Anti-icing super-hydrophobic and super-smooth nano coating material as well as preparation method and application thereof

Abstract

The invention discloses an anti-icing super-hydrophobic and super-smooth nano coating material as well as a preparation method and application thereof, and relates to the technical field of nano coatings. The anti-icing super-hydrophobic and super-smooth nano coating material provided by the invention comprises polymer grafted SiO2 particles, the particles comprise silane coupling agent modified nano SiO2 cores, PAMAM intermediate layers and perfluoropolyether shells, the introduction of PAMAM improves the grafting density of perfluoropolyether on the surface of nano SiO2, and the perfluoropolyether not only reduces the surface energy of a coating, but also improves the anti-icing performance of the coating. Moreover, the tail end of a molecular chain can move freely so as to simulate a lubricating effect similar to liquid, so that the coating disclosed by the invention not only can realize super-hydrophobic performance, but also can have super-smooth performance. The coating material disclosed by the invention is sprayed on the surface of a base material, so that the anti-icing super-hydrophobic and super-smooth nano coating can be obtained, and the coating and the base material have excellent binding force.

Description

Technical Field

[0001] The present invention relates to the technical field of nano coatings, and in particular to an anti-icing super-phobic and super-slip nano coating material and a preparation method and application thereof. Background Art

[0002] Insulators are important components in power systems, playing the role of isolating voltage and supporting conductors. Under normal working conditions, insulators can effectively prevent conduction between high-voltage live bodies or between live bodies and the ground, ensuring stable operation of the system. However, under extreme weather conditions such as freezing rain, rime, snow and other ice-covered phenomena may appear on the surface of insulators. These ice condensed on the surface of insulators often blend in with impurities and dirt in the air, greatly reducing the electrical barrier performance of the insulators. In the case of severe icing, the sheds of the insulators may even be bridged by ice, resulting in reduced insulation strength and shortened leakage distance, which in turn causes frequent ice flashes, seriously affecting the safety of the power system.

[0003] Hydrophobic modification of the surface of insulator materials can effectively delay the process of ice formation on the insulator surface. However, under extreme weather conditions, the droplets on the hydrophobic surface cannot be removed in time after condensing into ice. These ice surfaces replace the original hydrophobic surface, and subsequent icing is still difficult to avoid. In addition, the construction of a hydrophobic surface usually requires increasing the roughness of the material surface, which results in condensation pinning of tiny droplets in the air in the pores on the surface of the insulator material under extreme weather conditions. When the degree of supercooling is large, these micro-droplets will become nucleation points for ice crystal growth, greatly increasing the bonding force between the surface ice and the substrate, making it more difficult to remove.

[0004] In recent years, researchers have proposed a new passive anti-icing technology, namely a super-slip coating. A super-slip coating specifically refers to a coating that is not wetted by external liquids and is extremely easy to slide off (with an extremely small sliding angle). The root cause is the presence of lubricating liquid molecules with low surface energy, chemically bonded liquid-like molecules, or both on the surface of the coating. Among them, when there are chemically bonded liquid-like (generally polymer) molecules on the surface of the coating, one end of the polymer chain segment is fixed to the surface of the substrate, and the other end is evenly arranged on the surface of the substrate in a freely movable manner, thereby simulating a liquid-like lubrication effect, significantly reducing the adhesion between external water droplets and the substrate, thereby effectively preventing the adhesion of droplets and ice accumulation on the surface, and not easily causing the pinning phenomenon of droplets and ice crystals.

[0005] Combining the two coating mechanisms to construct a super-hydrophobic and super-slip coating can achieve a longer-lasting anti-icing effect, but research in this area still needs to be deepened. In addition, since the insulators used in power facilities such as substations are mostly made of ceramic and glass materials, their surfaces are smooth and it is difficult to form a strong bond with the coating, especially the super-hydrophobic coating: the surface energy of the super-hydrophobic material is low, and the bonding force between it and the surface of the insulator base is even lower, which makes the coating on the insulator surface easy to peel off, has poor durability, and cannot be used for a long time. Summary of the invention

[0006] In order to address the deficiencies in the prior art, the present invention provides an anti-icing super-phobic and super-slippery nano-coating material, in which dendritic polymers PAMAM (polyamide-amine) and PFPE (perfluoropolyether) are successively grafted onto nano-SiO2 particles modified with a silane coupling agent to obtain polymer-grafted SiO2 particles SiO2-PAMAM-PFPE with a core-shell structure. The anti-icing super-phobic and super-slippery nano-coating can be obtained by spraying its dispersion on the surface of a substrate, and the coating of the present invention has excellent bonding strength with the substrate.

[0007] Another object of the present invention is to provide a method for preparing an anti-icing super-phobic and super-slippery nano-coating material.

[0008] Another object of the present invention is to provide a method for preparing an anti-icing super-phobic and super-slippery nano-coating.

[0009] The above-mentioned purpose of the present invention is achieved through the following technical solutions: An anti-icing super-phobic and super-slip nano coating material comprises, from the inside to the outside, a core, an intermediate layer and an outer shell, wherein the core comprises nano-SiO2 particles modified by a silane coupling agent, the intermediate layer comprises polyamide-amine, and the outer shell comprises perfluoropolyether modified by acyl chloride.

[0010] The anti-icing super-phobic and super-slippery nano-coating material (which can be represented by SiO2-PAMAM-PFPE) provided by the present invention is first grafted with a dendritic polymer PAMAM (polyamide-amine) on the surface of nano-SiO2 particles, providing a large number of active sites for the grafting of acyl chloride-modified PFPE (perfluoropolyether), so that the acyl chloride-modified PFPE can be grafted to the surface of the nano-SiO2 particles to form a shell through a nucleophilic addition reaction between acyl chloride and amine; and these active sites provided by PAMAM are distributed in a dendritic manner, avoiding the effects of steric hindrance and the like that affect the subsequent grafting density of PFPE, so that high-density PFPE grafting can be achieved on the SiO2-PAMAM surface, and the grafting of PFPE can reduce the surface energy, and the material in the present invention can form a rough structure through the accumulation of nanoparticles after being coated on the surface of the substrate, and the combination of the two factors of low surface energy + rough texture can make the coating formed by the present invention have super-hydrophobicity. However, compared with conventional super-hydrophobic surfaces, the present invention introduces PAMAM and PFPE into nano-SiO2 particles at the same time, which can make the ends of PFPE move freely (PFPE molecular chains have high flexibility), thereby simulating a liquid-like lubrication effect, so that the contact between the coating surface and water can be changed from micro-nano-level solid-liquid contact to molecular-level liquid-liquid contact, reducing the adhesion resistance of droplets rolling on the coating surface, so the coating in the present invention can have super-slip performance, reducing the friction coefficient of external droplets on the coating surface, effectively slowing down the nucleation and growth of ice crystals on the coating surface, and preventing the pinning effect of ice crystals from affecting the anti-icing performance of the coating. At the same time, the contact between the outermost PFPE of the material in the present invention and the substrate is similar to solid-liquid contact. Even if the surface energy of the material in the present invention is reduced, the solid-liquid contact method can reduce the number of air gaps between the coating material and the substrate, so the coating material in the present invention can still form a good bond with the substrate even if the surface energy is reduced. In summary, the coating provided by the present invention has excellent bonding with the substrate while having both high hydrophobicity and super-slip properties.

[0011] Preferably, the silane coupling agent includes an amino-based silane coupling agent.

[0012] The surface of nano-SiO2 particles contains hydroxyl groups. After reacting with amino silane coupling agents, amino groups can be grafted onto the surface. On this basis, a dendritic polymer PAMAM intermediate layer can be formed on the surface of the nano-SiO2 particles through chemical bonding.

[0013] In a specific embodiment of the present invention, the amino-based silane coupling agent includes 3-aminopropyltriethoxysilane.

[0014] More preferably, the silane coupling agent-modified nano-SiO2 particles are prepared by reacting nano-SiO2 particles with a silane coupling agent in a mass ratio of (50-80):35, and the reaction temperature is 50-100°C.

[0015] In a specific embodiment of the present invention, the reaction is carried out in solution.

[0016] More specifically, the solution includes toluene. More specifically, the mass ratio of toluene to nano-SiO2 particles is (350-450):65.

[0017] More specifically, the reaction time is 1 to 3 h.

[0018] More specifically, the reaction is carried out under shaking conditions.

[0019] More specifically, the reaction further includes a drying step. More specifically, the drying temperature is 50-60°C.

[0020] Preferably, the particle size of the nano-SiO2 particles is 10-60 nm.

[0021] More preferably, the particle size of the nano-SiO2 particles is 20-50 nm.

[0022] Preferably, the thickness of the intermediate layer is 200-500 nm.

[0023] Preferably, the thickness of the shell is 60-300 nm.

[0024] More preferably, the shell has a thickness of 150-300 nm.

[0025] It should be noted that the test method for particle size and thickness in the present invention is: perform cross-sectional SEM test on the material, take 10 samples in turn to observe the particle size of the core, the thickness of the middle layer and the shell and calculate their arithmetic mean values, and take the nearest integer as the final value.

[0026] Preferably, the polyamide-amine is prepared by reacting methyl acrylate and ethylenediamine in a mass ratio of (15-40): (300-800), and the reaction temperature is 20-30°C.

[0027] More preferably, the polyamide-amine is prepared by reacting methyl acrylate and ethylenediamine in a mass ratio of (25-40): (500-600).

[0028] By reacting methyl acrylate and ethylenediamine, a dendritic PAMAM polyamide-amine can be constructed, in which the "branches" of the dendritic polymer are mainly ethylenediamine structures, and methyl acrylate can be regarded as the "nodes" that form new branches. By controlling the ratio of the two compounds within the above range, a more suitable dendritic PAMAM can be obtained, which can ensure hydrophobicity (too many "branches" of PAMAM may lead to a decrease in hydrophobicity) and maximize the grafting density of the subsequent chlorinated PFPE.

[0029] More preferably, the mass ratio of the nano-SiO2 particles modified by the silane coupling agent to methyl acrylate is 60:(15-40).

[0030] More preferably, the mass ratio of the nano-SiO2 particles modified by the silane coupling agent to methyl acrylate is 60:(25-40).

[0031] After controlling the ratio of methyl acrylate and ethylenediamine, the structure of the dendritic PAMAM remains basically unchanged. On this basis, adjusting the mass ratio of methyl acrylate and nano-SiO2 particles modified by silane coupling agent is conducive to obtaining PAMAM with a more appropriate grafting amount, thereby obtaining better performance. Too much grafting of PAMAM can also easily lead to a decrease in the hydrophobicity of the coating.

[0032] More preferably, the average molecular weight of the acyl chloride-modified perfluoropolyether is 1000-4000.

[0033] More preferably, the mass ratio of the nano-SiO2 particles modified by the silane coupling agent to the perfluoropolyether modified by acyl chloride is (80-95): (5-20).

[0034] More preferably, the mass ratio of the nano-SiO2 particles modified by the silane coupling agent to the perfluoropolyether modified by acyl chloride is (85-90): (10-15).

[0035] The present invention also protects a method for preparing the above-mentioned anti-icing super-phobic and super-slip nano coating material, comprising the following steps: S1. Mix nano-SiO2 particles modified by a silane coupling agent with methyl acrylate, react at 40-80°C to obtain SiO2-MA, add ethylenediamine and continue to react at 20-30°C to obtain SiO2-PAMAM; S2. The SiO2-PAMAM obtained in step S1 is mixed with the perfluoropolyether modified by acyl chloride, and a grafting reaction is carried out at 60-100° C. After the reaction, an anti-icing super-phobic and super-slippery nano-coating material can be obtained.

[0036] In a specific embodiment of the present invention, the reaction time at 40-80° C. in step S1 is 3-5 h.

[0037] In a specific embodiment of the present invention, the reaction at 40-80° C. in step S1 is carried out in an inert atmosphere. More specifically, the inert atmosphere is a nitrogen atmosphere.

[0038] In a specific embodiment of the present invention, the reaction in step S1 is carried out in a solution at 40-80° C., and the solution includes methanol. More specifically, the volume of the methanol is 450-500 mL.

[0039] In a specific embodiment of the present invention, the reaction at 40-80° C. in step S1 is carried out under shaking conditions.

[0040] In a specific embodiment of the present invention, after obtaining SiO2-MA by reaction at 40-80°C in step S1, the step of drying the SiO2-MA is also included.

[0041] In a specific embodiment of the present invention, the time for continuing the reaction of adding ethylenediamine in step S1 is 10 to 14 hours.

[0042] In a specific embodiment of the present invention, the step S1 of adding ethylenediamine and continuing the reaction is carried out in a solution, and the solution includes methanol. More specifically, the volume of the methanol is 350-450 mL.

[0043] In a specific embodiment of the present invention, the step S1 of adding ethylenediamine and continuing the reaction is carried out under shaking conditions.

[0044] In a specific embodiment of the present invention, after adding ethylenediamine to continue the reaction to obtain SiO2-PAMAM in step S1, a step of drying the SiO2-PAMAM is also included.

[0045] In a specific embodiment of the present invention, the method for preparing the acyl chloride-modified perfluoropolyether in step S2 comprises the following steps: The carboxyl terminal perfluoropolyether can be chlorinated by mixing excess SOCl2 and reacting at 40-60°C for 1-2 h to obtain chlorinated perfluoropolyether.

[0046] More specifically, after reacting at 40-60° C., the step of heating the mixture to 80-100° C. and continuing the reaction for 5-15 min is also included.

[0047] The purpose of continuing the reaction by heating is to remove unreacted SOCl2.

[0048] In a specific embodiment of the present invention, the grafting reaction in step S2 is carried out in a water bath under reflux conditions.

[0049] In a specific embodiment of the present invention, the grafting reaction time in step S2 is 22 to 26 hours.

[0050] In a specific embodiment of the present invention, after obtaining the anti-icing super-phobic and super-slippery nano-coating material in step S2, the process further includes the steps of filtration and drying. More specifically, the drying step is performed at 50-70° C. for 22-26 hours.

[0051] The present invention also provides a method for preparing an anti-icing super-phobic and super-slip nano coating, comprising the following steps: The anti-icing super-repellent and super-slippery nano-coating material dispersion is sprayed on the surface of the substrate and solidified to form an anti-icing super-repellent and super-slippery nano-coating on the surface of the substrate.

[0052] In a specific embodiment of the present invention, the substrate may be glass.

[0053] In a specific embodiment of the present invention, the dispersion of the anti-icing super-repellent and super-slippery nano-coating material includes an anti-icing super-repellent and super-slippery nano-coating material SiO2-PAMAM-PFPE and a solvent, and the solvent includes butyl acetate, ethanol and FEVE-type fluorocarbon resin. More specifically, the mass ratio of butyl acetate, ethanol and FEVE-type fluorocarbon resin is (600-1000): (300-500): 50. More specifically, the mass ratio of the solvent to SiO2-PAMAM-PFPE is (950-1550): (60-100).

[0054] In a specific embodiment of the present invention, the method for preparing the dispersion comprises the following steps: mixing SiO2-PAMAM-PFPE with a solvent, stirring for 30 min, and ultrasonically dispersing for 10 min.

[0055] Preferably, the method further includes a step of plasma activating the surface of the substrate before spraying.

[0056] More preferably, the plasma activation is performed using plasma gas, and the gas includes at least two of oxygen, nitrogen and argon.

[0057] More preferably, the plasma activation is: ionizing with a voltage of 300 W to 1000 W to obtain plasma gas and then activating it.

[0058] More preferably, the gas flow rate during the plasma activation is 5-100 sccm, and the plasma activation time is 5-30 min.

[0059] In a specific embodiment of the present invention, the step of cleaning the substrate is further included before the plasma activation.

[0060] More specifically, the cleaning includes the following steps: soaking the substrate surface with water to soften dirt and reduce friction, gently scrubbing the substrate surface with a soft brush or sponge to remove dirt, using a high-pressure water gun to clean the substrate as a whole, and using gas to dry the substrate surface after cleaning to complete the cleaning process. More specifically, the pressure of the high-pressure water gun is controlled at 500-1000 bar.

[0061] In a specific embodiment of the present invention, after the dispersion of the anti-icing super-phobic and super-slippery nano-coating material is sprayed on the surface of the substrate, the curing is thermal curing. More specifically, the thermal curing comprises the following steps: A solution containing photothermal material is sprayed on the surface of the film. After the photothermal material is cured, the film is coated on the surface of a substrate sprayed with an anti-icing super-repellent and super-slippery nano-coating material and irradiated with light, so that the coating material can be cured to form an anti-icing super-repellent and super-slippery nano-coating.

[0062] More specifically, the film includes at least one of polyethylene terephthalate (PET), polyethylene (PE), ethylene vinyl acetate (EVA), polypropylene (PP), polystyrene (PS) or polyvinyl chloride (PVC).

[0063] More specifically, the photothermal material includes at least one of carbon black, carbon nanotubes, and graphene.

[0064] More specifically, the solution containing the photothermal material also includes a resin cross-linking agent.

[0065] Compared with the prior art, the present invention has the following beneficial effects: The anti-icing super-repellent and super-slippery nano-coating prepared by the present invention has super-repellent and super-slippery properties, a static water contact angle of more than 143°, and a rolling angle of less than 8°, which can effectively prevent water droplets from adsorbing and staying on the coating surface. Therefore, it can be used for anti-icing on the surface of insulators. After 8 hours of testing under freezing rain conditions, no ice ridges appear on the surface of the insulator coated with the coating of the present invention. At the same time, the nano-coating provided by the present invention has excellent bonding strength with the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 This is a photo of the contact angle of a water drop on the glass surface used for insulators after plasma activation.

[0067] Figure 2 A photograph of the water drop contact angle on a glass surface used for insulators after being coated with the anti-icing super-phobic and super-slippery nano-coating in Example 1 of the present invention.

[0068] Figure 3The icing condition of an insulator sample (left) coated with the anti-icing super-phobic and super-slippery nano-coating of the present invention under simulated freezing rain conditions and its comparison with the untreated insulator (right). DETAILED DESCRIPTION

[0069] The present invention is further described below in conjunction with specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents. Among them, the raw material information used in each embodiment and comparative example is as follows: Carboxyl-terminated perfluoropolyether: Carboxyl-terminated PFPE, CAS No.: 51798-33-5, purchased from Fuzhou Taipuda New Materials Co., Ltd., with an average molecular weight of 2000.

[0070] Example 1 A method for preparing an anti-icing super-phobic and super-slip nano coating material comprises the following steps: S1. In a nitrogen atmosphere, 60 g of nano-SiO2 particles modified by silane coupling agent were mixed with 31 mL (29.6 g) of methyl acrylate and added to a flask containing 480 mL of methanol solvent. The mixture was shaken at 60°C for 4 hours to fully react and dried to obtain SiO2-MA. SiO2-MA was mixed with 600 mL (539.4 g) of ethylenediamine, added to 400 mL of methanol solvent at 25°C and shaken for reaction for 12 hours. After the reaction, the mixture was dried to obtain SiO2-PAMAM. S2. Mix 6.67 g of the perfluoropolyether modified by acyl chloride with the SiO2-PAMAM obtained in step S1 (the mass ratio of the nano-SiO2 particles modified by the silane coupling agent to the perfluoropolyether modified by acyl chloride in S1 is 90:10), reflux in a water bath at 80°C for 24 h for grafting reaction, and after the reaction, filter the obtained suspension and dry it at 60°C for 24 h to obtain the anti-icing super-repellent and super-slippery nano-coating material SiO2-PAMAM-PFPE; Step S1: The method for preparing nano-SiO2 particles modified by a silane coupling agent comprises the following steps: mixing 65 g of nano-SiO2 particles with a particle size of 20 nm with 35 mL (33.11 g) of a silane coupling agent 3-aminopropyltriethoxysilane, oscillating the mixture in 400 mL of a toluene solvent at 75° C. for 2 h, and drying the product at 55° C. to obtain nano-SiO2 particles modified by a silane coupling agent, wherein the particle size of the particles remains substantially unchanged before and after the modification; The preparation method of the PFPE modified by acyl chloride described in step S2 comprises the following steps: Excess SOCl2 and 60 g of carboxyl-terminated perfluoropolyether were mixed and reacted at 50°C for 1.5 h, and then the temperature was increased to 90°C for 10 min to remove unreacted SOCl2 to obtain acyl chloride-modified perfluoropolyether.

[0071] The anti-icing super-phobic and super-slippery nano-coating material prepared in this embodiment includes a core, an intermediate layer and an outer shell from the inside to the outside. The core includes nano-SiO2 particles with a particle size of 20 nm modified by a silane coupling agent, the intermediate layer includes a dendritic polymer polyamide-amine with a thickness of ~300 nm, and the outer shell includes a perfluoropolyether modified by acyl chloride with a thickness of ~200 nm.

[0072] Example 2 A method for preparing an anti-icing super-phobic and super-slip nano-coating material, which is different from Example 1 only in that: The silane coupling agent-modified nano-SiO2 particles in step S1 are prepared by reacting equal amounts of nano-SiO2 particles with a particle size of 10 nm with equal amounts of silane coupling agent.

[0073] The anti-icing super-phobic and super-slippery nano-coating material prepared in this embodiment includes a core, a middle layer and an outer shell from the inside to the outside. The core includes nano-SiO2 particles with a particle size of 10 nm modified by a silane coupling agent, the middle layer includes a dendritic polymer polyamide-amine with a thickness of ~320 nm, and the outer shell includes a perfluoropolyether modified by acyl chloride with a thickness of ~190 nm.

[0074] Example 3 A method for preparing an anti-icing super-phobic and super-slip nano-coating material, which is different from Example 1 only in that: The silane coupling agent-modified nano-SiO2 particles in step S1 are prepared by reacting equal amounts of nano-SiO2 particles with a particle size of 60 nm with equal amounts of silane coupling agent.

[0075] The anti-icing super-phobic and super-slippery nano-coating material prepared in this embodiment includes a core, a middle layer and an outer shell from the inside to the outside. The core includes nano-SiO2 particles with a particle size of 60 nm modified by a silane coupling agent, the middle layer includes a dendritic polymer polyamide-amine with a thickness of ~260 nm, and the outer shell includes a perfluoropolyether modified by acyl chloride with a thickness of ~200 nm.

[0076] Example 4 A method for preparing an anti-icing super-phobic and super-slip nano-coating material, which is different from Example 1 only in that: In step S1, the amount of methyl acrylate added is 40 mL (38.2 g), and the amount of ethylenediamine added is 800 mL (719.2 g).

[0077] The anti-icing super-phobic and super-slippery nano-coating material prepared in this embodiment includes a core, a middle layer and an outer shell from the inside to the outside. The core includes nano-SiO2 particles with a particle size of 20 nm modified by a silane coupling agent, the middle layer includes a dendritic polymer polyamide-amine with a thickness of ~420 nm, and the outer shell includes a perfluoropolyether modified by acyl chloride with a thickness of ~140 nm.

[0078] Example 5 A method for preparing an anti-icing super-phobic and super-slip nano-coating material, which is different from Example 1 only in that: In step S1, the amount of methyl acrylate added is 20 mL (19.1 g), and the amount of ethylenediamine added is 400 mL (359.6 g).

[0079] The anti-icing super-phobic and super-slippery nano-coating material prepared in this embodiment includes a core, an intermediate layer and an outer shell from the inside to the outside. The core includes nano-SiO2 particles with a particle size of 20 nm modified by a silane coupling agent, the intermediate layer includes a dendritic polymer polyamide-amine with a thickness of ~350 nm, and the outer shell includes a perfluoropolyether modified by acyl chloride with a thickness of ~180 nm.

[0080] Example 6 A method for preparing an anti-icing super-phobic and super-slip nano-coating material, which is different from Example 1 only in that: The mass of the perfluoropolyether modified by acyl chloride added in step S2 is 15 g (the mass ratio of the nano-SiO2 particles modified by the silane coupling agent to the perfluoropolyether modified by acyl chloride in S1 is 80:20).

[0081] The anti-icing super-phobic and super-slippery nano-coating material prepared in this embodiment includes a core, a middle layer and an outer shell from the inside to the outside. The core includes nano-SiO2 particles with a particle size of 20 nm modified by a silane coupling agent, the middle layer includes a dendritic polymer polyamide-amine with a thickness of ~300 nm, and the outer shell includes a perfluoropolyether modified by acyl chloride with a thickness of ~260 nm.

[0082] Example 7 A method for preparing an anti-icing super-phobic and super-slip nano-coating material, which is different from Example 1 only in that: The mass of the perfluoropolyether modified by acyl chloride added in step S2 is 3.16 g (the mass ratio of the nano-SiO2 particles modified by the silane coupling agent to the perfluoropolyether modified by acyl chloride in S1 is 95:5).

[0083] The anti-icing super-phobic and super-slippery nano-coating material prepared in this embodiment includes a core, an intermediate layer and an outer shell from the inside to the outside. The core includes nano-SiO2 particles with a particle size of 20 nm modified by a silane coupling agent, the intermediate layer includes a dendritic polymer polyamide-amine with a thickness of ~300 nm, and the outer shell includes a perfluoropolyether modified by acyl chloride with a thickness of ~60 nm.

[0084] Comparative Example 1 A method for preparing a nano coating material, which differs from Example 1 only in that: The PAMAM grafting in step S1 is not performed; that is, the nano-SiO2 particles modified by the silane coupling agent are directly reacted with the perfluoropolyether modified by acyl chloride.

[0085] The nano coating material prepared in this comparative example includes a core and a shell from the inside to the outside, wherein the core includes nano SiO2 particles with a particle size of 20 nm modified by a silane coupling agent, and the shell includes perfluoropolyether modified by acyl chloride and has a thickness of ~450 nm.

[0086] Comparative Example 2 A method for preparing a nano coating material, which differs from Example 1 only in that: The PEFE grafting in step S2 is not performed; that is, the reaction is terminated after SiO2-PAMAM is obtained in step S1.

[0087] The nano coating material prepared in this comparative example includes a core and a shell from the inside out, wherein the core includes nano SiO2 particles modified by a silane coupling agent and having a particle size of 20 nm, and the shell includes a dendritic polymer polyamide-amine and has a thickness of ~300 nm.

[0088] Comparative Example 3 A method for preparing a nano coating material, which differs from Example 1 only in that: Step S2 replaces the chlorinated perfluoropolyether with an equal mass of chlorinated FEP (fluoroethylene propylene).

[0089] The nano-coating material prepared in this comparative example includes a core, an intermediate layer and an outer shell from the inside to the outside, wherein the core includes nano-SiO2 particles with a particle size of 20 nm modified by a silane coupling agent, the intermediate layer includes a dendritic polymer polyamide-amine with a thickness of ~300 nm, and the outer shell includes FEP modified by acyl chloride with a thickness of ~200 nm.

[0090] Comparative Example 4 A method for preparing a nano coating material, which differs from Example 1 only in that: In step S1, no nano-SiO2 particles modified by a silane coupling agent are added, and methyl acrylate and ethylenediamine are directly reacted to form PAMAM.

[0091] The nano-coating material prepared in this comparative example includes a core and a shell from the inside out, wherein the core includes a dendritic polymer polyamide-amine with a thickness of ~320 nm, and the shell includes an acyl chloride-modified perfluoropolyether with a thickness of ~210 nm.

[0092] Performance test: Below, the coating materials obtained in the embodiment and the comparative example are sprayed on the glass surface and the insulator surface for the insulator, and the basic performance and anti-icing performance of the coating are tested after the coating is formed. The test scheme and the obtained effects are represented by Effect Examples 1 and 2.

[0093] Effect example 1: Basic performance test of coating Preparation of coating: The coating materials obtained in Examples 1 to 7 and Comparative Examples 1 to 4 were dispersed in a solvent composed of 800 g butyl acetate, 400 g ethanol and 50 g FEVE type fluorocarbon resin, stirred for 30 min, and then ultrasonically dispersed for 10 min to obtain a dispersion, which was sprayed onto the surface of the substrate (glass for insulators) and cured to obtain an anti-icing super-repellent and super-slippery nano-coating. The spraying amount was about 50 mg / cm 2 ; The surface of the substrate is cleaned and plasma activated before spraying, specifically: use deionized water to wet the surface of the substrate, clean the surface with a soft brush, and clean it again with a high-pressure water gun with a pressure of 500 bar. After cleaning, use an air gun to blow dry for 5 minutes, and then use an atmospheric plasma generator to activate the surface of the cleaned and dried substrate, introduce oxygen and argon with a flow rate of 50 sccm each, input 500 W plasma power, and evenly treat the surface of the substrate for 20 minutes; the curing is: carbon black and resin cross-linking agent are coated on the surface of the PET film, and after curing, the film is wrapped on the surface of the substrate sprayed with the coating material, and placed in natural sunlight for 4 hours to heat and cure the coating.

[0094] Coating hydrophobicity and lubricity test: The contact angle meter is used to test the coating hydrophobicity and lubricity, which are expressed as static water contact angle and sliding angle respectively. The coating film-base bonding test is evaluated with reference to the ISO2409 100-grid test standard, with a total of 0-5 levels, with 0 being the highest.

[0095] The specific performance test data is shown in Table 1 below: Table 1 Hydrophobicity and lubricity test data of the coatings of the embodiments and comparative examples It can be seen from Table 1 above that the anti-icing super-hydrophobic and super-slip nano-coating prepared by the present invention has super-hydrophobic properties, a static water contact angle of more than 143°, and a rolling angle of less than 8°, indicating excellent sliding performance and the ability to prevent water droplets from being adsorbed and staying on the coating surface.

[0096] Among them, according to the data of Examples 1 to 3, it can be seen that the use of nano-SiO2 particles with a particle size in the more preferred range of 20 to 50 nm in the present invention to construct the super-phobic and super-lubricant coating in the present invention (Example 1) can achieve better super-phobic and super-lubricant properties. This may be because, compared with nanoparticles with larger particle sizes, SiO2 particles with a size of 20 to 50 nm can make the coating have a higher surface roughness; and compared with nanoparticles with a smaller particle size, particles with a size of 20 to 50 nm can make the coating have a more suitable PAMAM and PFPE grafting rate.

[0097] According to the data of Examples 1, 4-5, it can be seen that the grafting amount of PAMAM on the surface of nano-SiO2 particles has an important influence on the contact angle and sliding angle of the coating (the ratio of methyl acrylate to ethylenediamine in Examples 1, 4-5 remains unchanged, and the structure of PAMAM remains basically unchanged). When the grafting amount of PFPE remains unchanged, the grafting amount of PAMAM is higher (Example 4). Since PAMAM itself is hydrophilic, the hydrophobicity of the coating will be reduced; however, a decrease in the grafting amount of PAMAM (Example 5) will affect the grafting amount of PFPE, which will also lead to a decrease in the hydrophobicity of the coating.

[0098] According to the data of Examples 1, 6 and 7, it can be seen that the amount of PFPE grafted on the surface of the nanoparticles also has an important influence on the contact angle and sliding angle of the coating. If the amount of PFPE grafted is too high (Example 6), the activity space of the PFPE flexible chain may be reduced, thereby reducing the hydrophobic and lubricating properties; while if the amount of PFPE grafted is too low (Example 7), the contact angle and sliding angle of the coating will be more affected.

[0099] According to Comparative Examples 1-2, it can be seen that in order to achieve super-phobic and super-lubricating properties in the coating provided by the present invention, two polymers, PAMAM and PFPE, must be grafted; according to Comparative Example 3, the highly flexible PFPE is replaced with FEP, and its surface still has a high contact angle and hydrophobicity, but because FEP does not have the high flexibility and liquid-like lubrication effect of PFPE, the coating does not have super-lubricating properties, resulting in a significant increase in the water droplet sliding angle of the coating. At the same time, the grafting of FEP will lead to a decrease in the surface energy of the particles, and then to a decrease in the bonding force between the coating and the substrate.

[0100] According to Comparative Example 4, PAMAM-PFPE is directly sprayed on the surface of the substrate. Due to the lack of nano-SiO2 particles, the surface of the substrate cannot form a rough texture, and thus its contact angle is not higher than 120°. However, since the substrate is grafted with high-density and high-flexibility PFPE chains under the action of PAMAM, the coating still has certain super-slip properties and presents a lower water droplet sliding angle.

[0101] Effect example 2: Anti-icing performance test of coating The untreated insulator (only the cleaning step) and the insulator coated with the anti-icing super-phobic and super-slippery nano-coating in Example 1 of the present invention were placed in a simulated freezing rain environment (-10°C, continuously sprayed with water at ~4°C) for anti-icing performance testing. After spraying for 0.5 h, the temperature was kept for 1.5 h, which was considered as one cycle. The ice condition on the surface of the insulator was observed after 4 cycles.

[0102] Specific performance test conditions are as follows Figure 3 As shown: The insulator with untreated surface (right) is covered with thick ice, while the treated insulator (left) has no ice coverage because water droplets cannot nucleate and freeze on its surface due to its high hydrophobicity and super-slippery surface.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An anti-icing super-repellent and super-slip nano coating material, characterized in that: The invention comprises a core, an intermediate layer and an outer shell from the inside to the outside, wherein the core comprises nano-SiO2 particles modified by a silane coupling agent, the intermediate layer comprises polyamide-amine, and the outer shell comprises perfluoropolyether modified by acyl chloride.

2. The anti-icing super-phobic and super-slip nano coating material according to claim 1, characterized in that: The silane coupling agent includes an amino silane coupling agent.

3. The anti-icing super-phobic and super-slip nano coating material according to claim 2, characterized in that: The silane coupling agent-modified nano-SiO2 particles are prepared by reacting nano-SiO2 particles with a mass ratio of (50-80):35 and a silane coupling agent, and the reaction temperature is 50-100°C.

4. The anti-icing super-phobic and super-slip nano coating material according to claim 1, characterized in that: Include at least one of the following (a) to (c): (a) The particle size of the nano-SiO2 particles is 10-60 nm; (b) the thickness of the intermediate layer is 200-500 nm; (c) The thickness of the shell is 60~300 nm.

5. The anti-icing super-phobic and super-slip nano coating material according to claim 4, characterized in that: The polyamide-amine is prepared by reacting methyl acrylate and ethylenediamine in a mass ratio of (15-40): (300-800), and the reaction temperature is 20-30°C.

6. The anti-icing super-phobic and super-slip nano coating material according to claim 5, characterized in that: The mass ratio of the nano-SiO2 particles modified by the silane coupling agent to methyl acrylate is 60:(15-40).

7. The anti-icing super-phobic and super-slip nano coating material according to claim 4, characterized in that: The average molecular weight of the acyl chloride-modified perfluoropolyether is 1000-400.

8. The anti-icing super-phobic and super-slip nano coating material according to claim 7, characterized in that: The mass ratio of the nano-SiO2 particles modified by the silane coupling agent to the perfluoropolyether modified by acyl chloride is (80-95): (5-20).

9. The method for preparing the anti-icing super-phobic and super-slip nano coating material according to any one of claims 1 to 8, characterized in that: The steps include: S1. Mix nano-SiO2 particles modified by a silane coupling agent with methyl acrylate, react at 40-80°C to obtain SiO2-MA, add ethylenediamine and continue to react at 20-30°C to obtain SiO2-PAMAM; S2. The SiO2-PAMAM obtained in step S1 is mixed with the perfluoropolyether modified by acyl chloride, and a grafting reaction is carried out at 60-100° C. After the reaction, an anti-icing super-phobic and super-slippery nano-coating material can be obtained.

10. A method for preparing an anti-icing super-phobic and super-slip nano coating, characterized in that: The steps include: The anti-icing super-repellent and super-slippery nano-coating material according to any one of claims 1 to 8 is sprayed on the surface of a substrate and solidified to form an anti-icing super-repellent and super-slippery nano-coating on the surface of the substrate.

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