Intrinsic corrosion-resistant and antibacterial graphene coating, and preparation method and application thereof

Abstract

The application provides intrinsic corrosion-resistant antibacterial graphene coating and a preparation method and application thereof; the intrinsic corrosion-resistant antibacterial graphene coating comprises at least a graphene antibacterial agent and an intrinsic antibacterial epoxy resin; the intrinsic antibacterial epoxy resin is prepared by catalytic reaction of shikimic acid and epichlorohydrin under an alkaline solution condition. By using the technical scheme of the application, the shikimic acid is used as a biological material to synthesize a biological epoxy resin with antibacterial performance, the biological epoxy resin can be directly reacted with a curing agent to form a film, thereby reducing the use of petroleum-based epoxy resins; in particular, the double bond of the biological epoxy resin with intrinsic antibacterial effect prepared by the application can form a pi-pi conjugate structure with the delocalized pi bond of graphene, improve the dispersion performance of graphene in the coating, and further improve the corrosion resistance of the composite coating; meanwhile, the biodegradation product of the coating during service can reduce the pollution to the environment to the greatest extent.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to the field of metal protection technology, and more specifically to an intrinsic anti-corrosion and antibacterial graphene coating, its preparation method, and its application. Background Technology

[0002] Currently, the epoxy resins used in industry are mainly bisphenol A diglycidyl ethers synthesized from bisphenol A. Bisphenol A is a thermosetting polymer material, widely used due to its strong adhesion, low shrinkage, and good corrosion resistance. However, the poor weather resistance, brittleness, poor impact resistance, and susceptibility to cracking after curing of epoxy resins have limited its application in the coatings industry.

[0003] Meanwhile, as a product of petrochemicals, epoxy resin is increasingly scarce. Developing bio-based epoxy resins based on renewable biomass resources to replace traditional petrochemical-based epoxy resins is an important way to alleviate the consumption of petrochemical resources.

[0004] Shikimic acid, scientifically known as 3,4,5-trihydroxy-1-cyclohexene-1-carboxylic acid, is widely found in natural plants such as star anise, Masson pine, and arborvitae. Shikimic acid and its derivatives possess anti-inflammatory, antibacterial, analgesic, antitumor, antithrombotic, and anti-cerebral ischemia effects, thus finding wide applications in the pharmaceutical and food industries. Furthermore, graphene is a material with excellent barrier properties; directly depositing graphene films on metal surfaces can isolate the substrate from corrosive environments. However, graphene's high surface energy, large specific surface area, and tendency to aggregate limit its dispersion in coatings. Therefore, graphene must be uniformly dispersed in organic coatings to fill the pores in the coating, block the penetration of corrosive media, and act as a barrier. Chinese invention patent CN116904090A disperses graphene in epoxy coatings. Graphene is pre-dispersed in an oil-phase epoxy resin before preparing a graphene-epoxy emulsion, allowing graphene to uniformly penetrate the emulsion polymer particles. This improves the water-based epoxy coating's shielding performance against water vapor, salt spray resistance, and corrosion resistance. However, this method relies solely on physical mixing, and the graphene oxide used has numerous water-absorbing functional groups on its surface, leading to protective failure during prolonged use. Another example is Chinese invention patent CN113930160A, which discloses a graphene-loaded silver ion diatomaceous earth antibacterial coating and its preparation method. While the diatomaceous earth increases the silver ion loading, its porous structure prevents metal ions from being exposed on the coating surface. Although this increases the silver ion loading, the synergistic effect on antibacterial activity is not significant.

[0005] Based on this, how to develop an intrinsic anti-corrosion and antibacterial graphene coating and its preparation method, using shikimic acid as a bio-based material for preparing epoxy resin, and simultaneously supplementing it with graphene loaded with silver phosphate / cerium dioxide as an antibacterial agent, to obtain a graphene coating with intrinsic anti-corrosion and antibacterial properties. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide an intrinsic anti-corrosion and antibacterial graphene coating, its preparation method and application, by using bio-based materials to synthesize a bio-based epoxy resin, and supplementing it with graphene with antibacterial properties as an antibacterial agent, thereby improving the antibacterial, corrosion-resistant and salt spray-resistant properties of the epoxy resin coating.

[0007] To achieve the above objectives, the present invention provides the following technical solution.

[0008] An intrinsic anticorrosive and antibacterial graphene coating comprises at least a graphene antibacterial agent and an intrinsic antibacterial epoxy resin; the intrinsic antibacterial epoxy resin is prepared by catalytic reaction of shikimic acid and epichlorohydrin under alkaline solution conditions.

[0009] Preferably, the preparation method of the intrinsic antibacterial epoxy resin includes dissolving shikimic acid in the alkaline solution, heating and adding epichlorohydrin and a catalyst, stirring and reacting at 90-120°C for 4-7 hours, cooling to room temperature, and obtaining the intrinsic antibacterial epoxy resin after post-treatment.

[0010] Preferably, the catalyst is benzyltrimethylammonium iodide.

[0011] Preferably, the graphene antibacterial agent comprises a graphene-supported silver phosphate / cerium dioxide antibacterial agent; wherein, silver phosphate and cerium dioxide are supported on the surface of the graphene sheet structure; and the graphene is graphene oxide.

[0012] Preferably, the preparation method of the graphene antibacterial agent includes: ultrasonically dispersing graphene oxide in deionized water to obtain a graphene dispersion; adding silver nitrate and cerium nitrate to the graphene dispersion, ultrasonically dispersing evenly, adding sodium phosphate, adjusting the pH, and carrying out a hydrothermal reaction in a high-pressure reactor to obtain a black powder product, which is the graphene-supported silver phosphate / cerium dioxide antibacterial agent.

[0013] Preferably, the mass ratio of graphene to cerium nitrate is 8 to 20:1.

[0014] Preferably, the mass ratio of graphene to silver phosphate is 8 to 25:1.

[0015] Preferably, the molar ratio of sodium phosphate to silver nitrate is 1 to 3:1.

[0016] Preferably, adjusting the pH value includes using ammonia or sodium hydroxide to adjust the pH to 10-10.5.

[0017] Preferably, the temperature of the hydrothermal reaction is 150–200°C, and the reaction time is 24–48 h.

[0018] Preferably, after the hydrothermal reaction, the product is washed and dried under vacuum to obtain the black powder product.

[0019] Preferably, by weight, the intrinsic anticorrosive and antibacterial graphene coating comprises 20-30 parts of intrinsic antibacterial epoxy resin, 5-10 parts of antibacterial agent, 20-45 parts of solvent, 15-20 parts of curing agent, 25-40 parts of filler, and 1.5-2.5 parts of additives.

[0020] Preferably, the additives include, but are not limited to, at least one of the following: anti-settling agent fumed silica, dispersant EFKA4010, and leveling agent BYK333.

[0021] Preferably, the solvent includes, but is not limited to, at least one of xylene, n-butanol, and acetone.

[0022] Preferably, the filler includes, but is not limited to, at least one of aluminum polyphosphate, iron oxide red, and talc.

[0023] Preferably, the curing agent includes, but is not limited to, at least one of polyamide, alicyclic amine and aromatic amine.

[0024] As another objective of the invention, the present invention also provides a method for preparing the above-mentioned intrinsically anti-corrosion and antibacterial graphene coating, comprising the following steps:

[0025] S1. Preparation of intrinsic antibacterial epoxy resin;

[0026] Shikimic acid is dissolved in an alkaline solution and heated to 90–120°C. Then epichlorohydrin and benzyltrimethylammonium iodide are added. The mixture is stirred at 90–120°C and 200 r / min for 4–7 h. After cooling to room temperature, the intrinsic antibacterial epoxy resin is obtained through post-treatment.

[0027] S2. Preparation of graphene antibacterial agent;

[0028] Silver nitrate and cerium nitrate were added to a graphene oxide dispersion and ultrasonically dispersed. Sodium phosphate was then added to adjust the pH to 10–10.5. The mixture was then hydrothermally reacted in a high-pressure reactor at 150–200°C for 24–48 hours. The product was washed 5–8 times with ethanol and aqueous solution and dried under vacuum to obtain a black powder, which is the graphene antibacterial agent loaded with silver phosphate / cerium dioxide. Cerium nitrate was hydrothermally reacted to obtain cerium hydroxide, which was then directly attached to the surface of graphene through in-situ growth. After drying under vacuum, cerium dioxide was obtained. Silver ions were also simultaneously adsorbed on the surface of graphene, ultimately loading silver nitrate and cerium dioxide particles onto the surface of graphene.

[0029] S3. Preparation of Intrinsic Anticorrosive and Antibacterial Graphene Coatings

[0030] Solvent, graphene antibacterial agent, and filler are added sequentially to the intrinsic antibacterial epoxy resin prepared in S1. The mixture is dispersed at 400-600 r / min for 10-15 min, then additives are added, and the mixture is stirred at 1500-2000 r / min for 20-40 min. Finally, epoxy curing agent is added and stirred until homogeneous to obtain the intrinsic anticorrosive and antibacterial graphene coating.

[0031] Preferably, the alkaline solution in S1 is a sodium hydroxide solution with a mass fraction of 15 wt%.

[0032] Preferably, in S2, the post-processing includes recovering excess epichlorohydrin by reducing pressure, removing the upper alkaline solution after standing, and then washing with boiling water and dehydrating to obtain the intrinsic antibacterial epoxy resin.

[0033] This invention synthesizes a bio-based epoxy resin through a catalytic reaction of shikimic acid and epichlorohydrin in an alkaline solution, using benzyltrimethylammonium iodide as the catalyst. The resulting bio-based epoxy resin exhibits intrinsic antibacterial properties, strong adhesion to metal substrates after curing, and provides excellent protection and antibacterial / bacteriostatic effects on the substrate.

[0034]

[0035] Graphene is a two-dimensional layered carbon material with stable chemical properties, strong water vapor barrier properties, and hydrophobicity, making it an excellent functional anti-corrosion filler. However, due to its large specific surface area and the easy interaction between the layers, it is prone to agglomeration, which is difficult to separate. Furthermore, the pores created between the agglomerated graphene layers form water vapor channels, reducing the barrier performance of the coating. Therefore, this invention addresses these problems by loading silver ions and cerium dioxide onto the graphene surface. By altering the similar charge properties of the graphene surface, the layers repel each other, thus preventing graphene agglomeration. On the other hand, by utilizing the delocalized large π-bond structure of graphene, a π-π conjugated structure is formed with the double bonds in the intrinsic antibacterial epoxy resin, allowing the graphene to be uniformly dispersed in the epoxy resin, effectively inhibiting graphene agglomeration and improving the anti-corrosion and barrier properties of the coating. This further enhances the long-term and efficient protective effect of the coating on the metal substrate.

[0036] Furthermore, by loading silver ions and cerium dioxide onto the surface of graphene, the contact area of ​​the antibacterial agent can be enhanced based on the huge specific surface area of ​​graphene, thereby improving the antibacterial effect of the coating; in particular, silver ions and cerium dioxide can be exposed on the surface of graphene and can be directly exposed to visible light, thus giving fuller play to their antibacterial properties.

[0037] The beneficial technical effects obtained by this invention are as follows:

[0038] 1. By adopting the technical solution of the present invention, bio-based epoxy resin is synthesized using shikimic acid as a bio-based material. It can directly react with the curing agent to form a film, thereby reducing the use of petroleum-based epoxy resin. In particular, the double bonds of the bio-based epoxy resin form a π-π conjugated structure with the delocalized large π bonds of graphene, which improves the dispersion performance of graphene in the coating and thus enhances the corrosion resistance of the composite coating. At the same time, the bio-based degradation products of the coating during service can minimize environmental pollution.

[0039] 2. This invention utilizes shikimic acid, which has antibacterial activity, as a raw material to synthesize a bio-based epoxy resin with intrinsic antibacterial properties. It has a certain bactericidal effect. When combined with graphene bactericide, the prepared graphene coating can have excellent bactericidal properties.

[0040] 3. The graphene antibacterial agent prepared using the technical solution of the present invention has silver phosphate / cerium dioxide directly loaded on the surface of graphene. On the one hand, the loaded silver phosphate / cerium dioxide can be directly exposed on the graphene surface and can produce a bactericidal effect under visible light. When used in combination with intrinsic antibacterial bio-based epoxy resin, it can play a synergistic role and improve the antibacterial rate of the coating. On the other hand, by loading silver phosphate / cerium dioxide on the surface of graphene, the graphene surface is charged, thereby avoiding the aggregation of graphene.

[0041] 4. The anti-corrosion and antibacterial coating prepared by the technical solution of the present invention, using intrinsic antibacterial epoxy resin as the main film-forming material and graphene-supported silver phosphate / cerium dioxide as the antibacterial agent, has a salt spray resistance of 1440h, a salt water resistance of 2000h, an impact resistance of 50kg·cm, a cross-cut adhesion grade of 1, a flexibility of 50kg·cm, and an antibacterial performance grade of 0, which can improve the long-term corrosion protection and antibacterial and bacteriostatic functions of metal substrates. Attached Figure Description

[0042] Figure 1 The infrared spectrum of the intrinsic antibacterial epoxy resin prepared in Example 1 of the present invention.

[0043] Figure 2 This is a 3000x magnified scanning electron microscope image of the graphene loaded with silver phosphate / cerium dioxide prepared in Example 1 of the present invention.

[0044] Figure 3 This is a 5000x magnified scanning electron microscope image of the graphene loaded with silver phosphate / cerium dioxide prepared in Example 1 of the present invention.

[0045] Figure 4 This is a photograph of the adhesion test of the anti-corrosion coating prepared in Example 1 of the present invention on tinplate using the 100-grid method. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0047] This invention provides an intrinsic anticorrosive and antibacterial graphene coating, comprising at least a graphene antibacterial agent and an intrinsic antibacterial epoxy resin; the intrinsic antibacterial epoxy resin is prepared by a catalytic reaction of shikimic acid and epichlorohydrin under alkaline solution conditions.

[0048] Preferably, the preparation method of the intrinsic antibacterial epoxy resin includes dissolving shikimic acid in the alkaline solution, heating and adding epichlorohydrin and a catalyst, stirring and reacting at 90-120°C for 4-7 hours, cooling to room temperature, and obtaining the intrinsic antibacterial epoxy resin after post-treatment.

[0049] Preferably, the catalyst is benzyltrimethylammonium iodide.

[0050] Preferably, the graphene antibacterial agent comprises graphene-loaded silver phosphate / cerium dioxide; wherein, the silver phosphate / cerium dioxide is loaded on the surface of the graphene, so that the graphene surface carries the same positive charge, and the graphene sheets can generate a repulsive effect, thereby preventing the graphene from agglomerating; at the same time, through the sheet-like structure of graphene, the contact area between silver ions and cerium dioxide is increased, and it can also be directly exposed to visible light, thereby enhancing the antibacterial effect of the antibacterial agent.

[0051] Preferably, the graphene is graphene oxide.

[0052] Unless otherwise specified, all raw materials or reagents used in this invention are commercially available.

[0053] The present invention will be further explained below with reference to the embodiments and accompanying drawings. The preparation method of the coating and the corresponding embodiments involved in the invention are not limited thereto.

[0054] Example 1

[0055] This embodiment provides an intrinsic anti-corrosion and antibacterial graphene coating, the specific preparation steps of which include:

[0056] 1. Preparation of intrinsic antibacterial epoxy resin

[0057] In a three-necked flask, 1 mol of shikimic acid was dissolved in 800 g of sodium hydroxide solution (sodium hydroxide mass fraction 15 wt%). The solution was heated to 100°C in an oil bath. Then, 7 mol of epichlorohydrin and 0.1 mol of benzyltrimethylammonium iodide were added. The mixture was kept at 100°C and stirred at 200 rpm for 4–7 h. After cooling to 25°C, excess epichlorohydrin was recovered by vacuum distillation. The mixture was allowed to stand for 3–5 h, and the upper alkaline layer was removed. The lower resin layer was then washed 8 times with boiling water. Finally, dehydration yielded the intrinsic antibacterial epoxy resin. (See also...) Figure 1 The image shows the infrared spectrum of the intrinsic antibacterial epoxy resin prepared in this embodiment, at 916 cm⁻¹. -1 and 1061em -1 The absorption peak at 1237 cm⁻¹ is an inverse symmetric peak for epoxy groups. -1 The absorption peak at 1186 cm⁻¹ is a symmetrical peak of the epoxy group. -1 and 2969em -1 The absorption peak at 1619 eC is the absorption peak of the CH deformation vibration in the cyclohexene skeleton of shikimic acid. -1 and 2355cm -1 The peak at this point represents the stretching vibration absorption peak of the C=C double bond in the cyclohexene skeleton of shikimic acid. The infrared spectrum results indicate that the epoxy group has been grafted onto shikimic acid.

[0058] 2. Preparation of antibacterial agents

[0059] 200g of graphene oxide was dissolved in 2L of deionized water and ultrasonically dispersed. 20g of silver nitrate and 22g of cerium nitrate were slowly added, and after uniform ultrasonic dispersion, 45g of sodium phosphate was added. The pH was adjusted to 10.5 with ammonia water, and the mixture was placed in a high-pressure reactor at 180℃ for hydrothermal reaction for 48 hours. The product was washed eight times with ethanol and aqueous solution, and dried under vacuum to obtain a black powder, which is the graphene-supported silver phosphate / cerium dioxide antibacterial agent. (See also...) Figure 2 and Figure 3 The images show electron microscope (EM) images of the prepared graphene loaded with silver phosphate / cerium dioxide at different magnifications. As can be seen from the images, silver and cerium ions are attached to the surface of the layered graphene. Due to the metal ions loaded on the graphene surface, the graphene is in a dispersed state under the influence of the charge of the metal ions.

[0060] 3. Preparation of Intrinsic Anticorrosive and Antibacterial Graphene Coatings

[0061] Add 15g xylene and 10g n-butanol to 25g of the prepared intrinsic antibacterial epoxy resin, stir at 500r / min until homogeneous, then add 8g of graphene antibacterial agent, 10g talc, and 20g iron oxide red prepared in step 2 in sequence, disperse at 800r / min for 15min, then add 0.5g of anti-settling agent fumed silica and 0.5g of dispersant EFKA4010, stir at 2000r / min for 30min, and finally add 5.5g of polyamide and 5.5g of alicyclic amine curing agent, stir until homogeneous, and the intrinsic anticorrosive and antibacterial graphene coating is obtained.

[0062] 4. Characterization of the anti-corrosion and antibacterial properties of intrinsic anti-corrosion and antibacterial graphene coatings

[0063] The coating was sprayed onto a carbon steel plate (substrate sandblasted to Sa2.5 grade) using compressed air and cured at room temperature (25℃) for 24 hours, with the film thickness controlled at 80±5μm, thus obtaining the intrinsic anti-corrosion and antibacterial coating. The adhesion, impact resistance, salt water resistance, salt spray resistance, and antibacterial properties of this coating are shown in Table 1. The antibacterial properties of the coating were evaluated using GB / T1741 "Test Method for Resistance to Mildew of Coating Films".

[0064] Figure 4 The image shows a cross-cut adhesion test of the coating prepared in this embodiment, which is sprayed onto a carbon steel plate. The cross-cut adhesion test result is 0, indicating that the coating has good bonding performance on the carbon steel plate.

[0065] Example 2

[0066] The method for preparing the intrinsic anti-corrosion and antibacterial graphene coating in this embodiment is basically the same as that in Example 1, except that 20g of talc powder and 10g of iron oxide red are added during coating preparation, while other properties remain unchanged. The adhesion, impact resistance, salt water resistance, salt spray resistance, and antibacterial properties of the coating prepared in this embodiment are shown in Table 1.

[0067] Comparative Example 1

[0068] The method described in Example 1 was followed, except that 25g of intrinsic antibacterial epoxy resin was replaced with 25g of commercially available epoxy resin E20 (purchased from Nan Ya Epoxy Resin (Kunshan) Co., Ltd.). The adhesion, impact resistance, salt water resistance, salt spray performance, and antibacterial properties of the coatings obtained in this comparative example are shown in Table 1.

[0069] Comparative Example 2

[0070] The method described in Example 1 was followed, except that no graphene antibacterial agent was added and the amount of talc added was increased to 18g. The adhesion, impact resistance, salt water resistance, salt spray performance, and antibacterial properties of the coating prepared in this comparative example are shown in Table 1.

[0071] Comparative Example 3

[0072] The method described in Example 1 was followed, except that 25g of intrinsic antibacterial epoxy resin was replaced with 25g of commercially available epoxy resin E20 (purchased from Nan Ya Epoxy Resin (Kunshan) Co., Ltd.), no antibacterial agent was added, and the amount of talc added was increased to 18g. The adhesion, impact resistance, salt water resistance, salt spray performance, and antibacterial properties of the coating in Comparative Example 3 are shown in Table 1.

[0073] Comparative Example 4

[0074] The difference between this comparative example and Example 1 is that graphene oxide, silver nitrate, and cerium nitrate were directly added to 25g of intrinsic antibacterial epoxy resin; the mass ratio of 200g graphene oxide, 20g silver nitrate, and 22g cerium nitrate was 10:1:1.1. The adhesion, impact resistance, salt water resistance, salt spray performance, and antibacterial properties of the coating prepared in this comparative example are shown in Table 1.

[0075] Table 1 shows the physical properties of the coatings used on carbon steel surfaces in the examples and comparative examples.

[0076] Physical properties Appearance 100-grid adhesion Impact resistance Salt water resistance Salt spray resistance Antibacterial properties Testing standards Visual inspection GB / T 9286 GB / 1732 ISO 4682 GB / T 1771 GB / T 1741 Example 1 smooth Level 0 50kg·cm Paint film blistering after 2000 hours Paint film blistering after 1440 hours Level 0 Example 2 smooth Level 1 50kg·cm Paint film blistering after 2000 hours Paint film blistering after 1440 hours Level 0 Comparative Example 1 smooth Level 0 50kg·cm Paint film blistering after 2500 hours Paint film blistering after 2000 hours Level 1 Comparative Example 2 smooth Level 0 50kg·cm Paint film blistering after 1500 hours Paint film blistering after 1000 hours Level 2 Comparative Example 3 smooth Level 1 50kg·cm Paint film blistering after 2000 hours Paint film blistering after 2000 hours No antibacterial properties Comparative Example 4 smooth Level 1 50kg·cm Paint film blistering after 1500 hours Paint film blistering after 1000 hours Level 1

[0077] Note: Antibacterial performance level 0 indicates that the coating has the best antibacterial performance.

[0078] By comparing the test results of Example 1 and Comparative Example 1, it is shown that the self-made antibacterial agent graphene loaded with silver phosphate / cerium dioxide has a certain antibacterial function and can improve the antibacterial performance of coatings prepared with commercially available epoxy resin.

[0079] Comparing the test results of Example 1 and Comparative Example 2, it was found that using intrinsic antibacterial epoxy resin as the film-forming material significantly improves the antibacterial performance of the coating film. The intrinsic antibacterial epoxy resin, combined with the antibacterial agent graphene-supported silver phosphate / cerium dioxide, exhibits synergistic antibacterial properties. A comparison of Comparative Example 2 and Comparative Example 3 shows that the intrinsic antibacterial epoxy resin prepared using shikimic acid possesses certain antibacterial properties. When combined with the graphene antibacterial agent for synergistic bactericidal effect, the resulting coating exhibits excellent bactericidal activity.

[0080] By comparing the test results of Example 1 and Comparative Example 3, the epoxy coating prepared without using intrinsic antibacterial epoxy resin and without adding antibacterial agent has no antibacterial properties.

[0081] By comparing the test results of Example 1 and Comparative Example 4, it was found that the graphene-supported silver phosphate / cerium dioxide used in Example 1 can significantly improve the salt water resistance and salt spray resistance of the coating; at the same time, it is also confirmed that the intrinsic antibacterial epoxy resin and the graphene antibacterial agent (graphene-supported silver phosphate / cerium dioxide) have synergistic antibacterial effects; in Comparative Example 4, the direct mixing method could not improve the aggregation of graphene, resulting in a significant decrease in its salt water resistance and salt spray resistance.

[0082] The above are merely preferred embodiments of the present invention and do not limit the scope of protection of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any changes, modifications, substitutions, integrations, and parameter alterations to these embodiments within the spirit and principles of the present invention, achieved through conventional substitutions or by achieving the same function without departing from the principles and spirit of the present invention, fall within the scope of protection of the present invention.

Claims

1. An intrinsically anticorrosive and antibacterial graphene coating, characterized in that, It includes at least graphene antibacterial agents and intrinsic antibacterial rings. Oxygen resin; the intrinsic antibacterial epoxy resin is prepared by catalytic reaction of shikimic acid and epichlorohydrin under alkaline solution conditions; The preparation method of the intrinsic antibacterial epoxy resin includes dissolving shikimic acid in the alkaline solution, heating and adding epichlorohydrin and a catalyst, stirring and reacting at 90-120°C for 4-7 hours, cooling to room temperature, and obtaining the intrinsic antibacterial epoxy resin after post-treatment. The graphene antibacterial agent comprises graphene-supported silver phosphate / cerium dioxide, wherein silver phosphate and cerium dioxide are supported on the surface of the graphene sheet structure; The preparation method of the graphene antibacterial agent includes: ultrasonically dispersing graphene in deionized water to obtain a graphene dispersion; adding silver nitrate and cerium nitrate to the graphene dispersion, ultrasonically dispersing evenly, adding sodium phosphate, adjusting the pH, and carrying out a hydrothermal reaction in a high-pressure reactor to obtain a black powder product, which is the graphene-supported silver phosphate / cerium dioxide antibacterial agent.

2. The intrinsic anti-corrosion and antibacterial graphene coating according to claim 1, characterized in that, The catalyst is benzyltrimethylammonium iodide.

3. The intrinsic anti-corrosion and antibacterial graphene coating according to claim 1, characterized in that, The graphene is graphene oxide.

4. The intrinsic anti-corrosion and antibacterial graphene coating according to claim 1, characterized in that, The mass ratio of graphene to cerium nitrate is 8–20:1; The mass ratio of graphene to silver nitrate is 8–25:1; And / or, the molar ratio of sodium phosphate to silver nitrate is 1 to 3:1; And / or, the pH adjustment includes adjusting the pH to 10-10.5 using ammonia or sodium hydroxide; And / or, the temperature of the hydrothermal reaction is 150–200°C; the reaction time is 24–48 h; After the hydrothermal reaction, the product was washed and dried under vacuum to obtain the black powder product.

5. The intrinsic anti-corrosion and antibacterial graphene coating according to any one of claims 1-4, characterized in that, By weight, it comprises at least 20-30 parts of the intrinsic antibacterial epoxy resin, 5-10 parts of the graphene antibacterial agent, 20-45 parts of solvent, 15-20 parts of curing agent, 25-40 parts of filler, and 1.5-2.5 parts of additives.

6. The intrinsic anti-corrosion and antibacterial graphene coating according to claim 5, characterized in that, The additive is one or a combination of one or more of the following: anti-settling agent fumed silica, dispersant EFKA4010, and leveling agent BYK333. The solvent is at least one of xylene, n-butanol, and acetone; The filler is at least one of aluminum polyphosphate, iron oxide red, and talc. The curing agent is one or a combination of polyamide, alicyclic amine and aromatic amine.

7. A method for preparing an intrinsically anti-corrosion and antibacterial graphene coating as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Preparation of intrinsic antibacterial epoxy resin; Shikimic acid is dissolved in an alkaline solution and heated to 90–120°C. Then epichlorohydrin and benzyltrimethylammonium iodide are added. The mixture is stirred at 90–120°C and 150–300 r / min for 4–7 h. After cooling to room temperature, the intrinsic antibacterial epoxy resin is obtained through post-treatment. S2. Preparation of graphene antibacterial agent; Silver nitrate and cerium nitrate were added to a graphene oxide dispersion and ultrasonically dispersed. Sodium phosphate was then added to adjust the pH to 10–10.

5. The mixture was then hydrothermally reacted in a high-pressure reactor at 150–200°C for 24–48 hours to obtain the product. The product was washed and then vacuum-dried to obtain a black powder product, which is the graphene antibacterial agent loaded with silver phosphate / cerium dioxide. S3. Preparation of Intrinsic Anticorrosive and Antibacterial Graphene Coatings Solvent, graphene antibacterial agent, and filler are added sequentially to the intrinsic antibacterial epoxy resin prepared in S1 for the first dispersion, then additives are added for the second dispersion, and finally curing agent is added and stirred evenly to obtain the intrinsic anticorrosive and antibacterial graphene coating.

8. The method for preparing the intrinsic anti-corrosion and antibacterial graphene coating according to claim 7, characterized in that, The alkaline solution mentioned in S1 is a sodium hydroxide or potassium hydroxide solution with a mass fraction of 15 wt%. The post-treatment includes recovering excess epichlorohydrin under reduced pressure, removing the upper alkaline layer after settling, and then washing with boiling water. The intrinsic antibacterial epoxy resin is obtained by washing and dehydration. The conditions for the first dispersion described in S3 include dispersion at 400-600 r / min for 10-15 min; The conditions for the second dispersion include stirring at 1500–2000 r / min for 20–40 min.

9. The application of an intrinsic anti-corrosion and antibacterial graphene coating as described in any one of claims 1-6 in the field of metal protection.

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