Graphdiyne anticorrosive coating, preparation method and application thereof

Abstract

The application discloses a graphdiyne anticorrosive paint and a preparation method and application thereof. The graphdiyne anticorrosive paint comprises components A and B. The component A comprises epoxy resin, fluorosilane modified graphdiyne nanosheet, epoxy functionalized nanosilica, pigment and filler, wetting dispersant, rheological aid and a first solvent. The component B comprises a curing agent and a second solvent. By simultaneously introducing the fluorosilane modified graphdiyne nanosheet and the epoxy functionalized nanosilica into the anticorrosive paint, the anticorrosive performance of the paint is significantly improved through the space synergy of the graphdiyne two-dimensional sheet layer and the zero-dimensional nanosilica particle, the interface enhancement of chemical bonding and the passivation performance synergy. The anticorrosive paint has the advantages of strong adhesion, excellent salt spray resistance and good hydrophobicity.

Description

Technical Field

[0001] This invention belongs to the field of coating technology. Specifically, this invention relates to a graphdiyne anticorrosive coating, its preparation method, and its application. Background Technology

[0002] Metal corrosion is a major global challenge. In fields such as marine engineering, petrochemicals, and transportation, anti-corrosion coatings are one of the most effective and economical protective measures. Epoxy resin coatings are widely used in heavy-duty corrosion protection due to their strong adhesion, resistance to chemical media, and excellent mechanical properties.

[0003] Graphdiyne is a novel two-dimensional carbon material composed of sp and sp2 hybridized carbon atoms, exhibiting a unique two-dimensional planar structure and uniformly distributed pores. Compared to graphene, graphdiyne possesses superior semiconductor properties and higher chemical reactivity. Its unique electronic structure and large conjugated system make it a promising candidate for corrosion protection.

[0004] However, graphylene, as a nanofiller, faces two major technical challenges in anti-corrosion coatings: first, the strong π-π interactions between graphylene sheets make them prone to agglomeration and difficult to disperse uniformly in the resin matrix; second, the interfacial bonding between graphylene and the organic resin matrix is ​​weak, which prevents it from fully utilizing its excellent physical shielding and chemical passivation properties.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a graphdiene anticorrosive coating, its preparation method, and its application. This coating employs a synergistic anticorrosive system of fluorosilane-modified graphdiene and epoxy-functionalized nano-silica. Through the spatial synergy of two-dimensional sheets and zero-dimensional nanoparticles, the enhanced interface of chemical bonding, and the synergistic passivation properties, the anticorrosive performance of the coating is significantly improved.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, embodiments of the present invention provide a graphdiyne anticorrosive coating, comprising component A and component B; wherein, component A comprises the following raw materials in parts by weight: 25-45 parts epoxy resin, 0.5-3.0 parts fluorosilane-modified graphdiyne nanosheets, 0.2-1.0 parts epoxy-functionalized nano-silica, 30-50 parts pigments and fillers, 0.2-1.5 parts wetting and dispersing agent, 0.2-2.0 parts rheology modifier, and 10-20 parts first solvent; component B comprises the following raw materials in parts by weight: 15-30 parts curing agent and 5-15 parts second solvent; the weight ratio of component A to component B is (3-6):1.

[0009] In some embodiments, the mass ratio of the fluorosilane-modified graphdiyne nanosheets to the epoxy-functionalized nano-silica is 1:(0.2-0.5).

[0010] In some embodiments, the fluorosilane-modified graphyne nanosheets are prepared by a method comprising the following steps: S1: Graphdiyne nanosheets are dispersed in an organic solvent and subjected to liquid phase exfoliation under ultrasonic assistance. The unexfoliated thick layer of graphdiyne is then removed by centrifugation to obtain a graphdiyne nanosheet dispersion. S2: Add fluorosilane to the graphyne nanosheet dispersion and stir to react; S3: The reaction product obtained in step S2 is centrifuged, washed, and dried to obtain the fluorosilane-modified graphdiyne nanosheets.

[0011] Further, in step S1, the graphdiyne nanosheets have a diameter of 0.5–5 μm and a thickness of 2–10 nm; the organic solvent includes at least one of N-methylpyrrolidone, dimethylformamide, and ethanol; the ultrasonic power is 300–600 W, and the ultrasonic time is 2–6 h. And / or, in step S2, the fluorosilane includes at least one of perfluorodecyltriethoxysilane and tridecafluorooctyltriethoxysilane, and the reaction temperature of the stirring reaction is 60-80°C and the reaction time is 8-12 h; And / or, in step S3, the drying method is vacuum drying, the vacuum drying temperature is 50-70℃, and the drying time is 20-30h.

[0012] In some embodiments, the epoxy-functionalized nano-silica is prepared by a method comprising the following steps: a) Add nano-silica to xylene and disperse by ultrasonication to obtain a nano-silica suspension; b) Mix γ-glycidoxypropyltrimethoxysilane with anhydrous ethanol and deionized water, and adjust the pH of the mixture to 4.0-5.0 with glacial acetic acid to carry out the hydrolysis reaction; c) The hydrolysis product obtained in step b) is added dropwise to the nano silica suspension, and the mixture is heated to carry out a reflux reaction. The resulting reaction product is separated by centrifugation, washed, and dried to obtain the epoxy-functionalized nano silica.

[0013] Furthermore, the mass ratio of the nano-silica to the γ-glycidoxypropyltrimethoxysilane is (1-3):1; And / or, the size of the nano-silica is 20-50 nm, and the ultrasonic dispersion time is 10-60 min; And / or, the hydrolysis reaction is carried out at room temperature for 10 to 60 minutes. And / or, the reflux reaction is carried out at a temperature of 120–130°C for 8–10 hours. And / or, the drying method is vacuum drying, the vacuum drying temperature is 80-90℃, and the drying time is 8-20h.

[0014] In some embodiments, the epoxy resin in component A includes at least one of bisphenol A type epoxy resin and bisphenol F type epoxy resin; And / or, the pigments and fillers include at least one of titanium dioxide, precipitated barium sulfate, talc, mica powder, calcium carbonate, and barite powder; And / or, the wetting and dispersing agent is a polymeric dispersant; And / or, the rheology modifier includes at least one of organic modified bentonite, polyamide wax, fumed silica, polyethylene wax, and modified hydrogenated castor oil; And / or, the first solvent includes at least one of xylene, n-butanol, cyclohexanone, toluene, butyl acetate, and propylene glycol methyl ether acetate.

[0015] In some embodiments, in component B, the curing agent is an amine curing agent; And / or, the second solvent includes at least one of xylene, n-butanol, ethanol, isopropanol, and ethyl acetate.

[0016] Secondly, embodiments of the present invention also provide a method for preparing a graphdiyne anticorrosive coating as described in the first aspect, comprising the following steps: (1) Mix and disperse epoxy resin, part of the first solvent and wetting and dispersing agent evenly to obtain a resin mixture; (2) Add pigments, fillers, fluorosilane-modified graphdiyne nanosheets and epoxy-functionalized nano-silica to the resin mixture and disperse it by ultrasonication; (3) Add the rheology modifier and the remaining first solvent to the mixture obtained in step (2), disperse evenly, filter and discharge to obtain component A; (4) Mix the curing agent and the second solvent evenly to obtain component B; (5) Mix the A component and the B component in a certain proportion to obtain the graphdiyne anti-corrosion coating.

[0017] Thirdly, the embodiments of the present invention further propose the application of a graphdiyne anti-corrosion coating as described in the first aspect or a graphdiyne anti-corrosion coating prepared by the preparation method described in the second aspect, that is, to use the graphdiyne anti-corrosion coating in the field of corrosion protection for steel structures, ships, bridges or marine engineering.

[0018] The advantages and beneficial effects of the embodiments of the present invention are as follows: The anti-corrosion coating of this invention utilizes a synergistic system of fluorosilane-modified graphdiyne nanosheets and epoxy-functionalized nano-silica to achieve spatial structural synergy between two-dimensional sheets and zero-dimensional particles, precisely filling the gaps between the sheets to form a dense physical shielding network. Simultaneously, it constructs a three-dimensional chemical cross-linking network of "nano-silica-graphdiyne-resin," significantly enhancing interfacial bonding. Furthermore, the two components synergistically promote the formation of a passivation film on the metal substrate, greatly improving anti-corrosion performance. The resulting graphdiyne anti-corrosion coating possesses advantages such as strong adhesion, excellent salt spray resistance, and good hydrophobic properties, making it widely applicable for anti-corrosion protection in steel structures, ships, bridges, and marine engineering. Detailed Implementation

[0019] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0020] In this invention, when a value is described as a range, it should be understood that such disclosure includes disclosure of all possible subranges within that range, as well as specific numerical values ​​falling within that range, regardless of whether specific numerical values ​​or specific subranges are explicitly specified.

[0021] In this invention, the terms “comprising” and “including” and their various variations mean that other elements or wholes may be included but are not specifically described.

[0022] In this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0023] In a first aspect, embodiments of the present invention provide a graphdiyne anticorrosive coating, comprising component A and component B; wherein, component A comprises the following raw materials in parts by weight: 25-45 parts epoxy resin, 0.5-3.0 parts fluorosilane-modified graphdiyne nanosheets, 0.2-1.0 parts epoxy-functionalized nano-silica, 30-50 parts pigments and fillers, 0.2-1.5 parts wetting and dispersing agent, 0.2-2.0 parts rheology modifier, and 10-20 parts first solvent; component B comprises the following raw materials in parts by weight: 15-30 parts curing agent and 5-15 parts second solvent; the weight ratio of component A to component B is (3-6):1.

[0024] This invention modifies graphyne nanosheets using fluorosilanes, grafting low-surface-energy fluorocarbon chains onto the surface of the graphyne nanosheets. On one hand, this reduces the surface energy of the graphyne nanosheets, weakening the interlayer π-π interactions and thus significantly improving their dispersibility. On the other hand, the fluorocarbon chains form a hydrophobic barrier in the coating, greatly reducing water molecule penetration. Simultaneously, the residual silanol groups on the surface of the modified graphyne nanosheets can form hydrogen bonds or chemical bonds with epoxy resin, enhancing interfacial bonding. Building upon this foundation, the present invention further introduces epoxy-functionalized nano-silica, which, through the synergistic spatial structure of two-dimensional sheets and zero-dimensional particles: fluorosilane-modified graphylene nanosheets form a "maze effect" to extend the path of the corrosive medium, while epoxy-functionalized nano-silica precisely fills the gaps between the sheets, refining the free volume of the coating and forming a denser physical shielding network; simultaneously, the epoxy groups on the surface of epoxy-functionalized nano-silica react chemically with the silanol groups on the surface of fluorosilane-modified graphylene and the resin matrix to construct a three-dimensional chemical cross-linking network of "epoxy-modified nano-silica-graphylene-resin," significantly enhancing interfacial bonding; and the fluorosilane-modified graphylene nanosheets and epoxy-functionalized nano-silica can synergistically promote the uniform and dense growth of the passivation film on the metal substrate surface, achieving anodic protection. Furthermore, this embodiment of the invention also forms a flexible cross-linked network of "point-to-surface contact" by precisely controlling the amount of epoxy-functionalized nano-silica. This enhances the shielding effect while avoiding the embrittlement of the coating caused by excessive rigid particles. Under the synergistic effect of multiple mechanisms, the anti-corrosion performance and mechanical properties of the coating are synergistically optimized.

[0025] In some embodiments, the mass ratio of the fluorosilane-modified graphdiyne nanosheets to the epoxy-functionalized nano-silica is 1:(0.2-0.5).

[0026] In the graphite-modified graphite-diene nanosheets of this invention, the amount of fluorosilane-modified graphite-diene nanosheets is 0.5–3.0 parts. If the amount of fluorosilane-modified graphite-diene nanosheets added is too high, it will lead to excessive stacking of the two-dimensional sheets, forming agglomerates and disrupting the continuity of the coating. Simultaneously, stress concentration will occur in the rigid sheets, resulting in decreased impact resistance and poor bending performance. However, if the amount added is too low, it will be difficult to form a continuous and effective "maze effect" physical shielding network, preventing the anti-corrosion performance from being fully realized. Therefore, controlling the amount of fluorosilane-modified graphite-diene nanosheets within the range of 0.5–3.0 parts is advantageous in this invention.

[0027] Furthermore, in the graphdiyne anticorrosive coating of this invention, the amount of epoxy-functionalized nano-silica is 0.2 to 1.0 parts. If the amount of epoxy-functionalized nano-silica added is too small, it will be difficult to effectively fill the gaps between the fluorosilane-modified graphdiyne sheets, and the improvement in physical shielding effect will be limited. However, if the amount added is too large, although the epoxy groups grafted on its surface can participate in cross-linking, too many rigid particles will restrict the movement of molecular chains, forming stress concentration and causing the coating to become brittle. At the same time, excessive nanoparticles are prone to agglomeration, which will destroy the uniformity of the coating formed by the coating. Therefore, in this invention, the amount is controlled within the range of 0.2 to 1.0 parts.

[0028] Furthermore, the inventors discovered that the ratio of fluorosilane-modified graphylene nanosheets to epoxy-functionalized nano-silica has a decisive influence on the synergistic effect. If the mass ratio of fluorosilane-modified graphylene to epoxy-functionalized nano-silica is too high (>1:0.2, i.e., epoxy-functionalized nano-silica is relatively insufficient), it will lead to insufficient filling of the gaps between the fluorosilane-modified graphylene sheets, resulting in limited improvement in the density of the coating. However, if the mass ratio of fluorosilane-modified graphylene to epoxy-functionalized nano-silica is too low (<1:0.5, i.e., epoxy-functionalized nano-silica is relatively excessive), the excessive nanoparticles will not only fill the gaps but also aggregate, leading to a decrease in coating toughness. At the same time, it may also disrupt the orientation and arrangement of the graphylene sheets, weakening the "maze effect". When the mass ratio of the two is controlled within the range of 1:(0.2 to 0.5), the epoxy-functionalized nano-silica is precisely distributed in the voids of the fluorosilane-modified graphylene sheets in the form of "discrete nanoparticles," forming a flexible cross-linked network of "point-to-surface contact." The nanoparticles fill the voids, refining the free volume, and their surface epoxy groups form chemical bonds with the silanol groups on the surface of the fluorosilane-modified graphylene and the resin matrix, constructing a three-in-one network of "epoxy-modified nano-silica-graphylene-resin." The appropriate amount of nanoparticles forming "point contact" rather than a continuous rigid phase between the sheets can maintain the molecular chain mobility and maintain the flexibility of the coating. Therefore, it is advantageous to control the mass ratio of fluorosilane-modified graphylene nanosheets to epoxy-functionalized nano-silica within the range of 1:(0.2 to 0.5) in the embodiments of the present invention.

[0029] In some embodiments, the fluorosilane-modified graphyne nanosheets are prepared by a method comprising the following steps: S1: Ultrasonic-assisted liquid phase exfoliation: Graphdiyne nanosheets are dispersed in an organic solvent and subjected to liquid phase exfoliation under ultrasonic assistance. The unexfoliated thick layer of Graphdiyne is then removed by centrifugation to obtain a Graphdiyne nanosheet dispersion. S2: Fluorosilane modification: Fluorosilane was added to the graphyne nanosheet dispersion, and the mixture was stirred to react; S3: Post-processing: The reaction product obtained in step S2 is centrifuged, washed, and dried to obtain the fluorosilane-modified graphyne nanosheets.

[0030] Furthermore, in step S1, the graphyne nanosheets have a diameter of 0.5–5 μm and a thickness of 2–10 nm. The inventors have found that if the diameter of the graphyne nanosheets is too small, their specific surface area becomes too large, easily causing agglomeration; however, if the diameter is too large, stress concentration in the coating can occur, affecting mechanical properties. The inventors have also found that when the graphyne nanosheets are too thin, dispersion becomes more difficult; however, when their thickness is too thick, the synergistic effect between the graphyne nanosheets and nano-silica weakens. Therefore, in this embodiment of the invention, the diameter and thickness of the graphyne nanosheets are controlled within the aforementioned ranges. The organic solvent includes at least one of N-methylpyrrolidone, dimethylformamide, and ethanol; the ultrasonic power is 300–600 W, and the ultrasonic time is 2–6 h. And / or, in step S2, the fluorosilane includes at least one of perfluorodecyltriethoxysilane and tridecafluorooctyltriethoxysilane, and the reaction temperature of the stirring reaction is 60-80°C and the reaction time is 8-12 h; And / or, in step S3, the drying method is vacuum drying, the vacuum drying temperature is 50-70℃, and the drying time is 20-30h.

[0031] In some embodiments, the epoxy-functionalized nano-silica is prepared by a method comprising the following steps: a) Add nano-silica to xylene and disperse by ultrasonication to obtain a nano-silica suspension; b) Mix γ-glycidoxypropyltrimethoxysilane with anhydrous ethanol and deionized water, and adjust the pH of the mixture to 4.0-5.0 with glacial acetic acid to carry out the hydrolysis reaction; c) The hydrolysis product obtained in step b) is added dropwise to the nano silica suspension, and the mixture is heated to carry out a reflux reaction. The resulting reaction product is separated by centrifugation, washed, and dried to obtain the epoxy-functionalized nano silica.

[0032] Furthermore, the mass ratio of the nano-silica to the γ-glycidoxypropyltrimethoxysilane is (1-3):1; And / or, the nano-silica is fumed silica with a size of 20-50 nm, and the ultrasonic dispersion time is 10-60 min; And / or, the hydrolysis reaction is carried out at room temperature for 10 to 60 minutes. And / or, the reflux reaction is carried out under a nitrogen atmosphere, at a reaction temperature of 120–130°C, and for a reaction time of 8–10 h; And / or, the drying method is vacuum drying, the vacuum drying temperature is 80-90℃, and the drying time is 8-20h.

[0033] In some embodiments, the epoxy resin in component A includes at least one of bisphenol A type epoxy resin (e.g., epoxy resin E51, etc.) and bisphenol F type epoxy resin; And / or, the pigments and fillers include at least one of titanium dioxide, precipitated barium sulfate, talc, mica powder, calcium carbonate, and barite powder; And / or, the wetting and dispersing agent is a polymeric dispersant, and the specific type of the polymeric dispersant is not particularly limited. Those skilled in the art can select it according to actual needs. For example, they can select dispersants such as BYK-110, BYK-111, BYK-130, BYK-140, BYK-161, and BYK-163. And / or, the rheology modifier includes at least one of organic modified bentonite, polyamide wax, fumed silica, polyethylene wax, and modified hydrogenated castor oil; And / or, the first solvent includes at least one of xylene, n-butanol, cyclohexanone, toluene, butyl acetate, and propylene glycol methyl ether acetate.

[0034] In some embodiments, the curing agent in component B is an amine curing agent (including polyamide curing agents, etc.). And / or, the second solvent includes at least one of xylene, n-butanol, ethanol, isopropanol, and ethyl acetate.

[0035] Secondly, embodiments of the present invention also provide a method for preparing a graphdiyne anticorrosive coating as described in the first aspect, comprising the following steps: (1) Mix and disperse epoxy resin, part of the first solvent and wetting and dispersing agent evenly to obtain a resin mixture; (2) Add pigments, fillers, fluorosilane-modified graphdiyne nanosheets and epoxy-functionalized nano-silica to the resin mixture and disperse it by ultrasonication; (3) Add the rheology modifier and the remaining first solvent to the mixture obtained in step (2), disperse evenly, filter and discharge to obtain component A; (4) Mix the curing agent and the second solvent evenly to obtain component B; (5) Mix the A component and the B component in a certain proportion to obtain the graphdiyne anti-corrosion coating.

[0036] It should be noted that components A and B in the graphdiyne anticorrosive coating of this invention are stored separately before application. However, in actual use, they can be directly mixed evenly in proportion before application.

[0037] Thirdly, the embodiments of the present invention further propose the application of a graphdiyne anti-corrosion coating as described in the first aspect or a graphdiyne anti-corrosion coating prepared by the preparation method described in the second aspect, that is, to use the graphdiyne anti-corrosion coating in the field of corrosion protection for steel structures, ships, bridges or marine engineering.

[0038] The following are non-limiting embodiments and comparative examples of the present invention. It should be noted that the schemes in the comparative examples are not prior art, but are only set up for comparison with the schemes in the embodiments, and are not intended to limit the present invention. Unless otherwise stated, all raw materials used in the embodiments and comparative examples are conventional commercially available products, or can be prepared by known methods; and the experimental methods in the embodiments that do not specify specific conditions are conventional methods and conditions well known in the art.

[0039] Example 1 This embodiment provides a graphdiyne anti-corrosion coating, comprising component A and component B; The components, by weight, include: 30 parts epoxy resin E51, 1.0 part fluorosilane-modified graphdiyne nanosheets, 0.4 parts epoxy-functionalized nano-silica, 40.6 parts pigments and fillers (15 parts titanium dioxide + 25.6 parts precipitated barium sulfate), 0.8 parts wetting and dispersing agent (BYK-163), 0.6 parts rheology modifier (organic modified bentonite), and 15 parts primary solvent (xylene / n-butanol volume ratio of 7:3). Component B includes: 20 parts of polyamide curing agent 651 and 5 parts of the second solvent (xylene).

[0040] In this embodiment, the above-mentioned fluorosilane-modified graphdiyne nanosheets are prepared by a method comprising the following steps: S1: Ultrasonic-assisted liquid phase exfoliation: 1.0 g of graphyne nanosheets (0.5-5 μm in diameter and 2-10 nm in thickness) were dispersed in 500 mL of N-methylpyrrolidone and subjected to liquid phase exfoliation under ultrasonic power of 500 W. After exfoliation for 4 h, the resulting product was centrifuged at 3000 rpm for 20 min to remove the unexfoliated thick layer of graphyne and the supernatant was taken to obtain the graphyne nanosheet dispersion. S2: Fluorosilane modification: 3.0 g of perfluorodecyltriethoxysilane was added to the above graphdiyne nanosheet dispersion and stirred at 70 °C for 10 h; S3: Post-processing: The reaction product obtained in step S2 is centrifuged and washed three times with anhydrous ethanol. Finally, it is vacuum dried at 60°C for 24 hours to obtain fluorosilane-modified graphdiyne nanosheets.

[0041] In this embodiment, the above-mentioned epoxy-functionalized nano-silica is prepared by a method including the following steps: a) Add 10g of fumed silica nanoparticles with a particle size of 35nm to xylene and ultrasonically disperse for 30min to obtain a silica nanoparticle suspension. b) Mix 5g of γ-glycidoxypropyltrimethoxysilane (KH560) with anhydrous ethanol and deionized water, adjust the pH of the mixture to 5.0 with glacial acetic acid, and hydrolyze at room temperature for 30 min. c) The hydrolysis product obtained in step b) is slowly added dropwise to the nano silica suspension obtained in step a). Under nitrogen protection, the temperature is raised to 125°C and refluxed for 9 hours. After the reaction is completed, the reaction product is centrifuged, washed three times with anhydrous ethanol, and then vacuum dried at 80°C for 12 hours to obtain nano silica with epoxy groups grafted on the surface, i.e. epoxy functionalized nano silica.

[0042] This embodiment also provides a method for preparing the above-mentioned graphdiyne anticorrosive coating, including the following steps: (1) Mix and disperse epoxy resin, half of the first solvent and wetting and dispersing agent evenly to obtain a resin mixture; (2) Add pigments, fillers, fluorosilane-modified graphdiyne nanosheets and epoxy-functionalized nano-silica to the above resin mixture and disperse them evenly by ultrasonication. (3) Add the rheology modifier and the remaining half of the first solvent to the mixture obtained in step (2), disperse evenly, filter and discharge to obtain component A; (4) Mix the curing agent and the second solvent evenly to obtain component B; (5) Mix component A and component B at a weight ratio of 4:1 to obtain the graphdiyne anticorrosive coating.

[0043] Example 2 This embodiment is basically the same as Example 1, except that in the preparation of fluorosilane-modified graphdiyne nanosheets, tridecafluorooctyltriethoxysilane is used instead of perfluorodecyltriethoxysilane in Example 1.

[0044] Example 3 This embodiment is basically the same as Embodiment 1, except that: in the graphdiyne anticorrosive coating of this embodiment, the amount of fluorosilane modified graphdiyne nanosheets is 1.5 parts, the amount of epoxy functionalized nano silica is 0.5 parts, the amount of precipitated barium sulfate is 24.6 parts, and the amount of organic modified bentonite is 0.8 parts.

[0045] Example 4 This embodiment is basically the same as Embodiment 1, except that: in the graphdiyne anticorrosive coating of this embodiment, the amount of fluorosilane modified graphdiyne nanosheets is 0.8 parts, the amount of epoxy functionalized nano silica is 0.3 parts, and the amount of precipitated barium sulfate is 25.9 parts.

[0046] Comparative Example 1 This comparative example is basically the same as Example 1, except that the anti-corrosion coating in this comparative example does not include fluorosilane-modified graphdiyne nanosheets and epoxy-functionalized nano-silica, and the amount of precipitated barium sulfate is increased to 27 parts.

[0047] Comparative Example 2 This comparative example is basically the same as Example 1, except that the graphdiyne anticorrosive coating in this comparative example does not include epoxy-functionalized nano-silica, and the amount of precipitated barium sulfate is 26 parts.

[0048] Comparative Example 3 This comparative example is basically the same as Example 1, except that: the graphdiyne anticorrosive coating of this comparative example does not include fluorosilane-modified graphdiyne nanosheets, and the amount of epoxy-functionalized nano-silica is 1.0 part and the amount of precipitated barium sulfate is 26 parts.

[0049] Comparative Example 4 This comparative example is basically the same as Example 1, except that: in the graphdiyne anticorrosive coating of this comparative example, unfunctionalized nano-silica is used instead of epoxy-functionalized nano-silica in Example 1.

[0050] Comparative Example 5 This comparative example is basically the same as Example 1, except that: in the graphdiyne anticorrosive coating of this comparative example, the amount of epoxy-functionalized nano silica is 2.0 parts and the amount of precipitated barium sulfate is reduced to 24 parts.

[0051] Comparative Example 6 This comparative example is basically the same as Example 1, except that: in the graphdiyne anticorrosive coating of this comparative example, the amount of fluorosilane modified graphdiyne nanosheets is 5.0 parts, the amount of epoxy functionalized nano silica is 0.5 parts, and the amount of precipitated barium sulfate is reduced to 22 parts.

[0052] The adhesion, salt spray resistance, impact resistance, water contact angle, and water vapor transmission rate of the coatings prepared in the above embodiments and comparative examples were tested according to relevant national standards, and the results are shown in Table 1.

[0053] 1) Adhesion: The adhesion was determined by the pull-off method according to GB / T 5210 standard.

[0054] 2) Salt spray resistance: The coating film condition was observed after 2000 hours of testing according to GB / T 1771 standard.

[0055] 3) Impact resistance: Tested according to GB / T 1732 standard.

[0056] 4) Water contact angle: The water contact angle of the coating surface is tested according to GB / T 30693 standard.

[0057] 5) Water vapor transmission rate: Tested according to ASTM D1653 standard to evaluate the density of the coating layer.

[0058] Table 1 Performance test results of the examples and comparative examples

[0059] As shown in Table 1, the graphdiyne anticorrosive coatings prepared in Examples 1-4 of this invention all have an adhesion strength ≥13.8 MPa, intact paint film after 2000h salt spray test, impact resistance 50cm, water contact angle ≥124°, and water vapor transmission rate ≤0.22g / m². 2 After 24 hours, it exhibited excellent overall performance. In contrast, the coating of Comparative Example 1 (fluorosilane-modified graphylene and epoxy-functionalized nano-silica) showed significantly inferior performance in all aspects compared to the examples, demonstrating that the addition of fluorosilane-modified graphylene and epoxy-functionalized nano-silica significantly improves the anti-corrosion performance of the coating. The coating of Comparative Example 2 (fluorosilane-modified graphylene only) showed inferior adhesion and water vapor transmission rate compared to the examples, indicating that hydrophobicity alone cannot achieve optimal interfacial bonding and shielding effects. The coating of Comparative Example 3 (epoxy-functionalized nano-silica only) showed inferior adhesion and water vapor transmission rate compared to the examples, indicating that nanoparticle filling alone has limited effect. The coating of Comparative Example 4 (using unfunctionalized nano-silica) showed inferior performance compared to the examples, demonstrating that epoxy functionalization of nano-silica is crucial for enhancing interfacial bonding. The anti-corrosion coatings prepared in Comparative Example 5 (excessive addition of nano-silica) and Comparative Example 6 (excessive addition of fluorosilane-modified graphylene) both showed a decrease in impact resistance, verifying the necessity of controlling the addition amount of fluorosilane-modified graphylene nanosheets and epoxy-functionalized nano-silica, as well as their ratio, for the two to exert a beneficial synergistic effect.

[0060] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0061] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A graphdiyne anticorrosive coating, characterized in that, The product comprises component A and component B. Component A comprises the following raw materials in parts by weight: 25-45 parts epoxy resin, 0.5-3.0 parts fluorosilane-modified graphdiyne nanosheets, 0.2-1.0 parts epoxy-functionalized nano-silica, 30-50 parts pigments and fillers, 0.2-1.5 parts wetting and dispersing agent, 0.2-2.0 parts rheology modifier, and 10-20 parts first solvent. Component B comprises the following raw materials in parts by weight: 15-30 parts curing agent and 5-15 parts second solvent. The weight ratio of component A to component B is (3-6):

1.

2. The graphitized ytylene anticorrosive coating according to claim 1, characterized in that, The mass ratio of the fluorosilane-modified graphdiyne nanosheets to the epoxy-functionalized nano-silica is 1:(0.2-0.5).

3. The graphitized ytylene anti-corrosion coating according to claim 1, characterized in that, The fluorosilane-modified graphyne nanosheets were prepared by a method comprising the following steps: S1: Graphdiyne nanosheets are dispersed in an organic solvent and subjected to liquid phase exfoliation under ultrasonic assistance. The unexfoliated thick layer of graphdiyne is then removed by centrifugation to obtain a graphdiyne nanosheet dispersion. S2: Add fluorosilane to the graphyne nanosheet dispersion and stir to react; S3: The reaction product obtained in step S2 is centrifuged, washed, and dried to obtain the fluorosilane-modified graphdiyne nanosheets.

4. The graphitized ytylene anti-corrosion coating according to claim 3, characterized in that, In step S1, the graphdiyne nanosheets have a diameter of 0.5–5 μm and a thickness of 2–10 nm; the organic solvent includes at least one of N-methylpyrrolidone, dimethylformamide, and ethanol; the ultrasonic power is 300–600 W and the ultrasonic time is 2–6 h. And / or, in step S2, the fluorosilane includes at least one of perfluorodecyltriethoxysilane and tridecafluorooctyltriethoxysilane, and the reaction temperature of the stirring reaction is 60-80°C and the reaction time is 8-12 h; And / or, in step S3, the drying method is vacuum drying, the vacuum drying temperature is 50-70℃, and the drying time is 20-30h.

5. The graphitized ytylene anti-corrosion coating according to claim 1, characterized in that, The epoxy-functionalized nano-silica was prepared by a method comprising the following steps: a) Add nano-silica to xylene and disperse by ultrasonication to obtain a nano-silica suspension; b) Mix γ-glycidoxypropyltrimethoxysilane with anhydrous ethanol and deionized water, and adjust the pH of the mixture to 4.0-5.0 with glacial acetic acid to carry out the hydrolysis reaction; c) The hydrolysis product obtained in step b) is added dropwise to the nano silica suspension, and the mixture is heated to carry out a reflux reaction. The resulting reaction product is separated by centrifugation, washed, and dried to obtain the epoxy-functionalized nano silica.

6. The graphitized ytylene anti-corrosion coating according to claim 5, characterized in that, The mass ratio of the nano-silica to the γ-glycidoxypropyltrimethoxysilane is (1-3):1; And / or, the size of the nano-silica is 20-50 nm, and the ultrasonic dispersion time is 10-60 min; And / or, the hydrolysis reaction is carried out at room temperature for 10 to 60 minutes. And / or, the reflux reaction is carried out at a temperature of 120–130°C for 8–10 hours. And / or, the drying method is vacuum drying, the vacuum drying temperature is 80-90℃, and the drying time is 8-20h.

7. The graphdiyne anticorrosive coating according to claim 1, characterized in that, In component A, the epoxy resin includes at least one of bisphenol A type epoxy resin and bisphenol F type epoxy resin; And / or, the pigments and fillers include at least one of titanium dioxide, precipitated barium sulfate, talc, mica powder, calcium carbonate, and barite powder; And / or, the wetting and dispersing agent is a polymeric dispersant; And / or, the rheology modifier includes at least one of organic modified bentonite, polyamide wax, fumed silica, polyethylene wax, and modified hydrogenated castor oil; And / or, the first solvent includes at least one of xylene, n-butanol, cyclohexanone, toluene, butyl acetate, and propylene glycol methyl ether acetate.

8. The graphitized ytylene anti-corrosion coating according to claim 1, characterized in that, In component B, the curing agent is an amine-based curing agent; And / or, the second solvent includes at least one of xylene, n-butanol, ethanol, isopropanol, and ethyl acetate.

9. A method for preparing a graphdiyne anticorrosive coating as described in any one of claims 1-8, characterized in that, Includes the following steps: (1) Mix and disperse epoxy resin, part of the first solvent and wetting and dispersing agent evenly to obtain a resin mixture; (2) Add pigments, fillers, fluorosilane-modified graphdiyne nanosheets and epoxy-functionalized nano-silica to the resin mixture and disperse it by ultrasonication; (3) Add the rheology modifier and the remaining first solvent to the mixture obtained in step (2), disperse evenly, filter and discharge to obtain component A; (4) Mix the curing agent and the second solvent evenly to obtain component B; (5) Mix the A component and the B component in a certain proportion to obtain the graphdiyne anti-corrosion coating.

10. The application of a graphdiyne anticorrosive coating as described in any one of claims 1-8 or a graphdiyne anticorrosive coating prepared by the preparation method as described in claim 9, characterized in that, The graphdiyne anticorrosion coating is used in the field of corrosion protection for steel structures, ships, bridges or marine engineering.

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