Self-repairing material based on titanium carbide fixed composite microcapsule and preparation method thereof

Abstract

The application provides a self-repairing material based on titanium carbide sheet layer material fixed composite microcapsules, and the self-repairing material comprises the following fillers for self-repairing: titanium carbide sheet layer material and composite microcapsules; wherein the composite microcapsules are formed by modified nano silicon balls loaded with corrosion inhibitors and microcapsules loaded with repair agents; the mass ratio of the titanium carbide sheet layer material, the modified nano silicon balls and the microcapsules is 3-5:1.5-2.5:1.5-2.5; the modified nano silicon balls are nano shell-core silicon balls obtained by loading corrosion inhibitors on nano silicon balls made of tetraethyl orthosilicate; and the microcapsules have urea-formaldehyde resin as a shell and repair agents as a core. The anti-corrosion epoxy coating prepared by using the titanium carbide sheet layer material as filler and supplemented by two kinds of self-repairing microcapsules can repair microcracks more quickly after the coating is broken by external stress impact.

Description

Technical Field

[0001] This invention belongs to the field of coating technology. It relates to a self-healing material, specifically a self-healing material / coating based on titanium carbide two-dimensional sheet material to fix multifunctional composite microcapsules and its preparation method. Background Technology

[0002] With continuous social progress and development, the desire for resources and economic benefits has led people to turn their attention to the ocean. Offshore operations and the construction of facilities on remote islands and reefs have become important aspects of building a maritime power. Currently, most of the marine environments of remote islands and reefs and offshore operations are typical tropical marine monsoon climates, characterized by an average annual sea surface temperature of nearly 30°C, an average annual air temperature of 28°C, and more than 200 days of rainfall annually. These conditions of high temperature, high humidity, high salinity, and strong radiation, coupled with intermittent monsoons and waves, easily corrode offshore equipment and marine engineering facilities on islands and reefs, causing serious damage, economic losses, and even safety accidents. Anti-corrosion coatings are one of the most effective and economical methods for treating marine engineering facilities. Among common coatings, epoxy anti-corrosion coatings, polyurethane anti-corrosion coatings, inorganic zinc-rich anti-corrosion coatings, and fluorocarbon coatings are widely used due to their good performance and cost-effectiveness. During construction and service, due to changes in load and environment, micro-cracks may appear on the coating surface. These cracks reduce the anti-corrosion effect, affecting the durability of the structure and equipment, and consequently, its normal use. Over time and with varying loads, cracks gradually widen, eventually forming fissures that extend to the surface of the structural material. Once fissures form, devices and facilities made of alloys and other materials become further susceptible to damage from external environmental factors, such as stress corrosion caused by seawater impacts, chloride ion corrosion in the air, and sulfate corrosion. These factors can all lead to material failure, severely impacting durability and potentially causing irreparable loss of life and property.

[0003] Preventing microcracks from affecting coating durability has gained increasing attention. Currently, intelligent anti-corrosion coatings with microcapsule self-healing properties offer a mature solution and are gradually becoming an important protective measure. Microcapsule self-healing coating technology first requires preparing a film-forming material as the outer shell, and then using a well-dispersed solid substance, droplet, or gas as the core to form microcapsules. The microcapsules, containing a repair fluid, and a catalyst are then dispersed in a polymer to prepare a self-healing coating containing microcapsules. When cracks develop in the polymer coating, the extending cracks cause the microcapsules to rupture, releasing the repair fluid which flows into the cracks through capillary action, preventing further crack propagation and achieving the repair function. White et al. (Correction-Autonomic healing of polymer composites, NATURE, Vol. 415, February 14, 2002) prepared microcapsules with urea-formaldehyde resin as the shell and cyclopentadiene dimer (DCPD) as the core via emulsion interfacial polymerization. The microcapsules were dispersed together with a Grubbs catalyst in an epoxy resin matrix. When cracks formed in the material, stress concentration at the crack tip triggered the microcapsules to rupture. The encapsulated DCPD then seeped into the crack under capillary action, encountering the embedded Grubbs catalyst. Under the catalyst's influence, a polymerization reaction occurred, achieving self-healing of the epoxy resin. However, due to the limited lifespan of Grubbs and the freezing point of DCPD (19.5–33.0 °C), this self-healing coating is not suitable for coating systems that form films at room temperature or lower temperatures. Its low post-repair strength and weak interfacial adhesion also limit its development.

[0004] CN1298420C discloses an epoxy powder coating containing microcapsule self-healing materials. This self-healing coating uses urea-formaldehyde resin as the capsule wall to encapsulate dicyclopentadiene. The coating also contains a Grubbs catalyst. When cracks in the outer coating extend directly, the urea-formaldehyde resin ruptures, and the dicyclopentadiene rapidly penetrates into the coating, interacting with the Grubbs catalyst and undergoing polymerization and cross-linking to achieve a repair effect. However, these microcapsules are prone to breakage during stirring, and the catalyst has low durability. After the coating is damaged by external force, small cracks appear, resulting in a slow repair response. Furthermore, due to the small internal volume of the microcapsules, it is difficult to repair and fill large-area cracks.

[0005] Ma et al. (Study on Polyurea-based Double-walled Microcapsule Self-healing Coating and Its Tensile Mechanical Properties, Coatings Industry, Vol. 50, No. 11, November 2020) published a study on polyurea-based double-walled self-healing microcapsules with external repair and internal fixation, and their preparation method. This microcapsule system uses an aliphatic isocyanate-amino-terminated polyether polymer as the repair agent, while an amino chain extender acts as the curing agent. The repair agent and curing agent are stored in the outer and inner capsule cores, respectively, to overcome the problem of insufficient contact between the repair agent and curing agent, thereby achieving rapid reaction and rapid crack repair. However, these micron-scale self-healing microcapsules are prone to rupture during the mixing and vibration of concrete samples, resulting in a small number of remaining microcapsules and a slow repair speed when facing microcrack propagation. Summary of the Invention

[0006] The technical objective of this invention is to address the shortcomings of existing technologies by providing a self-healing material, coating, and preparation method thereof based on titanium carbide sheet material immobilized composite microcapsules.

[0007] Specifically, this invention first provides a self-healing material based on titanium carbide sheet material fixed with composite microcapsules. The self-healing material includes the following fillers for self-healing: titanium carbide sheet material and composite microcapsules; wherein, the composite microcapsules are formed by modified silicon nanospheres loaded with corrosion inhibitors and microcapsules loaded with repair agents; wherein, the mass ratio of titanium carbide sheet material, modified silicon nanospheres and microcapsules is 3-5∶1.5-2.5∶1.5-2.5; the modified silicon nanospheres are nano-shell core silicon nanospheres obtained by loading corrosion inhibitors onto silicon nanospheres made of tetraethyl orthosilicate; the microcapsules have urea-formaldehyde resin as the shell and repair agent as the core.

[0008] Furthermore, the aforementioned filler is generally used in epoxy resin, that is, the self-healing material also includes epoxy resin, and the filler is dispersed in epoxy resin; wherein, the mass ratio of titanium carbide sheet material, modified nano-silicon spheres, microcapsules and epoxy resin is 3-5∶1.5-2.5∶1.5-2.5∶800-1200.

[0009] Among them, titanium carbide is a two-dimensional sheet material.

[0010] The modified nano-silicon spheres are modified core-shell silicon spheres loaded with corrosion inhibitors (the corrosion inhibitors are one or more of benzotriazole, stearic acid, pentaerythritol monooleate, octadecylamine oleate, cyclohexylamine stearate, α-mercaptobenzothiazole, and alkyl phosphate salts). The nano-silicon spheres are prepared by dispersing and drying tetraethyl orthosilicate, and then mixing them with the corrosion inhibitors and dispersing and drying them.

[0011] The microcapsules are microcapsules loaded with a repair agent (one or more of benzotriazole, aromatic isocyanate, non-aromatic isocyanate, castor oil, and alodin), with urea-formaldehyde resin as the shell and the repair agent as the core.

[0012] Modified silicon nanospheres and microcapsules responsible for the repair agent constitute the composite microcapsules of the present invention, and together with titanium carbide sheet material, constitute the self-healing filler in the self-healing material of the present invention, which is distributed into the coating to form a self-healing coating for use as an anti-corrosion coating on the substrate (e.g., an anti-corrosion coating of the present invention).

[0013] Furthermore, the self-modifying material based on titanium carbide sheet material immobilized composite microcapsules is obtained through the following preparation method, wherein the preparation of each component includes the following steps:

[0014] (1) Preparation of titanium carbide sheet material:

[0015] (1a) Weigh out the etching agent, deionized water and titanium aluminum carbide in a mass ratio of 10-20:15-25:2-4, mix them and stir at a speed of 600-800 rpm for 15-50 min, freeze-dry the precipitated powder to prepare titanium carbide sheet powder.

[0016] (1b) Take the above titanium carbide powder and dispersant in a mass ratio of 1-2:10-16, stir evenly, and then sonicate for 1 hour. Stir at 300-1000 rpm for 40-1500 min to obtain a composite aqueous phase. Dry and collect the aqueous phase to obtain a two-dimensional sheet titanium carbide material.

[0017] The etching agent can be one or more of the following: lithium fluoride, hydrochloric acid, hydrogen fluoride, sulfuric acid, etc., either diluted or undiluted.

[0018] The dispersant can be one or more of deionized water and tetrabutylammonium hydroxide.

[0019] (2) Preparation of modified silicon nanospheres:

[0020] (2a) Weigh appropriate amounts of hexadecyltrimethylammonium chloride, water and ethanol in a volume ratio of 6-10∶1-3∶1, and stir continuously at 200-500 rpm for 15-30 min at room temperature to obtain a uniformly dispersed solution.

[0021] (2b) Weigh triethanolamine and the above solution at a volume ratio of 1:5-20, mix them evenly, heat the mixture to 60°C, and add tetraethyl orthosilicate dropwise over 2-3 minutes. The volume ratio of the mixed solution to tetraethyl orthosilicate is 35-60:1. Continue stirring at 300-500 rpm for 10-30 minutes. Collect and dry the above mixed emulsion to obtain nano-silicon spheres.

[0022] (2c) Weigh out silicon spheres, corrosion inhibitor, modified dispersant and ethanol in a mass ratio of 2-5:10-15:8-16:80-120, mix them and stir continuously at 200-1000 rpm for 20-60 min at room temperature, and place them under vacuum and let them stand for 20-40 min; dry the obtained dispersion and collect it to obtain modified nano-core-shell silicon spheres.

[0023] The corrosion inhibitor is one or more of the following: benzotriazole, stearic acid, pentaerythritol monooleate, octadecylamine oleate, cyclohexylamine stearate, α-mercaptobenzothiazole, and alkyl phosphate salts.

[0024] The modified dispersants are: lignin, chlorosilane, hexamethyldisilazane, polydimethylsiloxane, dichlorodimethylsilane, etc.

[0025] (3) Preparation of microcapsules:

[0026] (3a) Take urea and 37% formaldehyde solution in a mass ratio of 1:2, mix and stir until completely dissolved, add triethanolamine dropwise, adjust the pH to 8-9, heat in a water bath to 70°C and react for 1 hour to obtain a transparent urea-formaldehyde prepolymer solution.

[0027] (3b) Add the well-mixed epoxy resin and ethyl phenylacetate to a three-necked flask, add distilled water and emulsifier. The mass ratio of epoxy resin, ethyl phenylacetate, distilled water and emulsifier is 6-50∶2-10∶4-20∶1-2. After heating to 50°C in a water bath, stir at a certain stirring rate for 1 hour and cool to 25°C to obtain a dispersion.

[0028] (3c) Add the urea-formaldehyde prepolymer to the above dispersion at a mass ratio of 1:5-10. After stirring for 30 min, add resorcinol, ammonium chloride, and sodium chloride, followed by the addition of defoamer and repair agent. The mass ratio of the five components is 40-70:30-80:35-55:1:200. The total mass ratio of the five components to the prepolymer is 5:180-600. After stirring for 30 min, adjust the pH to 3-4 with saturated citric acid solution, and continue stirring at a temperature less than 1°C per minute. -1 The temperature was increased to 60°C and the reaction was carried out for 3 hours. After the reaction was completed, the obtained microcapsules were filtered, washed, and dried under vacuum at 40°C for 2 days to obtain microcapsules encapsulated with the repair agent.

[0029] The emulsifier is one or more of azobenzimidazole, hexadecyltribromide, ammonium laurate, dodecyl dimethyl ammonium bromide, stearic acid, fatty acid glycerides, and benzalkonium chloride.

[0030] The defoaming agents are one or more of the following: n-octanol, polysiloxane, and palm oil.

[0031] The repair agent is one or more of the following: benzotriazole, aromatic isocyanate, non-aromatic isocyanate, castor oil, and alodin.

[0032] Furthermore, the self-healing material based on titanium carbide sheet material immobilized composite microcapsules provided by the present invention is obtained through the following method:

[0033] (1) Weigh out the titanium carbide sheet material, nano-modified silicon spheres, microcapsules and diluent, and mix them at 500 rpm at room temperature. The ratio of titanium carbide, nano-core-shell silicon spheres, microcapsules and diluent is 3-5:1.5-2.5:1.5-2.5:120-1000.

[0034] The diluent is one or more of xylene, toluene, n-butanol, and styrene.

[0035] (2) Weigh the above suspension, epoxy resin and curing agent according to the mass ratio of filler, epoxy resin and curing agent 6-10:800-1200:150-600, mix them and mechanically stir at 200-500 rpm at room temperature, add an appropriate amount of defoamer and sonicate until there are no bubbles, and then obtain the self-healing material of the present invention.

[0036] The curing agent can be aliphatic amine curing agent, alicyclic amine curing agent, aromatic amine curing agent, acid anhydride curing agent, polyamide curing agent, modified amine curing agent, tertiary amine curing agent, etc.

[0037] In addition, the present invention also provides an application of the above-mentioned self-healing material based on titanium carbide sheet material to fix composite microcapsules: an anti-corrosion coating, wherein the above-prepared viscous homogeneous liquid (self-healing material) is coated on the substrate to be protected, cured at 50°C for 12 hours, and cooled to ambient temperature to finally obtain an anti-corrosion organic coating.

[0038] The substrate to be protected is a metal, which can be the widely used aluminum material, or other metal materials such as iron, copper, and titanium.

[0039] Meanwhile, the present invention also provides a method for preparing a self-healing material based on titanium carbide sheet material to fix composite microcapsules, the method including the above-mentioned preparation steps (1a)-(1b), (2a)-(2c), (3a)-(3c) and (1)-(2), etc.

[0040] Furthermore, the present invention also provides a method for preparing an anti-corrosion coating. In addition to the steps of the above-mentioned method for preparing a self-healing material based on titanium carbide sheet material fixed composite microcapsules, the method also includes: (3) using a spin coater to spin coat the experimental sample at an appropriate speed to obtain a sample coated with a self-healing coating having titanium carbide two-dimensional sheet material fixed multifunctional microcapsules.

[0041] This invention utilizes titanium carbide sheet material supplemented with two types of self-healing microspheres / capsules as composite fillers to prepare an anti-corrosion epoxy coating that can more quickly self-repair microcracks after being fractured by external stress impact. Because the surface of the two-dimensional titanium carbide sheet material not only has micro- and nano-scale pores but also a large number of active groups, the exposure of surface active sites enhances the loading of silicon spheres and microcapsules within the epoxy resin-based coating, achieving the fixation of the microcapsules. Simultaneously, the titanium carbide sheet material, as a shielding material, can significantly improve the service life of the coating, improve the microstructure performance of the coating, thereby extending the intrusion path of corrosive media and enhancing the water resistance of the self-healing coating. Combining self-healing active anti-corrosion strategies with passive anti-corrosion strategies reduces the intrusion of corrosive ions. This coating can achieve self-repair without human intervention, maintaining high anti-corrosion performance for a long time, thus saving on the repair costs of anti-corrosion coatings.

[0042] Compared with existing technologies, this invention has the following advantages:

[0043] (1) Two-dimensional titanium carbide sheet material has a large specific surface area, is lightweight, and has good compatibility with multiple anti-corrosion coatings. Its surface has active groups and a large number of mesopores and micropores, which promote the fixation of microcapsules by titanium carbide sheet material, improve the dispersibility of silicon balls and microcapsules, and avoid the problem of reduced coating adhesion caused by the agglomeration of nanofillers; make the composite microcapsules more uniformly distributed and improve the repair reaction speed of microcracks.

[0044] (2) Unlike one-dimensional nanofillers, titanium carbide two-dimensional sheet nanofillers have a shielding function. As a hard component in anti-corrosion coatings, they can produce a "maze effect" on corrosive media, improve the microstructure performance of the coating, and prolong the penetration path of corrosive media inside the organic coating. Based on the passive anti-corrosion strategy, they act as a physical barrier in self-healing anti-corrosion coatings, slowing down the penetration rate of corrosive media and delaying the corrosion process.

[0045] (3) The composite microcapsules provided in this invention are mainly nano-silicon spheres loaded with corrosion inhibitors and urea-formaldehyde resin microcapsules loaded with repair agents. Therefore, when the silicon spheres and microcapsules are broken, the broken nanoparticles can form a hydrophobic layer in the crack during the repair process to prevent further water penetration.

[0046] (4) Compared with existing microcapsule self-healing technologies, highly dispersed multi-component composite microcapsules have the characteristics of faster repair response and longer corrosion resistance. This accelerates the repair effect, repairs cracks in a timely manner, and avoids more serious consequences and higher repair costs.

[0047] (5) The preparation process of the self-healing coating of the composite microcapsule with titanium carbide sheet material is simple, low in cost, low in volatile organic compound yield, and environmentally friendly and conducive to production.

[0048] (6) After the coating is damaged, the titanium carbide sheet material has good photothermal conversion ability under visible light induction, which can quickly kill bacteria through photothermal effect, and make the composite coating have excellent antibacterial properties. Attached Figure Description

[0049] Figure 1 This is a schematic diagram illustrating the synthesis and application pathway of a self-healing material based on titanium carbide sheet material immobilized composite microcapsules according to the present invention.

[0050] Figure 2 This is a scanning electron microscope image of the titanium carbide sheet material in a self-healing material based on titanium carbide sheet material immobilized composite microcapsules according to the present invention.

[0051] Figure 3 This is a scanning electron microscope image of modified silicon nanospheres loaded with corrosion inhibitors in a self-healing material based on titanium carbide sheet material immobilized composite microcapsules according to the present invention.

[0052] Figure 4 This is a Fourier transform infrared (FTIR) image of the corrosion inhibitor-loaded microcapsules in a self-healing material based on titanium carbide sheet material-fixed composite microcapsules according to the present invention.

[0053] Figure 5 This is a scanning electron microscope image of the microcapsules in a self-healing material based on titanium carbide sheet material immobilized with composite microcapsules according to the present invention.

[0054] Figure 6 This is a Nyquist diagram of a self-healing anti-corrosion coating according to the present invention.

[0055] Figure 7 This is a Bode plot of a self-healing anti-corrosion coating of the present invention at different corrosion times.

[0056] Figure 8 This is a Bode plot of a self-healing anti-corrosion coating of the present invention at different corrosion times. Detailed Implementation

[0057] The technical solutions in the embodiments of this invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0058] Example 1:

[0059] The present invention discloses a self-healing material / coating based on titanium carbide two-dimensional sheet material immobilizing multifunctional composite microcapsules, which is synthesized from component A, titanium carbide sheet material, component B, modified silicon nanospheres, component C, microcapsules and component D, epoxy resin.

[0060] (1) Preparation of component A:

[0061] (1a) Weigh appropriate amounts of titanium aluminum carbide, lithium fluoride, hydrochloric acid and deionized water, wherein the mass ratio of titanium aluminum carbide, lithium fluoride, hydrochloric acid and deionized water is 4:3:17:25. Stir at 600 rpm for 30 min to obtain a uniformly dispersed suspension. Freeze-dry the precipitated powder to prepare titanium carbide sheet powder.

[0062] (1b) Take an appropriate amount of titanium carbide and deionized water, wherein the mass ratio of titanium carbide to water is 1:10, sonicate for 1 h, and stir at 600 rpm and 30 °C for 1440 min to obtain a composite aqueous phase. Dry and collect the water in the tank to obtain a two-dimensional sheet titanium carbide material.

[0063] (2) Preparation of component B:

[0064] (2a) Weigh out appropriate amounts of hexadecyltrimethylammonium chloride, water and ethanol, wherein the volume ratio of hexadecyltrimethylammonium chloride to water and ethanol is 8:3:1. Stir continuously at 500 rpm for 30 min at room temperature to obtain a uniformly dispersed solution.

[0065] (2b) Weigh an appropriate amount of triethanolamine and the above solution, with a volume ratio of 1:15. Mix them thoroughly and heat the mixture to 60°C. Add an appropriate amount of tetraethyl orthosilicate dropwise over 2 minutes, with a volume ratio of the mixed solution to tetraethyl orthosilicate of 60:1. Continue stirring at 500 rpm for 30 minutes. Finally, collect and dry the above mixed emulsion to obtain nano-silicon spheres.

[0066] (2c) Weigh appropriate amounts of silica spheres, α-mercaptobenzothiazole, polydimethylsiloxane, and ethanol, with a mass ratio of silica spheres, α-mercaptobenzothiazole, polydimethylsiloxane, and ethanol of 5:10:8:90. Stir continuously at 300 rpm for 40 min at room temperature, and then place under vacuum for 40 min. Dry and collect the resulting dispersion to obtain modified core-shell silica nanospheres.

[0067] (3) Preparation of component C:

[0068] (3a) Take an appropriate amount of urea and 37% formaldehyde solution in a round-bottom flask, wherein the mass ratio of urea to formaldehyde is 1:2. After completely dissolving by magnetic stirring, add triethanolamine dropwise to adjust the pH to 8. Heat the mixture in a water bath to 70°C and react for 1 hour to obtain a transparent urea-formaldehyde prepolymer solution.

[0069] (3b) The uniformly mixed epoxy resin and ethyl phenylacetate were added to a three-necked flask, along with distilled water and a certain amount of hexadecyltribromide. The mass ratio of epoxy resin, ethyl phenylacetate, distilled water and hexadecyltribromide was 12:2:8:1. The mixture was heated to 50°C in a water bath and stirred at a certain stirring rate for 1 hour. The mixture was then cooled to 25°C to obtain a dispersion.

[0070] (3c) The urea-formaldehyde prepolymer was added to the above dispersion at a mass ratio of 1:5. After stirring for 30 min, resorcinol, ammonium chloride, and sodium chloride were added, followed by the dropwise addition of n-octanol and allotin. The mass ratio of the five components was 40:50:50:1:200. The total mass ratio of the five components to the prepolymer was 5:600. After stirring for 30 min, the pH was adjusted to 4 with saturated citric acid solution, and the mixture was stirred at a temperature less than 1°C for 1 min. -1 The temperature was increased to 60°C and the reaction was carried out for 3 hours. After the reaction was completed, the obtained microcapsules were filtered, washed, and dried under vacuum at 40°C for 2 days to obtain the microcapsules.

[0071] (4) Preparation of a self-healing coating with multifunctional microcapsules fixed by titanium carbide two-dimensional sheet material:

[0072] (4a) Weigh an appropriate amount of filler: titanium carbide sheet material, nano-core-shell silicon spheres, microcapsules, and a mixed solution of xylene and n-butanol, and stir at 500 rpm at room temperature. The mass ratio of titanium carbide sheet material, nano-core-shell silicon spheres, microcapsules, xylene, and n-butanol is 3:2:2:40:80.

[0073] (4b) Weigh appropriate amounts of the above suspension, epoxy resin, and polyamide curing agent, with a mass ratio of filler, epoxy resin, and curing agent of 10:800:350 in the suspension. Mechanically stir at 200 rpm at room temperature, add an appropriate amount of defoamer, and sonicate until no bubbles are present to obtain the self-healing material of the present invention.

[0074] (4c) A spin coater was used to spin coat the experimental sample (steel sheet) at an appropriate speed to obtain a sample coated with a self-healing coating containing multifunctional microcapsules fixed with two-dimensional titanium carbide sheet material.

[0075] The performance of the above-obtained anti-corrosion organic coating was tested:

[0076] The scanning electron microscopy results of component A are as follows: Figure 2 ;

[0077] The scanning electron microscopy results of component B are as follows: Figure 3 ;

[0078] The Fourier transform infrared test results of component C are as follows: Figure 4 Scanning electron microscopy test results are as follows: Figure 5 .

[0079] The final prepared coating was applied to the surface of a steel sheet, which was then immersed in simulated seawater. The coating impedance changed over time as follows: Figure 6 , 7 As shown in Figure 8, the change in coating impedance remains within one order of magnitude, indicating good material stability and corrosion resistance.

[0080] Example 2:

[0081] The present invention discloses a self-healing material / coating based on titanium carbide two-dimensional sheet material immobilizing multifunctional composite microcapsules, which is made of component A titanium carbide sheet material, component B modified silicon nanospheres, component C microcapsules and component D epoxy resin.

[0082] (1) Preparation of component A:

[0083] (1a) Weigh appropriate amounts of hydrogen fluoride, deionized water and titanium aluminum carbide, wherein the mass ratio of hydrogen fluoride, deionized water and titanium aluminum carbide is 10:25:4. Stir at 600 rpm for 50 min, freeze-dry the precipitated powder, and prepare titanium carbide sheet powder.

[0084] (1b) Take an appropriate amount of titanium carbide powder and tetrabutylammonium hydroxide, wherein the mass ratio of titanium carbide to tetrabutylammonium hydroxide is 1:16. After stirring evenly, sonicate in an argon atmosphere for 1 hour and stir at 400 rpm for 40 min to obtain a composite aqueous phase. Dry and collect the aqueous phase to obtain a two-dimensional sheet titanium carbide material.

[0085] (2) Preparation of component B:

[0086] (2a) Weigh out an appropriate amount of hexadecyltrimethylammonium chloride, water and ethanol, wherein the volume ratio of hexadecyltrimethylammonium chloride to water and ethanol is 6:1:1. Stir continuously at 500 rpm for 30 min at room temperature to obtain a uniformly dispersed solution.

[0087] (2b) Weigh an appropriate amount of triethanolamine and the above solution at a volume ratio of 1:20, mix them thoroughly, heat the mixture to 60°C, and add tetraethyl orthosilicate dropwise over 3 minutes. The volume ratio of the mixed solution to tetraethyl orthosilicate is 35:1. Continue stirring at 500 rpm for 20 minutes. Finally, collect and dry the above mixed emulsion to obtain nano-silicon spheres.

[0088] (2c) Weigh appropriate amounts of silica spheres, α-mercaptobenzothiazole, lignin, and ethanol, with a mass ratio of silica spheres, α-mercaptobenzothiazole, lignin, and ethanol of 2:15:15:120. Stir continuously at 800 rpm for 50 min at room temperature, then place under vacuum and let stand for 30 min. Dry and collect the resulting dispersion to obtain modified core-shell silica nanospheres.

[0089] (3) Preparation of component C:

[0090] (3a) Take an appropriate amount of urea and 37% formaldehyde solution in a round-bottom flask, wherein the mass ratio of urea to formaldehyde is 1:2. After completely dissolving by magnetic stirring, add triethanolamine dropwise to adjust the pH to 8.5. Heat in a water bath to 70°C and react for 1 hour to obtain a transparent urea-formaldehyde prepolymer solution.

[0091] (3b) The uniformly mixed epoxy resin and ethyl phenylacetate were added to a three-necked flask, and distilled water and hexadecyltribromide were added. The mass ratio of epoxy resin, ethyl phenylacetate, distilled water and hexadecyltribromide was 6:4:8:1. After heating to 50°C in a water bath, the mixture was stirred at a certain stirring rate for 1 hour and then cooled to 25°C to obtain a dispersion.

[0092] (3c) Add the urea-formaldehyde prepolymer to the above dispersion at a mass ratio of 1:10. After stirring for 30 min, add resorcinol, ammonium chloride, and sodium chloride, then add n-octanol and benzotriazole dropwise. The mass ratio of the five components is 50:30:35:1:200. The total mass ratio of the five components to the prepolymer is 1:40. After stirring for 30 min, adjust the pH to 3 with saturated citric acid solution, and continue stirring at a temperature less than 1°C for 1 min. -1 The temperature was increased to 60°C and the reaction was carried out for 3 hours. After the reaction was completed, the obtained microcapsules were filtered, washed, and dried under vacuum at 40°C for 2 days to obtain the microcapsules.

[0093] (4) Preparation of self-healing materials / coatings with multifunctional microcapsules fixed by titanium carbide two-dimensional sheet material:

[0094] (4a) Weigh an appropriate amount of filler: titanium carbide sheet material, nano-modified silicon spheres, microcapsules and n-butanol, and mix them at 500 rpm at room temperature. The ratio of titanium carbide, nano-core-shell silicon spheres, microcapsules and n-butanol is 3:2:2:120.

[0095] (4b) Weigh appropriate amounts of the above suspension, epoxy resin, and polyamide curing agent, and make the mass ratio of filler, epoxy resin, and curing agent in the suspension 10:800:200. Mechanically stir at 300 rpm at room temperature, add an appropriate amount of defoamer, and sonicate until no bubbles are present to obtain the self-healing material of the present invention.

[0096] (4c) The experimental sample was spin-coated at an appropriate speed using a spin coater and cured at 50°C for 12 hours to obtain a sample coated with a self-healing coating containing multifunctional microcapsules fixed by titanium carbide two-dimensional sheet material.

[0097] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A self-healing material based on titanium carbide sheet material immobilized composite microcapsules, characterized in that, The self-healing material comprises epoxy resin and filler for self-healing, wherein the filler is dispersed in the epoxy resin; the filler comprises: titanium carbide sheet material and composite microcapsules; wherein the composite microcapsules are formed by modified silicon nanospheres loaded with corrosion inhibitors and microcapsules loaded with repair agents; wherein the mass ratio of the titanium carbide sheet material, the modified silicon nanospheres, and the microcapsules is 3-5:1.5-2.5:1.5-2.5; the microcapsules have urea-formaldehyde resin as the shell and repair agent as the core; The titanium carbide sheet material is obtained by the following method: (1a) Weigh out the etching agent, deionized water and titanium aluminum carbide in a mass ratio of 10-20:15-25:2-4, mix them and stir at a speed of 600-800 rpm for 15-50 min, freeze-dry the precipitated powder to obtain titanium carbide sheet powder. (1b) Take the titanium carbide powder and dispersant obtained in step (1a) in a mass ratio of 1-2:10-16, stir evenly, and then sonicate for 1 hour. Stir at 300-1000 rpm for 40-1500 min to obtain a composite aqueous phase. Dry and collect the aqueous phase to obtain the two-dimensional titanium carbide sheet material. The etching agent is one or more of lithium fluoride, hydrochloric acid, hydrogen fluoride, and sulfuric acid, either diluted or undiluted. The dispersant is one or more of deionized water and tetrabutylammonium hydroxide; The modified silicon nanospheres are obtained by the following method: (2a) Weigh hexadecyltrimethylammonium chloride, water and ethanol in a volume ratio of 6-10:1-3:1, mix them and stir continuously at 200-500 rpm for 15-30 min at room temperature to obtain a uniformly dispersed solution. (2b) Weigh triethanolamine and the solution obtained in step (2a) at a volume ratio of 1:5-20, mix them evenly, heat the mixture to 60°C, and add tetraethyl orthosilicate dropwise over 2-3 minutes at a volume ratio of 35-60:1, while stirring at 300-500 rpm for 10-30 minutes; collect and dry the emulsion to obtain nano-silicon spheres; (2c) Weigh the nano-silicon spheres, corrosion inhibitor, modified dispersant and ethanol obtained in step (2b) in a mass ratio of 2-5:10-15:8-16:80-120, mix them and stir continuously at 200-1000 rpm for 20-60 min at room temperature, and place them under vacuum and let them stand for 20-40 min; dry and collect the resulting dispersion to obtain the modified nano-silicon spheres; The corrosion inhibitor is one or more of the following: benzotriazole, stearic acid, pentaerythritol monooleate, octadecylamine oleate, cyclohexylamine stearate, α-mercaptobenzothiazole, and alkyl phosphate salts. The modified dispersant is: lignin, chlorosilane, hexamethyldisilazane, polydimethylsiloxane, or dichlorodimethylsilane.

2. The self-healing material based on titanium carbide sheet material immobilized composite microcapsules according to claim 1, characterized in that, The mass ratio of the titanium carbide sheet material, the modified silicon nanospheres, the microcapsules, and the epoxy resin is 3-5:1.5-2.5:1.5-2.5:800-1200.

3. The self-healing material based on titanium carbide sheet material immobilized composite microcapsules according to claim 1, characterized in that, The microcapsules are obtained by the following method: (3a) Take urea and formaldehyde in a mass ratio of 1:2, mix them and stir them completely with magnetic stirring, then add triethanolamine dropwise and adjust the pH to 8-9. Heating to 70°C and reacting for 1 hour yields a urea-formaldehyde prepolymer solution; (3b) Mix epoxy resin and ethyl phenylacetate evenly, add distilled water and emulsifier. The mass ratio of epoxy resin, ethyl phenylacetate, distilled water and emulsifier is 6-50:2-10:4-20:1-2. Heat to 50°C and stir at a certain stirring rate for 1 hour. Cool to 25°C to obtain dispersion. (3c) Add the urea-formaldehyde prepolymer solution obtained in step (3a) to the dispersion obtained in step (3b) at a mass ratio of 1:5-10. After stirring for 30 min, add resorcinol, ammonium chloride, and sodium chloride, then add defoamer and repair agent. The mass ratio of the five components is 40-70:30-80:35-55:1:

200. The total mass of the five components added later is 5:180-600 to the mass ratio of the prepolymer. After stirring for 30 min, adjust the pH to 3-4 with saturated citric acid solution, and stir at a temperature less than 1°C for 1 min. -1 The temperature was increased to 60°C and reacted for 3 hours. After the reaction was completed, the mixture was filtered, washed, and dried under vacuum at 40°C for 2 days to obtain the microcapsules. The emulsifier is one or more of azobenzimidazole, hexadecyltribromide, ammonium laurate, dodecyl dimethyl ammonium bromide, stearic acid, fatty acid glycerides, and benzalkonium chloride. The defoamer is one or more of n-octanol, polysiloxane, and palm oil; The repair agent is one or more of benzotriazole, aromatic isocyanate, non-aromatic isocyanate, castor oil, and alodin.

4. The self-healing material based on titanium carbide sheet material immobilized composite microcapsules according to any one of claims 1-3, characterized in that, The self-healing material is obtained through the following method: (1) Weigh the titanium carbide sheet material, the modified silicon nanospheres, the microcapsules and the diluent, and mix them at 500 rpm at room temperature to obtain a suspension; wherein, the mass ratio of the titanium carbide sheet material, the modified silicon nanospheres, the microcapsules and the diluent is 3-5:1.5-2.5:1.5-2.5:120-1000; wherein, the diluent is one or more of xylene, toluene, n-butanol and styrene; (2) Weigh the suspension, epoxy resin and curing agent obtained in step (1) according to the mass ratio of filler, epoxy resin and curing agent 6-10:800-1200:150-600, mix them and mechanically stir them at 200-500 rpm at room temperature, add an appropriate amount of defoamer and sonicate until there are no bubbles to obtain the self-healing material.

5. An anti-corrosion coating, characterized in that, The coating comprises the self-healing material based on titanium carbide sheet material fixed composite microcapsules as described in claims 1-4.

6. The anti-corrosion coating according to claim 5, characterized in that, The self-healing material is coated onto the substrate to be protected, cured at 50°C for 12 hours, and then cooled to ambient temperature to obtain the coating.

7. A method for preparing a self-healing material based on titanium carbide sheet material immobilized composite microcapsules, characterized in that, The method includes the following steps: (1) Preparation of titanium carbide sheet material: (1a) Weigh out the etchant, deionized water and titanium aluminum carbide in a mass ratio of 10-20:15-25:2-4, mix them and stir at a speed of 600-800 rpm for 15-50 min, freeze-dry the precipitated powder to obtain titanium carbide sheet powder; the etchant is one or more of lithium fluoride, hydrochloric acid, hydrogen fluoride and sulfuric acid, whether diluted or undiluted. (1b) Take the titanium carbide powder and dispersant obtained in step (1a) in a mass ratio of 1-2:10-16, stir evenly, and then sonicate for 1 hour. Stir at 300-1000 rpm for 40-1500 min to obtain a composite aqueous phase. Dry and collect the aqueous phase to obtain the two-dimensional sheet titanium carbide sheet material. The dispersant is one or more of deionized water and tetrabutylammonium hydroxide. (2) Preparation of modified silicon nanospheres: (2a) Weigh hexadecyltrimethylammonium chloride, water and ethanol in a volume ratio of 6-10:1-3:1, mix them and stir continuously at 200-500 rpm for 15-30 min at room temperature to obtain a uniformly dispersed solution. (2b) Weigh triethanolamine and the solution obtained in step (2a) at a volume ratio of 1:5-20, mix them evenly, heat the mixture to 60°C, and add tetraethyl orthosilicate dropwise over 2-3 minutes at a volume ratio of 35-60:1, while stirring at 300-500 rpm for 10-30 minutes; collect and dry the emulsion to obtain nano-silicon spheres; (2c) Weigh the nano-silicon spheres, corrosion inhibitor, modified dispersant, and ethanol obtained in step (2b) at a mass ratio of 2-5:10-15:8-16:80-120, mix them, and stir continuously at 200-1000 rpm for 20-60 min at room temperature. Then place them under vacuum and let them stand for 20-40 min. Dry and collect the resulting dispersion to obtain the modified nano-silicon spheres. The corrosion inhibitor is one or more of benzotriazole, stearic acid, pentaerythritol monooleate, octadecylamine oleate, cyclohexylamine stearate, α-mercaptobenzothiazole, and alkyl phosphate salts. The modified dispersant is lignin, chlorosilane, hexamethyldisilazane, polydimethylsiloxane, or dichlorodimethylsilane. (3) Preparation of microcapsules: (3a) Take urea and formaldehyde in a mass ratio of 1:2, mix them and stir them completely with magnetic stirring, then add triethanolamine dropwise and adjust the pH to 8-9. Heating to 70°C and reacting for 1 hour yields a urea-formaldehyde prepolymer solution; (3b) Mix epoxy resin and ethyl phenylacetate evenly, add distilled water and emulsifier, the mass ratio of epoxy resin, ethyl phenylacetate, distilled water and emulsifier is 6-50:2-10:4-20:1-2, heat to 50°C, stir at a certain stirring rate for 1 hour, and cool to 25°C to obtain a dispersion; the emulsifier is one or more of azobenzimidazole, hexadecyltribromide, ammonium laurate, dodecyl dimethyl ammonium bromide, stearic acid, fatty acid glycerides, and benzalkonium chloride. (3c) Add the urea-formaldehyde prepolymer solution obtained in step (3a) to the dispersion obtained in step (3b) at a mass ratio of 1:5-10. After stirring for 30 min, add resorcinol, ammonium chloride, and sodium chloride, then add defoamer and repair agent. The mass ratio of the five components is 40-70:30-80:35-55:1:

200. The total mass of the five components added later is 5:180-600 to the mass ratio of the prepolymer. After stirring for 30 min, adjust the pH to 3-4 with saturated citric acid solution, and stir at a temperature less than 1°C for 1 min. -1 The temperature was increased to 60°C and reacted for 3 hours. After the reaction was completed, the mixture was filtered, washed, and dried under vacuum at 40°C for 2 days to obtain the microcapsules. The defoamer was one or more of n-octanol, polysiloxane, and palm oil. The repair agent was one or more of benzotriazole, aromatic isocyanate, non-aromatic isocyanate, castor oil, and alodin. (4) Preparation of the self-healing material: (4a) Weigh the titanium carbide sheet material, the modified silicon nanospheres, the microcapsules, and the diluent, and mix them at 500 rpm at room temperature to obtain a suspension; wherein the mass ratio of the titanium carbide sheet material, the modified silicon nanospheres, the microcapsules, and the diluent is 3-5:1.5-2.5:1.5-2.5:120-1000; wherein the diluent is one or more of xylene, toluene, n-butanol, and styrene. (4b) Weigh the suspension, epoxy resin and curing agent obtained in step (1) according to the mass ratio of filler, epoxy resin and curing agent 6-10:800-1200:150-600, mix them and mechanically stir them at 200-500 rpm at room temperature, add an appropriate amount of defoamer and sonicate until there are no bubbles to obtain the self-healing material.

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