A method for constructing a two-dimensional nanosheet-supported copper metal particle-based superlubricated thin film

Abstract

The application provides a method for constructing a two-dimensional nanosheet loaded copper metal particle-based super-smooth film, which comprises the following steps: in-situ dissociating a two-dimensional bulk material by plasma, and simultaneously depositing copper particles on the surface of the dissociated and thinned two-dimensional bulk material by a magnetron sputtering method to form a two-dimensional nanosheet loaded with copper particles; combining a flexible polymer on the surface of the two-dimensional nanosheet loaded with copper particles; and finally spraying the two-dimensional nanosheet loaded with copper particles as a spraying material on the surface of a substrate to obtain a super-smooth film. The super-smooth film is based on constructing a copper metal / two-dimensional nanomaterial heterogeneous pair on a friction interface to realize low adhesion. Meanwhile, the self-migration behavior of the crystal cluster formed by the aggregation of copper metal particles induced by friction continuously provides the interface with the heterogeneous pair through the polymer diffusion channel, which guarantees a stable super-smooth state and prolongs the wear life. The method overcomes the limitations of traditional chemical treatment and lubricating coating, is easy to realize large-area industrialized preparation, and is expected to become one of important means for prolonging the service life of moving parts.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lubricating material preparation, and relates to a method for constructing a two-dimensional nanosheet loaded copper metal particle-based super-smooth film. BACKGROUND

[0002] Friction and wear between moving mechanical parts often cause significant energy waste, environmental pollution and health problems, and lubrication becomes a key means to alleviate or solve harmful effects. Among them, superlubricity, i.e. nearly zero friction (friction coefficient less than 0.01), becomes a hot spot in tribology because the friction and wear of materials can be ignored. A major challenge is that the conditions for meeting the sustainability and robustness of superlubricity under long sliding distance and high contact pressure are relatively harsh, which greatly limits the practical engineering application.

[0003] So far, a large number of experimental and theoretical studies on superlubricity have mainly focused on a class of van der Waals materials, such as graphite, graphene, hexagonal boron nitride and molybdenum disulfide. The layered structure of this class of materials has a low interlayer shear resistance, which greatly reduces friction. However, due to the smoothness of atomic layers and the strict restriction of interlayer non-commensurate contact, which is a prerequisite for generating and maintaining structural superlubricity, it is difficult to expand the scale of application of this class of materials. Therefore, it is an urgent breakthrough point to design this class of materials through other methods and apply them to engineering scales. SUMMARY

[0004] Therefore, in order to solve the above technical problems, the purpose of the present application is to provide a method for constructing a two-dimensional nanosheet loaded copper metal particle-based super-smooth film. The method comprises the following steps: in-situ dissociating a two-dimensional bulk material by plasma bombardment, and simultaneously depositing copper particles onto the surface of the dissociated and thinned two-dimensional bulk material by a magnetron sputtering method to form a two-dimensional nanosheet loaded with copper particles; combining a flexible polymer on the surface of the two-dimensional nanosheet loaded with copper particles; and finally spraying the super-smooth film on the surface of the substrate as a spraying material. This super-smooth film is based on the construction of a copper metal / two-dimensional nanomaterial hetero-pair at the friction interface to achieve low adhesion. At the same time, the crystal clusters of copper metal particles aggregated by friction force form a self-migration behavior, which continuously provides the interface with the hetero-pair through the polymer diffusion channel, ensuring a stable super-smooth state and prolonging the wear life. This method overcomes the limitations of traditional chemical treatment and lubricating coatings, is easy to realize large-area industrialized preparation, and is expected to become one of the important means to prolong the service life of moving parts.

[0005] To achieve the above purpose, the technical scheme adopted is as follows:

[0006] A method for constructing a two-dimensional nanosheet loaded copper metal particle-based super-smooth film, comprising the following steps:

[0007] Step S1: dissociating and thinning a two-dimensional nanosheet by plasma bombardment

[0008] The two-dimensional nanosheets are loaded into a reactor, vacuum is drawn; plasma bombardment is performed by using a pulsed ion source to cause the two-dimensional nanosheets to be thinned by dissociation;

[0009] Step S2: The two-dimensional nanosheets loaded with copper particles are prepared by sputtering a copper target

[0010] The reactor in which the two-dimensional nanosheets thinned by dissociation obtained in step S1 is connected to a gas source, and the two-dimensional nanosheets loaded with copper particles are prepared by sputtering a copper target;

[0011] Step S3: The two-dimensional nanosheets loaded with copper particles are combined with a flexible polymer

[0012] The flexible polymer is uniformly mixed with deionized water to obtain a flexible polymer suspension; the two-dimensional nanosheets loaded with copper particles obtained in step S3 are slowly added to the flexible polymer suspension, and the flexible polymer is combined to the surface of the two-dimensional nanosheets loaded with copper particles to obtain a spraying liquid;

[0013] Step S4: Constructing a two-dimensional nanosheet loaded copper metal particle based super-slippery film by spraying method

[0014] After the substrate is pretreated, the spraying liquid obtained in step S3 is used to construct a two-dimensional nanosheet loaded copper metal particle based super-slippery film on the surface of the pretreated substrate by spraying method.

[0015] Further, the two-dimensional nanosheets in step S1 include one or more of graphene, hexagonal boron nitride, and MXene; the plasma in step S1 is hydrogen plasma; and the flexible polymer in step S3 includes one or more of chitosan and polyethyleneimine.

[0016] Further, the reactor is provided with a tray, the two-dimensional nanosheets are placed on the tray, and in steps S1 and S2, the tray always moves relative to the reactor to keep the two-dimensional nanosheets uniformly thinned and the copper particles uniformly loaded; and the volume of the two-dimensional nanosheet material is not more than 20% of the volume of the reactor.

[0017] Further, the hydrogen plasma bombardment conditions are a pulse bias of 150V-500V, a duty cycle of 60%-80%, and a bombardment time of 30min-90min.

[0018] Further, the gas source in step S2 is argon, and the specific conditions for preparing the two-dimensional nanosheets loaded with copper particles by sputtering a copper target are a pulse bias of 300V-800V, a target current of 1.0A-3.5A, and a sputtering time of 15min-90min.

[0019] Further, the specific method of combining the flexible polymer to the surface of the two-dimensional nanosheet loaded with copper particles in step S3 is: after the two-dimensional nanosheet loaded with copper particles is slowly added into the flexible polymer suspension, ultrasonic is used to promote the adsorption of the flexible polymer chain to the surface of the two-dimensional nanosheet loaded with copper particles; the mass ratio of the two-dimensional nanosheet loaded with copper particles to the flexible polymer is 2-4:3-5.

[0020] Further, in step S4:

[0021] The substrate is subjected to hydrogen peroxide and sulfuric acid soaking treatment to hydroxylate; after drying, a super-slippery film is constructed by using a spraying method; wherein the spraying temperature is 50-80℃, the pressure of the spray gun is 2-5MPa, the angle between the spray gun and the substrate is perpendicular; the concentration of the spraying liquid is 0.3-0.8mg / mL, and the drying time under room temperature is 1-3 days.

[0022] Further, the thickness of the two-dimensional nanosheet loaded with copper metal particle based super-slippery film is 1μm-3μm.

[0023] A two-dimensional nanosheet loaded with copper metal particle based super-slippery film, which is constructed by any one of the above construction methods.

[0024] An application method of a two-dimensional nanosheet loaded with copper metal particle based super-slippery film, wherein the super-slippery film is used to realize the super-slippery state of the surface of a relative motion component; the environment for realizing the super-slippery property of the super-slippery film includes: atmosphere with humidity<40%, glycerol and PAO oil; the counterpieces for realizing the super-slippery property of the super-slippery film include: stainless steel, various ceramic balls and aluminum oxide balls.

[0025] Advantages:

[0026] The advantages of the present application are embodied in:

[0027] The application provides a method for constructing a two-dimensional nanosheet loaded copper metal particle-based super-smooth film, which comprises the following steps: in-situ dissociating a two-dimensional bulk material by plasma, and simultaneously depositing copper particles on the surface of the dissociated and thinned two-dimensional bulk material by a magnetron sputtering method to form a two-dimensional nanosheet loaded with copper particles, combining a flexible polymer on the surface of the two-dimensional nanosheet loaded with copper particles, and finally spraying the two-dimensional nanosheet loaded with copper particles as a spraying material on the surface of a substrate to obtain a super-smooth film. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0029] Figure 1 Preparation technology schematic diagram of the two-dimensional nanosheet surface loaded with copper particles described in the embodiments of the present application;

[0030] Figure 2 XRD spectrum of the two-dimensional boron nitride nanosheet loaded with copper particles described in the embodiments of the present application;

[0031] Figure 3 Super-smooth behavior diagram of the two-dimensional boron nitride nanosheet loaded with copper particles / chitosan-based film described in the embodiments of the present application;

[0032] Figure 4 Schematic diagram of the film friction mechanism described in the embodiments of the present application. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0034] Embodiment 1:

[0035] A method for constructing a two-dimensional nanosheet loaded copper metal particle based super-slippery film, the preparation method comprising the following steps:

[0036] (1) Preparation of two-dimensional nanosheet loaded copper metal particles

[0037] As shown in Figure 1 , bulk hexagonal boron nitride powder (about 200 mL) is loaded into a 1 L shaking tank, the tray rotation speed is set to 50 rpm; open the mechanical pump to vacuum to 50 Pa, then open the Roots pump to vacuum to 2 Pa, and finally open the molecular pump to vacuum to 3 × 10 -3 Pa;

[0038] 200 sccm of hydrogen is introduced into the vacuum chamber, and plasma bombardment is performed using a pulsed ion source to facilitate the thinning of the bulk hexagonal boron nitride; wherein the hydrogen plasma bombardment conditions are a pulse bias of 500 V, a duty cycle of 60%, and a bombardment time of 40 min.

[0039] After the hydrogen plasma treatment is completed, 100 sccm of argon is introduced to sputter a copper target to prepare hexagonal boron nitride nanosheet loaded copper particles; wherein the pulse bias is 500 V, the target current is 1.0 A to 3.5 A, and the sputtering time is 15 min. The XRD of the prepared hexagonal boron nitride nanosheet loaded copper particles is shown in Figure 2 .

[0040] The tray and the shaking tank are in motion throughout the period, facilitating the thinning of the bulk hexagonal boron nitride and the uniformization of the copper particle loading.

[0041] (2) Electrostatic adsorption and combination of the polymer and the composite

[0042] Chitosan 15 mg is stirred and mixed with 30 mL of deionized water for 20 minutes to obtain a polymer suspension; 10 mg of hexagonal boron nitride nanosheet loaded copper particles are slowly added to the polymer suspension, and 300 W ultrasonic treatment for 1 hour can promote the adsorption of the polymer chains to the surface of the composite to obtain a spraying liquid.

[0043] (3) Construction of the super-slippery film

[0044] A 2 cm × 2 cm stainless steel sheet with a thickness of 1 mm is hydroxylated by soaking in hydrogen peroxide and sulfuric acid; after drying, a super-slippery film is constructed using a spraying method; wherein the spraying temperature is 50°C, the pressure of the spray gun is 2 MPa, and the spray gun is perpendicular to the substrate; 30 mL of the above spraying liquid diluent is used, the concentration of the spraying liquid diluent is 0.5 mg / mL, and the film is dried at room temperature for 1 day. The thickness of the film is 2.0 μm.

[0045] Example 2:

[0046] A method for constructing a two-dimensional nanosheet-supported copper metal particle-based superlubricated thin film is basically the same as that in Example 1, except that:

[0047] In step (1), the bulk hexagonal boron nitride powder is replaced by bulk graphite sheets, and the hydrogen plasma bombardment condition is a pulse bias voltage of 300V;

[0048] In step (2), chitosan is replaced with polyethyleneimine (MW1200).

[0049] Example 3:

[0050] A method for constructing a two-dimensional nanosheet-supported copper metal particle-based superlubricated thin film is basically the same as that in Example 1, except that:

[0051] In step (3), 50 mL of the above-mentioned spray liquid diluent is used, and the thickness of the film is 3.0 μm.

[0052] Example 4:

[0053] A method for constructing a two-dimensional nanosheet-supported copper metal particle-based superlubricated thin film is basically the same as that in Example 1, except that:

[0054] In step (1), bulk hexagonal boron nitride powder is replaced with bulk MXene;

[0055] In step (3), the concentration of the spraying liquid diluent is 0.8 mg / mL, and the thickness of the film is 3.0 μm.

[0056] Tribological properties and lifetime of the superlubricating thin films prepared in Examples 1-4:

[0057] The frictional properties and frictional mechanisms of the two-dimensional nanosheet-supported copper metal particle-based superlubricated films prepared in Examples 1-4 were verified, such as... Figure 3 and 4 As shown. Experimental environment: PAO6 oil was added; the friction conditions adopted the ball-disc rotation mode, the rotation radius was 4mm, the normal load was 12.0N, and the friction pair was a φ6mm aluminum oxide ball.

[0058] The test results are as follows:

[0059] The films prepared in Examples 1 and 3 are as follows: Figure 3 As shown, the coefficient of friction reaches 0.005, indicating a super-lubricated state and excellent tribological properties. After 24 hours of friction under these conditions, repeated start-stop cycles still maintain a low coefficient of friction, demonstrating that the film has excellent wear resistance.

[0060] The films prepared in Examples 2 and 4 demonstrate that replacing the two-dimensional material and polymer type can achieve a superlubricated state, and that changes in the concentration of the spraying solution have little effect on the tribological properties.

[0061] Comparative Example 1:

[0062] A method for constructing a two-dimensional nanosheet-supported copper metal particle-based superlubricated thin film is basically the same as that in Example 1, except that:

[0063] Instead of using hydrogen plasma to thin the bulk two-dimensional material hexagonal boron nitride, the bulk hexagonal boron nitride was directly used to sputter copper targets to prepare hexagonal boron nitride nanosheets loaded with copper particles. The other steps were the same as in Example 1.

[0064] The specific surface area of ​​the film obtained by this method is significantly reduced, and the lubricating phase cannot be effectively stored at the friction interface, resulting in the friction coefficient increasing to about 0.2, which is the intrinsic friction coefficient of the polymer matrix.

[0065] Comparative Example 2:

[0066] A method for constructing a two-dimensional nanosheet-supported copper metal particle-based superlubricated thin film is basically the same as that in Example 1, except that:

[0067] After hydrogen plasma thinning of bulk hexagonal boron nitride (BON) in a two-dimensional material, the bulk BON is directly used for bonding with the flexible polymer chitosan. This reduces the step of preparing BON nanosheets loaded with copper particles by sputtering a copper target. Other steps are the same as in Example 1.

[0068] The film obtained by this method does not use copper particles as a load, making it difficult to construct a copper metal / two-dimensional nanomaterial heterogeneous pair at the friction interface to achieve low adhesion. The coefficient of friction also increases significantly to about 0.3.

[0069] Comparative Example 3:

[0070] A method for constructing a two-dimensional nanosheet-supported copper metal particle-based superlubricated thin film is basically the same as that in Example 1, except that:

[0071] After preparing hexagonal boron nitride nanosheets loaded with copper particles, the binding of the copper-loaded hexagonal boron nitride nanosheets with the flexible polymer chitosan is omitted, that is, the binding step of the flexible polymer chitosan with the copper-loaded hexagonal boron nitride nanosheets is reduced. The other steps are the same as in Example 1.

[0072] The thin film obtained in this way does not use polymer bonding. The copper particles loaded on the two-dimensional nanosheets will be difficult to be effectively stored at the interface, and there will be no diffusion channels to facilitate the replenishment of the lubricating phase to the friction area, resulting in a significant increase in the coefficient of friction to about 0.5.

[0073] In summary, this invention provides a method for constructing a two-dimensional nanosheet-loaded copper metal particle-based superlubricating film. The method involves in-situ plasma dissociation of a two-dimensional bulk material and simultaneous magnetron sputtering to deposit copper particles onto the surface of the dissociated and thinned two-dimensional bulk material, forming copper particle-loaded two-dimensional nanosheets. A flexible polymer is then bonded to the surface of the copper particle-loaded two-dimensional nanosheets, and finally, this polymer is used as a spraying material to coat the substrate surface to obtain a superlubricating film. This superlubricating film achieves low adhesion by constructing a copper metal / two-dimensional nanomaterial heterogeneous pair at the friction interface. Simultaneously, friction induces the formation of self-migration clusters of copper metal particles, continuously providing this heterogeneous pair to the interface through polymer diffusion channels, ensuring a stable superlubricating state and extending wear life. This method overcomes the limitations of traditional chemical treatments and lubricating coatings, is easily achievable for large-area industrial production, and is expected to become one of the important means to extend the life of moving parts.

[0074] The above description is not intended to limit the present invention in any way. Although the present invention has been disclosed through the above embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for constructing a two-dimensional nanosheet supported copper metal particle based super-slippery thin film, characterized in that, The construction method comprises the following steps: Step S1: Plasma bombardment dissociation thinning two-dimensional nanosheet The two-dimensional nanosheet is loaded into a reactor and vacuumized; a pulsed ion source is used for plasma bombardment to promote dissociation and thinning of the two-dimensional nanosheet; Step S2: Preparing two-dimensional nanosheet loaded with copper particles by sputtering copper target The reactor in which the two-dimensional nanosheet after dissociation and thinning in step S1 is connected to a gas source, and two-dimensional nanosheet loaded with copper particles is prepared by sputtering copper target; Step S3: Combining two-dimensional nanosheet loaded with copper particles with flexible polymer The flexible polymer is uniformly mixed with deionized water to obtain a flexible polymer suspension; the two-dimensional nanosheet loaded with copper particles obtained in step S3 is slowly added to the flexible polymer suspension, and the flexible polymer is combined to the surface of the two-dimensional nanosheet loaded with copper particles to obtain a spraying liquid; Step S4: Constructing two-dimensional nanosheet loaded copper metal particle-based super-slippery film by spraying method After the substrate is pretreated, the spraying liquid obtained in step S3 is used to construct two-dimensional nanosheet loaded copper metal particle-based super-slippery film on the surface of the pretreated substrate by spraying method; The two-dimensional nanosheet in step S1 comprises one or more of graphene, hexagonal boron nitride and MXene; the plasma in step S1 is hydrogen plasma; the flexible polymer in step S3 comprises one or more of chitosan and polyethyleneimine.

2. A method for constructing a two-dimensional nanosheet supported copper metal particle based super-slick thin film as claimed in claim 1, wherein, The reactor is provided with a tray, and the two-dimensional nanosheet is placed on the tray; in steps S1 and S2, the tray always moves relative to the reactor to keep the two-dimensional nanosheet uniformly thinned and the copper particles uniformly loaded; the volume of the two-dimensional nanosheet material is not more than 20% of the volume of the reactor.

3. A method for constructing a two-dimensional nanosheet supported copper metal particle based super-slick thin film as claimed in claim 1, wherein, The hydrogen plasma bombardment conditions are pulse bias voltage of 150 V-500 V, duty cycle of 60%-80%, and bombardment time of 30 min-90 min.

4. A method for constructing a two-dimensional nanosheet supported copper metal particle based super-slick thin film as claimed in claim 1, wherein, The gas source in step S2 is argon, and the specific conditions for preparing two-dimensional nanosheet loaded with copper particles by sputtering copper target are pulse bias voltage of 300 V-800 V, target current of 1.0 A-3.5 A, and sputtering time of 15 min-90 min.

5. A method for constructing a two-dimensional nanosheet supported copper metal particle based super-slick thin film as claimed in claim 1, wherein, In step S3, the specific method for combining the flexible polymer to the surface of the two-dimensional nanosheet loaded with copper particles is as follows: after the two-dimensional nanosheet loaded with copper particles is slowly added to the flexible polymer suspension, ultrasonic is used to promote the adsorption of the flexible polymer chain to the surface of the two-dimensional nanosheet loaded with copper particles; the mass ratio of the two-dimensional nanosheet loaded with copper particles to the flexible polymer is 2-4:3-5.

6. A method for constructing a two-dimensional nanosheet supported copper metal particle based super-slick thin film as claimed in claim 1, wherein, In step S4: The substrate is hydroxylated by soaking in hydrogen peroxide and sulfuric acid; after drying, the super-slippery film is constructed by spraying method; wherein the spraying temperature is 50-80 ℃, the pressure of the spray gun is 2-5 MPa, the angle between the spray gun and the substrate is perpendicular, the concentration of the spraying liquid is 0.3-0.8 mg / mL, and the drying time at room temperature is 1-3 days.

7. A method for constructing a two-dimensional nanosheet supported copper metal particle based super-slick thin film as claimed in claim 1, wherein, The two-dimensional nanosheet loaded copper metal particle-based super-slippery film has a thickness of 1 μm-3 μm.

8. A two-dimensional nanosheet supported copper metal particle based super- slippery thin film, characterized in that, The construction method is constructed by any one of claims 1-7.

9. The application method of two-dimensional nanosheet loaded copper metal particle-based super-slick thin film according to claim 8, characterized in that, The super-slippery film is used to realize the super-slippery state of the surface of the relative motion component; the environment in which the super-slippery film realizes the super-slippery characteristic includes: atmosphere with humidity < 40%, glycerol, PAO oil; the counter-piece in which the super-slippery film realizes the super-slippery characteristic includes: stainless steel, various ceramic balls, aluminum oxide balls.

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