Preparation method of MXene / LDHs heterojunction self-assembled anticorrosion coating

Abstract

The application discloses a preparation method of MXene / LDHs heterojunction self-assembly anticorrosive paint and belongs to the technical field of marine engineering corrosion protection. The preparation method comprises the following steps: S1, adding MXene and LDHs into electrolyte solutions respectively, separating and air-drying MXene and LDHs in the electrolyte solutions to obtain MXene precipitates and LDHs precipitates; S2, respectively re-dissolving the air-dried MXene precipitates and LDHs precipitates in solvents and performing ultrasonic dispersion to obtain MXene solution and LDHs solution; S3, preparing a liquid battery tank, and dividing the liquid battery tank into a cathode area and an anode area by an insulating diaphragm; S4, adding the MXene solution into the cathode area of the liquid battery tank, adding the LDHs solution into the anode area of the liquid battery tank, and opening the power supply after the insulating diaphragm is removed; and S5, performing centrifugal treatment on the mixed solution in the liquid battery tank, collecting MXene / LDHs heterojunction precipitates and adding the MXene / LDHs heterojunction precipitates into anticorrosive paint. The application can improve the corrosion resistance of the paint and reduce the corrosion risk of marine engineering materials.

Description

Technical Field

[0001] This invention relates to the field of marine engineering corrosion protection technology, and in particular to a method for preparing MXene / LDHs heterostructure self-assembled anti-corrosion coatings. Background Technology

[0002] In the marine environment, the corrosion of sea breeze and salt spray significantly reduces the safe service life of engineering structures. Offshore facilities and equipment are more severely corroded, often resulting in problems such as rust, cracking, and coating peeling, and may even cause safety accidents such as fires and collapses.

[0003] In existing technologies, zinc-rich primers, epoxy micaceous iron oxide intermediate coats, and polyurethane topcoats are commonly used as anti-corrosion coatings. However, in the high temperature, high humidity, high salinity, strong ultraviolet radiation, and seasonal typhoon environment of the South China Sea, the long-term performance of the coatings still cannot meet the engineering requirements. When the coating is damaged or cracked, the corrosive medium will cause the phenomenon of "large cathode and small anode" in a local area, which will further aggravate the corrosion of the steel structure substrate at the damaged area and cause more serious rust perforation problems. Summary of the Invention

[0004] The purpose of this invention is to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a method for preparing MXene / LDHs heterojunction self-assembled anti-corrosion coatings, which can improve the anti-corrosion performance of the coatings and reduce the corrosion risk of marine engineering materials.

[0005] The preparation method of MXene / LDHs heterojunction self-assembled anti-corrosion coating according to some embodiments of the present invention includes...

[0006] S1: Add MXene to the electrolyte solution, separate and dry the MXene in the electrolyte solution to obtain MXene precipitate; add LDHs to the electrolyte solution, separate and dry the LDHs in the electrolyte solution to obtain LDHs precipitate.

[0007] S2: The dried MXene precipitate is redissolved in a solvent and ultrasonically dispersed to obtain an MXene solution. The dried LDHs precipitate is redissolved in a solvent to obtain an LDHs solution.

[0008] S3: The liquid battery tank is made using inert electrodes and DC power supply, and an insulating diaphragm divides the liquid battery tank into a cathode area and an anode area;

[0009] S4: Add MXene solution to the cathode region of the liquid battery tank, add LDHs solution to the anode region of the liquid battery tank, remove the insulating membrane and turn on the power to allow MXene and LDHs to react and form an MXene / LDHs heterojunction.

[0010] S5: Centrifuge the mixed solution in the liquid battery tank to collect the MXene / LDHs heterojunction precipitate, and add the obtained MXene / LDHs heterojunction precipitate to the anti-corrosion coating.

[0011] The method for preparing the MXene / LDHs heterojunction self-assembled anti-corrosion coating according to embodiments of the present invention has at least the following beneficial effects: MXene and LDHs are added to an electrolyte solution respectively. The functional groups on the surfaces of MXene and LDHs can adsorb ions in the electrolyte solution. In the liquid battery cell, the surface of MXene carries a negative charge and the surface of LDHs carries a positive charge. By applying an external electric field, the negatively charged MXene particles move towards the positive electrode, while the positively charged LDHs particles move towards the negative electrode. Under the action of the electric field, the MXene and LDHs particles undergo an electrochemical reaction between the cathode and anode regions. The MXene and LDHs particles with opposite charges attract each other under the action of the electric field and self-assemble into a heterostructure, forming a stable bond. Therefore, the physical barrier effect of MXene combined with the ion adsorption and exchange effect of LDHs can enhance the corrosion resistance of coatings. The interaction between the two can transform the anti-corrosion function of the coating from physical barrier to active adsorption and exchange, so that the coating attached to the metal has a more comprehensive and intelligent protective capability when facing corrosive ions. It achieves multi-functional anti-corrosion performance, including targeted adsorption of corrosive media, delaying the diffusion of corrosive media and enhancing the passivation effect of the substrate, thereby reducing the corrosion risk of marine engineering materials.

[0012] According to some embodiments of the present invention, in S1, the electrolyte solution contains F - Ca 2+ Mg 2+ Zn 2+ And Al 3+ .

[0013] According to some embodiments of the present invention, MXene and F - The molar ratio is greater than 1:5.

[0014] According to some embodiments of the present invention, LDHs and Ca 2+ Mg 2+ Zn 2+ And Al 3+ The molar ratio is greater than 1:5.

[0015] According to some embodiments of the present invention, in S1, an electrolyte solution containing MXene is subjected to ultrasonic treatment, static treatment and centrifugation in sequence to obtain an MXene precipitate, and an electrolyte solution containing LDHs is subjected to ultrasonic treatment, static treatment and centrifugation in sequence to obtain an LDHs precipitate.

[0016] According to some embodiments of the present invention, the settling time is greater than 24 hours;

[0017] According to some embodiments of the present invention, in S2, the solvent is pure water.

[0018] According to some embodiments of the present invention, in S2, the ultrasonic dispersion time is greater than 5 minutes;

[0019] According to some embodiments of the present invention, in S4, the voltage applied by the power supply ranges from 5 volts to 10 volts.

[0020] According to some embodiments of the present invention, in S4, the reaction time of MXene and LDHs is greater than or equal to 6 hours.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0023] Figure 1 This is a schematic flowchart of the preparation method of the MXene / LDHs heterojunction self-assembled anti-corrosion coating according to the first aspect of the present invention;

[0024] Figure 2 A comparison diagram of the coating impedance values ​​of a specific embodiment 1 of the preparation method of the MXene / LDHs heterojunction self-assembled anti-corrosion coating according to the first aspect of the present invention and a blank control sample;

[0025] Figure 3 This is a comparison chart of chloride ion permeation of a specific embodiment 2 of the preparation method of the MXene / LDHs heterojunction self-assembled anti-corrosion coating according to the first aspect of the present invention and a blank control sample;

[0026] Figure 4 This is a schematic diagram of the MXene / LDHs heterojunction smart coating protection in the application of the MXene / LDHs heterojunction according to the second aspect of the present invention.

[0027] Figure label:

[0028] MXene / LDHs heterojunction coating 100, MXene / LDHs heterojunction 110;

[0029] Ordinary coating 200;

[0030] Matrix 10, chloride ion 20. Detailed Implementation

[0031] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0032] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0033] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0034] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0035] refer to Figures 1 to 4 A method for preparing an MXene / LDHs heterojunction self-assembled anti-corrosion coating according to an embodiment of the present invention is described.

[0036] like Figure 1 As shown, the method for preparing the MXene / LDHs heterojunction self-assembled anti-corrosion coating according to the first aspect of the present invention includes:

[0037] S1: Add MXene to the electrolyte solution, separate and dry the MXene in the electrolyte solution to obtain MXene precipitate; add LDHs to the electrolyte solution, separate and dry the LDHs in the electrolyte solution to obtain LDHs precipitate.

[0038] Specifically, the electrolyte solution contains F - Ca 2+ Mg 2+ Zn 2+ And Al 3+ MXene and F - The molar ratio of LDHs to Ca is greater than 1:5. 2+ Mg 2+Zn 2+ And Al 3+ The molar ratio is greater than 1:5;

[0039] Specifically, MXene precipitate was obtained by sequentially subjecting an electrolyte solution containing MXene to ultrasonic treatment, settling treatment, and centrifugation treatment, and LDHs precipitate was obtained by sequentially subjecting an electrolyte solution containing LDHs to ultrasonic treatment, settling treatment, and centrifugation treatment, wherein the reaction time for settling treatment was greater than 24 hours.

[0040] S2: The dried MXene precipitate is redissolved in a solvent and ultrasonically dispersed to obtain an MXene solution. The dried LDHs precipitate is redissolved in a solvent to obtain an LDHs solution.

[0041] Specifically, to avoid other impurities in the water from damaging the ions already adsorbed on the surface of MXene and LDHs, pure water is used as the solvent. Thus, by using pure water for ultrasonic dispersion, the MXene and LDHs particles can be effectively redispersed and converted into an aqueous solution without introducing new ions or impurities. This helps to maintain the ionic state and surface properties of MXene and LDHs, thereby providing a clean environment and stable material state for the electrochemical reaction and self-assembly in subsequent steps.

[0042] Specifically, the ultrasonic dispersion time is greater than 5 minutes;

[0043] S3: The liquid battery tank is made using inert electrodes and DC power supply, and an insulating diaphragm divides the liquid battery tank into a cathode area and an anode area;

[0044] S4: Add MXene solution to the cathode region of the liquid battery tank, add LDHs solution to the anode region of the liquid battery tank, remove the insulating membrane and turn on the power to allow MXene and LDHs to react and form an MXene / LDHs heterojunction.

[0045] Specifically, the voltage applied by the power supply is in the range of 5 volts to 10 volts, and the reaction time of MXene and LDHs is not less than 6 hours;

[0046] S5: Centrifuge the mixed solution in the liquid battery tank to collect the MXene / LDHs heterojunction precipitate, and add the obtained MXene / LDHs heterojunction precipitate to the anti-corrosion coating.

[0047] It should be noted that MXene's two-dimensional structure provides a large surface area, offering more barrier interfaces and excellent physical barrier properties. This effectively prevents the penetration and diffusion of external corrosive ions into the coating, thus protecting the metal substrate. LDHs, on the other hand, are layered double hydroxides with excellent ion adsorption and exchange capabilities. They can interact with corrosive ions in the surrounding environment on the coating surface, intercepting and converting corrosive ions through ion exchange. This achieves multiple protection methods for the metal substrate, from physical barrier to cathodic protection. However, simply mixing them will cause the two substances to agglomerate, rendering them ineffective.

[0048] like Figure 4 As shown, when MXene and LDHs are added to an electrolyte solution, the functional groups on the surfaces of MXene and LDHs can adsorb ions in the electrolyte solution. In the liquid battery tank, MXene carries a negative charge and LDHs carries a positive charge. By applying an external electric field, the negatively charged MXene particles move towards the positive electrode, while the positively charged LDHs particles move towards the negative electrode. Under the influence of the electric field, MXene and LDHs particles undergo an electrochemical reaction between the cathode and anode regions. The MXene and LDHs particles with opposite charges attract each other and self-assemble into a heterogeneous structure, forming a stable bond. Thus, the physical barrier effect of MXene combined with the ion adsorption and exchange effect of LDHs enhances the corrosion resistance of the coating. The interaction between the two transforms the anti-corrosion function of the coating from physical barrier to active adsorption and exchange, giving the coating attached to the metal a more comprehensive and intelligent protective capability against corrosive ions. This achieves multifunctional anti-corrosion performance, including targeted adsorption of corrosive media, delaying the diffusion of corrosive media, and enhancing substrate passivation, thereby reducing the corrosion risk of marine engineering materials.

[0049] The preparation method of this MXene / LDHs heterojunction self-assembled anti-corrosion coating is illustrated below with two specific examples. Specific Implementation Example 1:

[0051] S1: Weigh 50 mg of MXene, 100 mg of LDHs and 100 mg of MgAl-LDHs powder samples. Add 50 mg of MXene to 100 mL of 1.5 mol / L NaF solution and add 100 mg of LDHs to 100 mL of 2 mol / L MgSO4 solution. Disperse the NaF solution containing MXene and the MgSO4 solution containing LDHs separately by ultrasonication for 5 min and let stand for 48 hours to allow them to fully adsorb ions. Centrifuge and collect the corresponding precipitates. Dry them in a cool place and collect them for later use.

[0052] S2: Weigh approximately 50 mg of dried MXene and approximately 100 mg of LDHs respectively. Weigh two 100 mL beakers of pure water and label them A and B respectively. Add 50 mg of MXene to beaker A and 100 mg of LDHs to beaker B. Disperse the two solutions by ultrasonication to prepare aqueous solutions of the two materials.

[0053] S3: A liquid battery tank with dimensions of 30cm×10cm×10cm is made of insulating plastic. The middle of the liquid battery tank is divided into a cathode area and an anode area by an insulating diaphragm. A titanium mesh inert electrode with dimensions of 10cm×10cm is placed in each of the two areas. The power supply is a DC power supply.

[0054] S4: Add MXene solution to the cathode area, add LDHs solution to the anode area, remove the insulating diaphragm, turn on the power, apply an 8V DC voltage, and set the reaction time to 8 hours;

[0055] S5: After the reaction is complete, the liquid in the liquid battery tank is centrifuged and the obtained MXene / LDHs heterojunction precipitate is collected, dried in a cool place, and then collected for later use.

[0056] The MXene / LDHs heterojunction prepared by the method of preparing MXene / LDHs heterojunction self-assembly anti-corrosion coating is added to the coating. The specific method is as follows: 5g of epoxy resin and 100mg of MXene / LDHs heterojunction are weighed, and the MXene / LDHs heterojunction is added to the epoxy resin. The mixture is stirred for 1 hour to make it evenly mixed, and an active protective coating is obtained.

[0057] A 10cm × 10cm Q235 steel plate was selected. After surface treatment, a novel MXene / LDHs heterojunction doped coating and an undoped epoxy resin coating were applied to different areas. The coating thickness was approximately 200 micrometers. After coating and drying, an accelerated test was conducted using a neutral salt spray test to measure the coating impedance values, and the results were obtained as follows: Figure 2 The results show that, thanks to the MXene barrier effect and LDHs ion adsorption and exchange, the impedance value of the novel coating doped with MXene / LDHs heterojunction is significantly higher than that of the blank control sample, both in the early stage of the experiment and after a long period of salt spray test. Therefore, the novel coating doped with MXene / LDHs heterojunction has strong anti-corrosion performance. Thus, the MXene / LDHs heterojunction plays a key role in improving the coating performance. Specific Implementation Example 2:

[0059] S1: Weigh 100 mg of MXene and 200 mg of CaZn-LDHs respectively. Add 100 mg of MXene to 100 mL of 3 mol / L NaF solution and add 200 mg of LDHs to 100 mL of 4 mol / L ZnSO4 solution. Disperse the NaF solution containing MXene and the MgSO4 solution containing LDHs separately by ultrasonication for 10 min and let stand for 48 hours to allow MXene and LDHs to fully adsorb ions. Then centrifuge and collect the precipitate. Dry it in a cool place and collect it for later use.

[0060] S2: Weigh approximately 50 mg of dried MXene and approximately 100 mg of LDHs respectively. Weigh two 100 mL beakers of pure water and label them A and B respectively. Add 50 mg of MXene to beaker A and 100 mg of LDHs to beaker B. Disperse the two solutions by sonication for 10 minutes to prepare aqueous solutions of the two materials.

[0061] S3: A liquid battery tank with dimensions of 30cm×10cm×10cm is made of insulating plastic. The middle of the liquid battery tank is divided into a cathode area and an anode area by an insulating diaphragm. A titanium mesh inert electrode with dimensions of 10cm×10cm is placed in each of the two areas. The power supply is a DC power supply.

[0062] S4: Add MXene solution to the cathode area, add LDHs solution to the anode area, remove the insulating diaphragm, turn on the power, apply 10V DC voltage, and set the reaction time to 12 hours;

[0063] S5: After the reaction is complete, the liquid in the liquid battery tank is centrifuged and the obtained MXene / LDHs heterojunction precipitate is collected, dried in a cool place, and then collected for later use.

[0064] The MXene / LDHs heterojunction prepared by the method of preparing MXene / LDHs heterojunction self-assembly anti-corrosion coating is added to the coating. The specific method is as follows: 5g of epoxy resin and 100mg of MXene / LDHs heterojunction are weighed, and the MXene / LDHs heterojunction is added to the epoxy resin. The mixture is stirred for 1 hour to make it evenly mixed, and an active protective coating is obtained.

[0065] A 10cm x 10cm Q235 steel plate was selected. After surface treatment, a novel MXene / LDHs heterojunction doped coating and an undoped epoxy resin coating were applied to different areas. The coating thickness was approximately 200 micrometers. After coating and drying, the coating performance was evaluated using a chloride ion penetration resistance test. The chloride ion penetration test results are as follows: Figure 3As shown, thanks to the barrier effect of MXene and the ion adsorption and exchange of LDHs, the test value of the novel coating doped with MXene / LDHs heterojunction is only 23.63% of that of the blank control sample. This indicates that the novel coating doped with MXene / LDHs heterojunction has strong resistance to chloride ion penetration. Therefore, the MXene / LDHs heterojunction plays a key role in improving the coating performance.

[0066] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for preparing an MXene / LDHs heterojunction self-assembled anti-corrosion coating, characterized in that, include: S1: Add MXene to the electrolyte solution, separate and dry the MXene in the electrolyte solution to obtain MXene precipitate; add LDHs to the electrolyte solution, separate and dry the LDHs in the electrolyte solution to obtain LDHs precipitate. S2: The dried MXene precipitate is redissolved in a solvent and ultrasonically dispersed to obtain an MXene solution. The dried LDHs precipitate is then redissolved in a solvent to obtain an LDHs solution. The MXene solution contains F. - LDHs solutions contain Ca 2+ Mg 2+ Zn 2+ And Al 3+ ; S3: The liquid battery tank is made using inert electrodes and DC power supply, and an insulating diaphragm divides the liquid battery tank into a cathode area and an anode area; S4: Add MXene solution to the cathode region of the liquid battery tank, add LDHs solution to the anode region of the liquid battery tank, remove the insulating membrane and turn on the power to allow MXene and LDHs to react and form an MXene / LDHs heterojunction. S5: Centrifuge the mixed solution in the liquid battery tank to collect the MXene / LDHs heterojunction precipitate, and add the obtained MXene / LDHs heterojunction precipitate to the anti-corrosion coating.

2. The preparation method of the MXene / LDHs heterojunction self-assembled anti-corrosion coating according to claim 1, characterized in that, MXene and F - The molar ratio is greater than 1:

5.

3. The preparation method of the MXene / LDHs heterojunction self-assembled anti-corrosion coating according to claim 1, characterized in that, LDHs and Ca 2+ Mg 2+ Zn 2+ And Al 3+ The molar ratio is greater than 1:

5.

4. The preparation method of the MXene / LDHs heterojunction self-assembled anti-corrosion coating according to claim 1, characterized in that, In S1, an electrolyte solution containing MXene is subjected to ultrasonic treatment, static treatment, and centrifugation in sequence to obtain MXene precipitate, and an electrolyte solution containing LDHs is subjected to ultrasonic treatment, static treatment, and centrifugation in sequence to obtain LDHs precipitate.

5. The preparation method of the MXene / LDHs heterojunction self-assembled anti-corrosion coating according to claim 4, characterized in that, The settling time should be greater than 24 hours.

6. The method for preparing the MXene / LDHs heterojunction self-assembled anti-corrosion coating according to claim 1, characterized in that, In S2, the solvent is pure water.

7. The method for preparing the MXene / LDHs heterojunction self-assembled anti-corrosion coating according to claim 1, characterized in that, In S2, the ultrasonic dispersion time is greater than 5 minutes.

8. The method for preparing the MXene / LDHs heterojunction self-assembled anti-corrosion coating according to claim 1, characterized in that, In S4, the voltage applied by the power supply ranges from 5 volts to 10 volts.

9. The method for preparing the MXene / LDHs heterojunction self-assembled anti-corrosion coating according to claim 1, characterized in that, The reaction time of MXene and LDHs is greater than or equal to 6 hours.

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