Multifunctional supramolecular composite based on GO-CeMOF, preparation method thereof and application of anticorrosive coating

Abstract

This invention relates to a multifunctional supramolecular composite material based on GO-CeMOF, its preparation method, and its application in anti-corrosion coating technology. The GO-CeMOF-based multifunctional supramolecular composite material uses a graphene oxide-metal-organic framework (MOF) as the matrix. The metal ions in the MOF are rare earth metal ions, and the rare earth metal ions include at least cerium ions. A metal-polyphenol coordination supramolecular network layer is loaded on the surface of the MOF. The polyphenol compound used to form the metal-polyphenol coordination supramolecular network layer contains at least two ortho- and posterior-positioned phenolic hydroxyl groups. This invention can improve the density and mechanical properties of the coating structure, enhance the barrier protection and corrosion resistance of the coating, endow the coating with photothermal self-healing response, and give the coating high weather resistance and long-term service performance.

Description

Technical Field

[0001] This application relates to the field of anti-corrosion coating technology, and in particular to a multifunctional supramolecular composite material based on GO-CeMOF, its preparation method, and the application of the anti-corrosion coating. Background Technology

[0002] Metallic materials are widely used in marine, industrial, and infrastructure environments. However, during long-term service, they are susceptible to corrosion due to the combined effects of moisture, oxygen, salt ions, and microorganisms. Corrosion not only leads to structural failure but can also cause serious economic losses and safety hazards. Therefore, developing high-performance anti-corrosion coatings has become an important technical approach to extending the service life of metallic materials.

[0003] Organic anti-corrosion coatings are widely used due to their ease of application, low cost, and wide applicability. However, traditional organic coatings mainly rely on physical barriers to block corrosive media. Once microcracks or localized damage occur during service, corrosive media can penetrate along the defects to the metal interface, triggering a corrosion reaction. Furthermore, factors such as ultraviolet radiation, mechanical stress, and microbial adhesion can accelerate coating performance degradation. Epoxy resin coatings, with their excellent adhesion and impermeability, are widely used in marine environments for corrosion protection. However, epoxy resins have poor weather resistance, making long-term service performance in complex environments difficult.

[0004] In recent years, researchers have attempted to improve the overall protective performance of coatings by introducing two-dimensional nanomaterials, metal-organic frameworks, and functional corrosion inhibitors. Among these, graphene oxide possesses excellent layered structure and barrier properties, while cerium-based materials are considered environmentally friendly corrosion inhibitors. However, in existing technologies, the dispersion, interfacial compatibility, and synergistic effects of these functional components in the coating system remain limited, making it difficult to simultaneously achieve mechanical enhancement, active protection, and multifunctional synergistic protection. For example, patent CN 115678411A proposes a method for preparing GO / Ce... The method of MOF@PDA / PU superhydrophobic self-healing anti-corrosion coating, using GO / Ce MOFs are used as coating fillers, and polydopamine is introduced to chemically modify graphene oxide, thereby improving the mechanical properties and superhydrophobic stability of the coating. However, this approach is mainly applied to polyurethane systems, with few reports on epoxy resin coating systems. GO nanosheets are prone to agglomeration in epoxy resin systems, easily generating interfacial defects, affecting density and weather resistance, and hindering long-term service performance in complex environments. Therefore, it is necessary to develop a composite material system with stable structure, good interfacial compatibility, and multifunctional synergistic protective capabilities, which is of great significance for improving the long-term service performance of anti-corrosion coatings. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects and shortcomings of the prior art and provide a multifunctional supramolecular composite material based on GO-CeMOF, which can improve the density and mechanical properties of the coating structure, improve the barrier protection and corrosion resistance of the coating, endow the coating with photothermal response self-healing, and give the coating high weather resistance and long-term service performance.

[0006] Another objective of this invention is to provide a method for preparing a multifunctional supramolecular composite material based on GO-CeMOF.

[0007] Another object of the present invention is to provide an anti-corrosion coating composition.

[0008] The above-mentioned objective of this invention is achieved through the following technical solution: This invention provides a multifunctional supramolecular composite material based on GO-CeMOF, using graphene oxide-metal-organic framework as the matrix, wherein the metal ions in the metal-organic framework are rare earth metal ions, and the rare earth metal ions include at least cerium ions, and the surface of the graphene oxide-metal-organic framework is loaded with a metal-polyphenol coordination supramolecular network layer, wherein the polyphenol compound used to form the metal-polyphenol coordination supramolecular network layer contains at least two ortho-phenolic hydroxyl groups.

[0009] The multifunctional supramolecular composite material based on GO-CeMOF of this invention achieves multi-scale structural synergy by constructing a graphene oxide-cerium-based metal-organic framework-metal polyphenol coordination supramolecular network layer, and has the following effects: (1) Improve the density and mechanical properties of the coating structure. The composite of two-dimensional sheet structure graphene oxide and cerium-based metal-organic framework has good barrier properties and improves the barrier protection ability of the coating. At the same time, the metal-polyphenol coordination supramolecular network layer further enhances the interfacial bonding, so that the composite material can form a stable multi-scale reinforced structure in the coating, thereby significantly improving the density, mechanical strength and adhesion of the coating structure.

[0010] (2) Improve the barrier protection and corrosion resistance of the coating. The two-dimensional sheet structure of graphene oxide can effectively extend the diffusion path of corrosive media such as moisture, oxygen and chloride ions in the coating. At the same time, the cerium-based metal-organic framework structure can release corrosion inhibitors such as cerium ions in the corrosive environment, thereby forming a protective layer on the metal surface, further inhibiting the corrosion reaction, and achieving the synergistic effect of physical barrier and active corrosion inhibition.

[0011] (3) Imparting the photothermal response self-healing function of the coating. The supramolecular layer formed by metal-polyphenol coordination has good photothermal conversion characteristics. Under near-infrared light irradiation, it can generate local thermal effect, thereby promoting local flow of the coating matrix and filling microcracks, realizing the self-healing of the micro-damaged area of ​​the coating, and thus improving the long-term protective stability of the coating.

[0012] (4) Improve the weather resistance and antibacterial properties of the coating. The polyphenol structure can absorb ultraviolet radiation and remove free radicals generated during photo-oxidation, thereby delaying the aging of the coating; at the same time, the synergistic effect of metal ions and polyphenol structure can inhibit bacterial growth, giving the coating good antibacterial properties, and further improving the overall service performance of the coating in complex environments.

[0013] In some embodiments, the rare earth metal ions are lanthanide rare earth metal ions, including but not limited to cerium, lanthanum, samarium, neodymium, and praseodymium; preferably, the rare earth metal ions are cerium and / or lanthanum ions; more preferably, the cerium ion content in the rare earth metal ions is not less than 70 wt%.

[0014] In some embodiments, the rare earth metal ion is a cerium ion.

[0015] In some embodiments, the polyphenol compound is a compound containing at least one catechol group and / or a pyrogallol group.

[0016] In some embodiments, the polyphenolic compound is selected from at least one of tannic acid, gallic acid, and catechin.

[0017] The metal ions in the metal-polyphenol coordination supramolecular network layer of this invention, which can coordinate with phenolic hydroxyl groups, can achieve the purpose of this invention. Preferably, the metal ions in the metal-polyphenol coordination supramolecular network layer are selected from at least one of Cu, Fe, Zn, Co, and Zr ions.

[0018] This invention provides a method for preparing a multifunctional supramolecular composite material based on GO-CeMOF, comprising the following steps: S1, a cerium-containing soluble metal salt and organic ligand are added to a graphene oxide dispersion to carry out a coordination reaction and in situ grow a cerium metal-organic framework on the surface of graphene oxide, thereby obtaining a GO-CeMOF composite material. S2, the GO-CeMOF composite material is dispersed in a deionized solvent, a polyphenol compound solution is added and stirred evenly, so that the polyphenol compound is adsorbed on the surface of the GO-CeMOF composite material to obtain a mixture; S3, add a metal ion solution to the mixture to allow the metal ions to coordinate with the polyphenol compound, thereby constructing a metal-polyphenol supramolecular network layer on the surface of the GO-CeMOF composite material.

[0019] In some embodiments, the coordination reaction conditions in step S1 are: reaction temperature 25-120°C, reaction time 2-24 h.

[0020] The organic ligands described in this invention can be selected from any organic ligands used in constructing MOFs in the art, preferably polycarboxylic acid ligands and / or imidazole ligands; more preferably, the organic ligands are selected from at least one of butynedioic acid, terephthalic acid, trimesic acid, 2-aminoterephthalic acid, terephthalic acid, 2-methylimidazolium, imidazole, benzimidazole and 2-aminobenzimidazole.

[0021] Preferably, in step S1, the cerium-containing soluble metal salt contains only cerium ions, that is, the cerium-containing soluble metal salt is a soluble cerium metal salt. Specifically, the soluble cerium metal salt is selected from at least one of cerium nitrate, cerium chloride, cerium sulfate, cerium ammonium nitrate, cerium acetate, and cerium trifluoromethanesulfonate.

[0022] In some embodiments, in step S1, the mass ratio of graphene oxide, soluble metal salt and organic ligand is (0.1-2):(20-60):(10-30).

[0023] Preferably, in step S1, the concentration of graphene oxide is 0.1-2 mg / mL, the concentration of soluble metal salt is 20-60 mg / mL, and the concentration of organic ligand is 10-30 mg / mL.

[0024] In some embodiments, in step S2, the polyphenol compound is adsorbed onto the surface of the GO-CeMOF composite material through hydrogen bonding or π-π interaction, and the reaction time is 30 min-12 h.

[0025] In some embodiments, in step S2, the mass ratio of the GO-CeMOF composite material to the polyphenol compound is (1-4):(0.1-1).

[0026] In some embodiments, in step S3, the conditions for the coordination reaction between metal ions and polyphenol compounds are: reaction time 30 min-12 h, and temperature 25±5℃.

[0027] In some embodiments, in step S3, the mass ratio of the metal ion to the polyphenol compound is (2-10):(0.1-1).

[0028] Preferably, in step S3, the concentration of the GO-CeMOF composite material is 5-20 mg / mL, the concentration of the polyphenol compound is 0.5-5 mg / mL, and the concentration of the metal ion is 10-50 mg / mL.

[0029] The present invention provides an anti-corrosion coating composition comprising the aforementioned GO-CeMOF-based multifunctional supramolecular composite material.

[0030] In some embodiments, the product comprises, by weight, 12-18 parts epoxy resin, 0.04-0.5 parts multifunctional supramolecular composite material, 3-8 parts diluent, and 7-13 parts curing agent.

[0031] Preferably, the diluent is a mixture of anhydrous ethanol and water, and more preferably, the mass ratio of ethanol to deionized water is (0.5-2):(2-6).

[0032] In some embodiments, the curing agent is selected from at least one of triethylenetetramine, diethylenetriamine, and polyetheramine. Preferably, the content of the curing agent is 60-70 wt.% of the epoxy resin.

[0033] In some embodiments, the multifunctional supramolecular composite material accounts for 0.1-2 wt.% of the anti-corrosion coating composition.

[0034] The anti-corrosion coating composition of the present invention is used to form an anti-corrosion coating on the surface of a metal substrate, wherein the metal substrate is selected from any one of carbon steel, magnesium alloy, titanium alloy, copper alloy and aluminum alloy.

[0035] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a multifunctional supramolecular composite material based on GO-CeMOF. By constructing a composite structure in which two-dimensional materials graphene oxide, metal-organic frameworks and polyphenol metal supramolecular networks work synergistically, the coating can simultaneously possess multiple functions such as structural reinforcement, barrier protection, active corrosion inhibition, self-healing and weather resistance and antibacterial properties, which significantly improves the comprehensive protective performance, weather resistance and long-term service reliability of the anti-corrosion coating. Attached Figure Description

[0036] Figure 1 This is a TEM image of the GO-CeMOF-CuPN multifunctional supramolecular composite material from Example 1.

[0037] Figure 2 The images shown are cross-sectional SEM images of the epoxy coatings in Examples 2 and Comparative Examples 1-3. Figure 2 A is the epoxy coating of Comparative Example 1. Figure 2 B is the epoxy coating of Comparative Example 2. Figure 2C represents the epoxy coating of Comparative Example 3. Figure 2 D is the epoxy coating of Example 2.

[0038] Figure 3 Electrochemical impedance spectroscopy (EIS) spectra of the epoxy coatings of Examples 2 and Comparative Examples 1-3 after long-term immersion in simulated seawater.

[0039] Figure 4 The images show the results of scratch repair on the epoxy coatings of Examples 2 and Comparative Examples 1-3 under 808 nm NIR irradiation. Figure 4 A is the epoxy coating of Comparative Example 1. Figure 4 B is the epoxy coating of Comparative Example 2. Figure 4 C represents the epoxy coating of Comparative Example 3. Figure 4 D is the epoxy coating of Example 2.

[0040] Figure 5 The images show cross-sectional SEM images of the epoxy coatings in Examples 2 and Comparative Examples 1-3 after aging under strong ultraviolet irradiation. Figure 5 A is the epoxy coating of Comparative Example 1. Figure 5 B is the epoxy coating of Comparative Example 2. Figure 5 C represents the epoxy coating of Comparative Example 3. Figure 5 D is the epoxy coating of Example 2.

[0041] Figure 6 The images show the antibacterial results of the epoxy coatings used in Examples 2 and Comparative Examples 1-3 against *Escherichia coli*. Figure 6 A is the epoxy coating of Comparative Example 1. Figure 6 B is the epoxy coating of Comparative Example 2. Figure 6 C represents the epoxy coating of Comparative Example 3. Figure 6 D is the epoxy coating of Example 2. Detailed Implementation

[0042] The present invention will be further described below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise stated, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0043] Example 1 A GO-CeMOF-CuPN multifunctional supramolecular composite material, with graphene oxide-metal-organic framework as the matrix, wherein the surface of the graphene oxide-metal-organic framework is loaded with a metal-polyphenol coordination supramolecular network layer.

[0044] The graphene oxide has a D50 particle size of 23.34 μm and a thickness of 0.8-1.2 nm, and was purchased from Jiangsu Jicang Nanotechnology Co., Ltd.

[0045] The metal-organic framework is a cerium-based metal-organic framework (CeMOF) coordinated with cerium ions and butynedioic acid.

[0046] The metal-polyphenol coordination supramolecular network layer is a copper-tannic acid supramolecular network composite structure (CuPN).

[0047] The preparation method of the GO-CeMOF-CuPN multifunctional supramolecular composite material includes the following steps: S101, a cerium-containing soluble metal salt and organic ligand are added to a graphene oxide dispersion to carry out a coordination reaction and in situ grow a cerium metal-organic framework on the surface of graphene oxide, thereby obtaining a GO-CeMOF composite material. Specifically, 50 mg of graphene oxide was ultrasonically dispersed in 50 mL of deionized water, followed by the addition of 2 g of cerium ammonium nitrate and 0.75 g of butynediic acid. This resulted in a reaction system with graphene oxide concentrations of 1 mg / mL, cerium ammonium nitrate concentrations of 40 mg / mL, and butynediic acid concentrations of 15 mg / mL. The mixture was stirred at room temperature for 14 h using a magnetic stirrer, yielding a pale yellow turbid liquid. This liquid was centrifuged, washed four times with deionized water, and a pale yellow solid was obtained. Finally, the solid was transferred to a drying oven and dried at 50 °C for 20 h to obtain a pale yellow powdered GO-CeMOF.

[0048] S102, the GO-CeMOF composite material is dispersed in a deionized solvent, a polyphenol compound solution is added and stirred evenly, so that the polyphenol compound is adsorbed on the surface of the GO-CeMOF composite material to obtain a mixture; Specifically, 200 mg of GO-CeMOF was added to 10 mL of a deionized aqueous solution with pH=9, and then 60 mg of tannic acid was added to the solution. The mixture was stirred continuously for 6 hours, so that the polyphenolic compounds were adsorbed onto the surface of the GO-CeMOF composite material through hydrogen bonding and / or π-π interaction, thus obtaining a mixture.

[0049] S103, a metal ion solution is added to the mixture to allow the metal ions to coordinate with the polyphenol compound, thereby constructing a metal-polyphenol supramolecular network layer on the surface of the GO-CeMOF composite material.

[0050] Specifically, the mixture was added to an aqueous solution containing 500 mg of copper chloride and stirred continuously for 6 hours. At this time, the concentration of GO-CeMOF was 10 mg / mL, the concentration of tannic acid was 3 mg / mL, and the concentration of copper chloride was 25 mg / mL. After the reaction was completed, the mixture was centrifuged, washed four times with deionized water to obtain a black solid, and finally transferred to a vacuum drying oven and dried at 50°C for 20 hours to obtain a black powdery GO-CeMOF-CuPN multifunctional supramolecular composite material.

[0051] Example 2 A GO-CeMOF-CuPN composite material modified epoxy coating is formed by curing an anti-corrosion coating composition comprising the GO-CeMOF-CuPN multifunctional supramolecular composite material described in Example 1.

[0052] The anti-corrosion coating composition comprises, by weight, 15 parts epoxy emulsion, 0.25 parts GO-CeMOF-CuPN multifunctional supramolecular composite material, 5 parts diluent, and 9.75 parts curing agent (65 wt.% of epoxy emulsion content).

[0053] The epoxy emulsion in question is sourced from Shanghai Runtan New Materials Technology Co., Ltd., and is designated as MU-618.

[0054] The GO-CeMOF-CuPN multifunctional supramolecular composite material is the GO-CeMOF-CuPN multifunctional supramolecular composite material prepared in Example 1; The diluent is a mixture of anhydrous ethanol and water in a mass ratio of 1:3.

[0055] The curing agent is polyetheramine, sourced from Shanghai Aladdin Biochemical Technology Co., Ltd., D-230.

[0056] The preparation method of the GO-CeMOF-CuPN composite material modified epoxy coating includes the following steps: S201, Preparation of anti-corrosion coating composition: Epoxy emulsion, GO-CeMOF-CuPN multifunctional supramolecular composite material and diluent with a mass ratio of 15:0.25:5 are mixed and magnetically stirred for 60 min. Then, 65 wt.% of curing agent polyetheramine is added to the emulsion and stirred for 10 min. After mixing, the anti-corrosion coating composition is obtained.

[0057] S202, Coating film: The anti-corrosion coating composition obtained in step S201 is coated on the surface of the pre-treated carbon steel substrate. After drying and curing at 50°C for 48 hours, a GO-CeMOF-CuPN composite modified epoxy coating is obtained on the carbon steel surface. The dry film thickness of the composite coating is 100±10μm.

[0058] Example 3 The difference between the GO-CeMOF-CuPN composite material modified epoxy coating and Example 2 is that the polyphenol compound used to form the metal-polyphenol coordination supramolecular network layer in the multifunctional supramolecular composite material of this example is gallic acid.

[0059] Example 4 The difference between the GO-CeMOF-ZnPN composite material modified epoxy coating and Example 2 is that the metal ion used to form the metal-polyphenol coordination supramolecular network layer in this example is zinc ion, which is added with zinc chloride as the zinc source and the concentration of zinc chloride is 25 mg / mL.

[0060] Comparative Example 1 An epoxy coating, which differs from Example 2 in that: this comparative example does not contain the GO-CeMOF-CuPN multifunctional supramolecular composite material; The method for preparing the epoxy coating includes the following steps: S21. Epoxy emulsion and diluent are mixed at a mass ratio of 15:5 and magnetically stirred for 60 minutes. Then, 65 wt.% of the curing agent polyetheramine is added and stirred for 10 minutes. After mixing, an epoxy resin coating is obtained.

[0061] S22, this epoxy resin coating is applied to the surface of the pre-treated carbon steel substrate, and after drying and curing at 50°C for 48 hours, an epoxy coating is obtained on the carbon steel surface; the dry film thickness of the epoxy coating is 100±10μm.

[0062] Comparative Example 2 A GO-modified epoxy coating differs from Example 2 in that: this comparative example uses GO nanosheets instead of the GO-CeMOF-CuPN multifunctional supramolecular composite material in Example 2; The method for preparing the GO-modified epoxy coating includes the following steps: S21, Preparation of anti-corrosion coating composition: Epoxy emulsion, GO nanosheets and diluent in a mass ratio of 15:0.25:5 are mixed and magnetically stirred for 60 min. Then, 65 wt.% of the curing agent polyetheramine is added to the emulsion and stirred for 10 min. After mixing, the anti-corrosion coating composition is obtained.

[0063] S22, Coating film: The anti-corrosion coating composition obtained in S21 is coated on the surface of the pre-treated carbon steel substrate. After drying and curing at 50°C for 48 hours, a GO modified epoxy coating is obtained on the carbon steel surface. The dry film thickness of the composite coating is 100±10μm.

[0064] Comparative Example 3 A GO-CeMOF modified epoxy coating differs from Example 2 in that: in this comparative example, GO-CeMOF is used instead of the GO-CeMOF-CuPN multifunctional supramolecular composite material in Example 2; the GO-CeMOF is prepared according to step S101 of the preparation method in Example 1.

[0065] The preparation method of the GO-CeMOF modified epoxy coating includes the following steps: S21, Preparation of anti-corrosion coating composition: Epoxy emulsion, GO-CeMOF and diluent in a mass ratio of 15:0.25:5 are mixed and magnetically stirred for 60 min. Then, 65 wt.% of curing agent polyetheramine is added to the emulsion and stirred for 10 min. After mixing, the anti-corrosion coating composition is obtained.

[0066] S22, Coating film: The anti-corrosion coating composition obtained in S21 is coated on the surface of the pre-treated carbon steel substrate. After drying and curing at 50°C for 48 hours, a GO-CeMOF modified epoxy coating is obtained on the carbon steel surface. The dry film thickness of the composite coating is 100±10μm.

[0067] Performance testing 1. Microstructure testing of composite materials The GO-CeMOF-CuPN obtained in Example 1 was observed under a transmission electron microscope (TEM), and its morphology and structure were as follows: Figure 1 As shown; from Figure 1 As can be seen, CeMOF and CuPN achieve uniform growth on the GO surface, which reduces the agglomeration and wrinkling of GO itself and also helps to improve its dispersibility in epoxy coatings.

[0068] 2. Coating cross-sectional morphology test The coatings prepared in Example 2 and Comparative Examples 1-3 were subjected to liquid nitrogen embrittlement, and the fracture morphology was observed using scanning electron microscopy. Figure 2 As shown.

[0069] Depend on Figure 2 It can be seen that the cross-sectional morphology of Comparative Example 1 is smooth, exhibiting obvious brittle fracture properties, and also has obvious defects and pores; obvious interface defects were observed in Comparative Example 2, and local filler agglomeration was observed in Comparative Example 3, while the cross-sectional morphology of Example 2 is rough, exhibiting obvious ductile fracture characteristics, and no obvious defects were found. This indicates that the GO-CeMOF-CuPN supramolecular composite material can fill the defects inside the epoxy coating and improve its density and mechanical properties.

[0070] 3. Electrochemical impedance spectroscopy experiment of the coating The coatings prepared in each embodiment and comparative example were subjected to electrochemical testing in a 3.5 wt.% sodium chloride solution. After 100 days of electrochemical testing, the impedance modulus results are as follows: Figure 3 As shown.

[0071] The results show that the low-frequency impedance modulus of Example 2 remains consistently at 10. 9 ~10 10 Ω·cm2 Meanwhile, the low-frequency impedance modulus of comparative examples 1-3 remained consistently at 10. 7 ~10 9 Ω·cm 2 The corrosion resistance of the epoxy coating modified by GO-CeMOF-CuPN supramolecular composite material was significantly improved compared with that of the coatings in Comparative Examples 1-3, indicating the good long-term corrosion resistance of the epoxy coating modified by GO-CeMOF-CuPN supramolecular composite material.

[0072] Meanwhile, the impedance modulus results of the GO-CeMOF-CuPN composite modified epoxy coatings in Examples 3-4 are comparable to those in Example 2.

[0073] 4. Photothermal response self-healing experiment of the coating Scratches were introduced onto the surfaces of the coatings prepared in Examples 2 and 1-3, and the damaged areas were irradiated with near-infrared (NIR) light at a wavelength of 808 nm for 150 s. The self-healing properties of the coatings were observed, and the results are as follows: Figure 4 As shown.

[0074] The results show that the scratch width in Example 2 decreased from 56.6 μm to 24.5 μm, a reduction of 32.1 μm, while the scratch width reduction in Comparative Examples 1-3 was only 0.8 μm, 3.2 μm, and 3.1 μm, respectively. This comparison confirms that the GO-CeMOF-CuPN supramolecular composite material can achieve self-repair of coating defect areas through photothermal conversion with the assistance of 808 nm NIR, which helps to repair minor defects and thus improves the long-term protective stability of the coating.

[0075] 5. Weather resistance test of the coating The coatings prepared in Example 2 and Comparative Examples 1-3 were simultaneously placed under strong ultraviolet irradiation for 480 hours, and the weather resistance of the coatings was evaluated by observing the changes in the cross-sectional morphology of the coatings after irradiation. The relevant results are as follows: Figure 5 As shown.

[0076] The results show that the internal cross-sectional morphology of the coating in Example 2 remains dense and void-free, while the internal cross-sectional morphology of the coatings in Comparative Examples 1-3 is significantly disrupted, exhibiting a porous structure. This comparative result confirms that the GO-CeMOF-CuPN supramolecular composite material can significantly improve the weather resistance of the coating, thereby delaying the aging loss of the coating.

[0077] 6. Antibacterial performance test of the coating The coatings prepared in Examples 2 and 1-3 were placed in E. coli culture solutions containing the same concentration, and the antibacterial properties of the coatings were evaluated using the plate count method. The relevant results are as follows: Figure 6 As shown.

[0078] The results showed that the coating in Example 2 had a lower number of surface E. coli and smaller colonies, while the coatings in Comparative Examples 1-3 had a higher number of surface E. coli and larger colonies. This comparison confirms that the GO-CeMOF-CuPN supramolecular composite material can significantly improve the antibacterial properties of the coating, thereby enhancing its overall service performance in complex environments.

[0079] The above embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A multifunctional supramolecular composite material based on GO-CeMOF, characterized in that, Using graphene oxide-metal-organic framework as a matrix, the metal ions in the metal-organic framework are rare earth metal ions, and the rare earth metal ions include at least cerium ions. The surface of the graphene oxide-metal-organic framework is loaded with a metal-polyphenol coordination supramolecular network layer, and the polyphenol compound used to form the metal-polyphenol coordination supramolecular network layer contains at least two ortho-phenolic hydroxyl groups.

2. The multifunctional supramolecular composite material based on GO-CeMOF according to claim 1, characterized in that, The polyphenol compound is a compound containing at least one catechol group and / or a pyrogallol group.

3. The multifunctional supramolecular composite material based on GO-CeMOF according to claim 1, characterized in that, The polyphenolic compound is selected from at least one of tannic acid, gallic acid, and catechin.

4. The multifunctional supramolecular composite material based on GO-CeMOF according to claim 1, characterized in that, The metal ions in the metal-polyphenol coordination supramolecular network layer are selected from at least one of Cu, Fe, Zn, Co and Zr ions.

5. A method for preparing the multifunctional supramolecular composite material based on GO-CeMOF as described in any one of claims 1-4, characterized in that, Includes the following steps: S1, a cerium-containing soluble metal salt and organic ligand are added to a graphene oxide dispersion to carry out a coordination reaction and in situ grow a cerium metal-organic framework on the surface of graphene oxide, thereby obtaining a GO-CeMOF composite material. S2, the GO-CeMOF composite material is dispersed in a deionized solvent, a polyphenol compound solution is added and stirred evenly, so that the polyphenol compound is adsorbed on the surface of the GO-CeMOF composite material to obtain a mixture; S3, add a metal ion solution to the mixture to allow the metal ions to coordinate with the polyphenol compound, thereby constructing a metal-polyphenol supramolecular network layer on the surface of the GO-CeMOF composite material.

6. The method for preparing the multifunctional supramolecular composite material based on GO-CeMOF according to claim 5, characterized in that, In step S1, the organic ligand is selected from at least one of butynedioic acid, terephthalic acid, trimesoic acid, 2-aminoterephthalic acid, terephthalic acid, 2-methylimidazole, imidazole, benzimidazole and 2-aminobenzimidazole.

7. The method for preparing the multifunctional supramolecular composite material based on GO-CeMOF according to claim 5 or 6, characterized in that, In step S1, the mass ratio of graphene oxide, soluble metal salt and organic ligand is (0.1-2):(20-60):(10-30).

8. The method for preparing the multifunctional supramolecular composite material based on GO-CeMOF according to claim 5, characterized in that, In step S2, the mass ratio of the GO-CeMOF composite material to the polyphenol compound is (1-4):(0.1-1). In step S3, the mass ratio of the metal ion to the polyphenol compound is (2-10):(0.1-1).

9. A corrosion-resistant coating composition, characterized in that, The invention comprises the multifunctional supramolecular composite material based on GO-CeMOF as described in any one of claims 1-4.

10. The anti-corrosion coating composition according to claim 9, characterized in that, By weight, it includes: 12-18 parts epoxy resin, 0.04-0.5 parts multifunctional supramolecular composite material, 3-8 parts diluent, and 7-13 parts curing agent.

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