A super-hydrophobic self-repairing SH / PDA-Ti3C2Tx / MXene / epoxy resin anti-corrosion composite coating and its preparation method

Abstract

The present invention discloses a super hydrophobic self-repairing SH / PDA-Ti3C2T x MXene / epoxy resin anticorrosion composite coating and preparation method thereof, the present invention first uses γ-aminopropyltriethoxysilane, trimethoxy (1H, 1H, 2H, 2H-heptafluorodecyl) silane, and sodium hydroxide aqueous solution as raw materials to prepare a fluorine-containing prepolymer; then uses LiF and Ti3AlC2 as raw materials to prepare a single layer Ti3C2T x MXene nanosheets; fluorinated prepolymer, single-layer Ti3C2T x MXene nanosheets, DA-HCl, and n-dodecyl mercaptan were used as raw materials to prepare SH / PDA-MXene nanosheets; finally, they were blended with epoxy resin to prepare SH / PDA-Ti3C2T x MXene / epoxy resin composite coating. Results show that this composite coating exhibits excellent photothermal performance, corrosion resistance, superhydrophobicity, and self-healing properties, and therefore has broad application prospects in areas such as wings, wind turbine blades, and high-speed train hulls.

Description

Technical Field

[0001] The present invention relates to the field of polymer composite materials, and relates to a super hydrophobic self-repairing SH / PDA-Ti3C2T x MXene / epoxy resin anti-corrosion composite coating and preparation method thereof. Background Art

[0002] As a new type of two-dimensional nanomaterial, MXene nanosheets have the characteristics of high specific surface area, high barrier properties, high wear resistance, and rich surface adjustable functional groups (-OH, -O, -F, etc.). They have made substantial progress in many fields such as batteries, supercapacitors, and catalysis.

[0003] Studies have shown that: (1) by Ti3C2T x MXene surface modification can change its inherent hydrophilicity to hydrophobicity (Zhang, L., Zhang, H., Yu, X., Xu, L., Wang, D., Lu, X., Zhang, A., 2022. Superhydrophobic MXene Coating with Biomimetic Structure for Self-Healing Photothermal Deicing and Photoelectric Detector. ACS Appl. Mater. Interfaces 14, 53298-53313.); (2) MXene has been shown to have excellent photothermal conversion properties and can convert sunlight into thermal energy with high efficiency (Li, R., Zhang, L., Shi, L., Wang, P., 2017. MXeneTi3C2: An Effective 2D Light-to-Heat Conversion Material. ACS Nano 11, 3752-3759.); (3) MXene has a high specific surface area and high barrier properties, which can effectively block the ion diffusion path to a certain extent.

[0004] While doping with MXene nanosheets effectively improves the corrosion resistance of coatings, it has certain limitations. As the MXene nanosheet content in the coating increases, the coating's corrosion resistance decreases. Furthermore, due to the chemical instability of MXene nanosheets, they can undergo oxidative damage when exposed to water and oxygen, severely hindering their application in corrosion protection.

[0005] Epoxy resins offer excellent chemical and abrasion resistance, as well as strong adhesion. Using epoxy coatings as a physical barrier to isolate metal coatings from the external environment is one of the most commonly used surface protection technologies. However, over the long term, single epoxy coatings are inevitably damaged by external factors, leading to defects such as microcracks and voids. These defects allow O₂, Cl⁻, and H⁺ ions to penetrate the epoxy coating, thereby reducing its corrosion resistance.

[0006] In recent years, researchers have proposed incorporating self-healing components into epoxy networks to achieve self-repair of defects and damage in epoxy coatings, thereby improving the corrosion resistance and durability of epoxy coatings. However, epoxy coatings with self-healing properties alone still cannot meet the requirements for long-term corrosion protection in high-salt and high-humidity environments. Therefore, it is crucial to improve the corrosion resistance of coatings under harsh conditions and to prepare modified MXene-epoxy composite coatings with excellent superhydrophobicity, corrosion resistance, and self-healing properties. Summary of the Invention

[0007] In view of the technical problems existing in the background technology, the purpose of the present invention is to provide a super hydrophobic self-repairing SH / PDA-Ti3C2T x MXene / epoxy resin anti-corrosion composite coating and preparation method thereof.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] The first aspect of the present invention provides a super hydrophobic self-repairing SH / PDA-Ti3C2T x The preparation method of the MXene / epoxy resin anti-corrosion composite coating comprises the following steps:

[0010] S1. Preparing a fluorine-containing prepolymer (FCP): dispersing γ-aminopropyltriethoxysilane in ethanol to obtain an ethanol solution of γ-aminopropyltriethoxysilane, then adding trimethoxy(1H,1H,2H,2H-heptafluorodecyl)silane and an aqueous sodium hydroxide solution, stirring and reacting to obtain a fluorine-containing prepolymer (FCP);

[0011] S2. Preparation of single-layer Ti3C2T x MXene nanosheets: LiF was dissolved in HCl, and then Ti3AlC2 was added, etched, and purified to obtain a single layer of Ti3C2T x MXene nanosheets;

[0012] S3. Preparation of SH / PDA-Ti3C2T x MXene, recorded as SH / PDA-MXene nanosheets: single-layer Ti3C2T xMXene nanosheets were dispersed in a Tris-HCl buffer solution, and then DA-HCl was added. The mixture was first ultrasonically treated in an ice-water bath, and then stirred at 50-60°C for reaction. Then, n-dodecanethiol was added and the reaction was continued. After purification, SH / PDA-MXene nanosheets were obtained.

[0013] S4. Preparation of SH / PDA-Ti3C2T x MXene / epoxy resin composite coating: SH / PDA-MXene nanosheets were ultrasonically dispersed in anhydrous ethanol, and then fluorinated prepolymer (FCP), 2,2' diaminodiphenyl disulfide (ADP) and epoxy resin were added and stirred evenly to obtain a first dispersion, which was then sprayed onto the pretreated substrate to obtain a semi-cured coating surface; then SH / PDA-MXene nanosheets, 2,2' diaminodiphenyl disulfide (ADP), fluorinated prepolymer (FCP) and epoxy resin were blended in ethanol and ultrasonically dispersed to obtain a second dispersion, which was then sprayed onto the surface of the semi-cured coating to form a rough interface, and finally SH / PDA-Ti3C2T x MXene / epoxy composite coating.

[0014] Preferably, in step S1, the stirring reaction temperature is 75-85° C., and the reaction time is 6-10 h.

[0015] Preferably, in step S1, the mass ratio of the γ-aminopropyltriethoxysilane, trimethoxy (1H, 1H, 2H, 2H-heptafluorodecyl) silane and the sodium hydroxide aqueous solution is 9-11:15-25:4-6:1-3; the trimethoxy (1H, 1H, 2H, 2H-heptafluorodecyl) silane and the sodium hydroxide aqueous solution are sequentially added to the ethanol solution of γ-aminopropyltriethoxysilane.

[0016] Preferably, the mass ratio of the γ-aminopropyltriethoxysilane to ethanol is 1-2:91; and the mass volume concentration of sodium hydroxide in the sodium hydroxide aqueous solution is 1-3 g / L.

[0017] Preferably, in step S2, the etching temperature is 40-60° C., and the etching time is 48-60 h.

[0018] Preferably, in step S2, the usage ratio of LiF, HCl and Ti3AlC2 is 3.2g:40mL:2g.

[0019] Preferably, in step S2, the specific steps of the purification treatment are: the etched solution is subjected to acid washing and centrifugation with HCl solution, water washing and centrifugation until the precipitate shows obvious swelling and the upper liquid is dark green, ice water bath ultrasonication under Ar atmosphere for 10 to 30 minutes, and then the upper liquid is taken by centrifugation and freeze-dried to obtain a single layer of Ti3C2T x MXene nanosheets.

[0020] Preferably, in step S3, the ultrasonic treatment time in the ice-water bath is 10 to 30 minutes, the stirring reaction time is 8 to 12 hours, and the continued reaction time is 6 to 8 hours.

[0021] Preferably, in step S3, the single layer Ti3C2T x The dosage ratio of MXene nanosheets, Tris-HCl buffer solution, DA-HCl and n-dodecanethiol is 0.6-1.2 g:500 mL:1.0 g:0.2-0.8 mL.

[0022] Preferably, in step S4, in the first dispersion, the ratio of SH / PDA-MXene nanosheets, anhydrous ethanol, fluorinated prepolymer (FCP), 2,2'-diaminodiphenyl disulfide (ADP), and epoxy resin is 0.025-0.1 g: 5 mL: 0-2 g: 1 g: 3 g.

[0023] Preferably, in step S4, in the second dispersion, the ratio of SH / PDA-MXene nanosheets, anhydrous ethanol, fluorinated prepolymer, 2,2'-diaminodiphenyl disulfide (ADP), and epoxy resin is 0.3-0.6 g: 10 mL: 0.01-0.03 g: 0.05 g: 0.1 g.

[0024] Preferably, in step S4, the pretreated substrate is pretreated, and the specific pretreatment steps of the Q235 carbon steel sheet are: connecting the Q235 carbon steel sheet (20mm×40mm×1mm) with the copper wire, and sealing the remaining surfaces with epoxy resin except for one side exposed to the air; then polishing the steel sheet sample using sandpaper with a particle size of 320, 600, and 800, respectively, using DI water for preliminary washing, and then ultrasonically in a 50% acetone solution to remove surface oil and impurities; subsequently, immersing it in an aqueous solution containing 1wt% KH550, 8wt% DI water and 91%wt ethanol, and finally rinsing it with ethanol and drying it in air.

[0025] The second aspect of the present invention is to provide SH / PDA-Ti3C2T obtained by the above preparation method. x MXene / epoxy composite coating.

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

[0027] (1) The present invention first uses γ-aminopropyltriethoxysilane, trimethoxy (1H, 1H, 2H, 2H-heptafluorodecyl) silane, and sodium hydroxide aqueous solution as raw materials to prepare a fluorine-containing prepolymer; then uses LiF and Ti3AlC2 as raw materials to prepare a single-layer Ti3C2T x MXene nanosheets; then fluorinated prepolymer, single-layer Ti3C2T x A surface hydrophobic functionalized MXene nanosheet, SH / PDA-MXene nanosheet, was designed using MXene nanosheets, DA-HCl, and n-dodecyl mercaptan as raw materials. The designed SH / PDA-MXene nanosheet was then blended with epoxy resin to prepare SH / PDA-Ti3C2T3 with good photothermal and anti-corrosion properties by spray coating. x MXene / epoxy resin composite coating. Among them, dopamine is in situ polymerized on the surface of MXene nanosheets, which effectively improves the chemical stability of MXene nanosheets and provides a large number of reaction sites. At the same time, polydopamine and n-dodecyl mercaptan are successfully linked through Michael addition and other reactions, which greatly reduces the surface energy of MXene nanosheets and transforms MXene from a superhydrophilic material (CA=0°) to a hydrophobic material (CA=95.8°). The prepared coating has excellent photothermal effect and superhydrophobicity, which significantly improves the corrosion resistance of the epoxy resin coating. After being immersed in 3.5% NaCl solution for a long time (60 days), the SPMFAE coating can still maintain a high anti-corrosion performance; in addition, the superhydrophobicity of the coating after being immersed in 3.5% NaCl solution for a long time (60 days) is quickly restored under 2.80Sun, and the anti-corrosion performance of the coating is also greatly improved. This is due to the SH / PDA-Ti3C2T x The excellent photothermal effect of MXene materials allows the damaged coating to heat up rapidly under sunlight, thereby promoting the self-repair of the damaged area. x MXene / epoxy resin anti-corrosion composite coating has excellent photothermal properties, anti-corrosion properties, superhydrophobic properties and mechanical self-healing properties, and has broad application prospects in the fields of wings, wind turbine blades, high-speed train shells, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1Ti3C2T prepared in Example 1 x 、PDA-Ti3C2T x Fourier transform infrared spectra of MXene and SH / PDA-MXene nanosheets;

[0030] Figure 2 Ti3C2T prepared in Example 1 x 、PDA-Ti3C2T x X-ray photoelectron spectra of MXene and SH / PDA-MXene nanosheets;

[0031] Figure 3 Scanning electron microscopy images of various materials: (a) Ti3AlC2; (b) multilayer Ti3C2T x MXene; (c) single-layer Ti3C2T x MXene nanosheets; (g)-(i) are SH / PDA-MXene nanosheets;

[0032] Figure 4 Ti3C2T x and X-ray diffraction patterns of SH / PDA-MXene nanosheets;

[0033] Figure 5 For single-layer Ti3C2T x Atomic force scanning electron microscopy image of MXene nanosheets;

[0034] Figure 6 Cross-sectional SEM images of epoxy resin (EP) coating and composite coating obtained in Examples 1-3: (a) epoxy resin (EP); (b) SPMFAE 0.5％ ; (c)SPMFAE 1.0％ ; (d)SPMFAE 2.0％ ;

[0035] Figure 7 The water contact angle changes: (a) single layer Ti3C2T x MXene nanosheets; (b) SH / PDA-MXene nanosheets;

[0036] Figure 8 Polarization curves of bare Q235 board, EP, SPMFAE0.5%, SPMFAE1.0%, SPMFAE2.0% and W-SPMFAE2.0% coatings after immersion in 3.5wt% NaCl solution for 24h;

[0037] Figure 9 This is the relationship between the time and temperature of the SPMFAE coating under xenon lamp irradiation;

[0038] Figure 10Infrared thermal images of SPMFAE coating at various stages;

[0039] Figure 11 Epoxy resin (EP) coating and SH / PDA-Ti3C2T x Anti-corrosion performance test results of MXene / epoxy resin composite coating;

[0040] Figure 12 For single-layer Ti3C2T x MXene nanosheets (a) and SH / PDA-Ti3C2T x Schematic diagram of the synthesis route of MXene (b). DETAILED DESCRIPTION

[0041] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may also be implemented in other embodiments without these specific details.

[0042] Example 1

[0043] Reference Figure 12 , a superhydrophobic self-repairing SH / PDA-Ti3C2T x The preparation method of MXene / epoxy resin anti-corrosion composite coating includes the following specific steps:

[0044] (1) Pretreatment of Q235 carbon steel: Q235 carbon steel (20mm×40mm×1mm) was used as the substrate, and the steel sheet was connected to the copper wire. Except for one side exposed to the air, the other sides were sealed with epoxy resin. The steel sheet samples were then polished using sandpaper with a grit of 320, 600, and 800, respectively. They were initially washed with DI water, and then ultrasonically treated in a 50% acetone solution for 1 hour to remove surface oil and impurities. Subsequently, they were immersed in an aqueous solution containing 1wt% KH550, 8wt% DI water, and 91%wt ethanol for 2 hours, and finally rinsed three times with ethanol and dried in air.

[0045] (2) Preparation of fluorinated prepolymer (FCP): 11.065 g of γ-aminopropyltriethoxysilane was placed in a flask containing 20 g of ethanol and stirred at room temperature for 30 min. Then, 5.683 g of trimethoxy(1H,1H,2H,2H-heptafluorodecyl)silane and 1.5 g (3 g / L) of sodium hydroxide aqueous solution were quickly added in sequence. After installing a reflux condenser, the mixture was stirred at 80°C for 8 h. After the reaction was completed, the reflux condenser was removed and the solvent was evaporated using a rotary evaporator to obtain a viscous and transparent fluorinated prepolymer (FCP);

[0046] (3) Preparation of single-layer Ti3C2T xMXene nanosheets, denoted as Ti3C2T x MXene: 3.2 g of LiF was dissolved in a polytetrafluoroethylene reactor containing 40 mL of 9 M HCl and stirred for 10 min until completely dissolved. Then, 2 g of 200 mesh Ti3C2T x The powder was stirred and etched at 40 ° C for 48 h. After the reaction was completed, the etching solution was washed by 1M HCl solution for 2-3 times (3500 rpm, 1 min), and then washed by centrifugation for multiple times (3500 rpm, 1 min) until the precipitate showed obvious swelling and the upper liquid was dark green, thus obtaining multilayer Ti3C2T x MXene (referred to as multilayer Ti3C2T x ), ultrasonicated in an ice-water bath for 30 min under an Ar atmosphere; finally, the upper liquid was freeze-dried by centrifugation (5500 rpm, 10 min) to obtain a single-layer Ti3C2T x MXene nanosheets;

[0047] (4) Preparation of SH / PDA-Ti3C2T x MXene, recorded as SH / PDA-MXene nanosheets: Weigh 1.0 g of freeze-dried single-layer Ti3C2T x MXene nanosheets were dispersed in 500 mL of Tris-HCl buffer (15 mM, pH ≥ 8.5); then, 1.0 g of DA-HCl was quickly added and stirred, and ultrasonic treatment was performed in an ice-water bath for 10 min; after the ultrasonic treatment, the resulting homogeneous solution was exposed to the air and stirred at 60 ° C and 550 rpm for 8 h to obtain PDA-Ti3C2T x MXene (abbreviated as PDA-Ti3C2T x ); Subsequently, 0.6 mL of n-dodecanethiol was slowly added and the reaction was continued for 6 h. After the reaction was completed, the reaction product was repeatedly washed with DI water and centrifuged (6000 rpm, 1 min), and finally freeze-dried to a constant weight to obtain SH / PDA-MXene nanosheets;

[0048] (5) Preparation of SH / PDA-Ti3C2T xMXene / epoxy resin composite coating: 0.05g SH / PDA-MXene nanosheets were dispersed in 5mL anhydrous ethanol and ultrasonically dispersed for 1h. Subsequently, 1g FCP, 1g APD, and 3g epoxy resin were mixed and added to the above dispersion. The dispersion was homogenized by stirring and then sprayed onto the pretreated substrate through a sprayer. 0.50g SH / PDA-MXene nanosheets, 0.03g APD, 0.05g FCP, and 0.1g epoxy resin were blended in 10mL ethanol and ultrasonically dispersed uniformly. The mixture was then sprayed onto the surface of the semi-cured coating to form a rough interface and cured to obtain SH / PDA-Ti3C2T x MXene / epoxy resin anti-corrosion composite coating (denoted as SPMFAE 1.0％ ).

[0049] Example 2

[0050] A superhydrophobic self-repairing SH / PDA-Ti3C2T x The preparation method of the MXene / epoxy resin anti-corrosion composite coating comprises the following steps:

[0051] (1) Pretreatment of Q235 carbon steel: same as in Example 1;

[0052] (2) Preparation of fluorinated prepolymer (FCP): 11.065 g of γ-aminopropyltriethoxysilane was placed in a flask containing 20 g of ethanol and stirred at room temperature for 30 min. Then, 5.683 g of trimethoxy(1H,1H,2H,2H-heptafluorodecyl)silane and 1.5 g (3 g / L) of sodium hydroxide aqueous solution were quickly added in sequence. After installing a reflux condenser, the mixture was stirred at 80°C for 8 h. After the reaction was completed, the reflux condenser was removed and the solvent was evaporated using a rotary evaporator to obtain viscous and transparent FCP.

[0053] (3) Preparation of single-layer Ti3C2T x MXene nanosheets: 3.2 g of LiF was completely dissolved in a polytetrafluoroethylene reactor containing 40 mL of 9 M HCl and stirred for 10 min. Then, 2 g of 200 mesh Ti3AlC2 powder was slowly added to the above solution and etched at 40 ° C for 48 h. After the reaction, the etched solution was acid-washed and centrifuged (3500 rpm) with 1 M HCl solution 2-3 times, and then washed with water by multiple centrifugation (3500 rpm, 1 min) until the precipitate showed obvious swelling and the upper liquid was dark green, obtaining multilayer Ti3C2T x MXene (referred to as multilayer Ti3C2T x ); ultrasonication in an ice-water bath for 30 min under an Ar atmosphere; finally, the upper layer of liquid was freeze-dried by centrifugation (5500 rpm, 10 min) to obtain a single-layer Ti3C2Tx MXene nanosheets;

[0054] (4) Preparation of SH / PDA-MXene nanosheets: Weigh 1.0 g of freeze-dried single-layer Ti3C2T x MXene nanosheets were dispersed in 500 mL of Tris-HCl (15 mM, pH ≥ 8.5) buffer solution; then, 1.0 g of DA-HCl was quickly added and stirred, and ultrasonic treatment was performed in an ice-water bath for 10 min. After the ultrasonic treatment, the obtained homogeneous solution was exposed to the air and stirred at 60 ° C and 550 rpm for 8 h to obtain PDA-Ti3C2T x MXene; then, n-dodecanethiol (0.6 mL) was slowly added and the reaction was continued for 6 h. After the reaction was completed, the reaction product was repeatedly washed with DI water and centrifuged (6000 rpm, 1 min); finally, it was freeze-dried to a constant weight to obtain SH / PDA-MXene nanosheets;

[0055] (5) Preparation of SH / PDA-Ti3C2T x MXene / epoxy resin composite coating: 0.025g SH / PDA-MXene nanosheets were dispersed in 5mL of anhydrous ethanol and ultrasonically dispersed for 1h. Subsequently, 1g FCP, 1g APD, and 3g epoxy resin were mixed and added to the above dispersion; the dispersion was homogenized by stirring and then sprayed onto the pretreated substrate through a sprayer; 0.50g SH / PDA-MXene nanosheets, 0.03g APD, 0.05g FCP, and 0.1g epoxy resin were blended in 10mL of ethanol, ultrasonically dispersed, and sprayed onto the surface of the semi-cured coating to form a rough interface and completely cured to obtain SH / PDA-Ti3C2T x MXene / epoxy resin composite coating (denoted as SPMFAE 0.5％ ).

[0056] Example 3

[0057] A superhydrophobic self-repairing SH / PDA-Ti3C2T x The preparation method of the MXene / epoxy resin anti-corrosion composite coating specifically comprises the following steps:

[0058] (1) Pretreatment of Q235 carbon steel: same as in Example 1;

[0059] (2) Preparation of fluorinated prepolymer (FCP): 11.065 g of γ-aminopropyltriethoxysilane was placed in a flask containing 20 g of ethanol and stirred at room temperature for 30 min. Then, 5.683 g of trimethoxy(1H,1H,2H,2H-heptafluorodecyl)silane and 1.5 g (3 g / L) of sodium hydroxide aqueous solution were quickly added in sequence. After installing a reflux condenser, the mixture was stirred at 80°C for 8 h. After the reaction was completed, the reflux condenser was removed and the solvent was evaporated using a rotary evaporator to obtain a viscous, transparent FCP.

[0060] (3) Preparation of single-layer Ti3C2T x MXene nanosheets: 3.2g LiF was completely dissolved in a polytetrafluoroethylene reactor containing 40mL 9M HCl and stirred for 10min. Then, 2g 200 mesh Ti3AlC2 powder was slowly added to the above solution and etched at 40°C for 48h with continuous stirring. After the reaction, the etching solution was acid-washed and centrifuged 2-3 times with 1M HCl solution (3500rmp, 1min). It was then washed with water by multiple centrifugation (3500rmp, 1min) until the precipitate showed obvious swelling and the upper liquid was dark green. It was ultrasonicated in an ice-water bath under Ar atmosphere for 30min; finally, the upper liquid was freeze-dried by centrifugation (5500rmp, 10min) to obtain a single layer of Ti3C2T x MXene nanosheets;

[0061] (4) Preparation of SH / PDA-MXene nanosheets: Weigh 1.0 g of freeze-dried single-layer Ti3C2T x MXene nanosheets were dispersed in 500 mL of Tris-HCl (15 mM, pH ≥ 8.5) buffer solution; then, 1.0 g of DA-HCl was quickly added and stirred, and ultrasonic treatment was performed in an ice-water bath for 10 min. After the ultrasonic treatment, the obtained homogeneous solution was exposed to the air and stirred at 60 ° C and 550 rpm for 8 h to obtain PDA-Ti3C2T x MXene; Subsequently, n-dodecanethiol (0.6 mL) was slowly added and the reaction was continued for 6 h. After the reaction was completed, the reaction product was repeatedly washed with DI water and centrifuged (6000 rpm, 1 min); finally, it was freeze-dried to a constant weight to obtain SH / PDA-MXene nanosheets;

[0062] (5) Preparation of SH / PDA-Ti3C2T xMXene / epoxy resin composite coating: 0.075g SH / PDA-MXene nanosheets were dispersed in 5mL of anhydrous ethanol and ultrasonically dispersed for 1h. Subsequently, 1g of fluorinated prepolymer (FCP), 1g of 2,2'diaminodiphenyl disulfide (APD), and 3g of epoxy resin were mixed and added to the above dispersion. The dispersion was homogenized by stirring and then sprayed onto the pretreated substrate through a sprayer; 0.50g of SH / PDA-MXene nanosheets, 0.03g of APD, 0.05g of FCP, and 0.1g of epoxy resin were blended in 10mL of ethanol and ultrasonically dispersed uniformly. The mixture was then sprayed onto the surface of the semi-cured coating to form a rough interface and completely cured to obtain SH / PDA-Ti3C2T x MXene / epoxy composite coating (SPMFAE 1.5％ ).

[0063] Example 4

[0064] A superhydrophobic self-repairing SH / PDA-Ti3C2T x The preparation method of the MXene / epoxy resin anti-corrosion composite coating specifically comprises the following steps:

[0065] (1) Pretreatment of Q235 carbon steel: same as in Example 1;

[0066] (2) Preparation of fluorinated prepolymer (FCP): 11.065 g of γ-aminopropyltriethoxysilane was placed in a flask containing 20 g of ethanol and stirred at room temperature for 30 min. Then, 5.683 g of trimethoxy(1H,1H,2H,2H-heptafluorodecyl)silane and 1.5 g (3 g / L) of sodium hydroxide aqueous solution were quickly added in sequence. After installing a reflux condenser, the mixture was stirred at 80°C for 8 h. After the reaction was completed, the reflux condenser was removed and the solvent was evaporated using a rotary evaporator to obtain viscous and transparent FCP.

[0067] (3) Preparation of single-layer Ti3C2T x MXene nanosheets: 3.2g LiF was completely dissolved in a polytetrafluoroethylene reactor containing 40mL 9M HCl and stirred for 10min. Then, 2g 200-mesh Ti3AlC2 powder was slowly added to the above solution and etched at 40°C for 48h. After the reaction, the etched solution was acid-washed and centrifuged 2-3 times with 1M HCl solution (3500rmp, 1min); then, it was washed with water by centrifugation multiple times (3500rmp, 1min) until the precipitate showed obvious swelling and the upper liquid was dark green. It was ultrasonicated in an ice-water bath under Ar atmosphere for 30min. Finally, the upper liquid was freeze-dried by centrifugation (5500rmp, 10min) to obtain a single layer of Ti3C2T x MXene nanosheets;

[0068] (4) Preparation of SH / PDA-MXene nanosheets: Weigh 1.0 g of freeze-dried single-layer Ti3C2T x MXene nanosheets were dispersed in 500 mL of Tris-HCl (15 mM, pH ≥ 8.5) buffer solution. Then, 1.0 g of DA-HCl was quickly added and stirred, followed by ultrasonic treatment in an ice-water bath for 10 min. After ultrasonication, the resulting homogeneous solution was exposed to air and stirred at 550 rpm at 60°C for 8 h to obtain PDA-Ti3C2T x MXene; Subsequently, n-dodecanethiol (0.6 mL) was slowly added and the reaction was continued for 6 h. After the reaction was completed, the reaction product was repeatedly washed with DI water and centrifuged (6000 rpm, 1 min). Finally, it was freeze-dried to a constant weight to obtain SH / PDA-MXene nanosheets;

[0069] (5) Preparation of SH / PDA-Ti3C2T x MXene / epoxy resin composite coating: 0.10g SH / PDA-Ti3C2T x MXene nanosheets were dispersed in 5 mL of anhydrous ethanol and ultrasonically dispersed for 1 h. Subsequently, 1 g of FCP, 1 g of APD, and 3 g of IPO epoxy resin were mixed and added to the dispersion. The dispersion was homogenized by stirring and then sprayed onto the pretreated substrate using a sprayer. 0.50 g of SH / PDA-Ti3C2T x MXene, 0.03 g APD, 0.05 g FCP and 0.1 g epoxy resin were blended in 10 mL ethanol and ultrasonically dispersed uniformly. The mixture was then sprayed onto the surface of the semi-cured coating to form a rough interface and completely cured to obtain SH / PDA-Ti3C2T x MXene / epoxy composite coating (SPMFAE 2.0％ ).

[0070] Example 5

[0071] A superhydrophobic self-repairing SH / PDA-Ti3C2T x The preparation method of the MXene / epoxy resin anti-corrosion composite coating comprises the following steps:

[0072] (1) Pretreatment of Q235 carbon steel: same as in Example 1;

[0073] (2) Preparation of fluorinated prepolymer (FCP): 11.065 g of γ-aminopropyltriethoxysilane was placed in a flask containing 20 g of ethanol and stirred at room temperature for 30 min. Then, 5.683 g of trimethoxy(1H,1H,2H,2H-heptafluorodecyl)silane and 1.5 g (3 g / L) of sodium hydroxide aqueous solution were quickly added in sequence. After installing a reflux condenser, the mixture was stirred at 80°C for 8 h. After the reaction was completed, the reflux condenser was removed and the solvent was evaporated using a rotary evaporator to obtain a viscous and transparent FCP.

[0074] (3) Preparation of single-layer Ti3C2T x MXene nanosheets: 3.2g LiF was completely dissolved in a polytetrafluoroethylene reactor containing 40mL 9M HCl and stirred for 10min. Then, 2g 200 mesh Ti3AlC2 powder was slowly added to the above solution and etched at 40°C for 48h. After the reaction, the etching solution was centrifuged 2-3 times with 1M HCl solution (3500rmp, 1min), followed by multiple centrifugal washings (3500rmp, 1min) until the precipitate showed obvious swelling and the upper liquid was dark green. It was ultrasonicated in an ice-water bath under an Ar atmosphere for 30min. Finally, the upper liquid was freeze-dried by centrifugation (5500rmp, 10min) to obtain a single layer of Ti3C2T x MXene nanosheets;

[0075] (4) Preparation of SH / PDA-MXene nanosheets: Weigh 1.0 g of freeze-dried single-layer Ti3C2T x MXene nanosheets were dispersed in 500 mL of Tris-HCl (15 mM, pH ≥ 8.5) buffer solution. Then, 1.0 g of DA-HCl was quickly added and stirred. The mixture was ultrasonically treated for 10 min in an ice-water bath. After the ultrasonic treatment, the resulting homogeneous solution was exposed to the air and stirred at 60 ° C for 8 h at a speed of 550 rpm to obtain PDA-Ti3C2T x MXene; Subsequently, n-dodecanethiol (0.6 mL) was slowly added and the reaction was continued for 6 h. After the reaction was completed, the reaction product was repeatedly washed with DI water and centrifuged (6000 rpm, 1 min). Finally, it was freeze-dried to a constant weight to obtain SH / PDA-MXene nanosheets;

[0076] (5) Preparation of SH / PDA-Ti3C2T xMXene / epoxy resin composite coating: 0.15g SH / PDA-MXene nanosheets were dispersed in 5mL of anhydrous ethanol and ultrasonically dispersed for 1h. Subsequently, 1g FCP, 1g APD, and 3g epoxy resin were mixed and added to the above dispersion. The dispersion was homogenized by stirring and then sprayed onto the pretreated substrate through a sprayer. 0.50g SH / PDA-MXene nanosheets, 0.03g APD, 0.05g FCP, and 0.1g epoxy resin were blended in 10mL of ethanol and ultrasonically dispersed uniformly, and sprayed onto the surface of the semi-cured coating to form a rough interface and completely cured to obtain SH / PDA-Ti3C2T x MXene / epoxy composite coating (SPMFAE 3.0％ ).

[0077] Comparative Example 1

[0078] (1) Pretreatment of Q235 carbon steel: same as in Example 1.

[0079] (2) Preparation of fluorinated prepolymer (FCP): First, 11.065 g of γ-aminopropyltriethoxysilane was placed in a flask containing 20 g of ethanol and stirred at room temperature for 30 min. Then, 5.683 g of trimethoxy(1H,1H,2H,2H-heptafluorodecyl)silane and 1.5 g (3 g / L) of sodium hydroxide aqueous solution were quickly added in sequence. After installing a reflux condenser, the mixture was stirred at 80°C for 8 h. After the reaction was completed, the reflux condenser was removed and the solvent was evaporated using a rotary evaporator to obtain a viscous, transparent FCP.

[0080] (3) Preparation of Ti3C2T x MXene nanosheets: 3.2g LiF was completely dissolved in a polytetrafluoroethylene reactor containing 40mL9M HCl and stirred for 10min. Then, 2g 200 mesh Ti3AlC2 nanosheets were slowly added to the above solution and etched at 40°C for 48h. After the reaction, the etching solution was acid-washed and centrifuged 2-3 times with 1M HCl solution (3500rmp, 1min). It was then washed with water by multiple centrifugations (3500rmp, 1min) until the precipitate showed obvious swelling and the upper liquid was dark green. It was ultrasonicated in an ice-water bath for 30min (80Hz) under an Ar atmosphere. Finally, the upper liquid was taken by centrifugation (5500rmp, 10min) and freeze-dried to obtain a single-layer Ti3C2T x MXene nanosheets.

[0081] (4) Preparation of SH / PDA-MXene nanosheets: 1.0 g of freeze-dried single-layer MXene nanosheets was weighed and dispersed into 500 mL of Tris-HCl (15 mM, pH ≥ 8.5) buffer solution. Then, 1.0 g of DA-HCl was quickly added and stirred, and ultrasonic treatment was performed in an ice-water bath for 10 min. After the ultrasonic treatment, the obtained homogeneous solution was exposed to the air and stirred at 550 rpm at 60 ° C for 8 h to obtain PDA-Ti3C2T x MXene; then, n-dodecanethiol (0.6 mL) was slowly added and the reaction was continued for 6 h. After the reaction was completed, the reaction product was repeatedly washed with DI water and centrifuged (6000 rpm, 1 min).

[0082] (5) Preparation of SH / PDA-Ti3C2T x MXene epoxy resin composite coating: 0.10g SH / PDA-MXene nanosheets were dispersed in 5mL anhydrous ethanol and ultrasonically dispersed for 1h. Subsequently, 1g FCP, 1g APD, and 3g epoxy resin were mixed and added to the above dispersion. The dispersion was homogenized by stirring and then sprayed onto the pretreated substrate using a sprayer to obtain a fully cured hydrophobically modified MXene-epoxy resin composite coating (W-SPMFAE) without a rough interface. 2.0％ ).

[0083] Fourier transform infrared spectrometer (Nicolet 6700 FT-IR) was used to analyze the Ti3C2T x , single-layer Ti3C2T x MXene nanosheets and SH / PDA-MXene nanosheets were characterized, and the results are shown in Figure 1-6 .

[0084] Figure 1 shows Ti3C2T x MXene, PDA-Ti3C2T x MXene and SH / PDA-Ti3C2T x FT-IR spectrum analysis curve of MXene. Figure 1 The results showed that 3433cm -1 The broad absorption peak at is a typical hydroxyl absorption peak, Ti3C2T x and SH / PDA-Ti3C2T x The surface of MXene is rich in hydroxyl groups. x The presence of surface hydroxyl groups is beneficial to subsequent surface modification. x In the infrared absorption spectrum, at 2925cm -1 and 2853cm -1There are two inconspicuous absorption peaks, which are caused by the symmetric stretching vibration and asymmetric stretching vibration of the C-H bond. In addition, SH / PDA-Ti3C2T x In the infrared spectrum of MXene, there are two obvious infrared absorption peaks at this position, and the absorption frequency shifts to high wavenumbers and becomes sharp, indicating that it contains a large number of alkyl chains, which may come from n-dodecyl mercaptan. x Curves of MXene and SH / PDA-Ti3C2T x The curve of MXene is at 1603 cm -1 and 1250cm -1 There are peaks on the left and right, which are caused by the stretching vibration of CO bond and phenolic hydroxyl or aromatic benzene ring, indicating that dopamine has been successfully introduced into Ti3C2T x In addition, SH / PDA-Ti3C2T x The curve of MXene is at 1075 cm -1 A sharp and obvious infrared absorption peak appears, which is caused by the stretching vibration of the CSC bond, further demonstrating that n-dodecanethiol has been successfully introduced into the polydopamine system.

[0085] Figure 2 shows Ti3C2T x MXene, PDA-Ti3C2T x MXene and SH / PDA-Ti3C2T x XPS wide scan of MXene, Figure 2 The results show that SH / PDA-Ti3C2T x The S2p peak appeared in MXene, and the C1s peak was significantly enhanced, proving the successful grafting of dopamine and n-dodecyl mercaptan.

[0086] Figure 3 Shows the unetched multilayer Ti3C2T x MXene, ultrasonically treated single-layer Ti3C2T x MXene and SH / PDA-Ti3C2T x Scanning electron microscope image of MXene. Figure 3 (a) shows the unetched Ti3C2T x The morphology shows a bulk structure without etching. The accordion structure can be observed from the SEM results ( Figure 3 (b)) and lamellar structures ( Figure 3 (c)). Figure 3 (c) The laser pen irradiation experiment shows that the laser forms a stable light path in the solution, which indirectly proves that Ti3C2T xExfoliation of MXene nanosheets. Figure 3 (gi) shows SH / PDA-Ti3C2T modified with dopamine and n-dodecyl mercaptan. x SEM results of MXene, compared with Ti3C2T x Smooth surface of MXene nanosheets, SH / PDA-Ti3C2T x The surface of MXene nanosheets has a distinct granular structure, which is caused by the in situ self-polymerization of dopamine on its surface to form polydopamine.

[0087] Depend on Figure 4-6 The results show that single-layer Ti3C2T x MXene nanosheets, SH / PDA-Ti3C2T x MXene nanosheets and SH / PDA-Ti3C2T x MXene / epoxy resin composite coating was successfully synthesized. In summary, the present invention successfully prepared SH / PDA-Ti3C2T x MXene / epoxy composite coating.

[0088] Performance testing

[0089] Figure 7 a and Figure 7 b shows Ti3C2T x The results of water drop contact test of MXene and SH / PDA-MXene nanosheets. It is not difficult to find that Ti3C2T x The water contact angle of MXene decreases rapidly ( Figure 7 a). At 0.06s, Ti3C2T x The water contact angle of MXene is 35.4°, and after 18 seconds, the water droplet completely wets the surface (Video S1). In contrast, SH / PDA-MXene has a lower surface energy, and after a period of infiltration, the contact angle remains stable at 95.8° ( Figure 7 b). This indirectly proves that Ti3C2T x The hydrophobic modification of MXene surface was successful.

[0090] Figure 8 The dynamic polarization curves of bare Q235 board, EP, SPMFAE0.5%, SPMFAE1.0%, SPMFAE2.0% and W-SPMFAE2.0% coatings after immersion in 3.5wt% NaCl solution for 24h are shown. The polarization curve results show that the i corr It is nearly two orders of magnitude higher than that of EP coating, which are 2.16×10 -5 A.cm -2and 7.57×10 -11 A.cm -2 . And the R of Bare sample p It is also five orders of magnitude lower than that of EP coating, which are 1.80KΩ·cm 2 and 4.58×10 5 KΩ·cm 2 . It shows that epoxy resin has a good protective effect on metal. 2.0% SH / PDA-Ti3C2T is doped in epoxy resin. x After MXene materials, W-SPMFAE 2.0％ Coating i corr (3.17×10 -13 A.cm -2 ) and v corr (3.69×10 -8 mm·y -1 ) is about two orders of magnitude lower than that of EP coating, R p This is because the filler builds a multi-layer barrier system in the epoxy resin coating, which blocks the path of the corrosive medium that should have diffused evenly in the coating, resulting in a longer diffusion path and time for the corrosive medium in the coating, and even makes it difficult to penetrate the metal surface. 2.0％ Compared with the coating, SPMFAE 2.0％ Coating E corr To be 240.14mV higher, i corr (6.17×10 -13 A.cm -2 ) and v corr (7.18×10 -8 mm·y -1 ) is also nearly half as low. At the same time, the polarization resistance R p Increased to 2.26×10 8 KΩ·cm 2 These results are consistent with Figure 5 Elements (Cl - and Na + ) distributions support each other, indicating that the super-hydrophobic surface structure can effectively prevent the penetration and damage of the corrosive medium to the coating surface, thereby improving the corrosion resistance of the coating. x The effect of MXene filler content on the anti-corrosion performance of the coating was compared with SPMFAE 0.5％ 、SPMFAE 1.0％ and SPMFAE 2.0％ It is not difficult to find that with the SH / PDA-Ti3C2T x The proportion of MXene filler in the coating increases, and its E corrMore and more positive, R p The value is getting higher and higher, i corr and v corr These results all indicate that the increase of coating fillers can improve the corrosion resistance of the coating to a certain extent. The Tafel polarization curve results show that after 24 hours of immersion, SPMFAE 2.0％ The coating has the best corrosion resistance.

[0091] Figure 9 The relationship between the time and temperature of SPMFAE coating under xenon lamp irradiation is shown. x The photothermal effect of the SPMFAE coating of MXene material was studied by controlling the current with 280mW / cm 2 The photothermal properties of the SPMFAE superhydrophobic coating were studied by irradiating it with a 2.80 sun xenon lamp to simulate sunlight. From 0 to 60 seconds, the coating's average temperature rise rate reached approximately 0.7°C / s under 2.80 sun xenon lamp illumination. Over time, the temperature rise gradually slowed. However, after 300 seconds of illumination, the coating still reached a maximum temperature of 106.4°C (from an initial temperature of 22.8°C).

[0092] Figure 10 The infrared thermal images of the SPMFAE coating under different irradiation stages are shown. It is not difficult to find that the overall temperature rise trend of the coating is from the middle to the surrounding area. After 300s of irradiation, the temperature of the coating tends to be consistent. This further shows that the SPMFAE coating has a significant photothermal effect and proves that the SH / PDA-Ti3C2T x MXene materials play an important role in the photothermal effect of coatings.

[0093] Figure 11 The EIS curves and equivalent circuit simulation diagrams of EP, SPMFAE0.5%, SPMFAE1.0%, SPMFAE2.0% and W-SPMFAE2.0% immersed in 3.5wt% NaCl solution for 60 days are described. Generally speaking, a large diameter of the semicircular impedance arc can indicate excellent barrier performance. Figure 11 aThe results show that SPMFAE 2.0％ The Nyquist curve of the coating is semicircular, and the diameter of the impedance arc is significantly larger than that of other coatings, indicating that the SPMFAE 2.0％ The coating has the highest corrosion resistance. At the same time, EP, SPMFAE 0.5％ and W-SPMFAE 2.0％ The coatings all showed a second time constant in the low frequency region, indicating that EP, SPMFAE 0.5％ and W-SPMFAE2.0％ The coating no longer has good barrier properties, and the corrosive medium has penetrated into the substrate through defects such as micropores, causing corrosion. Figure 11 As shown in b, all coatings are steep in the high-frequency region and become gentle in the low-frequency region, and SPMFAE 2.0％ The value of the coating is significantly higher than that of other coatings, indicating that it has better long-term anti-corrosion performance in 3.5wt% NaCl solution. Figure 11 c The results show that compared with other coatings, SPMFAE 2.0％ The coating shows the largest phase angle, indicating that the SPMFAE 2.0％ The coating has the best dielectric properties. To further analyze the corrosion mechanism of each coating, two equivalent circuit models (ECM) were used to simulate EP and SPMFAE. 0.5％ 、SPMFAE 1.0％ 、SPMFAE 2.0％ and W-SPMFAE 2.0％ Corrosion circuit diagram of the coating. In this model, R s is the solution resistance, R a is the air layer resistance, Q a is the constant phase of the air layer, Q a is the constant phase of the air layer; R c is the resistance of the coating; Q c is the constant phase of the coating; R ct and Q dl They represent the resistance and double layer constant phase generated by charge transfer, respectively. Their values ​​are related to the diffusion reaction between the organic layer and the metal interface. The significance of the constant phase Q is that when the electrode surface is uneven and causes dispersion, capacitance is used instead to compensate for the deviation from the ideal capacitance behavior. The smaller the value, the better the anti-corrosion performance. When the constant phase index n = 1, the constant phase corresponds to an ideal capacitor. When the constant phase index n = 0, the constant phase is equivalent to an ideal resistor. Figure 11 ECM analysis of EP and W-SPMFAE shown in D1 2.0％ The EIS data of the coating after exposure to 3.5wt% NaCl solution for 60 days shows the same curve characteristics as Figure 11 The curve characteristics in a correspond to each other. In addition, using Figure 11 The model in d2 explains SPMFAE in more detail 0.5％ 、SPMFAE 1.0％ and SPMFAE 2.0％ The anti-corrosion principle of the coating. The results show that the SPMFAE coating with superhydrophobicity is better than the EP coating and the W-SPMFAE without superhydrophobicity. 2.0％ The coating has better anti-corrosion performance. The improvement of corrosion resistance can be attributed to two aspects. On the one hand, SH / PDA-Ti3C2Tx MXene nanosheets form a hierarchical structure within the coating, providing a strong barrier. Furthermore, the super-hydrophobic surface's micron-nanostructure traps air, forming a stable air layer on the coating's surface, effectively preventing the penetration of corrosive media.

[0094] The present invention effectively improves the chemical stability of MXene nanosheets and provides a large number of reaction sites by in-situ polymerization of dopamine on the surface of MXene nanosheets. At the same time, polydopamine and n-dodecyl mercaptan are successfully linked through reactions such as Michael addition, which greatly reduces the surface energy of MXene nanosheets and transforms MXene from a superhydrophilic material (CA=0°) to a hydrophobic material (CA=95.8°). The prepared coating has excellent photothermal effect and superhydrophobicity, significantly improving the corrosion resistance of the epoxy resin coating. After 60 days of immersion in 3.5% NaCl solution, the SPMFAE coating still maintains a high anti-corrosion performance. In particular, SH / PDA-Ti3C2T x The optimal doping level of MXene nanosheets for enhancing the long-term corrosion resistance of epoxy resin coatings is approximately 1.0 wt%. Furthermore, the superhydrophobicity of the coating recovered rapidly at 2.80 Sun after immersion in 3.5% NaCl solution for 60 days. Simultaneously, the anti-corrosion performance of the coating also improved significantly. This is due to the SH / PDA-Ti3C2T x The excellent photothermal effect of MXene materials allows damaged coatings to rapidly heat up under sunlight, promoting self-repair of damaged areas. In summary, the epoxy resin composite coating prepared by this invention exhibits excellent photothermal, corrosion-resistant, superhydrophobic, and mechanical self-repairing properties.

[0095] The present invention is not limited to the above-mentioned specific implementation methods. Various changes made by ordinary technicians in this field based on the above-mentioned concept without creative work are all within the scope of protection of the present invention.

Claims

1. A superhydrophobic self-repairing SH / PDA-Ti3C2T x The preparation method of MXene / epoxy resin anti-corrosion composite coating is characterized in that: The following steps are involved: S1. Preparing a fluorine-containing prepolymer: dispersing γ-aminopropyltriethoxysilane in ethanol to obtain an ethanol solution of γ-aminopropyltriethoxysilane, then adding trimethoxy(1H,1H,2H,2H-heptafluorodecyl)silane and an aqueous sodium hydroxide solution, stirring and reacting to obtain a fluorine-containing prepolymer; S2. Preparation of single-layer Ti3C2T x MXene nanosheets: LiF was dissolved in HCl, and then Ti3AlC2 was added for etching reaction and purification to obtain a single layer of Ti3C2T x MXene nanosheets; S3. Preparation of SH / PDA-MXene nanosheets: Monolayer Ti3C2T x MXene nanosheets were dispersed in a Tris-HCl buffer solution, and then DA-HCl was added. The mixture was first ultrasonically treated in an ice-water bath and then stirred at 50-60°C for reaction. n-Dodecyl mercaptan was then added and the reaction was continued. After purification, SH / PDA-MXene nanosheets were obtained. The single-layer Ti3C2T x The ratio of MXene nanosheets, Tris-HCl buffer solution, DA-HCl, and n-dodecanethiol is 0.6-1.2 g:500 mL:1.0 g:0.2-0.8 mL; S4. Preparation of SH / PDA-Ti3C2T x MXene / epoxy resin composite coating: SH / PDA-MXene nanosheets were ultrasonically dispersed in anhydrous ethanol, and then fluorinated prepolymer, 2,2' diaminodiphenyl disulfide and epoxy resin were added and stirred evenly to obtain a first dispersion. The first dispersion was then sprayed onto the pretreated substrate to obtain a semi-cured coating. SH / PDA-MXene nanosheets, 2,2' diaminodiphenyl disulfide, fluorinated prepolymer and epoxy resin were then blended in ethanol and ultrasonically dispersed to obtain a second dispersion. The second dispersion was then sprayed onto the surface of the semi-cured coating to form a rough interface, and finally SH / PDA-Ti3C2T x MXene / epoxy resin composite coating.

2. The super-hydrophobic self-repairing SH / PDA-Ti3C2T3 according to claim 1 x The preparation method of MXene / epoxy resin anti-corrosion composite coating is characterized in that: In step S1, the stirring reaction temperature is 75-85° C., and the reaction time is 6-10 h.

3. The super-hydrophobic self-repairing SH / PDA-Ti3C2T3 according to claim 1 x The preparation method of MXene / epoxy resin anti-corrosion composite coating is characterized in that: In step S1, the mass ratio of the γ-aminopropyltriethoxysilane, ethanol, trimethoxy(1H,1H,2H,2H-heptafluorodecyl)silane and sodium hydroxide aqueous solution is 9-11:15-25:4-6:1-3.

4. The super-hydrophobic self-repairing SH / PDA-Ti3C2T3 according to claim 1 x The preparation method of MXene / epoxy resin anti-corrosion composite coating is characterized in that: In step S2, the etching temperature is 40-60°C, and the etching time is 48-60 hours.

5. The super-hydrophobic self-repairing SH / PDA-Ti3C2T3 according to claim 1 x The preparation method of MXene / epoxy resin anti-corrosion composite coating is characterized in that: In step S2, the usage ratio of LiF, HCl, and Ti3AlC2 is 3.0-3.2 g: 30-40 mL: 1-2 g.

6. The super-hydrophobic self-repairing SH / PDA-Ti3C2T3 according to claim 1 x The preparation method of MXene / epoxy resin anti-corrosion composite coating is characterized in that: In step S3, the ultrasonic treatment time in the ice-water bath is 10-30 min, the stirring reaction time is 8-12 h, and the continued reaction time is 6-8 h.

7. The super-hydrophobic self-repairing SH / PDA-Ti3C2T3 according to claim 1 x The preparation method of MXene / epoxy resin anti-corrosion composite coating is characterized in that: In step S4, in the first dispersion, the ratio of SH / PDA-MXene nanosheets, anhydrous ethanol, fluorine-containing prepolymer, 2,2'-diaminodiphenyl disulfide, and epoxy resin is 0.025~0.1g:5mL:0~2g:1g:3g.

8. The super-hydrophobic self-repairing SH / PDA-Ti3C2T3 according to claim 1 x The preparation method of MXene / epoxy resin anti-corrosion composite coating is characterized in that: In step S4, in the second dispersion, the ratio of SH / PDA-MXene nanosheets, anhydrous ethanol, fluorine-containing prepolymer, 2,2'-diaminodiphenyl disulfide, and epoxy resin is 0.3-0.6 g: 10 mL: 0.01-0.03 g: 0.05 g: 0.1 g.

9. A super-hydrophobic self-repairing SH / PDA-Ti3C2T prepared by the preparation method according to any one of claims 1 to 8 x MXene / epoxy resin anti-corrosion composite coating.

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