Anticorrosive paint with self-early warning and self-repairing functions as well as preparation method and application of anticorrosive paint

Abstract

The invention provides an anticorrosive coating with self-early warning and self-repairing functions as well as a preparation method and application thereof, and relates to the technical field of coatings. According to the preparation method, an efficient corrosion inhibitor BTA (benzotriazole) and a corrosion early warning agent APhen (1, 10-phenanthroline-5-amino) are loaded into MSN (mesoporous silica) at the same time, and the bifunctional composite nanomaterial (BTA + APhen-MSN) is prepared. According to the invention, on the premise of not increasing preparation process steps, collaborative loading of BTA and APhen is realized; through the synergistic loading of BTA and APhen, the total loading amount of functional substances in the MSN can be increased, so that the corrosion inhibition performance of the composite nano material is improved on the premise of ensuring that the composite nano material has good damage self-early warning performance.

Description

Technical Field

[0001] The present invention provides an anti-corrosion coating with self-warning and self-repairing functions, a preparation method and application thereof, and belongs to the technical field of coatings. Background Art

[0002] Organic coatings are currently one of the most widely used methods for metal corrosion protection. Traditional organic coatings often act as physical barriers, protecting the metal substrate by reducing the penetration of corrosive media. However, during the service life of the coating, problems such as mechanical wear and natural aging can cause damage to the coating. If these coating damages are not promptly addressed, the coating's protective properties will rapidly deteriorate, ultimately leading to coating failure and substrate corrosion. Currently, the detection and repair of microscopic damage within the coating mostly requires manual labor or special equipment, which greatly increases labor and economic costs. With the continuous development of anti-corrosion technology, it has become possible to use intelligent anti-corrosion coatings to detect and repair coating damage.

[0003] Intelligent self-warning coatings can convert environmental changes associated with coating damage into visible fluorescence or color signals, thereby indicating the location of damage. Because fluorescence signals rely on ultraviolet excitation, their practical application is limited. Intelligent anti-corrosion coatings that use color signals for damage warning have garnered widespread attention. One of the most common methods for preparing self-warning coatings is to incorporate corrosion warning agents (such as APhen, tannic acid, and phenolphthalein) into the coating. These agents convert corrosion products (metal ions, H+, or OH-) at the coating damage site into visible color signals. For example, Galvao et al. dispersed MSN loaded with phenolphthalein reagent into acrylic polyurethane coating as a self-warning coating on aluminum alloy surface; once the coating is damaged, the metal substrate at the damaged site undergoes electrochemical corrosion, and its cathode product OH- will react with phenolphthalein in the coating, causing the damaged site of the coating to turn red, thereby successfully achieving unassisted detection of micro-damage of the coating (Galvao TLP, Sousa I, Wilhelm M, et al. Improving the functionality and performance of AA2024 corrosion sensing coatings with nanocontainers[J]. Chemical Engineering Journal, 2018, 341: 526-538.). Compared with pH indicators, metal ion indicators have higher detection sensitivity and can therefore more accurately identify changes in trace ion concentrations, thereby achieving precise positioning of coating defects and metal corrosion sites. For example, by doping MSN loaded with tannic acid (TA) in epoxy resin, an intelligent self-warning coating for steel surface can be successfully prepared. The TA released at the coating damage site can react with the steel corrosion product Fe 3+ The combination forms a black chelate to achieve precise positioning of coating damage (Wang J, Tan W, Yang H, et al. Towards weathering and corrosion resistant, self-warning and self-healing epoxy coatings with tannicacid loaded nanocontainers[J]. Npj Materials Degradation, 2023, 7: 39.).

[0004] Smart self-repairing coatings can spontaneously repair coating damage and restore coating function after the coating is damaged. According to the repair mechanism, smart self-repairing coatings are divided into triggered self-repairing coatings and spontaneous self-repairing coatings. After the coating is damaged, the triggered self-repairing coating can use internal chemical bonds or special functional groups to trigger a series of chemical and physical reactions to achieve molecular structure reorganization and repair the coating damage. However, it relies on external energy supply (such as near-infrared light, laser, ultrasound, etc.), which does not conform to the concept of "self-repair". On the contrary, the spontaneous self-repairing coating can achieve self-repair of damage by releasing the self-repairing agent in the early stage of coating damage by pre-embedding the self-repairing agent in the matrix. Among them, corrosion inhibitors (such as BTA, 8-hydroxyquinoline and 2-mercaptobenzothiazole, etc.) are a common self-repairing agent. Doping corrosion inhibitors in the coating matrix is ​​the simplest and most controllable solution for preparing self-repairing coatings. For example, Mirzakhanzadeh et al. doped two corrosion inhibitors, zinc aluminum polyphosphate (ZAPP) and 2-mercaptobenzothiazole (MBI), into the epoxy-polyamide coating on the steel surface. Under the synergistic effect of the two, the composite coating showed higher corrosion resistance efficiency and more lasting corrosion resistance (Mirzakhanzadeh Z, Kosari A, Moayed MH, et al. Enhanced corrosion protection of mild steel by the synergetic effect of zinc aluminum polyphosphate and 2-mercaptobenzimidazole inhibitors incorporated in epoxy-polyamide coatings[J]. Corrosion Science, 2018, 138: 372-379.).

[0005] Single-function smart anticorrosion coatings provide only a single protective mechanism and are unable to cope with the demands of multi-factor corrosion environments. If smart anticorrosion coatings with both self-warning and self-repairing capabilities could be developed, these shortcomings could be overcome, thereby extending the coating's service life. Simultaneously doping a corrosion inhibitor and a corrosion warning agent into the coating matrix is ​​the simplest and most controllable approach to preparing dual-function coatings. However, direct doping of the corrosion inhibitor and the self-warning agent can lead to a "burst release" phenomenon, which compromises the long-term corrosion resistance of the coating. Encapsulating the corrosion inhibitor and the corrosion warning agent in micro / nanocontainers can effectively address this issue. Common micro / nanocontainers include mesoporous silica (MSN), halloysite nanotubes (HNTs), montmorillonite (MMT), and polymer capsules. For example, Wang et al. loaded coumarin and BTA, respectively, into PDVB-graft-P(DVB-co-AA) microspheres to prepare two pH-responsive composite nanocontainers. These nanocontainers were uniformly dispersed in EP and successfully fabricated on steel surfaces an anticorrosion coating with both self-healing and self-warning capabilities. The coating can respond to the pH changes produced by steel corrosion and release coumarin and BTA at the same time. The fluorescence properties of coumarin can realize self-warning of coating damage, and BTA can realize self-repair of coating damage by forming a dense complex on the steel surface (Wang JP, Wang JK, Zhou Q, et al. Adaptive polymeric coatings with self-reporting and self-healing dual functions from porous core-shell nanostructures [J]. Macromolecular Materials and Engineering, 2018, 303 (4): 1700616.). However, the preparation and doping of dual capsules will lead to uneven distribution of capsules, and the dual function requires an increase in the amount of capsules, which will destroy the integrity of the coating and affect the corrosion resistance of the coating. To solve the above problems, intelligent self-repairing and self-warning coatings based on single capsules have become a research hotspot.

[0006] For example, Wang et al. dispersed MSN loaded with APhen into epoxy resin to prepare an anti-corrosion coating on the steel surface; once the coating was damaged, the APhen released from the coating could not only react with Fe 2+The combination generates a red chelate complex that provides a damage warning function and can also form a chemical adsorption film on the steel surface to inhibit corrosion reactions and achieve preliminary repair of coating damage (Wang JK, Ma LW, Guo X, et al. Two birds with one stone: Nanocontainers with synergetic inhibition and corrosion sensing abilities towards intelligent self-healing and self-reporting coating [J]. Chemical Engineering Journal, 2022, 433: 134515.). However, the APhen loading of MSN is limited (15.6 wt.%), making the self-healing performance of the coating insufficient. Summary of the Invention

[0007] In light of this, the present invention provides an anti-corrosion coating with self-warning and self-repairing functions and a preparation method thereof. The present invention simultaneously loads the highly effective corrosion inhibitor BTA (benzotriazole) and the corrosion warning agent APhen (1,10-phenanthroline-5-amino) into mesoporous silica (MSN) to prepare a dual-functional composite nanomaterial (BTA+APhen@MSN).

[0008] The present invention is specifically achieved by the following method:

[0009] A method for preparing an anti-corrosion coating with self-warning and self-repairing functions comprises the following steps:

[0010] (1) Preparation of BTA+APhen@MSN composite powder

[0011] Benzotriazole and 1,10-phenanthroline-5-aminobenzoate are added to an alkaline aqueous solution at 60-80°C, stirred evenly, and then a template agent, hexadecyltrimethylammonium bromide, is added and stirred to dissolve to obtain an alkaline solution; an ethanol solution containing ethyl orthosilicate is then added dropwise and stirred to react; after the reaction is complete, a precipitate is obtained by centrifugation; the precipitate is washed and dried to obtain a BTA+APhen@MSN composite powder;

[0012] (2) Preparation of BTA+APhen@MSN / EP coating

[0013] The BTA+APhen@MSN composite powder is evenly mixed with epoxy resin, and a curing agent is added to obtain a BTA+APhen@MSN / EP coating.

[0014] Preferably, the benzotriazole content in the BTA+APhen@MSN composite powder is 8 wt.% to 18 wt.%;

[0015] The content of 1,10-phenanthroline-5-amino group in the BTA+APhen@MSN composite powder is 8 wt.% to 25 wt.%.

[0016] Preferably, the alkaline aqueous solution in step (1) is a NaOH aqueous solution or an ammonia aqueous solution with a pH of 10 to 12.

[0017] Preferably, the concentration of the template agent hexadecyltrimethylammonium bromide in the alkaline solution is 2.2 g / L.

[0018] Preferably, the volume ratio of the ethyl orthosilicate to the alkaline solution is 1:8.

[0019] Preferably, in step (2), the mass ratio of BTA+APhen@MSN composite powder to epoxy resin is 0.01 to 0.1:1.

[0020] Preferably, the curing agent in step (2) is T-31 epoxy resin curing agent.

[0021] More preferably, the mass ratio of the curing agent to the epoxy resin in step (2) is 1:2-4.

[0022] The present invention also provides an application of the anti-corrosion coating with self-warning and self-repairing functions, which is to evenly apply the anti-corrosion coating with self-warning and self-repairing functions on the surface of the substrate, and obtain an anti-corrosion coating with self-warning and self-repairing functions after curing at room temperature.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention achieves the synergistic loading of BTA and APhen without adding additional preparation steps. This synergistic loading of BTA and APhen can increase the total loading of functional substances within the MSN, thereby improving the corrosion inhibition performance of the composite nanomaterial while ensuring good damage self-warning performance. Subsequently, BTA+APhen@MSN is added to epoxy resin to prepare an intelligent anti-corrosion coating (BTA+APhen@MSN / EP) on the substrate surface, which combines defect self-warning and damage self-repair functions.

[0025] The anti-corrosion coating of the present invention can form an anti-corrosion coating on the surface of a substrate. When damage occurs, the coating can spontaneously indicate the damage site and perform self-repair in a timely manner to improve the corrosion resistance and service life of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Nyquist plots of the EP coating (left) and BTA+APhen@MSN / EP coating (right) immersed in 3.5 wt.% NaCl solution for 60 days;

[0027] Figure 2 Surface morphology changes of scratched EP coating and scratched BTA+APhen@MSN / EP coating during immersion in 3.5% NaCl solution;

[0028] Figure 3 Nyquist plot (left) and Bode plot (right) of the cross-hatched BTA+APhen@MSN / EP coating during immersion in 3.5 wt.% NaCl solution for 5 days. DETAILED DESCRIPTION

[0029] To make the purpose, technical solutions and advantages of the present invention more clear, the preferred embodiments of the present invention are further described in detail below with reference to the examples. Based on the examples in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] (1) Measure 100 mL of deionized water and slowly add ammonia solution until the pH value of the mixed solution stabilizes at 12. Transfer the solution to a constant temperature water bath and adjust the water bath temperature to 80°C. After the solution temperature stabilizes, add 0.10 g of BTA and 0.20 g of APhen to the solution and stir for 30 min. Subsequently, add 0.22 g of hexadecyltrimethylammonium bromide (CTAB) template to the solution and continue stirring for 60 min to ensure its complete dissolution. Finally, slowly add 5 mL of ethanol solution of tetraethylorthosilicate (TEOS) (the volume fraction of TEOS is 25%) dropwise, stir vigorously for 2 hours, and control the stirring speed to avoid bubbles in the mixed solution. After the reaction is completed, place the mixed solution in a centrifuge tube and centrifuge at 4000 r / min for 3 min to separate the precipitate. Remove the supernatant, wash with deionized water, and then place the washed precipitate in a constant temperature drying oven at 70°C to dry for 12 h to obtain BTA+APhen@MSN composite powder.

[0032] (2) BTA+APhen@MSN composite powder was mixed with epoxy resin at a mass ratio of 3:100, stirred with a magnetic stirrer for 10 min, and ultrasonically treated for 20 min. T-31 epoxy resin curing agent was added at a mass ratio of epoxy resin to curing agent of 2:1, stirred for 3 min, and allowed to stand for 30 min to obtain BTA+APhen@MSN / EP coating.

[0033] (3) The BTA+APhen@MSN / EP coating was dripped onto the Q235 steel surface and applied in a uniform, unidirectional manner using a thickness-controlled applicator to form a uniform, smooth coating with a thickness of 50 μm. After curing at room temperature for 12 h, a dual-functional anti-corrosion coating with both self-warning and self-repairing properties, namely the BTA+APhen@MSN / EP coating, was obtained.

[0034] Example 2

[0035] (1) Measure 100 mL of deionized water and slowly add 4 mol / L NaOH solution until the pH value of the mixed solution stabilizes at 10. Transfer the solution to a constant temperature water bath and adjust the water bath temperature to 70°C. After the solution temperature stabilizes, add 0.15 g BTA and 0.25 g APhen to the solution and stir for 50 min. Subsequently, add 0.22 g hexadecyltrimethylammonium bromide (CTAB) template to the solution and continue stirring for 30 min to ensure its complete dissolution. Finally, slowly add 5 mL of ethanol solution of tetraethyl orthosilicate (TEOS) (the volume fraction of TEOS is 25%) dropwise, stir vigorously for 1 h, and control the stirring speed to avoid bubbles in the mixed solution. After the reaction is completed, place the mixed solution in a centrifuge tube and centrifuge at 4000 r / min for 5 min to separate the precipitate. The supernatant was removed, and the mixture was washed with deionized water. The washed precipitate was then placed in a constant temperature drying oven at 90° C. and dried for 16 h to obtain BTA+APhen@MSN composite powder.

[0036] (2) BTA+APhen@MSN composite powder and epoxy resin were mixed at a mass ratio of 2:100, stirred for 15 min using a magnetic stirrer, and then ultrasonicated for 10 min. T-31 epoxy resin curing agent was added at a mass ratio of epoxy resin / curing agent of 2:1, followed by epoxy resin curing agent according to the ratio, stirred for 5 min, and then ultrasonicated for 20 min to obtain the BTA+APhen@MSN / EP coating.

[0037] (3) The BTA+APhen@MSN / EP coating was dripped onto the Q235 steel surface and applied in a uniform, unidirectional manner using a thickness-controlled applicator to form a uniform, smooth film with a thickness of 100 μm. After curing at room temperature for 16 h, a dual-functional anti-corrosion coating with both self-warning and self-repair properties, namely the BTA+APhen@MSN / EP coating, was obtained.

[0038] Example 3

[0039] (1) Measure 100 mL of deionized water and slowly add ammonia solution until the pH value of the mixed solution stabilizes at 12. Transfer the solution to a constant temperature water bath and adjust the water bath temperature to 65°C. After the solution temperature stabilizes, add 0.20 g of BTA and 0.30 g of APhen to the solution and stir for 30 min. Subsequently, add 0.22 g of hexadecyltrimethylammonium bromide (CTAB) template to the solution and continue stirring for 45 min to ensure its complete dissolution. Finally, slowly add 5 mL of ethanol solution of tetraethyl orthosilicate (TEOS) (the volume fraction of TEOS is 25%) dropwise, stir vigorously for 2.5 h, and control the stirring speed to avoid bubbles in the mixed solution. After the reaction is completed, place the mixed solution in a centrifuge tube and centrifuge at 4000 r / min for 6 min to separate the precipitate. Remove the supernatant, wash with deionized water, and then place the washed precipitate in a constant temperature drying oven at 80°C to dry for 20 h to obtain BTA+APhen@MSN composite powder.

[0040] (2) BTA+APhen@MSN composite powder was added to epoxy resin at a mass ratio of 5:100, stirred for 20 min using a magnetic stirrer, and ultrasonically treated for 10 min. T-31 epoxy resin curing agent was added at a mass ratio of epoxy resin to curing agent of 2:1, stirred for 10 min, and allowed to stand for 20 min to obtain BTA+APhen@MSN / EP coating.

[0041] (3) The BTA+APhen@MSN / EP coating was dripped onto the Q235 steel surface and applied in a uniform, unidirectional manner using a thickness-controlled applicator to form a 200 μm thick, uniform film. After curing at room temperature for 24 h, a dual-functional anti-corrosion coating with both self-warning and self-repair properties, namely the BTA+APhen@MSN / EP coating, was obtained.

[0042] Example 4

[0043] (1) Measure 100 mL of deionized water and slowly add 4 mol / L NaOH solution until the pH value of the mixed solution stabilizes at 11. Transfer the solution to a constant temperature water bath and adjust the water bath temperature to 80°C. After the solution temperature stabilizes, add 0.30 g BTA and 0.20 g APhen to the solution and stir for 40 minutes. Subsequently, add 0.22 g hexadecyltrimethylammonium bromide (CTAB) template to the solution and continue stirring for 30 minutes to ensure its complete dissolution. Finally, slowly add 5 mL of ethanol solution of tetraethyl orthosilicate (TEOS) (the volume fraction of TEOS is 25%) dropwise, stir vigorously for 1 hour, and control the stirring speed to avoid bubbles in the mixed solution. After the reaction is completed, place the mixed solution in a centrifuge tube and centrifuge at 4000 r / min for 8 minutes to separate the precipitate. The supernatant was removed, and the mixture was washed with deionized water. The washed precipitate was placed in a constant temperature drying oven at 60°C and dried for 16 h to obtain a BTA+APhen@MSN composite sample.

[0044] (2) BTA+APhen@MSN composite powder was added to epoxy resin at a mass ratio of 8:100, stirred for 20 min using a magnetic stirrer, and ultrasonically treated for 20 min. T-31 epoxy resin curing agent was added at a mass ratio of epoxy resin to curing agent of 4:1, stirred for 20 min, and allowed to stand for 20 min to obtain BTA+APhen@MSN / EP coating.

[0045] (3) The BTA+APhen@MSN / EP coating was dripped onto the Q235 steel surface and applied in a uniform, unidirectional manner using a thickness-controlled applicator to form a uniform, smooth film with a thickness of 100 μm. After curing at room temperature for 16 h, a dual-functional anti-corrosion coating with both self-warning and self-repair properties, namely the BTA+APhen@MSN / EP coating, was obtained.

[0046] Example 5

[0047] (1) Measure 100 mL of deionized water and slowly add 4 mol / L NaOH solution until the pH value of the mixed solution stabilizes at 11. Transfer the solution to a constant temperature water bath and adjust the water bath temperature to 75°C. After the solution temperature stabilizes, add 0.20 g BTA and 0.30 g APhen to the solution and stir for 60 minutes. Subsequently, add 0.22 g hexadecyltrimethylammonium bromide (CTAB) template to the solution and continue stirring for 60 minutes to ensure its complete dissolution. Finally, slowly add 5 mL of ethanol solution of tetraethylorthosilicate (TEOS) (the volume fraction of TEOS is 25%) dropwise, stir vigorously for 3 hours, and control the stirring speed to avoid bubbles in the mixed solution. After the reaction is completed, place the mixed solution in a centrifuge tube and centrifuge at 4000 r / min for 5 minutes to separate the precipitate. The supernatant was removed, and the mixture was washed with deionized water. The washed precipitate was placed in a constant temperature drying oven at 80°C and dried for 16 h to obtain BTA+APhen@MSN composite powder.

[0048] (2) BTA+APhen@MSN composite powder was added to epoxy resin at a mass ratio of 1:10, stirred for 15 min using a magnetic stirrer, and ultrasonically treated for 25 min. T-31 epoxy resin curing agent was added at a mass ratio of epoxy resin / curing agent of 2:1, stirred for 20 min, and allowed to stand for 15 min to obtain BTA+APhen@MSN / EP coating.

[0049] (3) The BTA+APhen@MSN / EP coating was dripped onto the Q235 steel surface and applied in a uniform, unidirectional manner using a thickness-controlled applicator to form a uniform, smooth film with a thickness of 150 μm. After curing at room temperature for 20 h, a dual-functional anti-corrosion coating with both self-warning and self-repair properties, namely the BTA+APhen@MSN / EP coating, was obtained.

[0050] The performance of the BTA+APhen@MSN / EP coating prepared in Example 1 was compared with that of a blank EP coating, as follows:

[0051] (1) Corrosion resistance test

[0052] The electrochemical impedance spectra of the blank EP coating and the BTA+APhen@MSN / EP coating after immersion in 3.5wt.% NaCl solution for 60 days were measured using an Autolab 302 electrochemical workstation. Figure 1 After immersion for 60 days, the impedance arc radius of the BTA+APhen@MSN / EP coating is 7 to 8 times that of the blank EP coating, indicating that the BTA+APhen@MSN / EP coating has good long-term corrosion resistance.

[0053] (2) Self-warning performance test

[0054] The EP coating and BTA+APhen@MSN / EP coating with artificial scratches on the surface (scratch size is 15 mm × 0.1 mm) were immersed in 3.5% NaCl solution, and the morphological changes near the scratches were observed. Figure 2 As shown in the figure, after 30 minutes of continuous immersion, the scratched BTA+APhen@MSN / EP coating exhibits a distinct red color at the scratched area. This color becomes even more pronounced after immersion for 2 hours, demonstrating the BTA+APhen@MSN / EP coating's excellent self-warning properties. However, the blank EP coating exhibits no red color development, only a slight brown rust mark.

[0055] (3) Self-repair performance test:

[0056] The electrochemical impedance spectroscopy of the artificially scratched EP coating and BTA+APhen@MSN / EP coating immersed in 3.5% NaCl for 5 days was measured using an Autolab 302 electrochemical workstation. Figure 3 As shown. During the immersion period, the low-frequency impedance modulus of the scratched EP coating continued to decrease; after five days of immersion, the impedance modulus of the coating was only 8% to 10% of that before immersion, indicating that the steel substrate was continuously corroded. The low-frequency impedance modulus of the scratched BTA+APhen@MSN / EP coating first decreased and then increased; and after two days of immersion, three capacitive arcs and three phase angle peaks appeared in the electrochemical impedance spectrum of the scratched BTA+APhen@MSN / EP coating, showing the characteristics of three time constants. This shows that the loaded BTA and APhen released from the coating formed a protective film layer on the scratched bare steel surface, which repaired the coating to a certain extent. After five days of immersion, the impedance modulus increased to 1.2 to 1.3 times that before immersion, proving that the BTA+APhen@MSN / EP coating has good self-healing properties.

[0057] The embodiments described above are some, but not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

Claims

1. A method for preparing an anti-corrosion coating with self-warning and self-repairing functions, characterized in that: The following steps are involved: (1) Preparation of BTA+APhen@MSN composite powder Benzotriazole and 1,10-phenanthroline-5-aminobenzoate are added to an alkaline aqueous solution at 60-80°C, stirred evenly, and then a template agent, hexadecyltrimethylammonium bromide, is added and stirred to dissolve to obtain an alkaline solution; an ethanol solution containing ethyl orthosilicate is then added dropwise and stirred to react; after the reaction is complete, a precipitate is obtained by centrifugation; and the precipitate is washed and dried to obtain a BTA+APhen@MSN composite powder. (2) Preparation of BTA+APhen@MSN / EP coating The BTA+APhen@MSN composite powder is evenly mixed with epoxy resin, and then a curing agent is added to obtain a BTA+APhen@MSN / EP coating.

2. The method for preparing the anti-corrosion coating with self-warning and self-repairing functions according to claim 1, characterized in that: The benzotriazole content in the BTA+APhen@MSN composite powder is 8 wt.% to 18 wt.%; The content of 1,10-phenanthroline-5-amino group in the BTA+APhen@MSN composite powder is 8 wt.% to 25 wt.%.

3. The method for preparing the anti-corrosion coating with self-warning and self-repairing functions according to claim 1, characterized in that: The alkaline aqueous solution in step (1) is a NaOH aqueous solution or an ammonia aqueous solution with a pH of 10 to 12.

4. The method for preparing the anti-corrosion coating with self-warning and self-repairing functions according to claim 1, characterized in that: The concentration of the template agent hexadecyltrimethylammonium bromide in the alkaline solution is 2.2 g / L.

5. The method for preparing the anti-corrosion coating with self-warning and self-repairing functions according to claim 1, characterized in that: The volume ratio of the tetraethyl orthosilicate to the alkaline solution is 1:

8.

6. The method for preparing the anti-corrosion coating with self-warning and self-repairing functions according to claim 1, characterized in that: In step (2), the mass ratio of BTA+APhen@MSN composite powder to epoxy resin is 0.01 to 0.1:

1.

7. The method for preparing the anti-corrosion coating with self-warning and self-repairing functions according to claim 1, characterized in that: The curing agent in step (2) is T-31 epoxy resin curing agent.

8. The method for preparing the anti-corrosion coating with self-warning and self-repairing functions according to claim 7, characterized in that: The mass ratio of the curing agent to the epoxy resin in step (2) is 1:2-4.

9. An anti-corrosion coating with self-warning and self-repair functions, characterized in that: The method is prepared by any one of claims 1 to 8.

10. The use of the anti-corrosion coating with self-warning and self-repairing functions as claimed in claim 9, characterized in that: The anti-corrosion coating with self-warning and self-repairing functions is evenly coated on the surface of a substrate, and cured at room temperature to obtain an anti-corrosion coating with self-warning and self-repairing functions.

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