A fluorine-containing nano protective coating and its preparation method and application

Abstract

The present invention proposes a fluorine-containing nano protective coating and its preparation method and application, which belong to the field of coating technology. The surface of Ti3C2‑MXenes is modified with tannic acid, coated with wrinkled graphene oxide, coupled with fluorine-containing silicone and sulfur-containing silane coupling agents, and reduced, and a surface click reaction occurs to obtain a nano modifier, which is evenly stirred and mixed with a polyurethane resin, a dispersant, a defoaming agent and a solvent, and evenly applied to the surface of an electronic motherboard, ventilated and maintained to obtain a fluorine-containing nano protective coating. The fluorine-containing nano protective coating prepared by the present invention greatly improves the high and low temperature resistance, waterproofness, anti-fouling, self-cleaning, weather resistance, corrosion resistance, anti-ultraviolet aging, antistatic and wear resistance of the coating by adding a nano modifier, and the mechanical properties are enhanced, the adhesion is improved, and it is used for surface coating of electronic materials, which improves the durability of the material and has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a fluorine-containing nano protective coating and a preparation method and application thereof. Background Art

[0002] Superhydrophobic coatings (surface static contact angle greater than 150°) have attracted considerable attention due to their water-repellent, anti-fouling, anti-oxidation, and self-cleaning properties. Transparent superhydrophobic coatings, which not only possess superhydrophobic surface properties but also exhibit excellent visible light transmittance, have enormous potential applications in outdoor optoelectronic and display devices, self-cleaning glass in high-rise buildings, and windshields for automobiles and aircraft.

[0003] Currently, there is not much research on transparent superhydrophobic coatings, and the preparation methods mainly include sol-gel method, phase separation method, self-assembly method and plasma method.

[0004] There are methods for preparing super-hydrophobic coatings using the sol-gel method. For example, Chinese invention patent application CN101362632A prepares a transparent film by immersing a transparent substrate material into a sol prepared by chelating organic aluminum salts using the sol-gel method by a pulling method; Nakajima A et al. (Adv Mater. 1999, (11): 1365-1368) add a sublimable powdered compound Al(C2H7O2)3 to a silica sol or an aluminum sol to prepare a transparent coating. These coatings are all heat-treated to obtain a certain degree of roughness and then modified with extremely low free energy perfluoroalkyl chlorosilane or perfluoroalkyl alkoxysilane to obtain a transparent highly hydrophobic coating. HMShang et al. (Thin Solid Films. 2005, (472): 37-43) used TEOS, MPS, and MTES as raw materials, and dip-coated the silica sol obtained by hydrolysis on the surface of a glass slide. The silica sol was then self-assembled under the action of CTMS and TFCS. The transparency of the resulting silica-based transparent film was higher than 90%, and the maximum contact angle reached nearly 165°.

[0005] Methods for preparing super-hydrophobic coatings using plasma methods, such as Hozumi et al. (Thin Solid Films. 1997, 303: 222-225), used chemical vapor deposition (CVD) to obtain a certain degree of surface roughness on the deposited film. Silanes containing perfluoroalkyl groups were then used as the gas source to produce a transparent super-hydrophobic film through plasma treatment. Li Guoxing et al. (Applied Surface Science. 2008, (254): 5299-5303) used magnetron sputtering technology to deposit a boron nitride film on a silicon substrate. The surface was then treated with CF4 plasma to obtain a dual-scale roughness, resulting in a transparent super-hydrophobic film with a contact angle of 159°.

[0006] Methods for preparing superhydrophobic coatings using self-assembly methods, such as Javier Bravo et al. (Langmuir. 2007, (23): 7293-7298), used the LBL self-assembly method to dip-coat three layers onto a glass slide. The first adsorption layer was PAH / SPS, which enhanced the bonding between the polymer and the nanoparticles; the middle layer was PAH / silica (50+20 nm), which provided the dual-scale roughness structure required for superhydrophobicity; and the top layer was PAH / silica (20 nm), which used silane to reduce the surface free energy of the film. The film had a contact angle of 160°, a receding angle of less than 10°, and an optical transmittance greater than 90% in the visible light region. Chinese invention patent CN101519278B assembles negatively charged oxide nanoparticles and cationic polymer LBL layer by layer. Although the transmittance is high, the process is cumbersome and requires modification with low-surface-energy long-chain perfluorosilane by chemical deposition after sintering at 400°C. The raw materials are expensive and the conditions are harsh. Chinese invention patent CN101407648B deposits silica colloids onto conductive glass by electrophoresis. The transmittance is high, but it cannot be prepared on a large scale.

[0007] The above coating methods are complex and expensive to prepare, and require harsh chemical conditions and processes, all of which limit the widespread industrial application of super-hydrophobic coatings. Therefore, there is a need for a method for producing transparent super-hydrophobic surfaces that is simple to operate, uses readily available raw materials, and can be prepared and applied on a large scale. Summary of the Invention

[0008] The purpose of the present invention is to propose a fluorine-containing nano protective coating and its preparation method and application. The preparation method is simple, prevents the polarization of the carbon anode plate, has the advantages of low porosity, low ash content, high mechanical strength, high volume density, significantly improved service life, low resistivity, etc., and has broad application prospects.

[0009] The technical solution of the present invention is achieved as follows:

[0010] The present invention provides a method for preparing a fluorine-containing nano protective coating. The surface of Ti3C2-MXenes is modified with tannic acid, coated with wrinkled graphene oxide, coupled with fluorine-containing silicone and sulfur-containing silane coupling agents, and reduced, so as to generate a surface click reaction to obtain a nano modifier. The nano modifier is stirred and evenly mixed with a polyurethane resin, a dispersant, a defoaming agent and a solvent, and the mixture is evenly applied to the surface of an electronic mainboard and maintained in a ventilated environment to obtain a fluorine-containing nano protective coating.

[0011] As a further improvement of the present invention, the following steps are included:

[0012] S1. Preparation of modified Ti3C2-MXenes: Ti3C2-MXenes were added to water, tannic acid, and a catalyst were added, and the mixture was heated and stirred to react. The mixture was centrifuged, washed, and dried to obtain modified Ti3C2-MXenes.

[0013] S2. Preparation of wrinkled graphene oxide @Ti3C2-MXenes: Modified Ti3C2-MXenes and graphene oxide were added to water, ultrasonically dispersed, spray-dried, and ball-milled to obtain wrinkled graphene oxide @Ti3C2-MXenes.

[0014] S3. Preparation of modified wrinkled graphene oxide @Ti3C2-MXenes: Fluorosiloxane and sulfur-containing silane coupling agents were added to ethanol, followed by the addition of wrinkled graphene oxide @Ti3C2-MXenes. The mixture was heated and stirred for reaction, centrifuged, washed, and dried to obtain modified wrinkled graphene oxide @Ti3C2-MXenes.

[0015] S4. Reduction: The modified wrinkled graphene oxide@Ti3C2-MXenes is reduced with hydrazine hydrate vapor to obtain modified wrinkled graphene@Ti3C2-MXenes;

[0016] S5. Click chemistry reaction: Modified wrinkled graphene@Ti3C2-MXenes, 2,2-dimethoxy-2-phenylacetophenone, and methyl acrylate were added to N,N-dimethylformamide, irradiated with UV light, centrifuged, washed, and dried to prepare a nano-modifier.

[0017] S6. Preparation of fluorine-containing nano protective coating: stir and mix the nano modifier, polyurethane resin, dispersant, defoaming agent and solvent, apply evenly to the surface of the electronic motherboard, and maintain in a ventilated environment to obtain the fluorine-containing nano protective coating.

[0018] As a further improvement of the present invention, the mass ratio of Ti3C2-MXenes, tannic acid and catalyst in step S1 is 10:3-5:0.5-1, the temperature of the heating and stirring reaction is 40-50°C, the time is 2-4h, and the catalyst is a Tris-HCl solution with a pH of 8-9.

[0019] As a further improvement of the present invention, the mass ratio of the modified Ti3C2-MXenes and graphene oxide in step S2 is 3-5:2-3.

[0020] As a further improvement of the present invention, the mass ratio of the fluorinated siloxane, the sulfur-containing silane coupling agent, and the wrinkled graphene oxide @Ti3C2-MXenes in step S3 is 3-5:1-2:10, the temperature of the heating and stirring reaction is 45-55°C, and the time is 1-3h. The fluorinated siloxane is selected from 1H,1H,2H,2H-perfluorodecyltriethoxysilane, 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, dodecafluoroheptylpropyltrimethoxysilane, dodecafluoroheptylpropylmethyldimethoxysilane, 3,3,3-trifluoropropylmethyldimethoxysilane, 3 , at least one of 3,3-trifluoropropyltrimethoxysilane, 1H,1H,2H,2H-perfluorooctyltriethoxysilane or 1H,1H,2H,2H-perfluorooctyltrimethoxysilane, preferably, the fluorine-containing silicone is a mixture of dodecafluoroheptylpropyltrimethoxysilane and dodecafluoroheptylpropylmethyldimethoxysilane, with a mass ratio of 8-10:2-3, and the sulfur-containing silane coupling agent is at least one of bis-(3-triethoxysilylpropyl)tetrasulfide, bis-(3-triethoxysilylpropyl)disulfide, mercaptopropyltriethoxysilane and γ-mercaptopropyltrimethoxysilane.

[0021] As a further improvement of the present invention, the time for the hydrazine hydrate steam reduction in step S4 is 7-10 hours.

[0022] As a further improvement of the present invention, the mass ratio of the modified wrinkled graphene @Ti3C2-MXenes, 2,2-dimethoxy-2-phenylacetophenone, and methyl acrylate in step S5 is 10:0.03-0.05:4-6, and the ultraviolet lamp irradiation time is 40-60s.

[0023] As a further improvement of the present invention, the mass ratio of the nano-modifier, polyurethane resin, dispersant, defoaming agent, and solvent in step S6 is 10-12:85-105:2-3:1-2:100-200, the solvent is selected from at least one of acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, dichloromethane, tetrahydrofuran, N,N-dimethylformamide, and dioxane, the dispersant is selected from at least one of oleyl amino oleate, polyethylene glycol 600, polyethylene glycol 400, and sodium oleate, and the defoaming agent is selected from at least one of propylene glycol, isopropyl alcohol, n-butanol, isooctyl alcohol, naphtha, and white mineral oil.

[0024] The present invention further protects a fluorine-containing nano protective coating prepared by the above preparation method.

[0025] The present invention further protects the use of the above-mentioned fluorine-containing nano protective coating in the preparation of waterproof electronic products.

[0026] The present invention has the following beneficial effects:

[0027] The present invention uses two-dimensional transition metal carbon titanium compounds Ti3C2-MXenes as the core material. Through the weak interaction of interlayer van der Waals forces, the resulting coating has good self-lubrication and wear resistance. At the same time, it has good modifiable properties. Through tannic acid surface modification, the two-dimensional material can be compounded with graphene oxide to form a composite. After spray drying, the solvent on the droplet surface evaporates rapidly, causing a change in surface tension and uneven shrinkage of the droplet surface, thereby forming a wrinkled structure that simulates the micron and nanometer-level rough structure of the "petal" and "lotus leaf" surface, thereby greatly improving the surface hydrophobicity of the coating. In addition, the hydroxyl groups of the surface graphene oxide can also undergo coupling reaction modification with fluorinated siloxanes and sulfur-containing silane coupling agents, thereby connecting the fluorinated structure to the nanostructure. At the same time, thiol groups are introduced. On the one hand, the fluorinated structure greatly improves the coating's high and low temperature resistance, waterproofing, anti-fouling, self-cleaning, weather resistance, corrosion resistance, UV aging resistance, antistatic and wear resistance, thereby greatly improving the overall performance of the coating. In addition, when the surface fluorosilane is damaged, the nanomodifier in the pores will move to the surface of the coating, thereby repairing the superhydrophobic surface and realizing its self-healing properties.

[0028] After being reduced with hydrazine hydrate vapor, graphene oxide is reduced to a graphene layered structure. Graphene has an ultra-thin thickness, good anti-friction and wear-resistant properties, and a small friction coefficient. It is a solid lubricating material with relatively stable properties, which makes the coating have better self-lubrication and wear resistance.

[0029] The resulting modified wrinkled graphene@Ti3C2-MXenes reacts with ene esters through a click chemistry reaction, adding polyacrylate hydrophobic groups to the surface of the nanomodifier. This improves the mechanical properties of the coating and further forms a rough, uneven micro-nanoscale structure layer, which increases the specific surface area and provides the necessary physical foundation for achieving superhydrophobic properties. Furthermore, the low surface energy helps increase the contact angle of water droplets, making it easier for water droplets to form spheres on the surface. It also improves the bonding ability with the substrate, forming a stable chemical bond, and resists corrosion from chemicals such as acids, alkalis, and salt spray. It also exhibits a self-cleaning function, allowing rainwater or water flow to remove dust and dirt from the surface. The introduction of a carbon polymer layer further enhances the surface's self-cleaning effect, making it easier to maintain in practical applications.

[0030] The fluorine-containing nano protective coating prepared by the present invention greatly improves the high and low temperature resistance, waterproofness, anti-fouling, self-cleaning, weather resistance, corrosion resistance, anti-ultraviolet aging, antistatic and wear resistance of the coating by adding a nano modifier. The mechanical properties are enhanced and the adhesion is improved. It is used for surface coating of electronic materials, improves the durability of the materials, and has broad application prospects. 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] Graphene oxide, with a sheet diameter of 2-5 μm, a monolayer rate of >99%, a thickness of 0.8-1.2 nm, and a purity of >99%, was purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.

[0033] Example 1

[0034] This embodiment provides a method for preparing a fluorine-containing nano-protective coating, comprising the following steps:

[0035] S1. Preparation of modified Ti3C2-MXenes: 10 g of Ti3C2-MXenes was added to 200 mL of water, along with 3 g of tannic acid and 0.5 g of catalyst. The mixture was heated to 40°C and stirred for 2 h. The mixture was centrifuged, washed, and dried to obtain the modified Ti3C2-MXenes.

[0036] The catalyst is a Tris-HCl solution with a pH of 8;

[0037] S2. Preparation of wrinkled graphene oxide @Ti3C2-MXenes: 3 g of modified Ti3C2-MXenes and 2 g of graphene oxide were added to 100 mL of water, ultrasonically dispersed at 1500 W for 10 min, spray dried, and ball milled for 1 h to obtain wrinkled graphene oxide @Ti3C2-MXenes.

[0038] S3. Preparation of modified wrinkled graphene oxide @Ti3C2-MXenes: 3 g of fluorinated siloxane and 1 g of sulfur-containing silane coupling agent were added to 200 mL of ethanol, followed by 10 g of wrinkled graphene oxide @Ti3C2-MXenes. The mixture was heated to 45°C and stirred for 1 h. The mixture was centrifuged, washed, and dried to obtain modified wrinkled graphene oxide @Ti3C2-MXenes.

[0039] The fluorine-containing siloxane is a mixture of dodecafluoroheptylpropyltrimethoxysilane and dodecafluoroheptylpropylmethyldimethoxysilane in a mass ratio of 8:2;

[0040] S4. Reduction: The modified wrinkled graphene oxide@Ti3C2-MXenes was reduced with hydrazine hydrate vapor for 7 h to obtain modified wrinkled graphene@Ti3C2-MXenes;

[0041] S5. Click chemistry reaction: 10 g of modified wrinkled graphene@Ti3C2-MXenes, 0.03 g of 2,2-dimethoxy-2-phenylacetophenone, and 4 g of methyl acrylate were added to 200 mL of N,N-dimethylformamide. The mixture was irradiated with UV light for 40 s, centrifuged, washed, and dried to obtain a nano-modifier.

[0042] S6. Preparation of fluorine-containing nano-protective coating: 10 g of nano-modifier, 85 g of polyurethane resin, 2 g of polyethylene glycol 600, 1 g of n-butanol, and 100 g of acetone were stirred and mixed for 15 minutes, and the mixture was evenly applied to the surface of the electronic motherboard. The mixture was ventilated and cured for 7 days to obtain a fluorine-containing nano-protective coating.

[0043] Example 2

[0044] This embodiment provides a method for preparing a fluorine-containing nano-protective coating, comprising the following steps:

[0045] S1. Preparation of modified Ti3C2-MXenes: 10 g of Ti3C2-MXenes was added to 200 mL of water, along with 5 g of tannic acid and 1 g of catalyst. The mixture was heated to 50°C and stirred for 4 h. The mixture was centrifuged, washed, and dried to obtain the modified Ti3C2-MXenes.

[0046] The catalyst is a Tris-HCl solution with a pH of 9;

[0047] S2. Preparation of wrinkled graphene oxide @Ti3C2-MXenes: 5 g of modified Ti3C2-MXenes and 3 g of graphene oxide were added to 100 mL of water, ultrasonically dispersed at 1500 W for 10 min, spray dried, and ball milled for 1 h to obtain wrinkled graphene oxide @Ti3C2-MXenes.

[0048] S3. Preparation of modified wrinkled graphene oxide @Ti3C2-MXenes: 5 g of fluorosiloxane and 2 g of γ-mercaptopropyltrimethoxysilane were added to 200 mL of ethanol, followed by 10 g of wrinkled graphene oxide @Ti3C2-MXenes. The mixture was heated to 55°C and stirred for 3 h. The mixture was centrifuged, washed, and dried to obtain modified wrinkled graphene oxide @Ti3C2-MXenes.

[0049] The fluorine-containing siloxane is a mixture of dodecafluoroheptylpropyltrimethoxysilane and dodecafluoroheptylpropylmethyldimethoxysilane in a mass ratio of 10:3;

[0050] S4. Reduction: The modified wrinkled graphene oxide@Ti3C2-MXenes was reduced with hydrazine hydrate vapor for 10 h to obtain modified wrinkled graphene@Ti3C2-MXenes;

[0051] S5. Click chemistry reaction: 10 g of modified wrinkled graphene@Ti3C2-MXenes, 0.05 g of 2,2-dimethoxy-2-phenylacetophenone, and 6 g of methyl acrylate were added to 200 mL of N,N-dimethylformamide. The mixture was irradiated with UV light for 60 s, centrifuged, washed, and dried to obtain a nano-modifier.

[0052] S6. Preparation of fluorine-containing nano-protective coating: 12 g of nano-modifier, 105 g of polyurethane resin, 3 g of polyethylene glycol 600, 2 g of white mineral oil, and 200 g of methyl ethyl ketone were stirred and mixed for 15 minutes, and the mixture was evenly applied to the surface of the electronic motherboard. The mixture was ventilated and cured for 7 days to obtain a fluorine-containing nano-protective coating.

[0053] Example 3

[0054] This embodiment provides a method for preparing a fluorine-containing nano-protective coating, comprising the following steps:

[0055] S1. Preparation of modified Ti3C2-MXenes: 10 g of Ti3C2-MXenes was added to 200 mL of water, along with 4 g of tannic acid and 0.7 g of catalyst. The mixture was heated to 45°C and stirred for 3 h. The mixture was centrifuged, washed, and dried to obtain the modified Ti3C2-MXenes.

[0056] The catalyst is a Tris-HCl solution with a pH of 8.5;

[0057] S2. Preparation of wrinkled graphene oxide @Ti3C2-MXenes: 4 g of modified Ti3C2-MXenes and 2.5 g of graphene oxide were added to 100 mL of water, ultrasonically dispersed at 1500 W for 10 min, spray dried, and ball milled for 1 h to obtain wrinkled graphene oxide @Ti3C2-MXenes.

[0058] S3. Preparation of modified wrinkled graphene oxide @Ti3C2-MXenes: 4 g of fluorosiloxane and 1.5 g of mercaptopropyltriethoxysilane were added to 200 mL of ethanol, followed by 10 g of wrinkled graphene oxide @Ti3C2-MXenes. The mixture was heated to 50°C and stirred for 2 h. The mixture was centrifuged, washed, and dried to obtain modified wrinkled graphene oxide @Ti3C2-MXenes.

[0059] The fluorine-containing siloxane is a mixture of dodecafluoroheptylpropyltrimethoxysilane and dodecafluoroheptylpropylmethyldimethoxysilane, with a mass ratio of 9:2.5;

[0060] S4. Reduction: The modified wrinkled graphene oxide@Ti3C2-MXenes was reduced with hydrazine hydrate vapor for 8 h to obtain modified wrinkled graphene@Ti3C2-MXenes;

[0061] S5. Click chemistry reaction: 10 g of modified wrinkled graphene@Ti3C2-MXenes, 0.04 g of 2,2-dimethoxy-2-phenylacetophenone, and 5 g of methyl acrylate were added to 200 mL of N,N-dimethylformamide. The mixture was irradiated with UV light for 50 s, centrifuged, washed, and dried to obtain a nano-modifier.

[0062] S6. Preparation of fluorine-containing nano-protective coating: 11 g of nano-modifier, 95 g of polyurethane resin, 2.5 g of polyethylene glycol 400, 1.5 g of isooctyl alcohol, and 150 g of cyclohexanone were stirred and mixed for 15 minutes, and the mixture was evenly applied to the surface of the electronic motherboard and ventilated and cured for 7 days to obtain a fluorine-containing nano-protective coating.

[0063] Example 4

[0064] Compared with Example 3, the difference is that the fluorine-containing siloxane is a single dodecafluoroheptylpropyltrimethoxysilane.

[0065] Example 5

[0066] Compared with Example 3, the difference is that the fluorine-containing silicone is a single dodecafluoroheptylpropylmethyldimethoxysilane.

[0067] Comparative Example 1

[0068] Compared with embodiment 3, the difference is that step S1 is not performed.

[0069] The details are as follows:

[0070] S1. Preparation of wrinkled graphene oxide @Ti3C2-MXenes: 4 g of Ti3C2-MXenes and 2.5 g of graphene oxide were added to 100 mL of water, ultrasonically dispersed at 1500 W for 10 min, spray-dried, and ball-milled for 1 h to obtain wrinkled graphene oxide @Ti3C2-MXenes.

[0071] S2. Preparation of modified wrinkled graphene oxide @Ti3C2-MXenes: 4 g of fluorosiloxane and 1.5 g of mercaptopropyltriethoxysilane were added to 200 mL of ethanol, followed by 10 g of wrinkled graphene oxide @Ti3C2-MXenes. The mixture was heated to 50°C and stirred for 2 h. The mixture was centrifuged, washed, and dried to obtain modified wrinkled graphene oxide @Ti3C2-MXenes.

[0072] The fluorine-containing siloxane is a mixture of dodecafluoroheptylpropyltrimethoxysilane and dodecafluoroheptylpropylmethyldimethoxysilane, with a mass ratio of 9:2.5;

[0073] S3. Reduction: The modified wrinkled graphene oxide @Ti3C2-MXenes was reduced with hydrazine hydrate vapor for 8 h to obtain modified wrinkled graphene @Ti3C2-MXenes;

[0074] S4. Click chemistry reaction: 10 g of modified wrinkled graphene@Ti3C2-MXenes, 0.04 g of 2,2-dimethoxy-2-phenylacetophenone, and 5 g of methyl acrylate were added to 200 mL of N,N-dimethylformamide. The mixture was irradiated with UV light for 50 s, centrifuged, washed, and dried to obtain a nano-modifier.

[0075] S5. Preparation of fluorine-containing nano-protective coating: 11 g of nano-modifier, 95 g of polyurethane resin, 2.5 g of polyethylene glycol 400, 1.5 g of isooctyl alcohol, and 150 g of cyclohexanone were stirred and mixed for 15 minutes, and the mixture was evenly applied to the surface of the electronic motherboard and ventilated and cured for 7 days to obtain a fluorine-containing nano-protective coating.

[0076] Comparative Example 2

[0077] Compared with Example 3, the difference is that steps S2 and S4 are not performed.

[0078] The details are as follows:

[0079] S1. Preparation of modified Ti3C2-MXenes: 10 g of Ti3C2-MXenes was added to 200 mL of water, along with 4 g of tannic acid and 0.7 g of catalyst. The mixture was heated to 45°C and stirred for 3 h. The mixture was centrifuged, washed, and dried to obtain the modified Ti3C2-MXenes.

[0080] The catalyst is a Tris-HCl solution with a pH of 8.5;

[0081] S2. Preparation of fluorosilane / mercaptosilane-modified Ti3C2-MXenes: 4 g of fluorosiloxane and 1.5 g of mercaptopropyltriethoxysilane were added to 200 mL of ethanol, followed by 10 g of modified Ti3C2-MXenes. The mixture was heated to 50°C and stirred for 2 h. The mixture was centrifuged, washed, and dried to obtain fluorosilane / mercaptosilane-modified Ti3C2-MXenes.

[0082] The fluorine-containing siloxane is a mixture of dodecafluoroheptylpropyltrimethoxysilane and dodecafluoroheptylpropylmethyldimethoxysilane, with a mass ratio of 9:2.5;

[0083] S3. Click chemistry reaction: 10 g of fluorosilane / mercaptosilane-modified TiC-MXenes, 0.04 g of 2,2-dimethoxy-2-phenylacetophenone, and 5 g of methyl acrylate were added to 200 mL of N,N-dimethylformamide. The mixture was irradiated with UV light for 50 s, centrifuged, washed, and dried to obtain a nano-modifier.

[0084] S4. Preparation of fluorine-containing nano-protective coating: 11 g of nano-modifier, 95 g of polyurethane resin, 2.5 g of polyethylene glycol 400, 1.5 g of isooctyl alcohol and 150 g of cyclohexanone were stirred and mixed for 15 minutes, and the mixture was evenly applied to the surface of the electronic motherboard and ventilated and cured for 7 days to obtain a fluorine-containing nano-protective coating.

[0085] Comparative Example 3

[0086] Compared with Example 3, the difference is that no fluorine-containing silicone is added in step S3.

[0087] The details are as follows:

[0088] S1. Preparation of modified Ti3C2-MXenes: 10 g of Ti3C2-MXenes was added to 200 mL of water, along with 4 g of tannic acid and 0.7 g of catalyst. The mixture was heated to 45°C and stirred for 3 h. The mixture was centrifuged, washed, and dried to obtain the modified Ti3C2-MXenes.

[0089] The catalyst is a Tris-HCl solution with a pH of 8.5;

[0090] S2. Preparation of wrinkled graphene oxide @Ti3C2-MXenes: 4 g of modified Ti3C2-MXenes and 2.5 g of graphene oxide were added to 100 mL of water, ultrasonically dispersed at 1500 W for 10 min, spray dried, and ball milled for 1 h to obtain wrinkled graphene oxide @Ti3C2-MXenes.

[0091] S3. Preparation of modified wrinkled graphene oxide @Ti3C2-MXenes: 5.5 g of mercaptopropyltriethoxysilane was added to 200 mL of ethanol, followed by 10 g of wrinkled graphene oxide @Ti3C2-MXenes. The mixture was heated to 50°C and stirred for 2 h. The mixture was centrifuged, washed, and dried to obtain modified wrinkled graphene oxide @Ti3C2-MXenes.

[0092] S4. Reduction: The modified wrinkled graphene oxide@Ti3C2-MXenes was reduced with hydrazine hydrate vapor for 8 h to obtain modified wrinkled graphene@Ti3C2-MXenes;

[0093] S5. Click chemistry reaction: 10 g of modified wrinkled graphene@Ti3C2-MXenes, 0.04 g of 2,2-dimethoxy-2-phenylacetophenone, and 5 g of methyl acrylate were added to 200 mL of N,N-dimethylformamide. The mixture was irradiated with UV light for 50 s, centrifuged, washed, and dried to obtain a nano-modifier.

[0094] S6. Preparation of fluorine-containing nano-protective coating: 11 g of nano-modifier, 95 g of polyurethane resin, 2.5 g of polyethylene glycol 400, 1.5 g of isooctyl alcohol, and 150 g of cyclohexanone were stirred and mixed for 15 minutes, and the mixture was evenly applied to the surface of the electronic motherboard and ventilated and cured for 7 days to obtain a fluorine-containing nano-protective coating.

[0095] Comparative Example 4

[0096] Compared with embodiment 3, the difference is that step S4 is not performed.

[0097] The details are as follows:

[0098] S1. Preparation of modified Ti3C2-MXenes: 10 g of Ti3C2-MXenes was added to 200 mL of water, along with 4 g of tannic acid and 0.7 g of catalyst. The mixture was heated to 45°C and stirred for 3 h. The mixture was centrifuged, washed, and dried to obtain the modified Ti3C2-MXenes.

[0099] The catalyst is a Tris-HCl solution with a pH of 8.5;

[0100] S2. Preparation of wrinkled graphene oxide @Ti3C2-MXenes: 4 g of modified Ti3C2-MXenes and 2.5 g of graphene oxide were added to 100 mL of water, ultrasonically dispersed at 1500 W for 10 min, spray dried, and ball milled for 1 h to obtain wrinkled graphene oxide @Ti3C2-MXenes.

[0101] S3. Preparation of modified wrinkled graphene oxide @Ti3C2-MXenes: 4 g of fluorosiloxane and 1.5 g of mercaptopropyltriethoxysilane were added to 200 mL of ethanol, followed by 10 g of wrinkled graphene oxide @Ti3C2-MXenes. The mixture was heated to 50°C and stirred for 2 h. The mixture was centrifuged, washed, and dried to obtain modified wrinkled graphene oxide @Ti3C2-MXenes.

[0102] The fluorine-containing siloxane is a mixture of dodecafluoroheptylpropyltrimethoxysilane and dodecafluoroheptylpropylmethyldimethoxysilane, with a mass ratio of 9:2.5;

[0103] S4. Click chemistry reaction: 10 g of modified oxidized wrinkled graphene@Ti3C2-MXenes, 0.04 g of 2,2-dimethoxy-2-phenylacetophenone, and 5 g of methyl acrylate were added to 200 mL of N,N-dimethylformamide. The mixture was irradiated with UV light for 50 s, centrifuged, washed, and dried to obtain a nano-modifier.

[0104] S5. Preparation of fluorine-containing nano-protective coating: 11 g of nano-modifier, 95 g of polyurethane resin, 2.5 g of polyethylene glycol 400, 1.5 g of isooctyl alcohol, and 150 g of cyclohexanone were stirred and mixed for 15 minutes, and the mixture was evenly applied to the surface of the electronic motherboard and ventilated and cured for 7 days to obtain a fluorine-containing nano-protective coating.

[0105] Comparative Example 5

[0106] Compared with embodiment 3, the difference is that step S5 is not performed.

[0107] The details are as follows:

[0108] S1. Preparation of modified Ti3C2-MXenes: 10 g of Ti3C2-MXenes was added to 200 mL of water, along with 4 g of tannic acid and 0.7 g of catalyst. The mixture was heated to 45°C and stirred for 3 h. The mixture was centrifuged, washed, and dried to obtain the modified Ti3C2-MXenes.

[0109] The catalyst is a Tris-HCl solution with a pH of 8.5;

[0110] S2. Preparation of wrinkled graphene oxide @Ti3C2-MXenes: 4 g of modified Ti3C2-MXenes and 2.5 g of graphene oxide were added to 100 mL of water, ultrasonically dispersed at 1500 W for 10 min, spray dried, and ball milled for 1 h to obtain wrinkled graphene oxide @Ti3C2-MXenes.

[0111] S3. Preparation of modified wrinkled graphene oxide @Ti3C2-MXenes: 4 g of fluorosiloxane and 1.5 g of mercaptopropyltriethoxysilane were added to 200 mL of ethanol, followed by 10 g of wrinkled graphene oxide @Ti3C2-MXenes. The mixture was heated to 50°C and stirred for 2 h. The mixture was centrifuged, washed, and dried to obtain modified wrinkled graphene oxide @Ti3C2-MXenes.

[0112] The fluorine-containing siloxane is a mixture of dodecafluoroheptylpropyltrimethoxysilane and dodecafluoroheptylpropylmethyldimethoxysilane, with a mass ratio of 9:2.5;

[0113] S4. Reduction: The modified wrinkled graphene oxide@Ti3C2-MXenes was reduced with hydrazine hydrate vapor for 8 h to obtain modified wrinkled graphene@Ti3C2-MXenes;

[0114] S5. Preparation of a fluorine-containing nano-protective coating: 11 g of modified wrinkled graphene@Ti3C2-MXenes, 95 g of polyurethane resin, 2.5 g of polyethylene glycol 400, 1.5 g of isooctyl alcohol, and 150 g of cyclohexanone were stirred and mixed for 15 minutes, and the mixture was evenly applied to the surface of an electronic motherboard and cured under ventilation for 7 days to obtain a fluorine-containing nano-protective coating.

[0115] Test Example 1

[0116] The antifouling performance of the fluorine-containing nano-protective coatings prepared in Examples 1-5 of the present invention and Comparative Examples 1-5 was tested.

[0117] QUVB2000h is artificial radiation exposure UV aging for 2000h.

[0118] The results are shown in Table 1.

[0119] Table 1

[0120]

[0121]

[0122] It can be seen from the above table that the fluorine-containing nano-protective coatings prepared in Examples 1-3 of the present invention have good anti-fouling properties.

[0123] Test Example 2

[0124] The fluorine-containing nano-protective coatings prepared in Examples 1-5 of the present invention and Comparative Examples 1-5 were subjected to comprehensive performance tests.

[0125] Wear resistance test: The coating wear resistance test is carried out in accordance with GB / T1768-2006.

[0126] Pencil hardness: According to the method of GB / T6739-2006, use pencils of gradually increasing hardness to draw across the coating surface at a 45° angle, and then observe the integrity of the coating surface until the coating surface is indented, scratched, or scratched. The hardness of the previous pencil is the hardness of the tested coating;

[0127] Adhesion test: According to the GB1720-2020 method, the coating integrity within the range of the circular roller line scratch is rated.

[0128] Contact angle test: The contact angle test was performed using an OCA40 contact angle meter from DataPhysics Instruments of Germany.

[0129] The results are shown in Table 2.

[0130] Table 2

[0131]

[0132]

[0133] It can be seen from the above table that the fluorine-containing nano protective coatings prepared in Examples 1-3 of the present invention have good comprehensive properties.

[0134] Test Example 3

[0135] The mechanical properties of the fluorine-containing nano-protective coatings prepared in Examples 1-5 of the present invention and Comparative Examples 1-5 were tested.

[0136] According to GB / T 19250-2013 Polyurethane Waterproof Coating standard, the tensile speed is 500mm / min and the test temperature is 25℃.

[0137] The results are shown in Table 3.

[0138] Table 3

[0139] Group Tensile strength (MPa) Elongation at break (%) Example 1 8.15 652 Example 2 8.17 655 Example 3 8.22 658 Example 4 8.09 642 Example 5 8.04 645 Comparative Example 1 7.84 622 Comparative Example 2 7.78 605 Comparative Example 3 7.92 631 Comparative Example 4 7.82 620 Comparative Example 5 7.95 635

[0140] It can be seen from the above table that the fluorine-containing nano protective coatings prepared in Examples 1-3 of the present invention have good mechanical properties.

[0141] Test Example 4

[0142] The fluorine-containing nano-protective coatings prepared in Examples 1-5 and Comparative Examples 1-5 were subjected to the following performance tests.

[0143] The water resistance test refers to GB / T1733-1993 "Determination of water resistance of paint films", the test temperature is 40℃, and the test time is 24h.

[0144] Acid resistance is tested according to the immersion method specified in GB / T9274-1988 "Determination of resistance of paints and varnishes to liquid media", with a sulfuric acid mass fraction of 5%. Defects are observed after immersion for 24 hours.

[0145] Neutral salt spray resistance test is carried out in accordance with the provisions of GB / T1771-2007 “Determination of neutral salt spray resistance of paints and varnishes”. The mass concentration of sodium chloride solution is (50±5) g / L and the pH is 6.7±2.

[0146] The organic solvent resistance test is carried out according to the manual wiping method specified in GB / T23989-2009 "Determination of Solvent Resistance of Coatings by Wiping Method". A finger wrapped in absorbent cotton is used to wipe back and forth 25 times to observe whether the coating is damaged and the substrate is exposed.

[0147] The results are shown in Table 4.

[0148] Table 4

[0149]

[0150]

[0151] It can be seen from the above table that the fluorine-containing nano-protective coatings prepared in Examples 1-3 of the present invention have good acid resistance, water resistance, salt spray resistance, and organic solvent resistance.

[0152] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a fluorine-containing nano protective coating, characterized in that: The following steps are involved: S1. Preparation of modified Ti3C2-MXenes: Ti3C2-MXenes were added to water, tannic acid, and a catalyst, heated and stirred for reaction, centrifuged, washed, and dried to obtain modified Ti3C2-MXenes. S2. Preparation of wrinkled graphene oxide@Ti3C2-MXenes: Modified Ti3C2-MXenes and graphene oxide were added to water, ultrasonically dispersed, spray-dried, and ball-milled to produce wrinkled graphene oxide@Ti3C2-MXenes. S3. Preparation of modified wrinkled graphene oxide @Ti3C2-MXenes: Fluorosiloxane and a sulfur-containing silane coupling agent were added to ethanol, followed by the addition of wrinkled graphene oxide @Ti3C2-MXenes. The mixture was heated and stirred for reaction, centrifuged, washed, and dried to obtain the modified wrinkled graphene oxide @Ti3C2-MXenes. The fluorinated siloxane was a mixture of dodecafluoroheptylpropyltrimethoxysilane and dodecafluoroheptylpropylmethyldimethoxysilane in a mass ratio of 8-10:2-3. S4. Reduction: Reducing the modified wrinkled graphene oxide@Ti3C2-MXenes with hydrazine hydrate vapor to produce modified wrinkled graphene@Ti3C2-MXenes. S5. Click chemistry reaction: Modified wrinkled graphene@Ti3C2-MXenes, 2,2-dimethoxy-2-phenylacetophenone, and methyl acrylate were added to N,N-dimethylformamide, irradiated with UV light, centrifuged, washed, and dried to produce a nano-modifier. S6. Preparation of a fluorine-containing nano-protective coating: A nano-modifier, a polyurethane resin, a dispersant, a defoaming agent, and a solvent are stirred and uniformly mixed, and the mixture is evenly applied to the surface of an electronic motherboard. The mixture is then ventilated and cured to obtain a fluorine-containing nano-protective coating.

2. The preparation method according to claim 1, characterized in that The mass ratio of Ti3C2-MXenes, tannic acid and catalyst in step S1 is 10:3-5:0.5-1, the temperature of the heating and stirring reaction is 40-50°C, the time is 2-4h, and the catalyst is a Tris-HCl solution with a pH of 8-9.

3. The preparation method according to claim 1, characterized in that The mass ratio of the modified Ti3C2-MXenes and graphene oxide in step S2 is 3-5:2-3.

4. The preparation method according to claim 1, characterized in that The mass ratio of the fluorinated siloxane, the sulfur-containing silane coupling agent, and the wrinkled graphene oxide @Ti3C2-MXenes in step S3 is 3-5:1-2:10, the temperature of the heated and stirred reaction is 45-55°C, and the time is 1-3h. The sulfur-containing silane coupling agent is at least one of bis-(3-triethoxysilylpropyl) tetrasulfide, bis-(3-triethoxysilylpropyl) disulfide, mercaptopropyltriethoxysilane, and γ-mercaptopropyltrimethoxysilane.

5. The preparation method according to claim 1, characterized in that The time for the hydrazine hydrate vapor reduction in step S4 is 7-10 hours.

6. The preparation method according to claim 1, characterized in that In step S5, the mass ratio of the modified wrinkled graphene@Ti3C2-MXenes, 2,2-dimethoxy-2-phenylacetophenone, and methyl acrylate is 10:0.03-0.05:4-6, and the ultraviolet lamp irradiation time is 40-60s.

7. The preparation method according to claim 1, characterized in that The mass ratio of the nano-modifier, polyurethane resin, dispersant, defoaming agent, and solvent in step S6 is 10-12:85-105:2-3:1-2:100-200, the solvent is selected from at least one of acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, dichloromethane, tetrahydrofuran, N,N-dimethylformamide, and dioxane, the dispersant is selected from at least one of oleyl amino oleate, polyethylene glycol 600, polyethylene glycol 400, and sodium oleate, and the defoaming agent is selected from at least one of propylene glycol, isopropyl alcohol, n-butanol, isooctyl alcohol, naphtha, and white mineral oil.

8. A fluorine-containing nano protective coating prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the fluorine-containing nano protective coating according to claim 8 in the preparation of waterproof electronic products.

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