Intelligent nano-particles for solid-liquid synergetic lubrication as well as preparation method and application of intelligent nano-particles

Abstract

The invention provides intelligent nanoparticles with solid-liquid synergistic lubrication and a preparation method and application thereof.The preparation method comprises the steps that a first solution containing a stabilizer and a second solution containing a polymer monomer without a polymerization inhibitor are mixed, then an initiator and a cross-linking agent are added, a first reaction is conducted, and a first product is obtained; dissolving dopamine hydrochloride and polyethyleneimine in an alkaline buffer solution, then adding the first product, and carrying out a second reaction to obtain a second product; and dispersing a dispersion liquid containing a solid lubricant and the second product in water, and carrying out a third reaction. According to the preparation method of the intelligent nano-particles for solid-liquid synergistic lubrication, the surfaces of the nano-particles are coated with a layer of polydopamine-polyethyleneimine copolymer, so that the outer surfaces of the nano-particles are positively charged, and the interface bonding property of the nano-particles with other materials is effectively improved; meanwhile, the liquid lubricant and the solid lubricant are loaded, so that the lubrication requirements of different scenes can be met.

Description

Technical Field

[0001] This application relates to the technical field of intelligent lubricating materials, and particularly to an intelligent nanoparticle for solid-liquid synergistic lubrication, a preparation method thereof, and an application thereof. Background Art

[0002] In recent years, microcontainers loaded with liquid lubricants have shown excellent lubrication effects as self-lubricating additives, including microcapsule self-lubricating materials and porous self-lubricating materials. The liquid lubricant is stored in microcapsules or porous materials with a core-shell structure by coating or impregnation methods. When the frictional stress destroys the microcontainer, the lubricant is released to the interface to play a lubricating role. The sizes of the self-lubricating microcapsules reported currently are generally in the micron scale. Introducing them into composite materials may have a certain negative impact on mechanical properties, and at the same time limits their use in coating materials. The pore size and the through-pore structure of porous materials also greatly affect their application scope. In addition, limited by the synthesis method, low-viscosity liquid lubricating oils are usually used for loading, which is difficult to meet the lubrication requirements of mechanical components under extreme conditions such as high temperature, high pressure, high speed, or heavy load. Summary of the Invention

[0003] In view of this, an object of this application is to provide a preparation method of an intelligent nanoparticle for solid-liquid synergistic lubrication. By surface-modifying the nanoparticle - coating a layer of polydopamine-polyethyleneimine copolymer on the surface of the nanoparticle to make its outer surface positively charged (the copolymer contains a large number of amino groups and shows a positive charge in solution), thereby effectively improving its interfacial binding property with other materials; at the same time, loading liquid lubricant and solid lubricant can meet the lubrication requirements of different scenarios; the intelligent nanoparticle prepared by this preparation method has a small particle size and good dispersibility, and has more advantages in the field of coating applications compared with large-size liquid-loaded microcapsules.

[0004] Another object of this application is to provide an intelligent nanoparticle for solid-liquid synergistic lubrication.

[0005] Another object of this application relates to the application of the intelligent nanoparticle for solid-liquid synergistic lubrication.

[0006] To achieve the above object, the first aspect of this application proposes a preparation method of an intelligent nanoparticle for solid-liquid synergistic lubrication, including:

[0007] Mixing a first solution containing a stabilizer with a second solution containing a polymer monomer from which an inhibitor has been removed, and then adding an initiator and a crosslinking agent to carry out a first reaction to obtain a first product; the second solution is a mixed solution of a polymer monomer from which an inhibitor has been removed and a liquid lubricant;

[0008] Dissolve dopamine hydrochloride and polyethyleneimine in an alkaline buffer solution, then add the first product and carry out a second reaction to obtain a second product;

[0009] Disperse the dispersion containing the solid lubricant and the second product in water and carry out a third reaction to obtain the solid-liquid synergistic lubricating intelligent nanoparticles.

[0010] In some embodiments, the stabilizer includes at least one of polyvinylpyrrolidone, gum arabic, polyvinyl alcohol, tricalcium phosphate, sodium polystyrene sulfonate, sodium dodecyl sulfonate, and sodium dodecyl sulfate.

[0011] In some embodiments, the first solution is a solution formed by completely dissolving the stabilizer in water, and the mass ratio of the stabilizer to water is 1:(100 - 300).

[0012] In some embodiments, the polymer monomer from which the inhibitor is removed includes at least one of styrene, methyl methacrylate, butyl acrylate, ethyl acrylate, and glycidyl methacrylate.

[0013] In some embodiments, the liquid lubricant includes at least one of base oil, synthetic oil, ionic liquid, and liquid lubricant containing two-dimensional materials.

[0014] In some embodiments, the mass ratio of the polymer monomer from which the inhibitor is removed to the liquid lubricant is 4:(3 - 12).

[0015] In some embodiments, the initiator includes at least one of azobisisobutyronitrile, potassium persulfate, and benzoyl peroxide.

[0016] In some embodiments, the first reaction is carried out under stirring in an inert gas atmosphere.

[0017] In some embodiments, the reaction temperature of the first reaction is 70 - 90 °C, and the reaction time of the first reaction is 6 - 24 h.

[0018] In some embodiments, the crosslinking agent includes at least one of benzoyl peroxide, dicumyl peroxide, divinylbenzene, diisocyanate, bismaleimide, and N,N'-methylenebisacrylamide.

[0019] In some embodiments, the alkaline buffer solution includes an alkaline tris(hydroxymethyl)aminomethane hydrochloride buffer solution.

[0020] In some embodiments, the pH of the alkaline buffer solution is 8 - 9.

[0021] In some embodiments, the mass ratio of dopamine hydrochloride, polyethyleneimine, and the basic buffer solution is about 1:1:(400 - 600).

[0022] In some embodiments, the mass ratio of the first product to the basic buffer solution is 1:(20 - 60).

[0023] In some embodiments, the reaction temperature of the second reaction is room temperature, and the reaction time of the second reaction is 6 - 24 h.

[0024] In some embodiments, the second reaction is carried out under stirring conditions.

[0025] In some embodiments, the solid lubricant includes at least one of graphite, graphene, black phosphorus, molybdenum disulfide, silicon dioxide, boron nitride, and MXene.

[0026] In some embodiments, the dispersion liquid containing the solid lubricant and the second product are dispersed in water, wherein the mass ratio of the solid lubricant, the second product, and water is 1:(20 - 200):(500 - 5000).

[0027] In some embodiments, the temperature of the third reaction is room temperature, and the reaction time of the third reaction is 24 - 48 h.

[0028] In some embodiments, the third reaction is carried out under stirring conditions.

[0029] In some embodiments, the dispersion liquid containing the solid lubricant is a solution formed by dispersing the solid lubricant in water.

[0030] In some embodiments, the method for preparing the intelligent nano - particles with solid - liquid synergistic lubrication further includes the steps of washing and freeze - drying respectively after the first reaction, the second reaction, and the third reaction.

[0031] In some embodiments, the first product is nano - particles with a core - shell structure, wherein the core material is a liquid lubricant, and the shell material is a polymer formed from a polymerization monomer with an inhibitor removed.

[0032] In some embodiments, the surface roughness of the second product is greater than that of the first product.

[0033] In some embodiments, the intelligent nano - particles with solid - liquid synergistic lubrication are nano - particles in which the second product is coated with the solid lubricant on its surface.

[0034] The second aspect of the present application proposes an intelligent nanoparticle for solid-liquid synergistic lubrication, which is prepared by the preparation method of the intelligent nanoparticle for solid-liquid synergistic lubrication described in the present application.

[0035] The third aspect of the present application relates to the application of the intelligent nanoparticle for solid-liquid synergistic lubrication described in the present application in an intelligent lubricating coating or a lubricating composite material.

[0036] The preparation method of the intelligent nanoparticle for solid-liquid synergistic lubrication described in the present application can at least bring the following beneficial effects:

[0037] By surface modification of the nanoparticles - coating a layer of polydopamine-polyethyleneimine copolymer on the surface of the nanoparticles to make its outer surface positively charged (the copolymer contains a large number of amino groups and shows a positive charge in solution), thereby effectively improving its interfacial bonding with other materials; at the same time, loading liquid lubricants and solid lubricants can meet the lubrication requirements of different scenarios; the intelligent nanoparticles prepared by this preparation method have small particle size and good dispersibility, and are more advantageous in the field of coating applications compared with large-size liquid-loaded microcapsules.

[0038] The additional aspects and advantages of the present application will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present application. Description of the Drawings

[0039] The above-mentioned and / or additional aspects and advantages of the present application will become obvious and easy to understand from the following description of the embodiments in conjunction with the drawings,

[0040] wherein:

[0041] Figure 1 It is a scanning electron microscope (SEM) image of the first product prepared in Example 1.

[0042] Figure 2 It is a scanning electron microscope (SEM) image of the intelligent nanoparticle for solid-liquid synergistic lubrication prepared in Example 1.

[0043] Figure 3 It is a scanning electron microscope (SEM) surface morphology image of the perfluoropolyether microcapsule (i.e., the first product) prepared in Example 4.

[0044] Figure 4 It is a scanning electron microscope (SEM) surface morphology image of the perfluoropolyether microcapsule coated with graphene oxide (i.e., the intelligent nanoparticle for solid-liquid synergistic lubrication, the third product) prepared in Example 4.

[0045] Figure 5 It is a comparison chart of the friction performance test results of the composite material containing the intelligent nanoparticle for solid-liquid synergistic lubrication prepared in Example 1 and the pure matrix material.

[0046] Figure 6 Scanning electron microscope (SEM) image of the first product prepared in Example 2.

[0047] Figure 7 Transmission electron microscope (TEM) image of the first product prepared in Example 2. Detailed implementation manners

[0048] The embodiments of the present application will be described in detail below. The embodiments are exemplary and are intended to explain the present application, and should not be construed as a limitation to the present application.

[0049] In the present application, the disclosure of a numerical range includes all values within the entire range and the disclosure of further sub-ranges, including the endpoints and sub-ranges given for these ranges.

[0050] In the present application, for the raw materials, equipment, etc. involved, unless otherwise specified, they are all raw materials and equipment that can be obtained through commercial channels or prepared by known methods; for the methods involved, unless otherwise specified, they are all conventional methods.

[0051] When the term "and / or" is used in a list containing two or more items, it means that any one of the listed items can be used alone or in combination with any one or more of the listed items. For example, the expression "A and / or B" is intended to mean A or B or A and B, that is, it only means A, only means B, or means the combination of A and B.

[0052] In the present application, normal temperature refers to 20 - 30 °C.

[0053] The preparation method of the intelligent nano-particles with solid-liquid synergistic lubrication according to the embodiments of the present application includes the following steps:

[0054] S101. Mix a first solution containing a stabilizer with a second solution containing a polymer monomer from which an inhibitor has been removed, and then add an initiator and a cross-linking agent to carry out a first reaction to obtain a first product; the second solution is a mixed solution of a polymer monomer from which an inhibitor has been removed and a liquid lubricant.

[0055] In the embodiments of the present application, the first solution is an aqueous phase, the second solution is an oil phase, and there is no fixed requirement for the addition ratio of the aqueous phase and the oil phase. In addition, there is no fixed ratio requirement for the addition dosages of the initiator and the cross-linking agent either.

[0056] Exemplarily, the mass ratio of the first solution to the second solution is 1:(2 - 10), including but not limited to 1:3, 1:5, or 1:7, etc.

[0057] Exemplarily, the additive mass of the initiator is 1 - 5% of the mass of the polymer monomer from which an inhibitor has been removed, including but not limited to 1.5%, 3%, or 4.5%, etc.

[0058] Exemplarily, the additive mass of the crosslinking agent is 10-50% of the mass of the polymer monomer from which the polymerization inhibitor has been removed, including but not limited to 20%, 30%, or 40%, etc.

[0059] It should be noted that in order to prevent the polymerization of vinyl monomers during storage, transportation, etc., a small amount of polymerization inhibitor is often added to the polymer monomer and removed before use. In the embodiments of the present application, since the polymerization inhibitor itself does not participate in the reaction and form products, the specific selection of the polymerization inhibitor is not concerned.

[0060] In some embodiments, the stabilizer includes at least one of, but is not limited to, polyvinylpyrrolidone, gum arabic, polyvinyl alcohol, tricalcium phosphate, sodium polystyrene sulfonate, sodium dodecyl sulfonate, sodium dodecyl sulfate, etc.

[0061] It should be noted that when two or more of the above-mentioned multiple substances are selected as the stabilizer, the multiple substances can be mixed in different mass ratios.

[0062] In some embodiments, the first solution is a solution formed by completely dissolving the stabilizer in water.

[0063] Exemplarily, water includes at least one of, but is not limited to, deionized water, distilled water, pure water, ultrapure water, etc., and preferably ultrapure water.

[0064] Exemplarily, the preparation method of the first solution is: dispersing the stabilizer in water, heating and stirring (not exceeding 80 °C) until the stabilizer is completely dissolved to obtain the first solution.

[0065] Exemplarily, the mass ratio of the stabilizer to water is 1:(100-300), such as 1:150, 1:100, 1:200, or 1:250, etc., and preferably 1:100.

[0066] In some embodiments, the polymer monomer from which the polymerization inhibitor has been removed includes at least one of, but is not limited to, styrene, methyl methacrylate, butyl acrylate, ethyl acrylate, glycidyl methacrylate, etc.

[0067] It should be noted that when the above-mentioned multiple substances are selected as the polymer monomer from which the polymerization inhibitor has been removed, the multiple substances can be mixed in different mass ratios.

[0068] In some embodiments, the liquid lubricant includes at least one of, but is not limited to, base oil, synthetic oil, ionic liquid, liquid lubricant containing two-dimensional materials, etc.

[0069] In some embodiments, the mass ratio of the polymer monomer with inhibitor removed to the liquid lubricant is 4:(3 - 12). In the examples of the present application, when the mass ratio of the polymer monomer with inhibitor removed to the liquid lubricant is within the above range, a core-shell structure capsule with good dispersibility can be formed; if the amount of the polymer monomer with inhibitor removed is too large, polymer spheres may be formed; if the amount of the liquid lubricant is too large, a capsule structure may not be formed.

[0070] Exemplarily, the mass ratio of the polymer monomer with inhibitor removed to the liquid lubricant includes but is not limited to 4:3, 4:5, 4:7, 4:8, 4:4, 4:6, 4:10, 4:11 or 4:12, etc., and preferably 4:5.

[0071] In some embodiments, the method for preparing the second solution is: dispersing the polymer monomer with inhibitor removed in the liquid lubricant and ultrasonically dispersing until uniformly mixed to obtain the second solution.

[0072] In some embodiments, the first solution containing the stabilizer and the second solution containing the polymer monomer with inhibitor removed are uniformly mixed and then the initiator is added.

[0073] In some embodiments, the initiator includes but is not limited to at least one of azobisisobutyronitrile, potassium persulfate, benzoyl peroxide, etc.

[0074] It should be noted that when the above-mentioned multiple substances are selected as the initiator, the multiple substances can be mixed in different mass ratios.

[0075] In some embodiments, the reaction temperature of the first reaction is 70 - 90 °C, including but not limited to 75 °C, 80 °C, 85 °C or 90 °C, etc.

[0076] In some embodiments, the reaction time of the first reaction is 6 - 24 h, including but not limited to 7 h, 10 h, 13 h, 16 h, 19 h or 21 h, etc., and preferably 8 h.

[0077] In some embodiments, the first reaction is carried out under stirring in an inert gas atmosphere.

[0078] Exemplarily, the inert gas includes but is not limited to at least one of nitrogen, argon, helium, etc.

[0079] In some embodiments, the crosslinking agent includes but is not limited to at least one of benzoyl peroxide, diisopropylbenzene peroxide, divinylbenzene, diisocyanate, bismaleimide, N,N'-methylenebisacrylamide, etc.

[0080] It should be noted that when the above-mentioned multiple substances are selected as the cross-linking agent, the multiple substances can be mixed in different mass ratios.

[0081] In addition, it should also be noted that in the embodiments of the present application, there is no strict requirement for the addition of the cross-linking agent. The earlier addition may cause an increase in the degree of cross-linking. Therefore, the cross-linking agent can be added simultaneously with the initiator, or can be added after a period of time after adding the initiator.

[0082] In some embodiments, the method for preparing the intelligent nanoparticles for solid-liquid synergistic lubrication further includes the steps of washing and freeze-drying after the first reaction.

[0083] Exemplarily, the solvent for washing after the first reaction is deionized water, and the number of washing times can be multiple.

[0084] Exemplarily, the temperature for freeze-drying after the first reaction is below -50°C, and the time is 24 - 48 h. In the embodiments of the present application, the freeze-drying can be carried out in a freeze dryer.

[0085] In some embodiments, the first product is nanoparticles with a core-shell structure, the core material is a liquid lubricant, and the shell material is a polymer formed by a polymerization monomer from which the inhibitor has been removed. Among them, the core material can be understood as the inner core, and the shell material can be understood as the outer shell. The shell material covers at least a part of the outer surface of the core material. In the embodiments of the present application, the first product has good dispersibility in an aqueous solution.

[0086] S102. Dissolve dopamine hydrochloride and polyethyleneimine in an alkaline buffer solution, and then add the first product to carry out a second reaction to obtain a second product.

[0087] In the embodiments of the present application, the functions of dopamine hydrochloride and polyethyleneimine are to form a polydopamine-polyethyleneimine copolymer, making its outer surface positively charged, and then successfully adsorbing negatively charged solid lubricants such as graphene oxide (GO) through electrostatic force.

[0088] In some embodiments, the alkaline buffer solution includes but is not limited to at least one of alkaline tris(hydroxymethyl)aminomethane hydrochloride buffer solution, etc., and preferably alkaline tris(hydroxymethyl)aminomethane hydrochloride buffer solution.

[0089] In some embodiments, the pH of the alkaline buffer solution is 8 - 9, such as 8, 8.3, 8.5, or 8.8, etc., and preferably 8.5.

[0090] As an optional example, the alkaline buffer solution is a tris(hydroxymethyl)aminomethane hydrochloride buffer solution with a pH of about 8.5.

[0091] Exemplarily, a tris(hydroxymethyl)aminomethane hydrochloride buffer solution with a pH of about 8.5 can be prepared in the laboratory or purchased through a commercial platform.

[0092] In some embodiments, the mass ratio of the dopamine hydrochloride, the polyethyleneimine, and the basic buffer solution is about 1:1:(400 - 600), including but not limited to 1:1:420, 1:1:470, 1:1:500, or 1:1:480, etc., and preferably 1:1:500.

[0093] In some embodiments, the mass ratio of the first product to the basic buffer solution is 1:(20 - 60), including but not limited to 1:25, 1:35, 1:47, 1:50, or 1:53, etc., and preferably 1:50.

[0094] In some embodiments, the reaction temperature of the second reaction is room temperature.

[0095] In some embodiments, the reaction time of the second reaction is 6 - 24 h, including but not limited to 8 h, 12 h, 16 h, or 20 h, etc.

[0096] In some embodiments, the second reaction is carried out under stirring conditions.

[0097] In some embodiments, the method for preparing the solid-liquid synergistic lubricating intelligent nanoparticles further includes the steps of washing and freeze-drying after the third reaction.

[0098] Exemplarily, the solvent for washing after the third reaction is deionized water, and the number of washing times can be multiple.

[0099] Exemplarily, the temperature for freeze-drying after the third reaction is below -50 °C, and the time is 24 - 48 h. In the examples of the present application, the freeze-drying can be carried out in a freeze dryer.

[0100] In some embodiments, the surface roughness of the second product is greater than that of the first product. That is, the second product is a nanoparticle with a rougher surface compared to the first product.

[0101] In the examples of the present application, the second product is a nanoparticle with a core-shell structure (having a core and a shell, and the shell coats at least a part of the outer surface of the core), specifically, a nanoparticle with a poly(dopamine)-polyethyleneimine copolymer coated on the surface of the first product. That is, the core is the first product, and the shell is the poly(dopamine)-polyethyleneimine copolymer.

[0102] S103. Disperse the dispersion containing the solid lubricant and the second product in water, and carry out a third reaction to obtain the solid-liquid synergistic lubricating intelligent nanoparticles.

[0103] In some embodiments, the solid lubricant includes but is not limited to at least one of graphite, graphene, black phosphorus, molybdenum disulfide, silicon dioxide, boron nitride, MXene, etc.

[0104] It should be noted that when multiple substances among the above are selected as the solid lubricant, the multiple substances can be mixed in different mass ratios.

[0105] In some embodiments, the dispersion liquid containing the solid lubricant and the second product are dispersed in water, where the mass ratio of the solid lubricant, the second product, and water is 1:(20 - 200):(500 - 5000), including but not limited to 1:50:500, 1:100:500, 1:150:500, 1:110:1000, 1:110:2500, or 1:110:4000, etc.

[0106] Exemplarily, the dispersion liquid containing the solid lubricant and the second product are dispersed in water, where the water includes but is not limited to at least one of deionized water, distilled water, pure water, ultrapure water, etc., and ultrapure water is preferred.

[0107] In some embodiments, the temperature of the third reaction is room temperature.

[0108] In some embodiments, the time of the third reaction is 24 - 48 h, including but not limited to 30 h, 35 h, 40 h, or 45 h, etc.

[0109] In some embodiments, the third reaction is carried out under stirring conditions.

[0110] In some embodiments, the dispersion liquid containing the solid lubricant is a solution formed by dispersing the solid lubricant in water (such as deionized water, etc.).

[0111] In some embodiments, the method for preparing the intelligent nano - particles with solid - liquid synergistic lubrication further includes the steps of washing and freeze - drying respectively after the third reaction.

[0112] Exemplarily, the solvent for washing after the third reaction is deionized water, and the number of washing times can be multiple.

[0113] Exemplarily, the temperature of freeze - drying after the third reaction is below - 50 °C, and the time is 24 - 48 h. In the examples of the present application, freeze - drying can be carried out in a freeze - dryer.

[0114] In some embodiments, the intelligent nanoparticles for solid-liquid synergistic lubrication are nanoparticles having a core-shell structure (with a core and a shell, and the shell coats at least a part of the outer surface of the core), specifically nanoparticles with the solid lubricant coated on the surface of the second product. That is, the core is the second product and the shell is the solid lubricant.

[0115] The preparation method of the intelligent nanoparticles for solid-liquid synergistic lubrication according to the embodiments of the present application involves surface modification of the nanoparticles - coating a layer of polydopamine-polyethyleneimine copolymer on the surface of the nanoparticles to make their outer surface positively charged (the copolymer contains a large number of amino groups and shows positive charges in solution), thereby effectively improving their interfacial binding with other materials; at the same time, loading liquid lubricants and solid lubricants can meet the lubrication requirements of different scenarios; the intelligent nanoparticles prepared by this preparation method have small particle sizes and good dispersibility, and are more advantageous in the field of coating applications compared with large-sized liquid-loaded microcapsules.

[0116] The intelligent nanoparticles for solid-liquid synergistic lubrication according to the embodiments of the present application are prepared by using the preparation method of the intelligent nanoparticles for solid-liquid synergistic lubrication according to the embodiments of the present application.

[0117] The intelligent nanoparticles for solid-liquid synergistic lubrication according to the embodiments of the present application can be widely applied to lubricating coatings or composite materials.

[0118] In the following non-limiting examples, certain features of the present technology are further illustrated.

[0119] I. Examples and Comparative Examples

[0120] Example 1

[0121] The preparation method of the intelligent nanoparticles for solid-liquid synergistic lubrication in this example includes the following steps:

[0122] (1) Preparation of the first solution: Weigh 1.2 g of polyvinylpyrrolidone, disperse it in 120 g of deionized water under heating at 70 °C, and stir magnetically until completely dissolved to obtain the first solution.

[0123] (2) Preparation of the second solution: Weigh 7.5 g of polyalphaolefin lubricating oil containing organomolybdenum additive PAO6 and 6 g of styrene as a polymerization inhibitor, and ultrasonically mix them to obtain the second solution.

[0124] (3) Preparation of the first product: Add the first solution obtained in step (1) and the second solution obtained in step (2) into a three-necked flask, stir well, add 0.175 g of azobisisobutyronitrile, react at 80 °C for 2 h under an inert gas atmosphere. Then, add 2 g of divinylbenzene and continue to react at 80 °C for 6 h. After the reaction, wash the product with deionized water, filter it, and freeze-dry it at -50 °C for 24 h to obtain a white powder, which is the first product. The SEM image of the first product is as shown in Figure 1 , with a particle size of about 300 - 500 nm. As can be seen from Figure 1 , the capsules exhibit a complete spherical morphology and have good dispersibility.

[0125] (4) Preparation of the second product: Disperse 0.2 g of polyethyleneimine and 0.2 g of dopamine hydrochloride in 100 ml of tris(hydroxymethyl)aminomethane hydrochloride buffer solution with a pH of 8.5. After complete dissolution, add 2 g of the white powder obtained in step (3) (i.e., the first product), and react at room temperature (25 °C) at a rotation speed of 400 rpm for 6 h. After the reaction, wash the product with deionized water, filter it, and freeze-dry it at -50 °C for 24 h to obtain a light brown powder, which is the second product.

[0126] (5) Preparation of the third product: Take 5 ml of graphene oxide dispersion with a concentration of 2 mg / L and 1 g of the brown powder obtained in step (4) (i.e., the second product), disperse them in 50 ml of deionized water, and react at room temperature (25 °C) at a rotation speed of 400 rpm for 6 h. After the reaction, wash the product with deionized water, filter it, and freeze-dry it at -50 °C for 24 h. The obtained dark brown powder is the third product, which is the solid-liquid synergistic lubricating intelligent nanoparticle of this example. The SEM image is as shown in Figure 2 , and as can be seen from Figure 2 , the solid-liquid synergistic lubricating intelligent nanoparticle of this example has a spherical structure, with a relatively uniform size distribution and good dispersibility.

[0127] Friction performance test:

[0128] Under the condition of a test load of 4 N and a sliding speed of 12 mm / s at room temperature (25 °C), a multifunctional friction and wear testing machine was used to measure the friction coefficients of the pure matrix material and the composite material respectively. The pure matrix material is epoxy resin (CAS Registry Number: 61788-97-4), and the composite material is composed of the pure matrix material (i.e., epoxy resin) and the solid-liquid synergistic lubricating intelligent nanoparticle prepared in Example 1. The mass content of the solid-liquid synergistic lubricating intelligent nanoparticle prepared in Example 1 in the composite material is 10%. The composite material was prepared by mixing the pure matrix material and the solid-liquid synergistic lubricating intelligent nanoparticle prepared in Example 1. The test results are as shown in Figure 5 , and as can be seen from Figure 5It can be seen that the addition of the intelligent nanoparticles with solid-liquid synergistic lubrication prepared in Example 1 significantly reduces the friction coefficient of the matrix material, showing excellent lubrication effect.

[0129] Example 2

[0130] The preparation method of the intelligent nanoparticles with solid-liquid synergistic lubrication in this example includes the following steps:

[0131] (1) Preparation of the first solution: Weigh 1.2 g of polyvinylpyrrolidone, disperse it in 120 g of deionized water under heating at 70 °C, and stir magnetically until completely dissolved to obtain the first solution.

[0132] (2) Preparation of the second solution: Weigh 15 g of poly-α-olefin lubricant containing organomolybdenum additive PAO6 and 12 g of styrene with a polymerization inhibitor remover, and ultrasonically mix them to obtain the second solution.

[0133] (3) Preparation of the first product: Add the first solution obtained in step (1) and the second solution obtained in step (2) into a three-necked flask, stir well, add 0.35 g of azobisisobutyronitrile, react at 80 °C under an inert gas atmosphere, add 1.5 g of divinylbenzene, and continue the reaction for 24 h. After the reaction is completed, wash with absolute ethanol and deionized water three times respectively, and freeze-dry at -50 °C for 24 h to obtain a white powder, which is the first product. The SEM image and TEM image of the first product are respectively as Figure 6 and Figure 7 shown. It can be seen from Figure 6 that the capsules present a complete spherical morphology and have good dispersibility. It can be seen from Figure 7 that the first product has a core-shell structure.

[0134] (4) Preparation of the second product: Disperse 0.2 g of polyethyleneimine and 0.2 g of dopamine hydrochloride in 100 ml of tris(hydroxymethyl)aminomethane hydrochloride buffer solution with a pH of 8.5. After complete dissolution, add 2 g of the white powder obtained in step (3) (i.e., the first product), and react at room temperature (25 °C) at a rotation speed of 400 rpm for 24 h. After the reaction is completed, wash the product with deionized water, filter, and freeze-dry at -50 °C for 24 h to obtain a light brown powder, which is the second product.

[0135] (5) Preparation of the third product: Take 5 ml of graphene oxide dispersion with a concentration of 2 mg / L and 1 g of the brown powder obtained in step (4) (i.e., the second product), disperse them in 50 ml of deionized water, react at room temperature (25 °C) at a rotation speed of 400 rpm for 24 h. After the reaction is completed, wash the product with deionized water, filter, and freeze-dry at -50 °C for 24 h. The obtained dark brown powder is the third product, that is, the intelligent nanoparticles with solid-liquid synergistic lubrication in this example.

[0136] Example 3

[0137] This example is basically the same as Example 1, except that:

[0138] In step (2), styrene is replaced by butyl acrylate.

[0139] Example 4

[0140] This example is basically the same as Example 1, except that:

[0141] In step (2), the polyalphaolefin lubricant containing the organomolybdenum additive PAO6 is replaced by perfluoropolyether.

[0142] Example 5

[0143] This example is basically the same as Example 1, except that:

[0144] In step (3), the initiator is potassium persulfate;

[0145] In step (4), the crosslinking agent is N,N-methylenebisacrylamide.

[0146] Example 6

[0147] This example is basically the same as Example 1, except that:

[0148] In step (5), 0.2 g of polyethyleneimine and 0.2 g of dopamine hydrochloride are dispersed in 90 ml of a tris(hydroxymethyl)aminomethane hydrochloride buffer solution with a pH of 8.5.

[0149] Example 7

[0150] This example is basically the same as Example 1, except that:

[0151] In step (5), 0.2 g of polyethyleneimine and 0.2 g of dopamine hydrochloride are dispersed in 110 ml of a tris(hydroxymethyl)aminomethane hydrochloride buffer solution with a pH of 8.5.

[0152] In this application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0153] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0154] Although the embodiments of this application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting this application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A preparation method of intelligent nanoparticles for solid-liquid synergistic lubrication, characterized in that, Comprising: Mixing a first solution containing a stabilizer with a second solution containing a polymer monomer from which an inhibitor has been removed, then adding an initiator and a crosslinking agent to carry out a first reaction to obtain a first product; The second solution is a mixed solution of a polymer monomer from which an inhibitor has been removed and a liquid lubricant; Dissolving dopamine hydrochloride and polyethyleneimine in an alkaline buffer solution, then adding the first product to carry out a second reaction to obtain a second product; Dispersing a dispersion containing a solid lubricant and the second product in water to carry out a third reaction to obtain the intelligent nanoparticles with solid-liquid synergistic lubrication.

2. The preparation method according to claim 1, characterized in that, The stabilizer includes at least one of polyvinylpyrrolidone, gum arabic, polyvinyl alcohol, tricalcium phosphate, sodium polystyrene sulfonate, sodium dodecyl sulfonate, sodium dodecyl sulfate; and / or, The first solution is a solution formed by completely dissolving the stabilizer in water, and the mass ratio of the stabilizer to water is 1:(100 - 300).

3. The preparation method according to claim 1, characterized in that The polymer monomer from which an inhibitor has been removed includes at least one of styrene, methyl methacrylate, butyl acrylate, ethyl acrylate, glycidyl methacrylate; and / or, The liquid lubricant includes at least one of base oil, synthetic oil, ionic liquid, liquid lubricant containing two-dimensional materials; and / or, The mass ratio of the polymer monomer from which an inhibitor has been removed to the liquid lubricant is 4:(3 - 12).

4. The preparation method according to claim 1, wherein The initiator includes at least one of azobisisobutyronitrile, potassium persulfate, benzoyl peroxide; and / or, The first reaction is carried out under stirring in an inert gas atmosphere; and / or, The reaction temperature of the first reaction is 70 - 90 °C, and the reaction time of the first reaction is 6 - 24 h.

5. The preparation method according to claim 1, wherein, The crosslinking agent includes at least one of dicumyl peroxide, divinylbenzene, diisocyanate, bismaleimide, N,N'-methylenebisacrylamide.

6. The preparation method according to claim 1, characterized in that, The alkaline buffer solution includes an alkaline tris(hydroxymethyl)aminomethane hydrochloride buffer solution; and / or, The pH of the alkaline buffer solution is 8 - 9; And / or, The mass ratio of the dopamine hydrochloride, the polyethyleneimine and the alkaline buffer solution is approximately 1:1:(400 - 600); and / or, The mass ratio of the first product to the alkaline buffer solution is 1:(20 - 60); and / or, The reaction temperature of the second reaction is room temperature, and the reaction time of the second reaction is 6 - 24 h; and / or, The second reaction is carried out under stirring.

7. The preparation method according to claim 1, wherein The solid lubricant includes at least one of graphite, graphene, black phosphorus, molybdenum disulfide, silicon dioxide, boron nitride, MXene; and / or, Dispersing the dispersion containing the solid lubricant and the second product in water, wherein the mass ratio of the solid lubricant, the second product and water is 1:(20 - 200):(500 - 5000); and / or, The temperature of the third reaction is room temperature, and the time of the third reaction is 24 - 48 h; and / or, The third reaction is carried out under stirring; and / or, The dispersion containing the solid lubricant is a solution formed by dispersing the solid lubricant in water; and / or, The method for preparing the intelligent nanoparticles with solid-liquid synergistic lubrication further includes the steps of washing and freeze-drying respectively after the first reaction, the second reaction and the third reaction.

8. The preparation method according to claim 1, characterized in that, The first product is nanoparticles with a core-shell structure, wherein the core material is a liquid lubricant and the shell material is a polymer formed from a polymerization monomer from which the polymerization inhibitor has been removed; and / or, The surface roughness of the second product is greater than that of the first product; and / or, The intelligent nanoparticles with solid-liquid synergistic lubrication are nanoparticles in which the second product is coated with the solid lubricant on the surface.

9. An intelligent nanoparticle for solid-liquid synergistic lubrication, characterized in that, Prepared by using the preparation method according to any one of claims 1 to 8.

10. Application of the intelligent nanoparticles with solid-liquid synergistic lubrication according to claim 9 in a lubricating coating or composite material.

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