High-stability MXene filler and preparation method of high-stability MXene filler in long-acting anticorrosive paint

Abstract

The invention relates to the technical field of anticorrosive coatings, in particular to a high-stability MXene filler and a preparation method of the high-stability MXene filler in a long-acting anticorrosive coating. The preparation method comprises the following steps: etching a precursor MAX phase through organic alkali to successfully prepare the high-stability MXene. And stirring and mixing the centrifugally washed and concentrated MXene with polyurethane emulsion to obtain the high-stability long-acting anticorrosive coating. Compared with a traditional fluorine-containing etching agent, the method is more environmentally friendly, the surface of the prepared MXene has rich oxygen groups, the stability of the MXene is greatly improved, and the dispersity of the MXene in an organic coating is enhanced. The water-based anti-corrosion coating is suitable for various organic anti-corrosion coatings, especially water-based organic anti-corrosion coatings, conforms to the green, environment-friendly and sustainable development concept of the coating industry, and has long-acting anti-corrosion capacity.

Description

Technical Field

[0001] This invention relates to the field of anti-corrosion coatings technology, and more specifically, to a highly stable MXene filler and its preparation method in long-lasting anti-corrosion coatings. Background Technology

[0002] Metallic materials, as the core structural foundation of marine engineering equipment, are exposed to high-salt, high-humidity, and highly corrosive marine environments for extended periods. Their corrosion failure severely restricts the service life of equipment and threatens the safety of marine engineering projects. Traditional organic anti-corrosion coatings, due to their inherent brittleness and solvent evaporation, are prone to internal microscopic defects such as cracks and micropores, leading to corrosion reactions at the damaged areas and premature protection failure. Therefore, the development of efficient protective technologies is imperative.

[0003] Two-dimensional materials, due to their large specific surface area, excellent mechanical properties, and optical characteristics, possess superior barrier effects, making them increasingly prominent in the field of corrosion protection. MXene, as a novel two-dimensional nanomaterial, not only possesses the advantages of traditional two-dimensional materials but also boasts a rich array of tunable functional groups on its surface. This results in excellent compatibility and dispersibility in organic coatings, effectively improving the corrosion resistance of coatings, making it a rising star. However, the easily oxidized nature of MXene limits its development in the corrosion field. Therefore, designing and preparing highly stable MXene nanofillers is essential, as it will significantly improve the stability and corrosion resistance of coatings. Summary of the Invention

[0004] This invention provides a highly stable MXene filler and its preparation method in long-lasting anti-corrosion coatings. The obtained highly stable nano-MXene filler has the advantages of high efficiency dispersibility and high stability, excellent anti-corrosion durability and environmental friendliness, solving the problems of poor stability of MXene materials and the easy generation of micropores and defects in water-based coatings in the prior art.

[0005] In a first aspect, the present invention provides a high-stability MXene packing material, wherein the MXene packing material is a fluorine-free and oxygen-terminated few-layer MXene; the specific preparation process is as follows: using Ti2AlC or Ti3AlC2 as the precursor MAX phase, an etching reaction is carried out by adding an organic base to the precursor MAX phase, and the Al atomic layers are selectively stripped by magnetic stirring. After the etching reaction is completed, the reaction product is obtained by centrifugation washing and drying with deionized water.

[0006] Preferably, the organic base is one or more of tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrapropylsodium hydroxide.

[0007] Preferably, the mass ratio of the precursor MAX phase to the organic base is 1:(10-15).

[0008] Preferably, the reaction temperature is 35-40 ºC and the reaction time is 72 h-96 h.

[0009] Secondly, this invention provides a method for preparing a highly stable MXene filler for use in a long-lasting anti-corrosion coating, comprising the following steps:

[0010] S1. Base surface grinding pretreatment;

[0011] S2. The MXene filler is added to water and ultrasonically dispersed to obtain an MXene dispersion;

[0012] S3. Add the MXene dispersion prepared in step S2 to the polymer resin and stir evenly to obtain a long-lasting anti-corrosion coating.

[0013] Preferably, the polymer resin is any one of epoxy resin, polyurethane, and acrylic resin.

[0014] Preferably, the solid content of the MXene filler in the anti-corrosion coating is 0.5%-3%.

[0015] Preferably, in step S3, the stirring rate is 200-500 r / min.

[0016] Thirdly, the present invention provides an application of a long-lasting anti-corrosion coating, wherein the long-lasting anti-corrosion coating is applied to the surface of a substrate and cured to obtain an anti-corrosion composite coating.

[0017] Preferably, the thickness of the anti-corrosion composite coating is 50-60 μm.

[0018] In summary, the present invention has the following beneficial effects:

[0019] 1. The anti-corrosion coating prepared by the present invention has excellent shielding properties. The high-stability MXene nanofiller prepared by the present invention has a two-dimensional sheet structure, with layers stacked between the sheets to form a dense physical barrier layer, which effectively increases the coating's impermeability and physical shielding effect.

[0020] 2. The MXene filler prepared by this invention has excellent stability and dispersibility. The surface of the prepared MXene has abundant oxygen functional groups, which not only improves the hydrophilic dispersibility of MXene, but also greatly increases the proportion of high oxidation state Ti. Therefore, the prepared MXene has excellent environmental stability and is not easily oxidized and degraded by (water, oxygen) corrosion factors.

[0021] 3. The anti-corrosion coating prepared by the present invention has excellent charge shielding ability. In the present invention, tetramethylammonium is grafted onto the MXene surface, which changes the conductivity of MXene and reduces the risk of MXene-induced galvanic corrosion leading to accelerated corrosion.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the scope of protection of the present invention. Attached Figure Description

[0023] Figure 1 These are XRD patterns of MXene prepared in Example 1 of this invention and raw material MAX.

[0024] Figure 2 This is a projection electron microscope image of the MXene nanomaterial prepared in Example 1 of this invention.

[0025] Figure 3 This is a scanning electron microscope image of the MXene nanomaterials prepared in Example 1 of this invention.

[0026] Figure 4 This is a method for synthesizing the MXene nanomaterials prepared in Example 1 of the present invention. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments can be obtained from commercially available sources.

[0028] The Q235 steel (25×50×2 mm) used in this invention was purchased from Shenzhen Kaichuang Metal Co., Ltd., tetramethylammonium hydroxide (TMAOH) was purchased from Aladdin Reagent Co., Ltd., and the MAX phase was purchased from Jilin Yiyi Technology Co., Ltd. (Jilin Province, China). All solvents and chemicals were analytical grade reagents and were used as received.

[0029] Example

[0030] Example 1

[0031] A method for preparing a highly stable MXene filler for use in long-lasting anti-corrosion coatings includes the following steps:

[0032] (1) 1 g of commercially available precursor MAX phase (Ti2AlC) was dispersed in 15 mL of 25% tetramethylammonium hydroxide solution. The mixture was magnetically stirred at 40 °C for 72 h. After the reaction was complete, the mixture was centrifuged, washed, and dried to obtain fluorine-free, oxygen-terminated few-layer Ti2CTx MXene. Its XRD pattern is shown below. Figure 1As shown, compared with the raw material MAX phase, the (002) characteristic peak of the prepared MXene shifts to a lower diffraction angle, and the Al-related (104) peak disappears in the structure, indicating that MXene was successfully prepared. Its transmission electron microscopy is shown in Figure 1. Figure 2 As shown, the nanomaterial is sheet-like, exhibiting a very clean, smooth surface and clear boundaries. Its scanning electron microscope image is as follows... Figure 3 As shown, the prepared MXene exhibits a typical two-dimensional sheet structure with a smooth, particle-free surface. This evidence indicates that the material retains its original sheet structure and has not been oxidized or degraded.

[0033] (2) Take 0.04 g of the prepared MXene and ultrasonically disperse it in deionized water for 30 min. Then add 2 g of 40% aqueous polyurethane and stir for 10 min. Set aside for later use. Pre-treat a 25×50 mm Q235 steel sheet by sanding it with sandpaper of roughness 80, 240 and 600 grit respectively to remove surface impurities and oxide layers. After sanding, ultrasonically treat and dry the substrate in anhydrous ethanol. Apply the above coating to the surface of the substrate, controlling the coating thickness to be 50 μm (±10 μm). The curing process is as follows: cure at room temperature for 48 h and then dry in a drying oven at 50 °C for 48 h.

[0034] The low-frequency impedance modulus of the coating in 3.5 wt% NaCl solution as a function of time is shown in Table 1.

[0035] Example 2

[0036] A method for preparing a highly stable MXene filler for use in long-lasting anti-corrosion coatings includes the following steps:

[0037] (1) Take 1 g of commercially available precursor MAX phase (Ti2AlC) and disperse it in 15 mL of 25% tetramethylammonium hydroxide solution. Stir magnetically at 40 °C for 72 h. After the reaction is completed, centrifuge, wash and dry to obtain fluorine-free and oxygen-terminated few-layer Ti2CT. x MXene.

[0038] (2) Take 0.08 g of the prepared MXene and ultrasonically disperse it in deionized water for 30 min. Then add 2 g of 40% aqueous polyurethane and stir for 10 min. Apply the above coating to the surface of the polished substrate, cure at room temperature for 48 h, and then dry in an oven at 50 °C for 48 h.

[0039] Example 3

[0040] A method for preparing a highly stable MXene filler for use in long-lasting anti-corrosion coatings includes the following steps:

[0041] (1) Take 1 g of commercially available precursor MAX phase (Ti2AlC) and disperse it in 15 mL of 25% tetramethylammonium hydroxide solution. Stir magnetically at 40 °C for 72 h. After the reaction is completed, centrifuge, wash and dry to obtain fluorine-free and oxygen-terminated few-layer Ti2C MXene.

[0042] (2) Take 0.16 g of the prepared MXene and ultrasonically disperse it in deionized water for 30 min. Then add 2 g of 40% aqueous polyurethane and stir for 10 min. Apply the above coating to the surface of the polished substrate, cure at room temperature for 48 h, and then dry in an oven at 50 °C for 48 h.

[0043] Example 4

[0044] A method for preparing a highly stable MXene filler for use in long-lasting anti-corrosion coatings includes the following steps:

[0045] (1) Take 1 g of commercially available precursor MAX phase (Ti2AlC) and disperse it in 15 mL of 25% tetramethylammonium hydroxide solution. Stir magnetically at 40 °C for 72 h. After the reaction is completed, centrifuge, wash and dry to obtain fluorine-free and oxygen-terminated few-layer Ti2CT. x MXene.

[0046] (2) Take 0.4 g of the prepared MXene and ultrasonically disperse it in deionized water for 30 min. Then add 2 g of 40% aqueous polyurethane and stir for 10 min. Apply the above coating to the surface of the polished substrate, cure at room temperature for 48 h, and then dry in an oven at 50 °C for 48 h.

[0047] Comparative Example 1

[0048] In contrast, this coating did not contain MXene filler. 2 g of 40% polyurethane coating was directly applied to the surface of the sanded substrate, cured at room temperature for 48 h, and then dried in an oven at 50 °C for 48 h.

[0049] The results of the low-frequency impedance modulus (|Z| 0.01 Hz) of Examples 1-4 and Comparative Example 1 after immersion in 3.5 wt% NaCl solution for 20 days are shown in Table 1.

[0050] Electrochemical performance testing: Electrochemical tests were conducted using the EnergylabXM electrochemical workstation with a high-power analytical capability, employing a three-electrode system. The coated sample was used as the working electrode, and the test area was 1 cm². 2Ag / AgCl was used as the reference electrode, and a platinum sheet as the counter electrode. After reaching a stable open-circuit potential, the electrode was subjected to a frequency range of 10 Hz in a 3.5 wt% NaCl solution under ambient conditions. 5 -10 -2 Hz EIS test.

[0051] Table 1: .

[0052] Table 1 shows that the test results indicate that the introduction of MXene filler significantly improves the corrosion resistance of the coating. Electrochemical impedance spectroscopy analysis shows that when the MXene addition amount is 1.5 wt%, the impedance value of the coating at a frequency of 0.01 Hz (|Z|) is significantly improved. 0.01Hz When the value reaches its maximum, it indicates that the coating exhibits the best corrosion resistance. It is worth noting that deviations from this optimal ratio in the MXene additive content (whether too high or too low) lead to a decrease in the coating's protective performance, demonstrating a clear dose-effect relationship between filler content and corrosion resistance.

[0053] The above description is merely an exemplary embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-stability MXene packing material, characterized in that, The MXene filler is mainly composed of few-layer Ti2CT with oxygen-rich surface terminals. x Materials; the specific preparation process is as follows: using Ti2AlC or Ti3AlC2 as the precursor MAX phase, an etching reaction is carried out by adding an organic base to the precursor MAX phase, and selectively peeling off the Al atomic layer by magnetic stirring. After the etching reaction is completed, the reaction product is obtained by centrifugation and drying with deionized water.

2. The high-stability MXene packing according to claim 1, characterized in that, The organic base is one or more of tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrapropylsodium hydroxide.

3. The high-stability MXene packing according to claim 1, characterized in that, The mass ratio of the precursor MAX phase to the organic base is 1:(10-15).

4. The high-stability MXene packing according to claim 1, characterized in that, The reaction temperature is 35-40 ºC, and the reaction time is 72 h-96 h.

5. The method for preparing the high-stability MXene filler according to any one of claims 1-3 in a long-lasting anti-corrosion coating, characterized in that, Includes the following steps: S1. Base surface grinding pretreatment; S2. The MXene filler is added to water and ultrasonically dispersed to obtain an MXene dispersion; S3. Add the MXene dispersion prepared in step S2 to the polymer resin and stir evenly to obtain a long-lasting anti-corrosion coating.

6. The preparation method of the high-stability MXene filler according to claim 5 in a long-lasting anti-corrosion coating, characterized in that, The polymer resin is any one of epoxy resin, polyurethane, and acrylic resin.

7. The preparation method of the high-stability MXene filler according to claim 5 in a long-lasting anti-corrosion coating, characterized in that, The solid content of the MXene filler in the anti-corrosion coating is 0.5%-3%.

8. The preparation method of the high-stability MXene filler according to claim 5 in a long-lasting anti-corrosion coating, characterized in that, In step S3, the stirring rate is 200-500 r / min.

9. The application of the long-lasting anti-corrosion coating according to any one of claims 1 to 4, characterized in that, The long-lasting anti-corrosion coating is applied to the surface of a substrate and cured to obtain an anti-corrosion composite coating.

10. The application of the long-lasting anti-corrosion coating according to claim 9, characterized in that, The thickness of the anti-corrosion composite coating is 50-60 μm.

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