Solid-liquid composite lubricating coating as well as preparation method and application thereof

Abstract

The invention relates to the technical field of lubricating coatings, in particular to a solid-liquid composite lubricating coating and a preparation method and application thereof. Tetraethoxysilane hydrolysate and silane compound hydrolysate containing carbon-carbon double bonds are subjected to polycondensation to form a network structure film, a carbon-carbon double bond structure is still preserved in the network structure, the carbon-carbon double bonds serve as grafting sites of the zwitterionic polymer brush, the zwitterionic polymer brush is grafted and modified on the surface of the silica sol, and the surface of the zwitterionic polymer brush is modified. And the zwitterionic polymer brush and the amino-modified molybdenum disulfide nanoparticles jointly form a solid-liquid composite lubricating coating. The zwitterionic polymer brush is connected to the surface of the silica sol through a covalent bond, so that the coating grafting strength and stability of the zwitterionic polymer brush are improved, and the effect of wetting the coating by the zwitterionic polymer brush is further achieved. Meanwhile, the molybdenum disulfide nano-particles can serve as a solid lubricating coating, the bearing capacity of the coating can be enhanced, and the antifriction effect can also be achieved under the high load.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricating coatings, and in particular to a solid-liquid composite lubricating coating and a preparation method and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] Mechanical components such as ship propellers and water-lubricated bearings have long relied on traditional lubricants (grease or mineral oil). However, these lubricants present several challenges: leaks can cause marine pollution; mineral oil and other traditional lubricants are difficult to degrade in the ocean, accumulating over time and impacting ecosystems; and, over extended periods of navigation, traditional lubricants are difficult to maintain and refill. Water lubrication technology, due to its environmentally friendly, energy-efficient, and low-maintenance advantages, has become a research hotspot.

[0004] The mechanism of water-lubricated coatings is that water forms a continuous fluid film between the contact surfaces of bearings or other mechanical components. This film can withstand a certain load and reduce direct contact, thereby reducing friction and wear. To ensure the stable formation and stability of the water film on the surface, water-lubricated coatings are usually prepared using hydrophilic materials. Zwitterionic polymer brushes are a high-quality material for preparing water-lubricated coatings due to their extremely strong hydrophilicity and ability to form a stable water film. However, existing polymer brush surface grafting processes usually use catechol substances such as dopamine as an intermediate layer to assist in grafting. However, in preliminary experiments, this method does not have strong bonding strength on the metal surface and will fail after 5 minutes of ultrasonic cleaning. It faces the problems of low bonding strength, poor stability, and easy detachment due to friction, which makes it difficult to meet the needs of water-lubricated coatings. On the other hand, compared with oil lubrication, water has a lower viscosity. Using only polymer brushes to achieve water lubrication usually faces the problem of insufficient load-bearing capacity and loses the lubricating effect under higher loads. Solid lubrication has an extremely high load-bearing capacity.

[0005] At the same time, long-term contact with water or seawater will lead to increased corrosion of mechanical parts such as ship propellers and water-lubricated bearings. At the same time, they will also be adhered to by marine fouling organisms such as barnacles and algae, affecting their normal use. Summary of the Invention

[0006] In order to overcome the above problems, the present invention provides a solid-liquid composite lubricating coating and a preparation method and application thereof.

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] A first aspect of the present invention provides a solid-liquid composite lubricating coating comprising:

[0009] The silica sol is modified with zwitterionic polymer brushes on its surface and amino-modified molybdenum disulfide nanoparticles are uniformly dispersed inside the silica sol.

[0010] In one or more embodiments, the silica sol has a thickness of 5 to 40 μm.

[0011] In one or more embodiments, the zwitterionic polymer brush has a thickness of 20 to 200 nm.

[0012] In one or more embodiments, the particle size of the amino-modified molybdenum disulfide nanoparticles is 100 to 500 nm.

[0013] In one or more embodiments, the silica sol is obtained by reacting a hydrolyzate of tetraethoxysilane with a hydrolyzate of a silane compound containing a carbon-carbon double bond.

[0014] Preferably, the preparation method of tetraethoxysilane hydrolyzate comprises:

[0015] Tetraethoxysilane is dispersed in an alcohol aqueous solution and hydrolyzed under acidic conditions to obtain it.

[0016] Preferably, the preparation method of the hydrolyzed solution of a silane compound containing a carbon-carbon double bond comprises:

[0017] The silane compound containing carbon-carbon double bonds is dispersed in an alcohol aqueous solution and hydrolyzed under acidic conditions to obtain the product.

[0018] Further preferably, the silane compound containing a carbon-carbon double bond includes one of methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxychlorosilane, trimethoxyvinylphenylsilane or allyltriethoxysilane, preferably methacryloxypropyltrimethoxysilane.

[0019] In one or more embodiments, the mass ratio of amino-modified molybdenum disulfide nanoparticles to silica sol is (0.5% to 5%):1.

[0020] A second aspect of the present invention provides a method for preparing the solid-liquid composite lubricating coating according to the first aspect, comprising the following steps:

[0021] (1) Tetraethoxysilane is dispersed in an alcohol aqueous solution and hydrolyzed under acidic conditions to obtain a tetraethoxysilane hydrolyzate;

[0022] (2) dispersing amino-modified molybdenum disulfide nanoparticles in tetraethoxysilane hydrolyzate to obtain a mixed solution;

[0023] (3) dispersing the silane compound containing a carbon-carbon double bond in an alcohol aqueous solution, and hydrolyzing the silane compound containing a carbon-carbon double bond under acidic conditions to obtain a hydrolyzate of the silane compound;

[0024] (4) mixing the hydrolyzed silane compound containing a carbon-carbon double bond with the mixed solution in step (2), coating the mixture on the surface of the substrate, and heat-treating the mixture to obtain a sample with silica sol, wherein amino-modified molybdenum disulfide nanoparticles are uniformly dispersed in the silica sol;

[0025] (5) placing the sample with silica sol in step (4) in a zwitterionic monomer solution, and modifying the surface of the silica sol with a zwitterionic polymer brush under the initiation of an initiator to obtain the solid-liquid composite lubricating coating.

[0026] In one or more embodiments, in step (1), the alcohol in the alcohol aqueous solution is a monohydric alcohol, preferably ethanol.

[0027] In one or more embodiments, in step (1), the acid providing the acidic environment is selected from hydrochloric acid, nitric acid and formic acid, preferably formic acid.

[0028] In one or more embodiments, in step (1), the volume ratio of tetraethoxysilane to alcohol and water is (1-5):10:(1-5).

[0029] In one or more embodiments, in step (1), the hydrolysis time is 8 to 24 hours.

[0030] In one or more embodiments, in step (2), the method for preparing amino-modified molybdenum disulfide nanoparticles comprises:

[0031] Molybdenum disulfide nanoparticles were dispersed in ethanol, and after the first stirring, KH550 and water were added. After the second stirring reaction, the mixture was centrifuged to obtain amino-modified MoS2 nanoparticles.

[0032] Preferably, the temperature of the first stirring reaction is 55 to 65° C., preferably 60° C.; the time of the first stirring reaction is 20 to 40 minutes, preferably 30 minutes.

[0033] Preferably, the temperature of the second stirring reaction is 55-65° C., preferably 60° C.; the time of the second stirring reaction is 5-8 h, preferably 6 h.

[0034] Preferably, the mass ratio of molybdenum disulfide nanoparticles to KH550 is (0.8-1.2) g:1 mL, preferably 1 g:1 mL.

[0035] In one or more embodiments, in step (3), the silane compound containing a carbon-carbon double bond includes one of methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxychlorosilane, trimethoxyvinylphenylsilane or allyltriethoxysilane, preferably methacryloxypropyltrimethoxysilane.

[0036] In one or more embodiments, in step (3), the alcohol in the alcohol aqueous solution is a monohydric alcohol, preferably ethanol.

[0037] In one or more embodiments, in step (3), the acid providing the acidic environment is selected from hydrochloric acid, nitric acid and formic acid, preferably formic acid.

[0038] In one or more embodiments, in step (3), the volume ratio of the silane compound containing a carbon-carbon double bond to the alcohol and water is (1-3):10:(1-3).

[0039] In one or more embodiments, in step (3), the hydrolysis time is 8 to 10 hours.

[0040] In one or more embodiments, in step (4), the volume ratio of hydrolyzate B to the mixed solution in step (2) is (2-3): (1-3).

[0041] In one or more embodiments, in step (4), the heat treatment temperature is 60 to 80° C., and the heat treatment time is 10 to 30 minutes.

[0042] In one or more embodiments, in step (5), the zwitterionic monomer in the zwitterionic monomer solution is selected from one of sulfobetaine, carboxybetaine and phosphorylcholine.

[0043] In one or more embodiments, in step (5), the concentration of the zwitterionic monomer is 0.1 to 0.5 g / mL.

[0044] In one or more embodiments, in step (5), the initiator is selected from photoinitiator 1173, benzophenone and ceric ammonium nitrate, preferably ceric ammonium nitrate.

[0045] In one or more embodiments, in step (5), under the initiation of an initiator, the reaction conditions are ultraviolet light irradiation or heating at 50-70° C.; and the reaction time is 1-36 hours.

[0046] The third aspect of the present invention provides the solid-liquid composite lubricating coating described in the first aspect or the solid-liquid composite lubricating coating prepared by the preparation method described in the second aspect for application to moving parts of aircraft in a maritime transportation environment.

[0047] The beneficial effects of the present invention are:

[0048] (1) In the present invention, the tetraethoxysilane hydrolyzate and the silane compound hydrolyzate containing carbon-carbon double bonds will condense to form a network structure film, and the carbon-carbon double bond structure is still preserved in this network structure. The carbon-carbon double bond serves as the grafting site of the zwitterionic polymer brush, and can be grafted and modified on the surface of the silica sol. The zwitterionic polymer brush and the amino-modified molybdenum disulfide nanoparticles together constitute a solid-liquid composite lubricating coating. The silica sol in the solid-liquid composite lubricating coating can not only be more firmly bonded to the metal surface, but the zwitterionic polymer brush is also connected to the silica sol surface through a covalent bond, thereby improving the grafting strength and stability of the zwitterionic polymer brush coating, thereby achieving the effect of the zwitterionic polymer brush water-wetting coating. At the same time, the molybdenum disulfide nanoparticles can act as a solid lubricating coating, which can enhance the bearing capacity of the coating and achieve a friction-reducing effect even under higher loads.

[0049] (2) The solid-liquid composite lubricating coating provided by the present invention not only has lubricating and friction-reducing effects, but also has anti-corrosion and anti-fouling effects. Silica sol can hinder the contact between corrosive particles and the surface of the metal substrate, thereby improving the anti-corrosion and anti-fouling effects of the metal substrate surface; molybdenum disulfide nanoparticles can further hinder the contact between corrosive particles and the surface of the metal substrate, thereby improving the anti-corrosion and anti-fouling effects of silica sol. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0051] Figure 1 It is the preparation process of solid-liquid composite lubricating coating;

[0052] Figure 2 SEM images of the metal substrate Bare after any treatment and the sample MoS2-SiSol-pSBMA with solid-liquid composite lubricating coating;

[0053] Figure 3 is the average friction coefficient of each group of coating samples;

[0054] Figure 4 Comparison of wear scars after friction of each group of coating samples;

[0055] Figure 5 This is a diagram showing the drag reduction effect of the solid-liquid composite lubricating coating at different Reynolds numbers;

[0056] Figure 6 The polarization curve of the solid-liquid composite lubricating coating, in which the inset is a comparison of the anti-corrosion effect;

[0057] Figure 7 are the adhesion SEM images of the coating samples in each group. DETAILED DESCRIPTION

[0058] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0059] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0060] The material of the metal substrate described in the following embodiments is brass.

[0061] Preparation of amino-modified MoS2 nanoparticles:

[0062] 2.5 g of molybdenum disulfide was weighed and added to 25 mL of ethanol. The mixture was stirred at 60°C for 30 minutes. Then, 5 mL of KH550 and 1 mL of water were added, and the mixture was stirred at 60°C for 6 hours. Finally, the product was placed in a centrifuge tube and centrifuged at 500 rpm for 5 minutes. The supernatant was removed, and the precipitate was collected. The product was then washed thoroughly with ethanol and centrifuged five times to obtain amino-modified molybdenum disulfide nanoparticles.

[0063] The particle size of the amino-modified molybdenum disulfide nanoparticles is 100-500 nm.

[0064] Example 1

[0065] Figure 1 For the preparation process of solid-liquid composite lubricating coating, refer to Figure 1 , prepare solid-liquid composite lubricating coating.

[0066] (1) A metal substrate is treated with plasma to obtain a roughened metal substrate. The plasma power is 60 W, the gas component is air atmosphere, and the treatment time is 10 min.

[0067] (2) Take 10 mL of ethanol, 2 mL of water, and 0.1 mL of formic acid, add them to a beaker and stir evenly, then add 2 mL of tetraethoxysilane under vigorous stirring, let it stand and hydrolyze for 12 hours to obtain tetraethoxysilane hydrolyzate.

[0068] (3) 0.05 g of amino-modified molybdenum disulfide nanoparticles was added to the tetraethoxysilane hydrolyzate obtained in step (1), and ultrasonically dispersed for 30 min to obtain a mixed solution.

[0069] (4) Take 10 mL of ethanol, 1 mL of water, and 0.1 mL of formic acid, add them to a beaker and stir evenly, then add 1 mL of methacryloxypropyltrimethoxysilane under vigorous stirring, let it stand for hydrolysis for 2 hours, and obtain methacryloxypropyltrimethoxysilane hydrolyzate.

[0070] (5) The methacryloyloxypropyltrimethoxysilane hydrolyzate in step (4) and the mixed solution in step (3) were mixed and stirred in a volume ratio of 1:1, and then coated on the surface of the metal substrate by spin coating at a spin coating speed of 10 rpm and a spin coating time of 1 minute. Thereafter, the obtained sample was placed in an oven at a heating temperature of 70° C. for 20 minutes until the sample was completely dry. After being thoroughly washed with anhydrous ethanol and deionized water, a sample with silica sol was obtained, in which amino-modified molybdenum disulfide nanoparticles were uniformly dispersed.

[0071] (6) The “grafting-from” method was used to prepare a zwitterionic polymer brush surface using methacryloylethyl sulfobetaine as a monomer and ammonium cerium nitrate as a catalyst by thermal initiation. Specifically, 50 mL of water was added with 10 g of methacryloylethyl sulfobetaine and 0.1 g of ammonium cerium nitrate. After fully dissolving, the sample with silica sol in step (5) was added. The reaction system was then placed in an oven and heated at a constant temperature of 50°C for 24 hours to graft methacryloylethyl sulfobetaine from the carbon-carbon double bond to the surface of the silica sol layer. Finally, the sample was thoroughly washed with anhydrous ethanol and deionized water to remove impurities such as loosely adsorbed polymers or monomers, and a sample with a solid-liquid composite lubricating coating was obtained, which was named MoS2-SiSol-pSBMA.

[0072] Comparative Example 1

[0073] The metal substrate without any treatment is named Bare.

[0074] Comparative Example 2

[0075] Compared with Example 1, no zwitterionic polymer brush was grafted and no amino-modified molybdenum disulfide nanoparticles were added.

[0076] (1) A metal substrate is treated with plasma to obtain a roughened metal substrate. The plasma power is 60 W, the gas component is air atmosphere, and the treatment time is 10 min.

[0077] (2) Take 10 mL of ethanol, 2 mL of water, and 0.1 mL of formic acid, add them to a beaker and stir evenly, then add 2 mL of tetraethoxysilane under vigorous stirring, let it stand and hydrolyze for 12 hours to obtain tetraethoxysilane hydrolyzate.

[0078] (3) Take 10 mL of ethanol, 1 mL of water, and 0.1 mL of formic acid, add them to a beaker and stir evenly, then add 1 mL of methacryloxypropyltrimethoxysilane under vigorous stirring, let it stand for hydrolysis for 2 hours, and obtain methacryloxypropyltrimethoxysilane hydrolyzate.

[0079] (5) The methacryloyloxypropyltrimethoxysilane hydrolyzate in step (3) and the tetraethoxysilane hydrolyzate in step (2) were mixed and stirred in a volume ratio of 1:1, and then coated on the surface of the metal substrate by spin coating at a spin coating speed of 10 rpm and a spin coating time of 1 minute. Thereafter, the obtained sample was placed in an oven at a heating temperature of 70°C for 20 minutes until the sample was completely dry. After being thoroughly washed with anhydrous ethanol and deionized water, a sample with silica sol was obtained, which was named SiSol.

[0080] Comparative Example 3

[0081] Compared with Example 1, no zwitterionic polymer brush was grafted.

[0082] (1) A metal substrate is treated with plasma to obtain a roughened metal substrate. The plasma power is 60 W, the gas component is air atmosphere, and the treatment time is 10 min.

[0083] (2) Take 10 mL of ethanol, 2 mL of water, and 0.1 mL of formic acid, add them to a beaker and stir evenly, then add 2 mL of tetraethoxysilane under vigorous stirring, let it stand and hydrolyze for 12 hours to obtain tetraethoxysilane hydrolyzate.

[0084] (3) 0.05 g of amino-modified molybdenum disulfide nanoparticles was added to the tetraethoxysilane hydrolyzate obtained in step (1), and ultrasonically dispersed for 30 min to obtain a mixed solution.

[0085] (4) Take 10 mL of ethanol, 1 mL of water, and 0.1 mL of formic acid, add them to a beaker and stir evenly, then add 1 mL of methacryloxypropyltrimethoxysilane under vigorous stirring, let it stand for hydrolysis for 2 hours, and obtain methacryloxypropyltrimethoxysilane hydrolyzate.

[0086] (5) The methacryloyloxypropyltrimethoxysilane hydrolyzate in step (4) and the mixed solution in step (3) were mixed and stirred in a volume ratio of 1:1, and coated on the surface of the metal substrate by spin coating at a spin coating speed of 10 rpm and a spin coating time of 1 minute. Thereafter, the obtained sample was placed in an oven at a heating temperature of 70°C for 20 minutes until the sample was completely dry. After being thoroughly washed with anhydrous ethanol and deionized water, a sample with silica sol was obtained, in which amino-modified molybdenum disulfide nanoparticles were uniformly dispersed. The sample was named MoS2-SiSol.

[0087] Comparative Example 4

[0088] Compared with Example 1, no amino-modified molybdenum disulfide nanoparticles were added.

[0089] (1) A metal substrate is treated with plasma to obtain a roughened metal substrate. The plasma power is 60 W, the gas component is air atmosphere, and the treatment time is 10 min.

[0090] (2) Take 10 mL of ethanol, 2 mL of water, and 0.1 mL of formic acid, add them to a beaker and stir evenly, then add 2 mL of tetraethoxysilane under vigorous stirring, let it stand and hydrolyze for 12 hours to obtain tetraethoxysilane hydrolyzate.

[0091] (3) Take 10 mL of ethanol, 1 mL of water, and 0.1 mL of formic acid, add them to a beaker and stir evenly, then add 1 mL of methacryloxypropyltrimethoxysilane under vigorous stirring, let it stand for hydrolysis for 2 hours, and obtain methacryloxypropyltrimethoxysilane hydrolyzate.

[0092] (5) The methacryloyloxypropyltrimethoxysilane hydrolyzate in step (3) and the tetraethoxysilane hydrolyzate in step (2) were mixed and stirred in a volume ratio of 1:1, and coated onto the surface of the metal substrate by spin coating at a spin coating speed of 10 rpm and a spin coating time of 1 minute. Thereafter, the obtained sample was placed in an oven at a heating temperature of 70° C. for 20 minutes until the sample was completely dry. After being thoroughly washed with anhydrous ethanol and deionized water, a sample with silica sol was obtained, in which amino-modified molybdenum disulfide nanoparticles were uniformly dispersed.

[0093] (6) The “grafting-from” method was used to prepare a zwitterionic polymer brush surface using methacryloylethyl sulfobetaine as a monomer and cerium ammonium nitrate as a catalyst by thermal initiation. Specifically, 50 mL of water was added with 10 g of methacryloylethyl sulfobetaine and 0.1 g of cerium ammonium nitrate. After fully dissolving, the sample with silica sol in step (5) was added. The reaction system was then placed in an oven and heated at a constant temperature of 50°C for 24 hours to graft methacryloylethyl sulfobetaine from the carbon-carbon double bond to the surface of the silica sol layer. Finally, the sample was thoroughly washed with anhydrous ethanol and deionized water to remove impurities such as loosely adsorbed polymers or monomers, and a sample with a solid-liquid composite lubricating coating was obtained, which was named SiSol-pSBMA.

[0094] Comparative Example 5

[0095] Preparation of dopamine-zwitterionic polymer brush samples:

[0096] Since it is difficult to directly graft the polymer brush onto the metal surface, this comparative example adopts a dopamine-assisted grafting process.

[0097] (1) A metal substrate is treated with plasma to obtain a roughened metal substrate. The plasma power is 60 W, the gas component is air atmosphere, and the treatment time is 10 min.

[0098] (2) Take 50 mL of Tris buffer solution, adjust the pH to 8.5, weigh 0.15 g of dopamine, 0.3 g of sodium alginate, and 0.1 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC), and place it at room temperature for 24 hours to allow dopamine to undergo Michael addition reaction with sodium alginate in an alkaline environment and deposit on the substrate surface. After thorough washing with deionized water, a dopamine-sodium alginate intermediate layer was obtained.

[0099] (3) The method of Example 1 was then used to prepare a polymer brush coating on the dopamine-sodium alginate intermediate layer. The "grafting-from" method was used, with methacryloylethyl sulfobetaine as a monomer and ammonium cerium nitrate as a catalyst, and a thermal initiation method was used to prepare a zwitterionic polymer brush surface. Specifically, 50 mL of water was added with 10 g of methacryloylethyl sulfobetaine and 0.1 g of ammonium cerium nitrate. After fully dissolving, the sample with the dopamine-sodium alginate intermediate layer in step (2) was added. The reaction system was then placed in an oven and heated at a constant temperature of 50°C for 24 hours to graft methacryloylethyl sulfobetaine from the abundant hydroxyl groups of sodium alginate to the surface of the silica sol layer. Finally, it was thoroughly washed with anhydrous ethanol and deionized water to remove impurities such as loosely adsorbed polymers or monomers, and a sample of a polymer brush coating without a silica sol intermediate layer was obtained, which was named pDA-pSBMA.

[0100] Figure 2 The SEM images of the metal substrate Bare after any treatment and the sample MoS2-SiSol-pSBMA with solid-liquid composite lubricating coating are respectively Figure 2 It can be seen from the figure that the surface morphology and microstructure of the coating have changed significantly after the coating is covered. The surface of the coating sample has an obvious gully-like structure and is evenly covered with a gully-like layer of material. This layer of material is the lubricating coating of the present invention.

[0101] Example 2

[0102] In order to verify that the zwitterions grafted onto silica sol have better stability, the effect of ultrasonic cleaning on the sample surface was studied.

[0103] Two brass samples, pDA-pSBMA and SiSol-pSBMA, were ultrasonically cleaned for 5, 10, 15, 20, 25, and 30 minutes, respectively. The changes in contact angle after ultrasonic cleaning were compared. After 5 minutes of ultrasonic cleaning, the polymer brushes on the pDA-pSBMA fell off, and the contact angle decreased from 20.1° to 80.4° for the brass. However, after 30 minutes of ultrasonic cleaning, the contact angle of the SiSol-pSBMA increased only to 25.2°, maintaining excellent wettability.

[0104] Example 3

[0105] The friction and wear reduction effects of different surfaces were tested using a friction and wear testing machine to verify the coating's improved friction and wear resistance. The specific method was as follows: Experiments were conducted at room temperature, artificial seawater was added to the liquid pool, and Bare, MoS2-SiSol, SiSol-pSBMA, and MoS2-SiSol-pSBMA samples were fixed to the liquid pool on the friction and wear testing machine. The friction method used was a ball-plane method, with a GCr15 steel ball as the ball and the plane representing each group of samples. The normal load was set to 2N, the friction rate was 100r / min, the friction radius was 12mm, and the friction was carried out for 20 minutes. The real-time friction coefficient and friction curve were recorded. After the friction was completed, the samples were rinsed with deionized water and placed under a five-axis confocal surface topography instrument to photograph the wear of the samples.

[0106] The friction and wear reduction effects of various surfaces were tested using a friction and wear testing machine to verify the coating's enhanced drag-reducing and lubricating properties. The specific method involved conducting the experiment at room temperature, adding artificial seawater to a liquid pool, attaching blank samples and samples coated with the coating to the rotor surface, and varying the Reynolds number on the sample surface by changing the rotational speed. The drag reduction rate was calculated based on the torque to verify the coating's drag-reducing and lubricating effects.

[0107] Figure 3is the average friction coefficient of each group of coating samples, Figure 3 It can be seen that the solid-liquid composite lubricating coating MoS2-SiSol-pSBMA has a lower friction coefficient than the uncoated surface, and the addition of amphoteric polymer brushes and amino-modified molybdenum disulfide nanoparticles can achieve a friction-reducing effect.

[0108] Figure 4 The comparison diagram of wear marks after friction of each group of coating samples is shown in Figure 2. Figure 4 It can be seen that the solid-liquid composite lubricating coating MoS2-SiSol-pSBMA has less wear than the uncoated surface, and the wear amount is less than that of simple water lubrication or solid lubrication. The solid lubricating coating formed by molybdenum disulfide can improve the overall load-bearing capacity and solve the problem of poor load-bearing capacity of water lubrication.

[0109] Figure 5 The drag reduction effect of the solid-liquid composite lubricating coating MoS2-SiSol-pSBMA at different Reynolds numbers. Figure 5 It can be seen that compared with the uncoated sample, the lubricating coating has different drag reduction effects at different Reynolds numbers, and has a better drag reduction and lubrication effect under the laminar flow state at low Reynolds numbers.

[0110] Example 4

[0111] Electrochemical corrosion experiments are used to test the corrosion conditions of different surfaces to verify the anti-corrosion effect of the solid-liquid composite lubricating coating. The specific method is as follows:

[0112] Prepare 3.5% sodium chloride solution as the electrolyte, and install the working electrode, auxiliary electrode and reference electrode in the electrolytic cell. Among them, the sample is used as the working electrode, the auxiliary electrode is a platinum sheet, and the reference electrode is SCE. Each group of samples is placed in the electrolyte and soaked for 6 hours before the Tafel polarization curve test. The Tafel starting potential and ending potential are set to -0.3V~0.3V respectively, the scanning speed is usually set to 1mV / s, the step height is set to 1mV, and the step time is set to 1s. Perform EIS test, the frequency range is set to 0.01Hz to 100kHz, the amplitude is 5mV, and the EIS test voltage is selected as OCP.

[0113] Figure 6 This is a comparison of the polarization curves of the solid-liquid composite lubricating coating MoS2-SiSol-pSBMA sample and the bare surface without coating and the corroded surface. Figure 6 It can be seen that the anti-corrosion effect of the coated samples is better than that of the uncoated samples, and they have certain anti-corrosion functions.

[0114] Example 5

[0115] The anti-algae adhesion experiment is used to test the anti-adhesion effect of different surfaces to verify the anti-fouling effect of the coating. The specific method is: immerse the coated and uncoated samples in algae culture medium, incubate for a period of time, and then rinse the sample surface with deionized water to remove loosely adsorbed algae. The sample is then placed in a 2.5% glutaraldehyde solution and fixed at 4°C for 4 hours. After fixation, use ethanol aqueous solution (70%, 80%, 90% and 100% v / v) to dehydrate in sequence, and each concentration is treated for 30 minutes. After dehydration, the sample is air-dried and analyzed using a scanning electron microscope. The anti-fouling performance of different samples is evaluated by recording the number of algae on the corresponding samples.

[0116] Figure 7 is the adhesion SEM image of the sample, Figure 7 It can be seen that the number of algae adhering to the coated samples is much smaller than that adhering to the uncoated samples, which proves that the coating has an excellent antifouling effect.

[0117] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A solid-liquid composite lubricating coating, characterized in that: include: The silica sol is modified with zwitterionic polymer brushes on its surface and amino-modified molybdenum disulfide nanoparticles are uniformly dispersed inside the silica sol.

2. The solid-liquid composite lubricating coating according to claim 1, characterized in that: The thickness of the silica sol is 5 to 40 μm; Alternatively, the zwitterionic polymer brush has a thickness of 20 to 200 nm; Alternatively, the particle size of the amino-modified molybdenum disulfide nanoparticles is 100 to 500 nm.

3. The solid-liquid composite lubricating coating according to claim 1, characterized in that: The silica sol is obtained by reacting a tetraethoxysilane hydrolyzate with a silane compound hydrolyzate containing a carbon-carbon double bond; Preferably, the preparation method of tetraethoxysilane hydrolyzate comprises: Tetraethoxysilane is dispersed in an alcohol aqueous solution and hydrolyzed under acidic conditions; Preferably, the preparation method of the hydrolyzed solution of a silane compound containing a carbon-carbon double bond comprises: The silane compound containing carbon-carbon double bonds is dispersed in an alcohol aqueous solution and hydrolyzed under acidic conditions to obtain; Alternatively, the mass ratio of amino-modified molybdenum disulfide nanoparticles to silica sol is (0.5% to 5%):

1.

4. The method for preparing the solid-liquid composite lubricating coating according to any one of claims 1 to 3, characterized in that: The steps include: (1) Tetraethoxysilane is dispersed in an alcohol aqueous solution and hydrolyzed under acidic conditions to obtain a tetraethoxysilane hydrolyzate; (2) dispersing amino-modified molybdenum disulfide nanoparticles in tetraethoxysilane hydrolyzate to obtain a mixed solution; (3) dispersing the silane compound containing a carbon-carbon double bond in an alcohol aqueous solution, and hydrolyzing the silane compound containing a carbon-carbon double bond under acidic conditions to obtain a hydrolyzate of the silane compound; (4) mixing the hydrolyzed silane compound containing a carbon-carbon double bond with the mixed solution in step (2), coating the mixture on the surface of the substrate, and heat-treating the mixture to obtain a sample with silica sol, wherein amino-modified molybdenum disulfide nanoparticles are uniformly dispersed in the silica sol; (5) placing the sample with silica sol in step (4) in a zwitterionic monomer solution, and modifying the surface of the silica sol with a zwitterionic polymer brush under the initiation of an initiator to obtain the solid-liquid composite lubricating coating.

5. The preparation method according to claim 4, wherein In step (1), the alcohol in the alcohol aqueous solution is a monohydric alcohol, preferably ethanol; Or, in step (1), the acid providing the acidic environment is selected from hydrochloric acid, nitric acid and formic acid, preferably formic acid; Alternatively, in step (1), the volume ratio of tetraethoxysilane to alcohol and water is (1-5):10:(1-5); Alternatively, in step (1), the hydrolysis time is 8 to 24 hours.

6. The preparation method according to claim 4, wherein In step (2), the preparation method of amino-modified molybdenum disulfide nanoparticles includes: MoS2 nanoparticles were dispersed in ethanol, and after the first stirring, KH550 and water were added. After the second stirring reaction, the mixture was centrifuged to obtain amino-modified MoS2 nanoparticles. Preferably, the temperature of the first stirring reaction is 55 to 65° C., preferably 60° C.; the time of the first stirring reaction is 20 to 40 minutes, preferably 30 minutes; Preferably, the temperature of the second stirring reaction is 55 to 65° C., preferably 60° C.; the time of the second stirring reaction is 5 to 8 hours, preferably 6 hours; Preferably, the mass ratio of molybdenum disulfide nanoparticles to KH550 is (0.8-1.2) g:1 mL, preferably 1 g:1 mL.

7. The preparation method according to claim 4, wherein In step (3), the silane compound containing a carbon-carbon double bond includes one of methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxychlorosilane, trimethoxyvinylphenylsilane or allyltriethoxysilane, preferably methacryloxypropyltrimethoxysilane; In step (3), the alcohol in the alcohol aqueous solution is a monohydric alcohol, preferably ethanol; Or, in step (3), the acid providing the acidic environment is selected from hydrochloric acid, nitric acid and formic acid, preferably formic acid; Alternatively, in step (3), the volume ratio of the silane compound containing a carbon-carbon double bond to the alcohol and water is (1-3):10:(1-3); Alternatively, in step (3), the hydrolysis time is 8 to 10 hours.

8. The preparation method according to claim 4, wherein In step (4), the volume ratio of hydrolyzate B to the mixed solution in step (2) is (2-3): (1-3); Alternatively, in step (4), the heat treatment temperature is 60 to 80° C., and the heat treatment time is 10 to 30 minutes.

9. The preparation method according to claim 4, wherein In step (5), the zwitterionic monomer in the zwitterionic monomer solution is selected from one of sulfobetaine, carboxybetaine and phosphorylcholine; Alternatively, in step (5), the concentration of the zwitterionic monomer is 0.1 to 0.5 g / mL; Or, in step (5), the initiator is selected from photoinitiator 1173, benzophenone and ammonium cerium nitrate, preferably ammonium cerium nitrate; Alternatively, in step (5), under the initiation of an initiator, the reaction conditions are ultraviolet light irradiation or heating at 50-70° C.; and the reaction time is 1-36 h.

10. The solid-liquid composite lubricating coating according to any one of claims 1 to 3 or the solid-liquid composite lubricating coating prepared by the preparation method according to any one of claims 4 to 9 is applied to movable parts of aircraft in a marine transportation environment.

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