Preparation method of titanium alloy anti-corrosion self-repairing intelligent coating used in marine environment

Abstract

The invention discloses a preparation method of a titanium alloy anti-corrosion self-repairing intelligent coating used in a marine environment, and the preparation method comprises the following steps: adding an antibacterial agent into a solvent, and uniformly stirring to prepare a core material of a microcapsule; the preparation method comprises the following steps: adding a piezoelectric polymer into a solvent, uniformly stirring, adding a spinnable polymer, and uniformly stirring to prepare a shell material of the microcapsule; carrying out electrostatic spinning by taking the core material and the shell material as a spinning solution, and freeze-drying the obtained electrostatic spinning fiber to obtain the microcapsule; and mixing the microcapsule, the high-molecular polymer containing the dynamic covalent bond, the coating carrier, the diluent, the dispersing agent and the curing agent, and uniformly stirring to obtain the intelligent coating. According to the method, corrosion prevention and timely repair of the titanium alloy surface in the severe ocean environment can be achieved, the mechanical performance of a titanium alloy part is effectively improved, and the service life of the titanium alloy part is effectively prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of titanium alloy anti-corrosion self-repairing methods, and specifically relates to a method for preparing a titanium alloy anti-corrosion self-repairing intelligent coating for use in a marine environment. Background Art

[0002] Titanium alloys are widely used in the field of marine engineering due to their excellent mechanical properties, corrosion resistance and low density, especially in submersibles, offshore oil and gas equipment, desalination equipment, and marine buildings and facilities. Due to the high salinity, high humidity, high flow rate and abundant microorganisms in the marine environment, these factors work together to make titanium alloy parts susceptible to microbial erosion. Especially in the early stage of immersion in seawater, biofilms composed of microorganisms will quickly form on the surface of titanium alloys. These biofilms will change the chemical environment of the material surface, resulting in uneven passivation film, thereby causing local corrosion and significantly reducing the mechanical properties and service life of titanium alloys.

[0003] At present, the traditional titanium alloy surface anti-corrosion methods mainly include surface passivation, micro-arc oxidation and surface coating. Among them, the surface passivation method and micro-arc oxidation method mainly form an oxide film on the surface of the titanium alloy through pickling, anodizing and micro-arc oxidation treatment to prevent further oxidation and corrosion. Although the process is simple, the thickness of the passivation film is limited, and the oxide film is porous, which is not enough to cope with the strong corrosion environment under seawater conditions. The surface coating method can select different types of coating materials to adapt to the harsh environment to significantly improve the wear resistance and corrosion resistance of titanium alloys. However, in the marine environment, the titanium alloy coating not only has the risk of being corroded by seawater, but also faces the dual challenges of wave impact and water flow changes. These factors can easily cause the coating to break or fall off, thereby quickly failing. In addition, the pH value in the marine environment has a significant effect on the corrosion behavior of titanium alloys. In acidic or locally acidified environments, the stability of the passivation film will be greatly reduced and the corrosion rate will increase. Therefore, it is very necessary to construct a titanium alloy anti-corrosion self-repairing intelligent coating for marine environments.

[0004] The Chinese patent "A preparation method and application of a titanium alloy antibacterial coating based on halloysite" (application number: CN202311109072.5, publication date: 2023.12.26, publication number: CN117281954A) discloses a preparation method and application of a titanium alloy antibacterial coating based on halloysite. The method first uses alkali solution and simulated body fluid to treat the titanium alloy, introduces hydroxyl groups on its surface, improves the binding force between HNTs and the matrix, and then utilizes the electrostatic attraction between HNTs and chitosan oligosaccharides (COS), as well as the electrostatic attraction between HNTs, COS and Al 3+The strong coordination bond between the two enables the long-term stability and antibacterial properties of the coating in simulated body fluids. However, when the coating is damaged, the coating prepared by this method cannot achieve self-repair, which greatly increases the maintenance cost and poses a serious safety hazard.

[0005] The Chinese patent "A method for preparing an antibacterial self-healing organosilicon coating" (application number: CN202411687388.7, publication date: 2024.12.27, publication number: CN119192999A) discloses a method for preparing an antibacterial self-healing organosilicon coating. The coating material prepared in this method is modified by synthesizing amino acids to modify polysiloxane. The amino and carboxyl groups chelate metal ions to achieve reversible cross-linking of polysiloxane, which can be repeated many times. The metal ions have antibacterial effects and extend the service life of the coating. However, due to the extremely complex marine conditions, the coating cannot be anti-corrosive and self-repaired according to the requirements of alloy material reagents, which can easily cause waste of antibacterial agents and self-repairing agents and have problems of poor timeliness. Summary of the invention

[0006] The purpose of the present invention is to provide a method for preparing a titanium alloy anti-corrosion self-repairing intelligent coating for use in a marine environment, which can achieve anti-corrosion and timely repair of the titanium alloy surface in a harsh marine environment, and effectively improve the mechanical properties and service life of titanium alloy parts.

[0007] The technical solution adopted by the present invention is a method for preparing a titanium alloy anti-corrosion self-repairing intelligent coating for use in a marine environment, which is specifically implemented according to the following steps: Step 1, adding the antibacterial agent into the solvent and stirring evenly to prepare the core material of the microcapsule; Step 2, adding the piezoelectric polymer to the solvent and stirring evenly, then adding the spinnable polymer and stirring evenly to prepare the shell material of the microcapsule; Step 3, using the core material obtained in step 1 and the shell material obtained in step 2 as spinning liquid for electrostatic spinning, and freeze-drying the obtained electrostatically spun fibers to obtain microcapsules; Step 4: Mix the microcapsules obtained in step 3, the high molecular polymer containing dynamic covalent bonds, the coating carrier, the diluent, the dispersant and the curing agent, and stir them evenly to obtain the smart coating.

[0008] The present invention is also characterized in that: In step 1, the antibacterial agent is nanosilver, triclosan or MOF nanoparticles, and the solvent is dichloromethane, ethanol or deionized water; the mass fraction of the antibacterial agent is 5 to 30%.

[0009] In step 1, the stirring temperature is 20-60° C., the stirring speed is 400-1500 rpm, and the stirring time is 1-12 h.

[0010] In step 2, the piezoelectric polymer is a mixture of one or more of polyvinylidene fluoride, zinc oxide or barium titanate, the spinnable polymer is a mixture of chitosan and nanocellulose in a mass ratio of 3 to 6:1 to 3, and the solvent is an acetic acid solution with a mass fraction of 0.5 to 3 wt%.

[0011] In step 2, the mass fraction of the piezoelectric polymer is 3-35%, and the mass fraction of the spinnable polymer is 5-20%.

[0012] In step 2, the stirring temperature of the two stirrings is 20-50° C., the stirring speed is 400-1500 rpm, and the stirring time is 1-12 h.

[0013] Step 3 is as follows: The core material and the shell material are placed in two syringes respectively. Under the spinning parameters of push speed ratio of 1:2-2:3, voltage of 15-30 kV, receiving distance of 15-20 cm, temperature of 20-30 ° C, and humidity of 10%-30%, the spinning solutions in the two syringes are pushed together into a mixed solution of NaOH and Na2SO4 for electrospinning. The temperature of the mixed solution is 25-80 ° C and the mass ratio of NaOH and Na2SO4 in the mixed solution is 1:1-5. Then, the microcapsules are obtained by freeze-drying for 12-36 hours.

[0014] In step 4, the mass percentages of the raw materials are: 5-25% of microcapsules, 5-10% of high molecular polymers containing dynamic covalent bonds, 45-65% of coating carriers, 1-2% of diluents, 1-5% of dispersants and 3-20% of curing agents, and the total content of the above components is 100%.

[0015] In step 4, the high molecular polymer containing dynamic covalent bonds is polyimide, polydimethylsiloxane or a polymer of tannic acid and sodium tetraborate; the coating carrier is epoxy resin, polyester or polyurea; the diluent is n-butanol or xylene; the dispersant is hexadecyltrimethylammonium bromide, polyoxyethylene stearyl ether or sodium polycarboxylate; and the curing agent is diethylenetriamine, polyamide or 2-methylimidazole.

[0016] In step 4, the stirring speed is 2000-8000 rpm, and the stirring time is 5-100 min.

[0017] The beneficial effects of the present invention are: (1) The shell layer of the microcapsule in the smart coating of the present invention is a piezoelectric layer. First, the piezoelectric material in the piezoelectric layer can effectively dissipate the shear stress generated by the impact of waves and the change of water flow, greatly reducing the risk of coating peeling caused by wave scouring; secondly, the shear stress generated by the impact of waves and the change of water flow can be effectively converted into electrical energy through the mechanoelectric conversion effect of the piezoelectric material. The electrical stimulation can adjust the potential of the bacterial biofilm, enhance the membrane permeability, destroy bacteria and hinder the formation of biofilm, especially in an acidic environment, which can stop the growth of 99% of the biofilm. Studies have shown that the corrosion rate of titanium alloy is the highest in an acidic environment; finally, the mechanoelectric conversion characteristics of the piezoelectric material can convert the absorbed energy into electrical energy, stimulate the release of antibacterial agents, play an early protective role, improve the corrosion resistance of titanium alloy parts, reduce the impact of biological pollution on titanium alloy parts, and effectively inhibit the growth and reproduction of bacteria; (2) Once the coating is damaged due to external factors, the intelligent coating material of the present invention can achieve molecular rearrangement and bond exchange in the crack area through the exchange reaction of dynamic chemical bonds in the repair material, through molecular movement or diffusion, and re-form new bonds, automatically repair microcracks and damage, reduce the risk of further damage, and provide long-term maintenance and repair capabilities for titanium alloy parts; (3) The method of the present invention achieves effective protection and self-repair of titanium alloy parts in marine environments by designing the composition, structure and function of the coating material, significantly improving the durability and reliability of titanium alloy parts, and effectively reducing equipment maintenance costs and replacement frequency. In addition, the coating material has low production costs and no special requirements for production equipment, and has good application prospects in the field of titanium alloy protective materials. (4) The coating material of the present invention can not only effectively solve the problems of biofouling and corrosion, but also effectively prevent microbial attachment and biofilm formation, reduce corrosion risks, and extend the service life of components, which is of great significance to the field of marine engineering. DETAILED DESCRIPTION

[0018] The present invention is described in detail below in conjunction with specific implementation modes.

[0019] The preparation method of the titanium alloy anti-corrosion self-repairing intelligent coating for marine environment of the present invention is specifically implemented according to the following steps: Step 1, preparing the core material of the microcapsule that releases the antibacterial agent in response to electrical stimulation, specifically comprising the following steps: adding the antibacterial agent into the solvent and stirring evenly, so as to obtain the core material of the microcapsule that releases the antibacterial agent in response to electrical stimulation; Among them, the antibacterial agent is nanosilver (AgNP S ), any one of triclosan or MOF nanoparticles, and the solvent is a mixture of one or more of dichloromethane, ethanol or deionized water.

[0020] The mass percentage of the antibacterial agent is 5-30%, the mass percentage of the solvent is 70-95%, the stirring temperature is 20-60°C, the stirring speed is 400-1500rpm, and the stirring time is 1-12h.

[0021] Step 2, preparing the shell material of the microcapsule that releases the antibacterial agent in response to electrical stimulation, specifically comprising the following steps: adding the piezoelectric polymer to the solvent and stirring evenly, then adding the spinnable polymer until stirring evenly, thereby obtaining the shell material of the microcapsule that releases the antibacterial agent in response to electrical stimulation; The piezoelectric polymer is a mixture of one or more of polyvinylidene fluoride (PVDF), zinc oxide (ZnO) or barium titanate (BaTiO3), the spinnable polymer is a mixture of chitosan and nanocellulose in a mass ratio of 3 to 6:1 to 3, and the solvent is an acetic acid solution with a mass fraction of 0.5 to 3 wt%.

[0022] The mass percentage of the piezoelectric polymer is 3-35%, the mass percentage of the spinnable polymer is 5-20%, and the mass percentage of the solvent is 45-92%. The stirring temperature of the two stirrings is 20-50° C., the stirring speed is 400-1500 rpm, and the stirring time is 1-12 hours.

[0023] Step 3, preparing microcapsules that release antimicrobial agents in response to electrical stimulation: The core material obtained in step 1 and the shell material obtained in step 2 are placed in two syringes respectively. Through the electrospinning method, under the spinning parameters of push speed ratio of 1:2-2:3, voltage of 15-30 kV, receiving distance of 15-20 cm, spinning temperature of 20-30°C, and humidity of 10%-30%, the spinning solutions in the two syringes are pushed together into a mixed solution of NaOH and Na2SO4 with a temperature of 25-80°C and a mass ratio of 1:1-5. After freeze-drying for 12-36 hours, microcapsules that release antibacterial agents in response to electrical stimulation can be obtained.

[0024] Step 4: Preparation of titanium alloy anti-corrosion self-repairing smart coating for use in marine environments: The microcapsules obtained in step 3, the high molecular polymer containing dynamic covalent bonds, the coating carrier, the diluent, the dispersant and the curing agent are mixed in a certain proportion, and high-speed stirring is performed at a stirring speed of 2000 to 8000 rpm and a stirring time of 5 to 100 min. After the components are evenly dispersed, a titanium alloy anti-corrosion self-repairing smart coating for use in marine environments can be obtained.

[0025] The mass percentages of the raw materials are: 5-25% microcapsules, 5-10% high molecular polymers containing dynamic covalent bonds, 45-65% coating carriers, 1-2% diluents, 1-5% dispersants and 3-20% curing agents, and the total content of the above components is 100%.

[0026] The high molecular polymer containing dynamic covalent bonds is polyimide, polydimethylsiloxane or a polymer of tannic acid and sodium tetraborate; the coating carrier material is epoxy resin, polyester or polyurea; the diluent is n-butanol or xylene; the dispersant is hexadecyltrimethylammonium bromide, polyoxyethylene stearyl ether or sodium polycarboxylate; and the curing agent is diethylenetriamine, polyamide or 2-methylimidazole.

[0027] Example 1 Step 1, preparing the core material of the microcapsule that releases the antibacterial agent in response to electrical stimulation: Silver nanoparticles (AgNP S ) was dissolved in deionized water, wherein the mass fraction of nanosilver was 20%, and stirred at 40°C at a speed of 1000 rpm for 6 hours to obtain a core material; Step 2, preparing the shell material of the microcapsule that releases the antibacterial agent in response to electrical stimulation: Dispersing zinc oxide and polyvinylidene fluoride in an acetic acid solution with a concentration of 1wt%, wherein the mass fraction of zinc oxide is 15%, and the mass fraction of polyvinylidene fluoride is 2%, stirring at a temperature of 40°C and a stirring speed of 1000rpm for 6 hours, adding a mixture of chitosan and nanocellulose with a mass ratio of 3:2, the mass of the mixture accounting for 8% of the total mass, and stirring for another 10 hours to obtain a shell material; Step 3, preparing microcapsules that release antimicrobial agents in response to electrical stimulation: The core material obtained in step 1 and the shell material obtained in step 2 are placed in two syringes respectively. Through the electrospinning method, under the spinning parameters of push speed ratio of 1:2, voltage of 15 kV, receiving distance of 15 cm, spinning temperature of 25 ° C, and humidity of 20%, the spinning solution is pushed into a mixed solution of NaOH and Na2SO4 with a temperature of 60 ° C and a mass ratio of 1:1. After freeze-drying for 24 hours, microcapsules are obtained.

[0028] Step 4: Preparation of titanium alloy anti-corrosion self-repairing smart coating for use in marine environments: The raw materials were weighed according to the following mass percentages: 20% microcapsules, 5% polyimide, 62% epoxy resin, 1% n-butanol, 2% polyoxyethylene stearyl ether, and 10% diethylenetriamine. The mixture was stirred at a high speed of 5000 rpm for 60 minutes to uniformly disperse the components, thereby obtaining a smart coating.

[0029] Example 2 Step 1, preparing the core material of the microcapsule that releases the antibacterial agent in response to electrical stimulation: The MOF nanoparticles (NH2-UiO-66) were dissolved in deionized water, wherein the mass fraction of the nanoparticles was 15%, and the core material was obtained after stirring at 1500 rpm at 50°C for 10 h. Step 2, preparing the shell material of the microcapsule that releases the antibacterial agent in response to electrical stimulation: Disperse zinc oxide in an acetic acid solution with a concentration of 1wt%, wherein the mass fraction of zinc oxide is 20%, stir at a temperature of 40°C and a stirring speed of 1500rpm for 4h, then add a mixture of chitosan and nanocellulose with a mass ratio of 4:1, the mass of the mixture accounts for 15% of the total mass, and stir for another 10h to obtain a shell material; Step 3, preparing microcapsules that release antimicrobial agents in response to electrical stimulation: The core material obtained in step 1 and the shell material obtained in step 2 were placed in two syringes respectively. The spinning solution was pushed into a mixed solution of NaOH and Na2SO4 with a temperature of 60°C and a mass ratio of 1:5 under the spinning parameters of push speed ratio of 1:2, voltage of 20 kV, receiving distance of 18 cm, spinning temperature of 25°C and humidity of 25% by electrospinning. After freeze-drying for 24 hours, microcapsules were obtained.

[0030] Step 4: Preparation of titanium alloy anti-corrosion self-repairing smart coating for use in marine environments: The raw materials were weighed according to the following mass percentages: 25% microcapsules, 6% polymer of tannic acid and sodium tetraborate, 50% polyester, 1% xylene, 3% hexadecyltrimethylammonium bromide, and 15% 2-methylimidazole. The mixture was stirred at a high speed of 8000 rpm for 80 minutes to uniformly disperse the components, thereby obtaining a smart coating.

[0031] Example 3 Step 1, preparing the core material of the microcapsule that releases the antibacterial agent in response to electrical stimulation: Dissolving triclosan in deionized water, wherein the mass fraction of triclosan is 20%, stirring at 50° C. and 1500 rpm for 10 hours, to obtain a core material; Step 2, preparing the shell material of the microcapsule that releases the antibacterial agent in response to electrical stimulation: Barium titanate and polyvinylidene fluoride are dispersed in an acetic acid solution with a concentration of 1wt%, wherein the mass fraction of barium titanate is 25% and the mass fraction of polyvinylidene fluoride is 1%. After stirring for 6 hours at a temperature of 50°C and a stirring speed of 1500rpm, a mixture of chitosan and nanocellulose with a mass ratio of 3:1 is added, and the mass of the mixture accounts for 20% of the total mass. After stirring for another 8 hours, a shell material is obtained; Step 3, preparing microcapsules that release antimicrobial agents in response to electrical stimulation: The core material obtained in step 1 and the shell material obtained in step 2 were placed in two syringes respectively. The spinning solution was pushed into a mixed solution of NaOH and Na2SO4 with a temperature of 50°C and a mass ratio of 1:3 by electrospinning under the spinning parameters of a push speed ratio of 1:2, a voltage of 22 kV, a receiving distance of 15 cm, a spinning temperature of 25°C, and a humidity of 15%. After freeze-drying for 30 hours, microcapsules were obtained.

[0032] Step 4: Preparation of titanium alloy anti-corrosion self-repairing smart coating for use in marine environments: The raw materials were weighed according to the following mass percentages: 15% microcapsules, 8% polydimethylsiloxane, 64.5% polyurea, 1.5% n-butanol, 3% sodium polycarboxylate, and 8% polyamide. The components were uniformly dispersed after high-speed stirring at 6000 rpm for 80 minutes to obtain a smart coating.

[0033] Example 4 Step 1, preparing the core material of the microcapsule that releases the antibacterial agent in response to electrical stimulation: The MOF nanoparticles (NH2-UiO-66) were dissolved in deionized water, wherein the mass fraction of the nanoparticles was 20%, and stirred at 50°C and 1500 rpm for 10 h to obtain the core material; Step 2, preparing the shell material of the microcapsule that releases the antibacterial agent in response to electrical stimulation: Disperse barium titanate and polyvinylidene fluoride in an acetic acid solution with a concentration of 1wt%, wherein the mass fraction of barium titanate is 20%, and the mass fraction of polyvinylidene fluoride is 2%. After stirring at a temperature of 50°C and a stirring speed of 1500rpm for 6 hours, add a mixture of chitosan and nanocellulose with a mass ratio of 3:2, the mass of the mixture accounts for 10% of the total mass, and stir for another 8 hours to obtain a shell material; Step 3, preparing microcapsules that release antimicrobial agents in response to electrical stimulation: The core material obtained in step 1 and the shell material obtained in step 2 were placed in two syringes respectively. The spinning solution was pushed into a mixed solution of NaOH and Na2SO4 with a temperature of 50°C and a mass ratio of 1:2 by electrospinning under the spinning parameters of a push speed ratio of 1:2, a voltage of 25 kV, a receiving distance of 15 cm, a spinning temperature of 25°C, and a humidity of 20%. After freeze-drying for 30 hours, microcapsules were obtained.

[0034] Step 4: Preparation of titanium alloy anti-corrosion self-repairing smart coating for use in marine environments: The raw materials were weighed according to the following mass percentages: 20% microcapsules, 6% polydimethylsiloxane, 60% polyurea, 1% n-butanol, 3% hexadecyltrimethylammonium bromide, and 10% diethylenetriamine. The mixture was stirred at a high speed of 6000 rpm for 80 minutes to uniformly disperse the components, thereby obtaining a smart coating.

[0035] Example 5 Step 1, preparing the core material of the microcapsule that releases the antibacterial agent in response to electrical stimulation: Dissolving nanosilver in ethanol, wherein the mass fraction of nanosilver is 30%, and stirring at 400 rpm for 1 hour at 60°C to obtain a core material; Step 2, preparing the shell material of the microcapsule that releases the antibacterial agent in response to electrical stimulation: Disperse zinc oxide in an acetic acid solution with a concentration of 0.5wt%, wherein the mass fraction of zinc oxide is 3%, stir at a temperature of 20°C and a stirring speed of 1300rpm for 12h, add a mixture of chitosan and nanocellulose with a mass ratio of 1:1, the mass of the mixture accounts for 15% of the total mass, and stir for another 10h to obtain a shell material; Step 3, preparing microcapsules that release antimicrobial agents in response to electrical stimulation: The core material obtained in step 1 and the shell material obtained in step 2 are placed in two syringes respectively. Through the electrospinning method, under the spinning parameters of push speed ratio of 2:3, voltage of 30 kV, receiving distance of 20 cm, spinning temperature of 20°C, and humidity of 30%, the spinning solution is pushed into a mixed solution of NaOH and Na2SO4 with a temperature of 80°C and a mass ratio of 1:2. After freeze-drying for 12 hours, microcapsules are obtained.

[0036] Step 4: Preparation of titanium alloy anti-corrosion self-repairing smart coating for use in marine environments: The raw materials were weighed according to the following mass percentages: 5% microcapsules, 10% polydimethylsiloxane, 65% polyester, 2% xylene, 5% polyoxyethylene stearyl ether, and 13% 2-methylimidazole. The mixture was stirred at a stirring speed of 2000 rpm for 100 min to uniformly disperse the components, thereby obtaining a smart coating.

[0037] Example 6 Step 1, preparing the core material of the microcapsule that releases the antibacterial agent in response to electrical stimulation: The MOF nanoparticles (NH2-UiO-66) were dissolved in dichloromethane, wherein the mass fraction of the nanoparticles was 5%, and stirred at 1500 rpm for 12 h at 20°C to obtain the core material; Step 2, preparing the shell material of the microcapsule that releases the antibacterial agent in response to electrical stimulation: Dispersing polyvinylidene fluoride in an acetic acid solution with a concentration of 3wt%, wherein the mass fraction of polyvinylidene fluoride is 35%, stirring at a temperature of 40°C and a stirring speed of 400rpm for 12h, adding a mixture of chitosan and nanocellulose with a mass ratio of 4:1, the mass of the mixture accounting for 20% of the total mass, and stirring for another 10h to obtain a shell material; Step 3, preparing microcapsules that release antimicrobial agents in response to electrical stimulation: The core material obtained in step 1 and the shell material obtained in step 2 were placed in two syringes respectively. The spinning solution was pushed into a mixed solution of NaOH and Na2SO4 with a temperature of 25°C and a mass ratio of 1:2 by electrospinning under the spinning parameters of push speed ratio of 1:2, voltage of 20 kV, receiving distance of 18 cm, spinning temperature of 30°C, and humidity of 10%. After freeze-drying for 36 hours, microcapsules were obtained.

[0038] Step 4: Preparation of titanium alloy anti-corrosion self-repairing smart coating for use in marine environments: The raw materials were weighed according to the following mass percentages: 23% microcapsules, 10% polyimide, 45% epoxy resin, 1% xylene, 1% hexadecyltrimethylammonium bromide, and 20% 2-methylimidazole. The mixture was stirred at a high speed of 8000 rpm for 10 min to uniformly disperse the components, thereby obtaining a smart coating.

[0039] The impedance modulus of the smart coatings prepared in Examples 1-6 was tested before and after immersion in seawater and compared with the epoxy resin coating. The results are shown in Table 1.

[0040] Table 1 Performance test results comparison table

[0041] It can be seen from the data listed in Table 1 that, compared with the traditional epoxy resin coating material, the titanium alloy anticorrosion self-repairing intelligent coating for marine environment prepared by the method of the present invention not only reduces the risk of coating peeling through energy dissipation and piezoelectric effect, but also realizes the on-demand release of antibacterial agents, improves the corrosion resistance of titanium alloy parts, and achieves the impedance modulus of titanium alloy material maintained at 7.82×10 after 14 days of dynamic seawater immersion. 9 Ω·cm 2 The intelligent coating of the present invention realizes the integration of anti-corrosion and self-repair of titanium alloy materials under harsh conditions, significantly improves the durability and reliability of titanium alloy parts in marine environments, and effectively reduces equipment maintenance costs and replacement frequency.

Claims

1. A method for preparing a titanium alloy anti-corrosion self-repairing intelligent coating for use in marine environments, characterized in that: Follow the steps below to implement it: Step 1, adding the antibacterial agent into the solvent and stirring evenly to prepare the core material of the microcapsule; Step 2, adding the piezoelectric polymer to the solvent and stirring evenly, then adding the spinnable polymer and stirring evenly to prepare the shell material of the microcapsule; Step 3, using the core material obtained in step 1 and the shell material obtained in step 2 as spinning liquid for electrostatic spinning, and freeze-drying the obtained electrostatically spun fibers to obtain microcapsules; Step 4: Mix the microcapsules obtained in step 3, the high molecular polymer containing dynamic covalent bonds, the coating carrier, the diluent, the dispersant and the curing agent, and stir them evenly to obtain the smart coating.

2. The method for preparing the titanium alloy anti-corrosion self-repairing intelligent coating for use in marine environments according to claim 1, characterized in that: In step 1, the antibacterial agent is nanosilver, triclosan or MOF nanoparticles, and the solvent is dichloromethane, ethanol or deionized water; the mass fraction of the antibacterial agent is 5 to 30%.

3. The method for preparing the titanium alloy anti-corrosion self-repairing intelligent coating for use in marine environments according to claim 1, characterized in that: In step 1, the stirring temperature is 20-60° C., the stirring speed is 400-1500 rpm, and the stirring time is 1-12 h.

4. The method for preparing the titanium alloy anti-corrosion self-repairing intelligent coating for use in marine environments according to claim 1, characterized in that: In step 2, the piezoelectric polymer is a mixture of one or more of polyvinylidene fluoride, zinc oxide or barium titanate, the spinnable polymer is a mixture of chitosan and nanocellulose in a mass ratio of 3 to 6:1 to 3, and the solvent is an acetic acid solution with a mass fraction of 0.5 to 3 wt%.

5. The method for preparing the titanium alloy anti-corrosion self-repairing intelligent coating for use in marine environments according to claim 1, characterized in that: In step 2, the mass fraction of the piezoelectric polymer is 3-35%, and the mass fraction of the spinnable polymer is 5-20%.

6. The method for preparing the titanium alloy anti-corrosion self-repairing intelligent coating for use in marine environments according to claim 1, characterized in that: In step 2, the stirring temperature of the two stirrings is 20-50° C., the stirring speed is 400-1500 rpm, and the stirring time is 1-12 h.

7. The method for preparing the titanium alloy anti-corrosion self-repairing intelligent coating for use in marine environments according to claim 1, characterized in that: Step 3 is as follows: The core material and the shell material are placed in two syringes respectively. Under the spinning parameters of push speed ratio of 1:2-2:3, voltage of 15-30 kV, receiving distance of 15-20 cm, temperature of 20-30 ° C, and humidity of 10%-30%, the spinning solutions in the two syringes are pushed together into a mixed solution of NaOH and Na2SO4 for electrospinning. The temperature of the mixed solution is 25-80 ° C and the mass ratio of NaOH and Na2SO4 in the mixed solution is 1:1-5. Then, the microcapsules are obtained by freeze-drying for 12-36 hours.

8. The method for preparing the titanium alloy anti-corrosion self-repairing intelligent coating for use in marine environments according to claim 1, characterized in that: In step 4, the mass percentages of the raw materials are: 5-25% of microcapsules, 5-10% of high molecular polymers containing dynamic covalent bonds, 45-65% of coating carriers, 1-2% of diluents, 1-5% of dispersants and 3-20% of curing agents, and the total content of the above components is 100%.

9. The method for preparing the titanium alloy anti-corrosion self-repairing intelligent coating for use in marine environments according to claim 1, characterized in that: In step 4, the high molecular polymer containing dynamic covalent bonds is polyimide, polydimethylsiloxane or a polymer of tannic acid and sodium tetraborate; the coating carrier is epoxy resin, polyester or polyurea; the diluent is n-butanol or xylene; the dispersant is hexadecyltrimethylammonium bromide, polyoxyethylene stearyl ether or sodium polycarboxylate; the curing agent is diethylenetriamine, polyamide or 2-methylimidazole.

10. The method for preparing the titanium alloy anti-corrosion self-repairing intelligent coating for use in marine environments according to claim 1, characterized in that: In step 4, the stirring speed is 2000-8000 rpm, and the stirring time is 5-100 min.

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