A dynamically covalently crosslinked I-PDMS / DEA@α-ZrP-SH self-healing anti-friction superhydrophobic anti-corrosion coating, its preparation method, and coating layer.

Abstract

This invention relates to a dynamically covalently crosslinked I-PDMS / DEA@α-ZrP-SH self-healing anti-friction superhydrophobic anti-corrosion coating, its preparation method, and the coating itself. It relates to the field of anti-corrosion coating technology and aims to solve the problem that existing superhydrophobic anti-corrosion coatings often suffer from reduced superhydrophobic performance and low anti-corrosion efficiency due to mechanical friction and harsh working environments, or are damaged by impact, thus causing the anti-corrosion ability to fail. The process includes: (1) preparing α-ZrP nanosheets using zirconium oxychloride octahydrate and phosphoric acid solution as raw materials; slowly adding diethanolamine to the α-ZrP suspension to intercalate diethanolamine (DEA) into α-ZrP to obtain DEA@α-ZrP; (2) adding n-dodecyl mercaptan to the DEA@α-ZrP suspension and allowing it to stand to graft n-dodecyl mercaptan onto the DEA@α-ZrP surface to obtain DEA@α-ZrP-SH nanosheets; (3) using PDMS as a coating substrate and diluting it, adding BTC to mix and obtain I-PDMS diluent, then adding DEA@α-ZrP-SH nanosheets, dispersing them evenly, adding a curing agent to obtain the self-cleaning thermally conductive and anti-corrosion coating of the present invention.

Description

Technical Field

[0001] This invention relates to the field of anti-corrosion coating technology, and more specifically, to a dynamically covalently cross-linked I-PDMS / DEA@α-ZrP-SH self-healing anti-friction superhydrophobic anti-corrosion coating, its preparation method, and the coating itself. Background Technology

[0002] Superhydrophobic coatings can keep metal surfaces non-wetting, achieving corrosion protection by reducing the interaction between the metal surface and corrosive media in water. Many aquatic animals and plants have superhydrophobic surfaces, possessing self-cleaning, anti-icing, anti-corrosion, and anti-fouling capabilities. Research indicates that because the stacked micro / nano structures of superhydrophobic surfaces provide an air layer between the solid surface and the droplet, reducing the actual contact area, the high air / solid ratio of this layered structure directly leads to droplet rolling. The synergistic effect of low surface energy materials and micro / nano-scale layered structures produces superhydrophobic surfaces. These studies have also proven applicable to the design of artificial surfaces.

[0003] Traditional superhydrophobic coatings achieve superhydrophobicity by embedding nanoparticles into the coating substrate to create a rough surface and then modifying the rough structure with low surface energy materials. However, under continuous friction or impact, the nanoparticles wear off, and defects appear in the rough structure, leading to a decrease in superhydrophobicity. Furthermore, when traditional coatings operate in harsh environments (acid / alkali solutions or organic solvent washing, ultraviolet radiation, high temperatures, etc.), the surface functional groups change or the hydrophobic long chains decompose, further reducing superhydrophobicity. Therefore, existing superhydrophobic anti-corrosion coatings still need improvement to meet the needs of harsh working environments.

[0004] Traditional superhydrophobic coatings suffer from poor ductility and relaxation, making them difficult to recover from deformation. Dynamic covalent bonds, which can continuously form and break without side reactions, have attracted attention in the synthesis and design of adaptive and dynamic polymer networks. During polymer network formation, the reversibility of these bonds generates dynamic network behaviors such as self-healing, ductility, and recyclability, meeting the design requirements of self-healing, anti-friction, and superhydrophobic coatings. Imine bonds are a type of dynamic covalent bond that can be obtained under mild conditions from the reaction of aldehyde and amino groups, with a bond dissociation energy of 147 kcal·mol⁻¹. -1 Polymer materials composed of imine bonds exhibit excellent mechanical properties. However, single dynamic covalent polymer networks have low corrosion resistance, contain pores during formation, cannot form a dense coating, and have poor abrasion resistance; the coating surface is easily contaminated with dirt, making it unsuitable for use as a self-cleaning anti-corrosion coating alone. It is necessary to compensate for the defects inside the coating to improve corrosion resistance. Summary of the Invention

[0005] The technical problem to be solved by this invention is:

[0006] In the prior art, superhydrophobic anti-corrosion coatings often suffer from reduced superhydrophobic performance and low anti-corrosion efficiency due to mechanical friction and harsh working environments, or the coating may be damaged by impact, thus causing the anti-corrosion ability to fail.

[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0008] This invention provides a method for preparing a dynamically covalently crosslinked I-PDMS / DEA@α-ZrP-SH self-healing anti-friction superhydrophobic anti-corrosion coating, comprising the following steps:

[0009] (1) α-ZrP nanosheets were prepared by hydrothermal reaction using zirconium oxychloride octahydrate and phosphoric acid solution as raw materials; α-ZrP nanosheets were added to organic solvent 1 to prepare α-ZrP suspension; diethanolamine was slowly added to α-ZrP suspension, and the mixture was sonicated and stirred to allow diethanolamine (DEA) to intercalate into α-ZrP to prepare DEA@α-ZrP.

[0010] (2) DEA@α-ZrP was dispersed in organic solvent II to obtain DEA@α-ZrP suspension. Dodecyl mercaptan was added to DEA@α-ZrP suspension and allowed to stand to allow dodecyl mercaptan to be grafted onto the surface of DEA@α-ZrP to obtain DEA@α-ZrP-SH nanosheets.

[0011] (3) Polydimethylsiloxane (PDMS) was used as the coating substrate and diluted. Trimethylolpropionate (BTC) was added and mixed evenly to obtain I-PDMS diluent. DEA@α-ZrP-SH nanosheets were then added to the I-PDMS diluent and ultrasonically dispersed to make them evenly dispersed. Finally, a curing agent was added to obtain I-PDMS / DEA@α-ZrP-SH self-cleaning thermally conductive and anti-corrosion coating.

[0012] Furthermore, the hydrothermal reaction temperature in step (1) is 150–300 °C.

[0013] Furthermore, in step (1), the concentration of the phosphoric acid solution is 9M, and the ratio of the phosphoric acid solution to zirconium oxychloride octahydrate is 40ml: 3.5~5g.

[0014] Further, in step (1), the organic solvent is acetone, and the ratio of α-ZrP, acetone and diethanolamine is 1g:100ml:(1.5~3)mL.

[0015] Furthermore, in step (1), the ultrasonic time is 1 to 4 hours, and the stirring time is 2 to 5 hours.

[0016] Furthermore, in step (2), the organic solvent is ethanol, and the ratio of DEA@α-ZrP, ethanol and n-dodecyl mercaptan is: 1g: 40ml: (0.645-1.146)g.

[0017] Furthermore, in step 2, the settling time is 2–5 hours to allow n-dodecyl mercaptan to be grafted onto the DEA@α-ZrP surface.

[0018] Further, in step (3), polydimethylsiloxane is diluted with tetrahydrofuran, and the ratio of polydimethylsiloxane, tetrahydrofuran dilution, pyromellitic methyl ester and DEA@α-ZrP-SH is: 0.8g: 7mL: (0.025~0.01)g: (0.5~2)g.

[0019] The present invention also provides a dynamically covalently crosslinked I-PDMS / DEA@α-ZrP-SH self-healing anti-friction superhydrophobic anti-corrosion coating, which is prepared by any of the methods described in the above technical solutions.

[0020] The present invention also provides a self-healing, anti-friction, superhydrophobic anti-corrosion coating, wherein the anti-corrosion coating is formed by the anti-corrosion coating described in the above technical solution.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] The DEA@α-ZrP-SH nanosheets of this invention exfoliate the layered structure of α-ZrP through small molecule amine intercalation, improving the dispersibility of the filler. During coating formation, the DEA@α-ZrP-SH nanosheets form a robust, layered, rough structure through van der Waals forces. Simultaneously, due to the dynamic characteristics of the I-PDMS crosslinking network, the coating can rapidly recover its superhydrophobic properties after a decrease in superhydrophobicity caused by friction. The I-PDMS / DEA@α-ZrP-SH coating of this invention exhibits dynamic characteristics. Free amine and aldehyde groups exist within the coating. After the decomposition of long-chain substances on the surface, driven by the minimization of free energy, the free amine and aldehyde groups diffuse towards the damaged areas and spontaneously recombine, maintaining the original low surface energy.

[0023] The self-healing superhydrophobic anti-friction and anti-corrosion coating of the present invention, I-PDMS / DEA@α-ZrP-SH, is applied to the surface of equipment to form a coating. On the one hand, DEA@α-ZrP-SH forms a micropillar structure on the surface of I-PDMS, enabling the coating to achieve self-cleaning, making it less prone to dirt adhesion and ice formation, while also providing good anti-corrosion effect. On the other hand, the self-healing and anti-friction capabilities of the I-PDMS / DEA@α-ZrP-SH coating effectively extend the service life of the coating under mechanical friction and harsh environments. Attached Figure Description

[0024] Figure 1The infrared spectra of α-ZrP, DEA@α-ZrP, and DEA@α-ZrP-SH in the embodiments of the present invention are shown below.

[0025] Figure 2 The proton nuclear magnetic resonance spectra of PDMS and I-PDMS in the embodiments of the present invention;

[0026] Figure 3 Here is a SEM image of the coating in an embodiment of the present invention;

[0027] Figure 4 These are AFM scan images of the coating in an embodiment of the present invention;

[0028] Figure 5 These are photographs of the coating and water contact angle in embodiments of the present invention;

[0029] Figure 6 The self-healing test results of the coating in the embodiments of the present invention. Figure 1 ;

[0030] Figure 7 The self-healing test results of the coating in the embodiments of the present invention. Figure 2 . Detailed Implementation

[0031] To enable those skilled in the art to better understand the present invention, exemplary embodiments or examples of the present invention will be described below in conjunction with the accompanying drawings. Obviously, the described embodiments or examples are merely some, not all, of the embodiments or examples of the present invention. All other embodiments or examples obtained by those skilled in the art based on the embodiments or examples of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0033] In a typical embodiment of the present invention, a method for preparing a dynamically covalently crosslinked I-PDMS / DEA@α-ZrP-SH self-healing anti-friction superhydrophobic anti-corrosion coating is provided, comprising the following steps:

[0034] (1) α-ZrP nanosheets were prepared by hydrothermal reaction using zirconium oxychloride octahydrate and phosphoric acid solution as raw materials; α-ZrP nanosheets were added to organic solvent 1 to prepare α-ZrP suspension; diethanolamine was slowly added to α-ZrP suspension, and the mixture was sonicated and stirred to allow diethanolamine (DEA) to intercalate into α-ZrP to prepare DEA@α-ZrP.

[0035] (2) DEA@α-ZrP was dispersed in organic solvent II to obtain DEA@α-ZrP suspension. Dodecyl mercaptan was added to DEA@α-ZrP suspension and allowed to stand to allow dodecyl mercaptan to be grafted onto the surface of DEA@α-ZrP to obtain DEA@α-ZrP-SH nanosheets.

[0036] (3) Polydimethylsiloxane (PDMS) was used as the coating substrate and diluted. Trimethylolpropionate (BTC) was added and mixed evenly to obtain I-PDMS diluent. DEA@α-ZrP-SH nanosheets were then added to the I-PDMS diluent and ultrasonically dispersed to make them evenly dispersed. Finally, a curing agent was added to obtain I-PDMS / DEA@α-ZrP-SH self-cleaning anti-corrosion coating.

[0037] In a typical embodiment of the present invention, the hydrothermal reaction temperature in step (1) is preferably 150–300°C. During the hydrothermal preparation of α-ZrP, the reaction temperature has a significant impact on the aspect ratio of the nanosheets. When the aspect ratio of α-ZrP is too large, a sharper, rougher structure can be obtained, which is beneficial for the formation of the superhydrophobic surface microstructure. However, the surface structural stability of the coating will be weakened, and the labyrinth effect inside the coating will be weakened, resulting in a decrease in corrosion resistance. When the aspect ratio is too low, the specific surface area of ​​the nanosheets increases, the interlayer van der Waals forces become stronger, and dispersion becomes difficult. In this embodiment, the inventors, through numerous experiments, have preferred a hydrothermal reaction temperature of 150–300°C.

[0038] In a typical embodiment of the present invention, the concentration of phosphoric acid solution in step (1) is preferably 9M, and the ratio of phosphoric acid solution to zirconium oxychloride octahydrate is preferably 40ml:3.5-5g. The concentration of phosphoric acid solution affects the crystal structure of α-ZrP during the hydrothermal preparation process. In this embodiment, the inventors, through extensive experimentation, have preferred a phosphoric acid solution concentration of 9M.

[0039] In a typical embodiment of the present invention, since diethanolamine is easily miscible in acetone to form a uniform dilution, the intercalation process is uniform. In step (1), the organic solvent is preferably acetone, and the ratio of α-ZrP, acetone, and diethanolamine is preferably 1g:100ml:(1.5~3)mL. In this embodiment, the inventors have determined the preferred ratio of α-ZrP, acetone, and diethanolamine through numerous experiments.

[0040] In a typical embodiment of the present invention, the ultrasonic time in step (1) is preferably 1 to 4 hours, and the stirring time is preferably 2 to 5 hours.

[0041] In a typical embodiment of the present invention, since dodecanethiol has good solubility in ethanol and α-ZrP can form a suspension in ethanol, the grafting effect is good. In step (2), the organic solvent is preferably ethanol, and the ratio of DEA@α-ZrP, ethanol and dodecanethiol is preferably 1g:40ml:(0.645-1.146)g.

[0042] In a typical embodiment of the present invention, the preferred settling time in step 2 is 2 to 5 hours to allow n-dodecyl mercaptan to be grafted onto the DEA@α-ZrP surface.

[0043] In a typical embodiment of the present invention, since tetrahydrofuran is easily volatile at room temperature, it has good compatibility with nanosheets as a PDMS diluent, making the coating uniformly mixed and the resulting coating less prone to defects; in step (3), tetrahydrofuran is preferably used to dilute polydimethylsiloxane, and the preferred ratio of polydimethylsiloxane, tetrahydrofuran dilution, pyromellitic methylformaldehyde and DEA@α-ZrP-SH is 0.8g:7mL:(0.025~0.01)g:(0.5~2)g.

[0044] The beneficial effects of this application will be explained below with reference to specific embodiments and comparative examples.

[0045] Example 1

[0046] (1) Preparation of α-ZrP

[0047] Take 30.55 mL of 95 wt% phosphoric acid, add 19.45 mL of deionized water, stir and mix well, then transfer to a 50 mL volumetric flask to prepare a 9 M phosphoric acid solution; take 40 mL of the 9 M phosphoric acid solution, add 3.5 g of ground zirconium oxychloride octahydrate to the phosphoric acid solution, stir and mix well, then place in a 50 mL Teflon-lined reactor and seal, and perform hydrothermal reaction at 200 °C for 5 h. After cooling to room temperature, take out the product, wash and centrifuge, dry under vacuum at 60 °C, and grind to obtain pure layered α-ZrP.

[0048] Preparation of DEA@α-ZrP

[0049] 1 g of α-ZrP was added to 100 mL of acetone, stirred and mixed evenly, and then sonicated to obtain an α-ZrP acetone suspension. Under sonication conditions, 1.5 mL of diethanolamine was added dropwise to the α-ZrP acetone suspension, and sonication was continued for 1 h. Then, the mixture was stirred at room temperature for 5 h until the reaction was complete. After the reaction was completed, the mixture was centrifuged at 5000 r / min, washed repeatedly with ethanol 3 times, vacuum dried at 60 °C, and ground to obtain DEA@α-ZrP.

[0050] (2) Preparation of DEA@α-ZrP-SH

[0051] Weigh 1g of DEA@α-ZrP and place it in a beaker. Add 40mL of ethanol as a solvent and sonicate for 10min to obtain a DEA@α-ZrP ethanol suspension. Add 0.645g of n-dodecyl mercaptan to the DEA@α-ZrP ethanol suspension, stir and mix evenly, and let stand for 3h to allow n-dodecyl mercaptan to be grafted onto the DEA@α-ZrP surface. After the reaction is complete, centrifuge at 5000rpm, wash repeatedly with ethanol and centrifuge 3 times, dry at 70℃, and grind to obtain DEA@α-ZrP-SH nanosheets.

[0052] (3) Preparation of self-cleaning anti-corrosion coatings

[0053] Add 7 mL of tetrahydrofuran to 0.8 g of polydimethylsiloxane and stir magnetically until homogeneous to obtain a diluted polydimethylsiloxane solution. Add 0.02 g of trimesin to the diluted polydimethylsiloxane solution and sonicate for 25 min to prepare I-PDMS. Add 0.5 g of DEA@α-ZrP-SH nanosheets to the I-PDMS solution, stir and mix again, and sonicate for 10 min to uniformly disperse the nanosheets in the diluted I-PDMS solution to obtain a self-cleaning preservative emulsion. Add 0.08 g of Dow Corning Sylgard 184 curing agent and stir for 10 min to obtain an I-PDMS / DEA@α-ZrP-SH coating.

[0054] Example 2

[0055] The difference between this embodiment and Embodiment 1 is that,

[0056] In step (1), 4g of ground zirconium oxychloride octahydrate was added to the phosphoric acid solution. In the preparation of DEA@α-ZrP, 2mL of diethanolamine was added dropwise to the α-ZrP acetone suspension.

[0057] Example 3

[0058] The difference between this embodiment and Embodiment 1 is that,

[0059] In step (1), 4.5 g of ground zirconium oxychloride octahydrate was added to the phosphoric acid solution. In the preparation of DEA@α-ZrP, 2.5 mL of diethanolamine was added dropwise to the α-ZrP acetone suspension.

[0060] Example 4

[0061] The difference between this embodiment and Embodiment 1 is that,

[0062] In step (1), 5g of ground zirconium oxychloride octahydrate was added to the phosphoric acid solution. In the preparation of DEA@α-ZrP, 3mL of diethanolamine was added dropwise to the α-ZrP acetone suspension.

[0063] Example 5

[0064] The difference between this embodiment and Embodiment 2 is that,

[0065] In step (2), 0.845 g of n-dodecyl mercaptan was added to the DEA@α-ZrP ethanol suspension.

[0066] Example 6

[0067] The difference between this embodiment and embodiment 3 is that,

[0068] In step (2), 0.977 g of n-dodecyl mercaptan was added to the DEA@α-ZrP ethanol suspension.

[0069] Example 7

[0070] The difference between this embodiment and embodiment 4 is that,

[0071] In step (2), 1.146 g of n-dodecyl mercaptan was added to the DEA@α-ZrP ethanol suspension.

[0072] Example 8

[0073] The difference between this embodiment and embodiment 5 is that,

[0074] In step (3), 0.04 g of pyromellitic aldehyde is added to the dilution of polydimethylsiloxane.

[0075] Example 9

[0076] The difference between this embodiment and embodiment 6 is that,

[0077] In step (3), 0.06 g of pyromellitic aldehyde is added to the dilution of polydimethylsiloxane.

[0078] Example 10

[0079] The difference between this embodiment and embodiment 7 is that,

[0080] In step (3), 0.08 g of pyromellitic aldehyde is added to the dilution of polydimethylsiloxane.

[0081] Example 11

[0082] The difference between this embodiment and embodiment 5 is that,

[0083] In step (1), the hydrothermal reaction conditions for the preparation of α-ZrP are: hydrothermal reaction at 150℃ for 5h.

[0084] Example 12

[0085] The difference between this embodiment and embodiment 5 is that,

[0086] In step (1), the hydrothermal reaction conditions for the preparation of α-ZrP are: hydrothermal reaction at 250℃ for 5 hours.

[0087] Example 13

[0088] The difference between this embodiment and embodiment 5 is that,

[0089] In step (1) the preparation of α-ZrP, the hydrothermal reaction conditions are: hydrothermal reaction at 300℃ for 5h.

[0090] Example 14

[0091] The difference between this embodiment and embodiment 5 is that,

[0092] In step (1) of the preparation of DEA@α-ZrP, 2 mL of diethanolamine was added dropwise to the α-ZrP acetone suspension, and sonicated for 2 h and stirred at room temperature for 4 h.

[0093] Example 15

[0094] The difference between this embodiment and embodiment 5 is that,

[0095] In step (1) of the preparation of DEA@α-ZrP, 2 mL of diethanolamine was added dropwise to the α-ZrP acetone suspension, and the mixture was sonicated for 3 h and stirred at room temperature for 3 h.

[0096] Example 16

[0097] The difference between this embodiment and embodiment 5 is that,

[0098] In step (1) of the preparation of DEA@α-ZrP, 2 mL of diethanolamine was added dropwise to the α-ZrP acetone suspension, and the mixture was sonicated for 4 h and stirred at room temperature for 2 h.

[0099] Example 17

[0100] The difference between this embodiment and embodiment 14 is that,

[0101] In step (2), 0.845 g of n-dodecyl mercaptan was added to the DEA@α-ZrP ethanol suspension, stirred and mixed evenly, and allowed to stand for 2 h to allow n-dodecyl mercaptan to be grafted onto the DEA@α-ZrP surface.

[0102] Example 18

[0103] The difference between this embodiment and embodiment 14 is that,

[0104] In step (2), 0.845 g of n-dodecyl mercaptan was added to the DEA@α-ZrP ethanol suspension, stirred and mixed evenly, and allowed to stand for 4 h to allow n-dodecyl mercaptan to be grafted onto the DEA@α-ZrP surface.

[0105] Example 19

[0106] The difference between this embodiment and embodiment 14 is that,

[0107] In step (2), 0.845 g of n-dodecyl mercaptan was added to the DEA@α-ZrP ethanol suspension, stirred and mixed evenly, and allowed to stand for 5 h to allow n-dodecyl mercaptan to be grafted onto the DEA@α-ZrP surface.

[0108] Example 20

[0109] The difference between this embodiment and embodiment 18 is that,

[0110] Step (3) Add 2g of DEA@α-ZrP-SH nanosheets to I-PDMS, stir and mix again, and sonicate for 10min to make the nanosheets uniformly dispersed in the diluted I-PDMS solution to obtain a self-cleaning preservative emulsion.

[0111] Example 21

[0112] The difference between this embodiment and embodiment 18 is that,

[0113] Step (3) Add 1.5g of DEA@α-ZrP-SH nanosheets to I-PDMS, stir and mix again, and sonicate for 10min to make the nanosheets uniformly dispersed in the diluted I-PDMS solution to obtain a self-cleaning preservative emulsion.

[0114] Example 22

[0115] The difference between this embodiment and embodiment 18 is that,

[0116] Step (3) Add 1g of DEA@α-ZrP-SH nanosheets to I-PDMS, stir and mix again, and sonicate for 10min to make the nanosheets uniformly dispersed in the diluted I-PDMS solution to obtain a self-cleaning preservative emulsion.

[0117] Comparative Example 1

[0118] (1) Preparation of α-ZrP

[0119] Take 30.55 mL of 95 wt% phosphoric acid, add 19.45 mL of deionized water, stir and mix well, then transfer to a 50 mL volumetric flask to prepare a 9 M phosphoric acid solution; take 40 mL of the 9 M phosphoric acid solution, add 4 g of ground zirconium oxychloride octahydrate to the phosphoric acid solution, stir and mix well, then place in a 50 mL Teflon-lined reactor and seal, and hydrothermally react at 200 °C for 5 h. After cooling to room temperature, take out the product, wash and centrifuge, dry under vacuum at 60 °C, and grind to obtain pure layered α-ZrP.

[0120] Preparation of DEA@α-ZrP

[0121] 1 g of α-ZrP was added to 100 mL of acetone, stirred and mixed evenly, and then sonicated to obtain an α-ZrP acetone suspension. Under sonication conditions, 2 mL of diethanolamine was added dropwise to the α-ZrP acetone suspension, and sonication was continued for 2 h. Then, the mixture was stirred at room temperature for 4 h until the reaction was complete. After the reaction was completed, the mixture was centrifuged at 5000 r / min, washed repeatedly with ethanol 3 times, dried under vacuum at 60 °C, and ground to obtain DEA@α-ZrP.

[0122] (2) Preparation of DEA@α-ZrP-SH

[0123] Weigh 1g of DEA@α-ZrP and place it in a beaker. Add 40mL of ethanol as a solvent and sonicate for 10min to obtain a DEA@α-ZrP ethanol suspension. Add 0.845g of n-dodecyl mercaptan to the DEA@α-ZrP ethanol suspension, stir and mix evenly, and let stand for 4h to allow n-dodecyl mercaptan to be grafted onto the DEA@α-ZrP surface. After the reaction is complete, centrifuge at 5000rpm, wash repeatedly with ethanol and centrifuge 3 times, dry at 70℃, and grind to obtain DEA@α-ZrP-SH nanosheets.

[0124] (3) Preparation of self-cleaning anti-corrosion coatings

[0125] Add 7 mL of tetrahydrofuran to 0.8 g of polydimethylsiloxane and stir magnetically until homogeneous to obtain a PDMS dilution. Add 1 g of DEA@α-ZrP-SH nanosheets, stir and mix again, and sonicate for 10 min to uniformly disperse the nanosheets in the PDMS dilution to obtain a self-cleaning preservative emulsion. Add 0.08 g of Dow Corning Sylgard 184 curing agent and stir for 10 min to obtain an I-PDMS / DEA@α-ZrP-SH coating.

[0126] Comparative Example 2

[0127] (1) Preparation of α-ZrP

[0128] Take 30.55 mL of 95 wt% phosphoric acid, add 19.45 mL of deionized water, stir and mix well, then transfer to a 50 mL volumetric flask to prepare a 9 M phosphoric acid solution; take 40 mL of the 9 M phosphoric acid solution, add 4 g of ground zirconium oxychloride octahydrate to the phosphoric acid solution, stir and mix well, then place in a 50 mL Teflon-lined reactor and seal, and hydrothermally react at 200 °C for 5 h. After cooling to room temperature, take out the product, wash and centrifuge, dry under vacuum at 60 °C, and grind to obtain pure layered α-ZrP.

[0129] (2) Preparation of self-cleaning anti-corrosion coatings

[0130] Add 7 mL of tetrahydrofuran to 0.8 g of polydimethylsiloxane and stir magnetically until homogeneous to obtain a diluted polydimethylsiloxane solution. Add 0.02 g of trimesin to the diluted polydimethylsiloxane solution and sonicate for 25 min to prepare I-PDMS. Add 1 g of α-ZrP nanosheets to the I-PDMS solution, stir and mix again, and sonicate for 10 min to uniformly disperse the nanosheets in the diluted I-PDMS solution to obtain a self-cleaning anti-corrosion emulsion. Add 0.08 g of Dow Corning Sylgard 184 curing agent and stir for 10 min to obtain an I-PDMS / α-ZrP coating.

[0131] The DEA@α-ZrP-SH / I-PDMS coatings prepared in Examples 1-22 and the coatings of Comparative Examples 1-2 were coated on Q235 steel sheets of 100×60×0.3mm, transferred to a vacuum drying oven and heated at 70°C for 8 hours to evaporate tetrahydrofuran; then cured in a forced-air drying oven at 100°C for 4 hours to obtain the coating.

[0132] Superhydrophobic tests were conducted on each coating: The water contact angle (CA, contact angle) of the coating was measured using a contact angle measuring instrument (Shanghai Xuanzhun Instruments, SZ-CAMB1 type contact angle measuring instrument). 800-grit sandpaper was cut to an appropriate size, placed on the coating, and a 200g weight was placed on the sandpaper. The sandpaper was dragged repeatedly to perform a cyclic friction test. The water contact angle was measured every 50 cycles.

[0133] A 3.5% NaCl solution was prepared as the electrolyte. A coated tinplate sheet was used as the working electrode, a graphite electrode as the auxiliary electrode, and a silver chloride electrode as the reference electrode to construct a three-electrode system. The corrosion resistance of the coating was analyzed using an electrochemical workstation.

[0134] Analysis was performed on α-ZrP, DEA@α-ZrP, and DEA@α-ZrP-SH in Example 22, such as... Figure 1 The infrared spectral analysis results shown indicate that at 1460 cm⁻¹... -1The appearance of a new absorption peak at 3175 cm⁻¹ indicates the presence of an NH bond; the weakening of the OH peak in α-ZrP proves that DEA has been successfully introduced into the α-ZrP interlayer; -1 A broadening of the peak at a certain point indicates the presence of an SH bond. For example... Figure 2 As shown, the a peak of PDMS and I-PDMS represents the ortho-equivalent hydrogen of tetrahydrofuran, the b peak represents the meta-equivalent hydrogen, and the s peak contains many impurity peaks, mainly including alkyl equivalent hydrogens on the siloxane molecular chain and amino-terminated H; in the spectrum of I-PDMS, a characteristic peak of imine bond H appears at 9.26 ppm, indicating that a Schiff base reaction occurred inside the I-PDMS coating, forming a dynamic imine bond. Figure 3 The SEM results show that α-ZrP is a hexagonal disc-shaped crystal. After DEA treatment, it forms a thin and dispersed plate-like structure; further treatment with n-dodecyl mercaptan did not show significant morphological changes, maintaining the original crystal structure. Figure 4 The AFM scanning analysis results shown in Table 1 indicate that a large number of micropillar structures exist on the surface of the DEA@α-ZrP-SH coating. Using the arithmetic mean deviation of the profile (Ra) as a parameter describing the average surface roughness and the root mean square deviation of the profile (Rq) as a parameter of the mean square roughness, the calculated values ​​are Ra = 204.630 nm and Rq = 257.242 nm. Figure 5 , Figure 6 As shown, the static contact angle of the DEA@α-ZrP-SH / I-PDMS coating was 162°. After cyclic rubbing tests, the contact angle decreased to 150° after 250 cycles and to 137° after 600 cycles, losing its superhydrophobic properties. Upon standing at 80°C for 1 hour, the dynamic imine bonds within the coating spontaneously recombinated, restoring the superhydrophobic effect and the contact angle to 159°. Table 2 shows the Tafel test results, indicating that the DEA@α-ZrP-SH / I-PDMS coating achieved an electrochemical impedance of 74043.19 Ω / cm. 2 The corrosion current reached 1.76 × 10⁻⁶. - 4 mA / cm 2 It has a good anti-corrosion effect.

[0135] In Comparative Example 1, the filler was DEA@α-ZrP-SH, and the coating substrate was PDMS. After adding a crosslinking agent, heating formed a long-chain stable structure. The crosslinking agent added to the PDMS decomposed upon heating, releasing free radicals. These free radicals were captured by the active silicon groups of polydimethylsiloxane, resulting in a crosslinking reaction. Because there are no imine bonds within the PDMS coating, it lacks self-healing capabilities. Figure 7As shown in the figure. In Comparative Example 2, the coating substrate was I-PDMS, and the filler was α-ZrP. The unintercalated α-ZrP sheets were not sufficiently dispersed, making it difficult to uniformly fill the pores and defects inside the coating, thus significantly reducing the anti-corrosion efficiency. The surface energy of α-ZrP nanosheets was higher than that of α-ZrP-SH nanosheets grafted with dodecyl mercaptan. Simultaneously, the α-ZrP sheets were thicker than those of DEA@α-ZrP, making it impossible to form a dense, rough structure on the coating surface, resulting in insufficient hydrophobicity of the coating, as detailed in Table 2.

[0136] Table 1

[0137]

[0138] Table 2

[0139]

[0140]

[0141] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for preparing a dynamically covalently cross-linked I-PDMS / DEA@α-ZrP-SH self-healing anti-friction superhydrophobic anti-corrosion coating, characterized in that, Includes the following steps: (1) α-ZrP nanosheets were prepared by hydrothermal reaction using zirconium oxychloride octahydrate and phosphoric acid solution as raw materials; α-ZrP nanosheets were added to organic solvent 1 to prepare α-ZrP suspension; diethanolamine was slowly added to α-ZrP suspension, and the mixture was sonicated and stirred to allow diethanolamine (DEA) to intercalate into α-ZrP to prepare DEA@α-ZrP. (2) DEA@α-ZrP was dispersed in organic solvent II to obtain DEA@α-ZrP suspension. Dodecyl mercaptan was added to DEA@α-ZrP suspension and allowed to stand to allow dodecyl mercaptan to be grafted onto the surface of DEA@α-ZrP to obtain DEA@α-ZrP-SH nanosheets. (3) Polydimethylsiloxane (PDMS) was used as the coating substrate and diluted. Trimethylolpropionate (BTC) was added and mixed evenly to obtain I-PDMS diluent. DEA@α-ZrP-SH nanosheets were then added to the I-PDMS diluent and ultrasonically dispersed to make them evenly dispersed. Finally, a curing agent was added to obtain I-PDMS / DEA@α-ZrP-SH anti-corrosion coating. In step (1), the ultrasonic time is 1-4 hours, and the stirring time is 2-5 hours; In step (2), the settling time is 2 to 5 hours to allow n-dodecyl mercaptan to be grafted onto the DEA@α-ZrP surface.

2. The preparation method of the dynamically covalently crosslinked I-PDMS / DEA@α-ZrP-SH self-healing anti-friction superhydrophobic anti-corrosion coating according to claim 1, characterized in that, The hydrothermal reaction temperature in step (1) is 150–300℃.

3. The preparation method of the dynamically covalently crosslinked I-PDMS / DEA@α-ZrP-SH self-healing anti-friction superhydrophobic anti-corrosion coating according to claim 2, characterized in that, In step (1), the concentration of phosphoric acid solution is 9M, and the ratio of phosphoric acid solution to zirconium oxychloride octahydrate is 40mL: 3.5~5g.

4. The preparation method of the dynamically covalently crosslinked I-PDMS / DEA@α-ZrP-SH self-healing anti-friction superhydrophobic anti-corrosion coating according to claim 3, characterized in that, In step (1), the organic solvent is acetone, and the ratio of α-ZrP, acetone and diethanolamine is 1g:100mL:(1.5~3)mL.

5. The preparation method of the dynamically covalently crosslinked I-PDMS / DEA@α-ZrP-SH self-healing anti-friction superhydrophobic anti-corrosion coating according to claim 4, characterized in that, In step (2), the second organic solvent is ethanol, and the ratio of DEA@α-ZrP, ethanol and n-dodecyl mercaptan is 1g: 40mL: (0.645-1.146)g.

6. The preparation method of the dynamically covalently crosslinked I-PDMS / DEA@α-ZrP-SH self-healing anti-friction superhydrophobic anti-corrosion coating according to claim 5, characterized in that, In step (3), polydimethylsiloxane is diluted with tetrahydrofuran. The ratio of polydimethylsiloxane, tetrahydrofuran, pyromellitic methyl ether and DEA@α-ZrP-SH is 0.8g: 7mL: (0.025~0.01)g: (0.5~2)g.

7. A dynamically covalently cross-linked I-PDMS / DEA@α-ZrP-SH self-healing, anti-friction, superhydrophobic, and anti-corrosion coating, characterized in that, Prepared by the method described in any one of claims 1-6.

8. A self-healing, anti-friction, superhydrophobic, and anti-corrosion coating, characterized in that, The anti-corrosion coating is formed from the anti-corrosion coating of claim 7.

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