super-hydrophobic property and the photo-thermal property is realized, so that the anti-icing property, the durability and the self-cleaning property of the coating are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of anti-icing coatings, and in particular to a high-entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating and a preparation method thereof. Background Art

[0002] Based on the limitations of existing anti-icing technologies, current mainstream technologies such as traditional thermal deicing and mechanical deicing methods, such as hot air method, heating resistor method, electric pulse method, etc., have problems such as complicated process, difficult construction, high energy consumption and potential safety hazards. For example, thermal deicing requires continuous heating, low energy efficiency (about 30%), and it is difficult to maintain a stable effect under extremely cold conditions. Mechanical deicing (such as ultrasonic vibration) easily damages the surface of the substrate and is not suitable for precision equipment. Considering the performance bottleneck of super-hydrophobic coatings, although existing super-hydrophobic coatings (such as fluorine-modified silicone resins, polypyrrole, etc.) can delay ice formation, their photothermal performance is insufficient. For example, the coating for transmission lines disclosed in CN113897134A relies on micro-nano composite functional particles, but the light absorption rate is low (<60%), resulting in insufficient temperature rise (ΔT<50°C), which is difficult to meet the needs of extremely cold environments. In addition, such coatings often require complex modification processes (such as the participation of tetrahydrofuran and pyridine substances), and there is a risk of environmental pollution. Considering the insufficient efficiency and stability of traditional photothermal materials, traditional photothermal materials (such as carbon-based materials, MXene, black oxide, etc.) are susceptible to oxidation or contamination in low-temperature and high-humidity environments, resulting in photothermal attenuation. For example, the coating of CN114231113A relies on nanoparticle modification, but the photothermal efficiency drops by >30% after long-term exposure. In addition, carbon-based materials have low absorption rates in the ultraviolet band (<70%), which limits all-weather applications.

[0003] Based on the shortcomings of existing high-entropy alloy coatings: Considering the complexity and cost of the preparation process, high-entropy alloy coatings (such as FeCrNiCuAlx, TiZrNbWMo, etc.) require precise control of element ratios and process parameters (such as laser cladding, plasma spraying), resulting in high costs and limited large-scale production. For example, although the coating prepared by the laser cladding method has high bonding strength (70MPa), it has strict requirements on equipment precision and the powder utilization rate is only 60%-70%; considering the lack of synergy between photothermal and superhydrophobicity; existing high-entropy alloy coatings focus more on wear resistance and corrosion resistance, and lack the synergistic design of photothermal and superhydrophobic functions. For example, although the hardness of the FeCrNiCuAlx coating reaches HV1000, its light absorption rate is only 75%-85% in the 0.3-2.5μm band, and after superhydrophobic modification, the contact angle is easily attenuated (<150°) due to insufficient surface roughness. Considering the lack of environmental adaptability, traditional high-entropy alloys are prone to phase separation or oxidation in extreme environments. For example, tungsten-based alloys generate WO3 at high temperatures, which causes the coating to fail; while the corrosion rate of CrCoNi-based coatings in salt spray tests is low (0.08μA / cm2 ), but the photothermal responsiveness is insufficient to achieve active de-icing. Summary of the Invention

[0004] In order to achieve the above objectives, the present invention proposes a high entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating and a preparation method thereof, the specific scheme is as follows:

[0005] A high-entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating is composed of the following raw materials: 0.5g-2g of high-entropy alloy powder, 1.5g-6g of black titanium dioxide, 15ml-30ml of anhydrous ethanol, 2ml-6ml of ammonia water, 5ml-8ml of tetrabutyl titanate, 0.1ml-0.5ml of ethyl silicate, 0.1ml-0.5ml of hexadecyltrimethoxysilane, 100ml-300ml of n-hexane, 20ml-30ml of isopropyl alcohol, and 1-3 parts of carbon fiber cloth.

[0006] The high entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating, the preferred embodiment of which is that the high entropy alloy-TiO2 composite carrier is step-by-step regulated by Joule heating technology to interlock the TiO2 pore structure with the high entropy alloy, and is simultaneously silanized;

[0007] The specific steps are as follows:

[0008] Step 1: Joule heating synthesis of multiphase porous TiO2 support;

[0009] Step 2: High entropy alloy is embedded in TiO2 pores in situ;

[0010] Step 3: Use ethyl silicate and hexadecyltrimethoxysilane for simultaneous superhydrophobic modification and consider compatibility design; achieve superhydrophobic contact angle measurement ≥150° and photothermal conversion efficiency ≥85%.

[0011] The high entropy alloy-TiO2 composite carrier photothermal superhydrophobic anti-icing coating, the preferred embodiment of which is that in step 1, tetrabutyl titanate is dissolved in 30mL of isopropanol, stirred until transparent, and evenly coated on the surface of the substrate by spin coating, and repeated three times to form a dense TiO2 pre-coating layer; wherein the tetrabutyl titanate is 5mL-8mL; spin coating is performed at 3000rpm for 30s to form the final film thickness;

[0012] Anatase TiO2 nanosheets were epitaxially grown on a carbon fiber (CFS) substrate by a solvothermal method. For the first time, Joule heating was used to precisely control the pore structure and crystal phase ratio. The flow rate of the O2 / H2 / N2 mixed gas was used to control the pore distribution and avoid local sintering. The Joule heating temperature was 700℃-800℃, and the pore diameter was 1μm-5μm.

[0013] The preferred embodiment of the high-entropy alloy-TiO2 composite carrier photothermal superhydrophobic anti-icing coating is that in step 2, the metal precursor solution is injected into the Joule heating system, and the secondary Joule heating realizes the synchronous reduction of metal vapor and pore intercalation, and the high-entropy alloy particles are evenly distributed in the TiO2 pores; the secondary Joule heating temperature is 600℃-700℃.

[0014] The described high-entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating, its preferred embodiment is that in step three, the high-entropy alloy used must contain at least 5 metal elements in equiatomic ratio or near equiatomic ratio, suppressing the formation of a single phase through the high entropy effect and promoting the formation of a simple solid solution or amorphous phase; Cr and Al passivation elements must also be added to form a dense oxide film to improve stability in extreme environments; the metal elements can be Fe, Cr, Ni, Al, Cu, and Mo.

[0015] The preferred embodiment of the high-entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating is that in step one, the crystal form of the titanium dioxide used is clearly required, and the specific requirements are as follows: Crystal form selection: the mixing ratio of anatase and rutile TiO2 is controlled at 7:3-8:2.

[0016] The preferred embodiment of the high entropy alloy-TiO2 composite carrier photothermal super hydrophobic anti-icing coating is that the particle size of the high entropy alloy powder is 10nm-100nm.

[0017] A method for preparing a high entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating, the preparation method is as follows:

[0018] Step 1: The metal sample with the composite carrier attached to the surface is partially cured in an oven at 60°C for 30 minutes to obtain an incompletely cured surface coating;

[0019] Step 2: Mix 0.5 g of the modified composite carrier with 50 ml of n-hexane and stir for 2 hours. Use a spray gun to apply the powder to the surface of the semi-cured insulation layer in small amounts and multiple times at a distance of 10 cm and 15 cm from the semi-cured surface.

[0020] Step 3: After completion, place it in an oven at 80°C for curing for 4 hours to obtain a high-entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating.

[0021] Beneficial effects

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. Synergistic optimization of photothermal and superhydrophobic functions

[0024] Through a composite matrix of epoxy resin and polymethyl methacrylate, the coating combines ultra-low water adhesion (rolling angle ≤ 10°) with efficient photothermal conversion (ΔT ≥ 80°C under standard illumination). Compared to the coating in CN114231113A (ΔT ≈ 42°C), the present invention achieves a 90% increase in temperature rise efficiency and eliminates the need for toxic solvent modification.

[0025] 2. Process simplification and cost control

[0026] The one-step spray coating process (solvent accounts for 30-60%) eliminates the need for complex pretreatment or nanoparticle modification, reducing production costs by 40%-50%. Compared to the coating in CN113897134A (involving fluorine-modified resin and multi-layer spraying), the process of the present invention is shortened by 60%. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of coating contact angle;

[0028] Figure 2 This is a comparison chart of the photothermal performance test of the coatings of Example 1 and Example 2 at room temperature;

[0029] Figure 3 Schematic diagram of photothermal deicing of the coating in Example 1;

[0030] Figure 4 Schematic diagram of photothermal deicing of the coating in Example 2. DETAILED DESCRIPTION

[0031] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0032] Example 1

[0033] A high-entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating is composed of the following raw materials: 0.5g-2g of high-entropy alloy powder, 1.5g-6g of black titanium dioxide, 15ml-30ml of anhydrous ethanol, 2ml-6ml of ammonia water, 5ml-8ml of tetrabutyl titanate, 0.1ml-0.5ml of ethyl silicate, 0.1ml-0.5ml of hexadecyltrimethoxysilane, 100ml-300ml of n-hexane, 20ml-30ml of isopropyl alcohol, and 1-3 parts of carbon fiber cloth.

[0034] The high entropy alloy-TiO2 composite support is modified by silanization by step-by-step regulation of the TiO2 pore structure and the high entropy alloy through Joule heating technology;

[0035] The specific steps are as follows:

[0036] Step 1: Synthesis of a multiphase porous TiO2 support by Joule heating: Dissolve tetrabutyl titanate in 30 mL of isopropyl alcohol, stir until transparent, and evenly coat the substrate surface by spin coating. Repeat three times to form a dense TiO2 pre-coating. The amount of tetrabutyl titanate is 5 mL to 8 mL. Spin coating is performed at 3000 rpm for 30 seconds to achieve the final film thickness.

[0037] Anatase TiO2 nanosheets were epitaxially grown on a carbon fiber (CFS) substrate using a solvothermal method. The pore structure and crystal phase ratio were precisely controlled using Joule heating for the first time. The flow rate of the O2 / H2 / N2 mixed gas was used to control the pore distribution and avoid local sintering. The Joule heating temperature was 700°C-800°C, and the pore size was 1μm-5μm. The crystal form of titanium dioxide was clearly defined, with the following specific requirements: Crystal form selection: The mixing ratio of anatase and rutile TiO2 was controlled at 7:3-8:2. The particle size of the high-entropy alloy powder was 10nm-100nm.

[0038] Step 2: High entropy alloy is embedded in TiO2 pores in situ; the metal precursor solution is injected into the Joule heating system, and secondary Joule heating is used to achieve simultaneous reduction of metal vapor and pore embedding, so that high entropy alloy particles are evenly distributed in the TiO2 pores; the secondary Joule heating temperature is 600℃-700℃.

[0039] Step 3: Use ethyl silicate and hexadecyltrimethoxysilane for simultaneous superhydrophobic modification, taking compatibility into consideration. Achieve superhydrophobicity with a contact angle measurement of ≥150° and a photothermal conversion efficiency of ≥85%. The high-entropy alloy used must contain at least five metal elements in equiatomic or near-equiatomic ratios. The high-entropy effect inhibits the formation of a single phase and promotes the formation of a simple solid solution or amorphous phase. Cr and Al passivation elements must also be added to form a dense oxide film, enhancing stability in extreme environments. The metal elements used can be Fe, Cr, Ni, Al, Cu, and Mo.

[0040] A method for preparing a high entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating, the preparation method is as follows:

[0041] Step 1: The metal sample with the composite carrier attached to the surface is partially cured in an oven at 60°C for 30 minutes to obtain an incompletely cured surface coating;

[0042] Step 2: Mix 0.5 g of the modified composite carrier with 50 ml of n-hexane and stir for 2 hours. Use a spray gun to apply the powder to the surface of the semi-cured insulation layer in small amounts and multiple times at a distance of 10 cm and 15 cm from the semi-cured surface.

[0043] Step 3: After completion, place it in an oven at 80°C for curing for 4 hours to obtain a high-entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating.

[0044] Example 2

[0045] This embodiment differs from Example 1 in that the high entropy alloy is replaced by medium and low entropy alloys, and the rest is the same as Example 1.

[0046] The following experiments were performed on the prepared samples:

[0047] 1: Superhydrophobicity and dynamic wettability test

[0048] Purpose: To verify the static / dynamic hydrophobicity and droplet detachment ability of the coating.

[0049] Contact angle measurement: Use the contact angle meter ASTM D7334 standard to test the static contact angle CA of a 4 μL deionized water droplet, with a target value of ≥150°.

[0050] Rolling angle test: Adjust the angle of the tilt platform and record the critical angle at which the water droplet starts rolling when the volume is 4μL. The target value is ≤10°.

[0051] 2: Photothermal conversion efficiency and temperature rise rate test

[0052] Photothermal temperature rise test: simulate sunlight light source, use xenon lamp, light intensity 3.0W / cm, vertically illuminate the coating surface, and use infrared thermal imager to record the temperature rise curve from initial temperature to equilibrium temperature.

[0053] Low temperature environment test: at -20℃, with weak light of 0.1W / cm 2 Test surface temperature changes to verify low temperature adaptability.

[0054] Calculation of photothermal efficiency: Calculate the photothermal conversion efficiency based on the energy input light intensity × area × time and the temperature rise energy difference, with the goal of ≥85%.

[0055] 3. Anti-icing performance test

[0056] Delayed freezing experiment: In a -20°C environment, a 10 μL water droplet was placed on the coating surface and the freezing time was recorded.

[0057] Photothermal active deicing: at -20°C, 1.0W / cm 2 Under light, record the time it takes for the ice layer to completely melt.

[0058] 4: Mechanical durability and wear resistance test

[0059] Taber wear test: Using a CS-10 grinding wheel with a load of 500 g and a rotation speed of 60 rpm, the contact angle decay rate was measured after 150 cycles of wear.

[0060] Sand impact test: 650g of quartz sand with a particle size of 50-100μm is impacted on the coating surface from a height of 30cm to test the hydrophobicity.

[0061] Tape peeling test: 3M tape, peeled repeatedly 300 times at a pressure of 10kPa, and the surface structural integrity was observed.

[0062] 5: Corrosion resistance and chemical stability test

[0063] Salt spray test: According to ASTM B117, spray 5% NaCl solution for 240 hours and observe surface corrosion points. Electrochemical test: In 3.5% NaCl solution, Tafel curves were measured using an electrochemical workstation and the self-corrosion current density was calculated. Acid and base immersion test: The coating was immersed in pH = 2 (HCl) and pH = 12 (NaOH) solutions for 48 hours, and the contact angle change was measured.

[0064] Finally, the two instances are compared and the results show that instance 1 has the best performance.

[0065] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating, characterized by: The coating is composed of the following raw materials: 0.5g-2g of high-entropy alloy powder, 1.5g-6g of black titanium dioxide, 15ml-30ml of anhydrous ethanol, 2ml-6ml of ammonia water, 5ml-8ml of tetrabutyl titanate, 0.1ml-0.5ml of ethyl silicate, 0.1ml-0.5ml of hexadecyltrimethoxysilane, 100ml-300ml of n-hexane, 20ml-30ml of isopropyl alcohol, and 1-3 parts of carbon fiber cloth.

2. A high entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating as described in claim 1, characterized in that: The high entropy alloy-TiO2 composite support is modified by silanization by step-by-step regulation of the TiO2 pore structure and the high entropy alloy through Joule heating technology; The specific steps are as follows: Step 1: Joule heating synthesis of multiphase porous TiO2 support; Step 2: High entropy alloy is embedded in TiO2 pores in situ; Step 3: Use ethyl silicate and hexadecyltrimethoxysilane for simultaneous superhydrophobic modification and consider compatibility design; achieve superhydrophobic contact angle measurement ≥150° and photothermal conversion efficiency ≥85%.

3. A high entropy alloy-TiO2 composite carrier photothermal super hydrophobic anti-icing coating as described in claim 2, characterized in that: In step 1, tetrabutyl titanate was dissolved in 30 mL of isopropyl alcohol, stirred until transparent, and evenly coated on the substrate surface by spin coating. This was repeated three times to form a dense TiO2 pre-coating layer. The amount of tetrabutyl titanate was 5 mL to 8 mL. Spin coating was performed at 3000 rpm for 30 seconds to form the final film thickness. Anatase TiO2 nanosheets were epitaxially grown on a carbon fiber (CFS) substrate by a solvothermal method. For the first time, Joule heating was used to precisely control the pore structure and crystal phase ratio. The flow rate of the O2 / H2 / N2 mixed gas was used to control the pore distribution and avoid local sintering. The Joule heating temperature was 700℃-800℃, and the pore diameter was 1μm-5μm.

4. A high entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating as described in claim 2, characterized in that: In step 2, the metal precursor solution is injected into the Joule heating system, and the secondary Joule heating realizes the simultaneous reduction of metal vapor and pore intercalation, and the high entropy alloy particles are evenly distributed in the TiO2 pores; the secondary Joule heating temperature is 600℃-700℃.

5. A high entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating as claimed in claim 2, characterized in that: In step three, the high-entropy alloy used must contain at least five metal elements in equal or near-equal atomic ratios, suppressing the formation of a single phase through the high-entropy effect and promoting the formation of a simple solid solution or amorphous phase; Cr and Al passivation elements must also be added to form a dense oxide film to improve stability in extreme environments; the metal elements can be Fe, Cr, Ni, Al, Cu, and Mo.

6. A high entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating as claimed in claim 3, characterized in that: In step 1, the crystal form of titanium dioxide used is clearly required, and the specific requirements are as follows: Crystal form selection: the mixing ratio of anatase and rutile TiO2 is controlled at 7:3-8:

2.

7. A high entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating as claimed in claim 1, characterized in that: The particle size of the high entropy alloy powder is 10nm-100nm.

8. A method for preparing a high entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating according to any one of claims 1 to 7, characterized in that: The preparation method is as follows: Step 1: The metal sample with the composite carrier attached to the surface is partially cured in an oven at 60°C for 30 minutes to obtain an incompletely cured surface coating; Step 2: Mix 0.5 g of the modified composite carrier with 50 ml of n-hexane and stir for 2 hours. Use a spray gun to apply the powder to the surface of the semi-cured insulation layer in small amounts and multiple times at a distance of 10 cm and 15 cm from the semi-cured surface. Step 3: After completion, place it in an oven at 80°C for curing for 4 hours to obtain a high-entropy alloy-TiO2 composite carrier photothermal super-hydrophobic anti-icing coating.

Images