Nano graphite lubricating oil and preparation method thereof

Abstract

The invention relates to the technical field of lubricating oil, in particular to nano graphite lubricating oil and a preparation method thereof. The composite material is specifically composed of PAO and nano-graphite, wherein the nano-graphite is composed of a graphene modified CeO2 nanosheet and a MoS2 graphdiyne compound; in the nano graphite lubricating oil, the mass percent of the graphene modified CeO2 nanosheet is 1%-3%, the mass percent of the MoS2 graphdiyne compound is 1%-3%, and the balance is PAO. According to the lubricating oil disclosed by the invention, the graphene modified CeO2 nanosheet and the MoS2 graphdiyne compound are creatively combined with PAO to form a novel nano graphite lubricating oil formula, so that the energy consumption of mechanical equipment is reduced, the operation efficiency and reliability of the mechanical equipment are improved, and the service life of the equipment is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricating oils, and in particular to a nano-graphite lubricating oil and a preparation method thereof. Background Art

[0002] In recent years, with the rapid development of industry, the challenges faced by the moving components of mechanical equipment under complex operating conditions such as high stress and high loads have become increasingly severe. Friction and wear between moving components have become a key factor in the failure of materials and mechanical equipment. More seriously, the friction between moving parts not only causes enormous economic losses but also leads to significant energy waste. Research shows that over 30% of global primary energy is consumed by friction processes, and the economic losses caused by friction and wear amount to hundreds of billions of yuan annually, posing a severe challenge to the sustainable development of industry. Against this backdrop, reducing friction and wear between moving components and optimizing lubrication performance have become strategic issues related to enhancing industrial competitiveness and conserving resources.

[0003] The application of advanced carbon materials in the field of tribology has recently attracted considerable attention. Graphite and its composites, in particular, have driven a new wave of carbon-based materials in tribology research thanks to their exceptional performance. Graphite's unique layered structure imparts exceptional self-lubricity, enabling it to excel in reducing friction and wear. It also possesses decompression and anti-wear capabilities, alleviating contact stresses to a certain extent, as well as a self-repair function, automatically repairing minor damage during friction.

[0004] Although graphene has good lipophilicity in lubricating oils, its proneness to agglomeration and precipitation remains a major challenge for its use as a lubricating oil additive. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a nano-graphite lubricating oil and a preparation method thereof.

[0006] The present invention is achieved through the following technical solutions:

[0007] A nanographite lubricant is composed of PAO-4 and nanographite, wherein the nanographite is composed of graphene-modified CeO2 nanosheets and MoS2 graphyne composites; in the nanographite lubricant, the mass percentage of the graphene-modified CeO2 nanosheets is 1% to 3%, the mass percentage of the MoS2 graphyne composite is 1% to 3%, and the balance is PAO.

[0008] Furthermore, the mass percentage of the graphene-modified CeO2 nanosheets is 1%, the mass percentage of the MoS2 graphyne complex is 3%, and the balance is PAO.

[0009] Furthermore, the preparation method of the graphene-modified CeO2 nanosheets is as follows:

[0010] 0.3 g of CeO2 nanosheets were dispersed in 20 mL of ethanol and ultrasonicated for 0.5 h. Then, 0.2 g of p-aminobenzoic acid was added, stirred for 3 h, centrifuged, and the precipitate was dried at 60 degrees Celsius to obtain p-aminobenzoic acid-modified CeO2 nanosheets.

[0011] 0.05 g of graphene was dispersed in 50 mL of ethanol, and then 6 g of para-aminobenzoic acid-modified CeO2 nanosheets were added, stirred for 3 h, centrifuged to obtain a precipitate, and vacuum dried at 60 degrees Celsius to obtain graphene-modified CeO2 nanosheets.

[0012] Furthermore, the preparation method of the CeO2 nanosheets is as follows:

[0013] 5 mmol Ce(NO3)3·6H2O and 0.5 g PVP were dissolved in 20 mL ethylene glycol to obtain solution A;

[0014] 7.5 mmol urea and 0.5 g PVP were dissolved in 15 mL EG to obtain solution B;

[0015] Solution B was slowly added to solution A and stirred for 20 minutes. The mixed solution was heated to 180 degrees Celsius and ultrasonically reacted for 6 hours. After the reaction, it was naturally cooled to room temperature and centrifuged. The precipitate was washed with ethanol at least 3 times and vacuum-dried at 65 degrees Celsius overnight to obtain CeO2 nanosheets.

[0016] Furthermore, the synthesis method of the MoS2 graphyne composite is:

[0017] 1 g of MoS2 nanoflowers and 0.2 g of hexaynylbenzene were mixed, dissolved in 20 mL of pyridine, and then slowly added to a three-necked flask containing 40 mL of pyridine and copper foil. The entire process was carried out under an argon (Ar) atmosphere. After refluxing for 18 h, the reaction system was cooled to room temperature, the precipitate was washed several times with DMF and ethanol, and then vacuum dried at 60 ° C to obtain a MoS2 graphyne complex.

[0018] Furthermore, the preparation method of the MoS2 nanoflower is:

[0019] 0.16 g of urea was dispersed in 60 mL of deionized water and stirred for 10 minutes, followed by the addition of 0.16 g of MoO3 and further stirring for 20 minutes. The mixture was placed in a 100 mL stainless steel reactor lined with polytetrafluoroethylene and reacted at 180°C for 48 hours. The precipitate was washed three times with deionized water by centrifugation and then vacuum dried at 60°C for 24 hours to obtain MoS2 nanoflowers.

[0020] Furthermore, the PAO is selected from one or more of PAO-2, PAO-4, PAO-6, PAO-10, PAO-40, PAO-100 and PAO-135. The PAO is selected from PAO-4, and has a flash point of 224°C.

[0021] The present invention also provides a method for preparing nanographite lubricant, comprising the following steps: sequentially adding graphene-modified CeO2 nanosheets and a MoS2 graphyne complex to PAO-4, heating, and ultrasonically dispersing the mixture for 0.5 hours to obtain the nanographite lubricant. The heating temperature is 40°C.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] The lubricant in this invention innovatively combines graphene-modified CeO2 nanoflakes and MoS2 graphyne complexes with PAO, creating a novel nanographite lubricant formula. This unique material combination works synergistically under various operating conditions, providing superior lubrication performance. During lubrication, the graphene-modified CeO2 nanoflakes and MoS2 graphyne complex form a uniform and stable lubricating film on the friction surface, effectively isolating the friction pair from direct contact, significantly reducing the coefficient of friction and wear rate. This helps reduce the energy consumption of mechanical equipment, improve its operating efficiency and reliability, and extend its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention.

[0025] Figure 1 This is the macroscopic image of the copper sheet after the three corrosion tests;

[0026] Figure 2 This is the SEM image of graphene-modified CeO2 nanosheets;

[0027] Figure 3 This is the SEM image of the MoS2 graphyne composite. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0029] The PAO-4 in the present invention has a flash point of 224° C., a viscosity index of 124, and a kinematic viscosity (Reese) of 3.9 at 100° C.

[0030] Preparation of graphene-modified CeO2 nanosheets in the present invention:

[0031] 5 mmol Ce(NO3)3·6H2O and 0.5 g PVP (polyvinyl pyrrolidone) were dissolved in 20 mL ethylene glycol to obtain solution A;

[0032] 7.5 mmol urea and 0.5 g PVP were dissolved in 15 mL EG to obtain solution B;

[0033] Solution B was slowly added to solution A and stirred for 20 minutes. The mixed solution was heated to 180 degrees Celsius and ultrasonically reacted for 6 hours. After the reaction, it was naturally cooled to room temperature and centrifuged. The precipitate was washed with ethanol at least 3 times and vacuum-dried at 65 degrees Celsius overnight to obtain CeO2 nanosheets.

[0034] 0.3 g of CeO2 nanosheets were dispersed in 20 mL of ethanol and ultrasonicated for 0.5 h. Then, 0.2 g of p-aminobenzoic acid was added, stirred for 3 h, centrifuged, and the precipitate was dried at 60 degrees Celsius to obtain p-aminobenzoic acid-modified CeO2 nanosheets.

[0035] 0.05 g of graphene was dispersed in 50 mL of ethanol, and then 6 g of para-aminobenzoic acid-modified CeO2 nanosheets were added, stirred for 3 h, centrifuged to obtain a precipitate, and vacuum dried at 60 degrees Celsius to obtain graphene-modified CeO2 nanosheets.

[0036] Synthesis of MoS2 Graphene Composite in the Present Invention:

[0037] 1 g of MoS2 nanoflowers and 0.2 g of hexaynylbenzene were mixed, dissolved in 20 mL of pyridine, and then slowly added to a three-necked flask containing 40 mL of pyridine and copper foil. The entire process was carried out under an argon (Ar) atmosphere. After refluxing for 18 h, the reaction system was cooled to room temperature, the precipitate was washed several times with DMF and ethanol, and then vacuum dried at 60 ° C to obtain a MoS2 graphyne complex.

[0038] The synthesis of MoS2 nanoflowers: 0.16g urea was dispersed in 60mL deionized water, stirred for 10 minutes, and then 0.16g MoO3 was added and stirred for another 20 minutes; the mixture was placed in a 100mL stainless steel reactor lined with polytetrafluoroethylene and reacted at 180°C for 48 hours; the precipitate was washed three times with deionized water by centrifugation, and then vacuum dried at 60°C for 24 hours to obtain MoS2 nanoflowers.

[0039] Example 1

[0040] A nanographite lubricant is composed of PAO-4 and nanographite, wherein the nanographite is composed of graphene-modified CeO2 nanosheets and MoS2 graphyne composites; the mass percentage of the graphene-modified CeO2 nanosheets in the nanographite lubricant is 1%, the mass percentage of the MoS2 graphyne composite is 1%, and the balance is PAO-4.

[0041] The preparation method of nanographite lubricant is as follows: graphene modified CeO2 nanosheets and MoS2 graphyne complex are added to PAO-4 in sequence, and ultrasonically dispersed at 40°C for 0.5h to obtain nanographite lubricant.

[0042] Example 2

[0043] A nanographite lubricant is composed of PAO-4 and nanographite, wherein the nanographite is composed of graphene-modified CeO2 nanosheets and MoS2 graphyne composites; in the nanographite lubricant, the mass percentage of the graphene-modified CeO2 nanosheets is 1%, the mass percentage of the MoS2 graphyne composite is 3%, and the balance is PAO-4.

[0044] The preparation method is the same as that of Example 1.

[0045] Example 3

[0046] A nanographite lubricant is composed of PAO-4 and nanographite, wherein the nanographite is composed of graphene-modified CeO2 nanosheets and MoS2 graphyne composites; in the nanographite lubricant, the mass percentage of the graphene-modified CeO2 nanosheets is 3%, the mass percentage of the MoS2 graphyne composite is 1%, and the balance is PAO-4.

[0047] The preparation method is the same as that of Example 1.

[0048] Example 4

[0049] A nanographite lubricant is composed of PAO-4 and nanographite, wherein the nanographite is composed of graphene-modified CeO2 nanosheets and MoS2 graphyne composites; in the nanographite lubricant, the mass percentage of the graphene-modified CeO2 nanosheets is 3%, the mass percentage of the MoS2 graphyne composite is 3%, and the balance is PAO-4.

[0050] The preparation method is the same as that of Example 1.

[0051] Example 5

[0052] A nanographite lubricant is composed of PAO-4 and nanographite, wherein the nanographite is composed of graphene-modified CeO2 nanosheets and MoS2 graphyne composites; the mass percentage of the graphene-modified CeO2 nanosheets in the nanographite lubricant is 2%, the mass percentage of the MoS2 graphyne composite is 2%, and the balance is PAO-4.

[0053] The preparation method is the same as that of Example 1.

[0054] Comparative Example 1

[0055] A nanographite lubricant, wherein the mass percentage of graphene-modified CeO2 nanosheets is 3% and the balance is PAO-4.

[0056] The preparation method of nanographite lubricant is as follows: adding graphene modified CeO2 nanosheets to PAO-4, ultrasonically dispersing at 40 ° C for 0.5 h, and obtaining nanographite lubricant

[0057] Comparative Example 2

[0058] A nanographite lubricant, wherein the mass percentage of the MoS2 graphyne compound is 1% and the balance is PAO-4.

[0059] The preparation method of nano-graphite lubricant is as follows: adding MoS2 graphyne complex to PAO-4, ultrasonically dispersing at 40℃ for 0.5h, and obtaining nano-graphite lubricant.

[0060] Test Example 1

[0061] According to GB / T 5096, first, polish the copper sheet with sandpaper, clean and wipe the surface of the copper sheet, and weigh the copper sheet. Then, take 50 mL of the lubricating oil in the example and comparative example and place it in a small test tube. Immerse the polished copper sheet in the oil sample to be tested. Use a cork with a vent hole to plug the test tube and place it in a constant temperature water bath at 100±1℃ for 3 hours. After the test, remove the copper sheet, repeatedly wash it with petroleum ether and alcohol, and finally compare it with the standard color card to determine the corrosion level.

[0062] The friction test was conducted under the following conditions: the applied load was 10 N and the steel disk rotation speed was 300 r / min.

[0063] Table 1 Performance test.

[0064] Corrosion level Average friction coefficient Example 1 1b 0.115 Example 2 1b 0.112 Example 3 1b 0.095 Example 4 1b 0.105 Example 5 1b 0.105 Comparative Example 1 1b 0.124 Comparative Example 2 1b 0.127

[0065] As can be seen from Table 1, when nanographite, namely graphene-modified CeO2 nanosheets or MoS2 graphyne complexes, is added to the base oil PAO-4, both the composite addition and the individual additions show excellent anti-corrosion performance. When nanographene-modified CeO2 nanosheets and MoS2 graphyne complexes are used in combination, especially when the mass ratio of the two is 1:3, they have better friction performance.

[0066] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A nano-graphite lubricant, characterized in that: The lubricant is composed of PAO and nanographite, wherein the nanographite is composed of graphene-modified CeO2 nanosheets and MoS2 graphyne complexes; the mass percentage of graphene-modified CeO2 nanosheets in the nanographite lubricant is 1% to 3%, the mass percentage of MoS2 graphyne complexes is 1% to 3%, and the balance is PAO.

2. The nano-graphite lubricant according to claim 1, wherein The mass percentage of the graphene-modified CeO2 nanosheets is 1%, the mass percentage of the MoS2 graphyne complex is 3%, and the balance is PAO.

3. The nano-graphite lubricant as claimed in claim 2, characterized in that The preparation method of the graphene-modified CeO2 nanosheets is as follows: 0.3 g of CeO2 nanosheets were dispersed in 20 mL of ethanol and ultrasonicated for 0.5 h. Then, 0.2 g of p-aminobenzoic acid was added, stirred for 3 h, centrifuged, and the precipitate was dried at 60 degrees Celsius to obtain p-aminobenzoic acid-modified CeO2 nanosheets. 0.05 g of graphene was dispersed in 50 mL of ethanol, and then 6 g of para-aminobenzoic acid-modified CeO2 nanosheets were added, stirred for 3 h, centrifuged to obtain a precipitate, and vacuum dried at 60 degrees Celsius to obtain graphene-modified CeO2 nanosheets.

4. The nano-graphite lubricant as claimed in claim 3, characterized in that The preparation method of the CeO2 nanosheets is as follows: 5 mmol Ce(NO3)3·6H2O and 0.5 g PVP were dissolved in 20 mL ethylene glycol to obtain solution A; 7.5 mmol urea and 0.5 g PVP were dissolved in 15 mL EG to obtain solution B; Solution B was slowly added to solution A and stirred for 20 minutes. The mixed solution was heated to 180 degrees Celsius and ultrasonically reacted for 6 hours. After the reaction, it was naturally cooled to room temperature and centrifuged. The precipitate was washed with ethanol at least 3 times and vacuum-dried at 65 degrees Celsius overnight to obtain CeO2 nanosheets.

5. The nano-graphite lubricant as claimed in claim 2, characterized in that The synthesis method of the MoS2 graphyne composite is: 1 g of MoS2 nanoflowers and 0.2 g of hexaynylbenzene were mixed, dissolved in 20 mL of pyridine, and then slowly added to a three-necked flask containing 40 mL of pyridine and copper foil. The entire process was carried out under an argon (Ar) atmosphere. After refluxing for 18 h, the reaction system was cooled to room temperature, the precipitate was washed several times with DMF and ethanol, and then vacuum dried at 60 ° C to obtain a MoS2 graphyne complex.

6. The nano-graphite lubricant as claimed in claim 5, characterized in that The preparation method of the MoS2 nanoflower is: 0.16 g of urea was dispersed in 60 mL of deionized water and stirred for 10 minutes, followed by the addition of 0.16 g of MoO3 and further stirring for 20 minutes. The mixture was placed in a 100 mL stainless steel reactor lined with polytetrafluoroethylene and reacted at 180°C for 48 hours. The precipitate was washed three times with deionized water by centrifugation and then vacuum dried at 60°C for 24 hours to obtain MoS2 nanoflowers.

7. The nano-graphite lubricant according to claim 1, wherein The PAO is selected from one or more of PAO-2, PAO-4, PAO-6, PAO-10, PAO-40, PAO-100 and PAO-135.

8. The nano-graphite lubricant according to claim 7, wherein The PAO is selected from PAO-4, and has a flash point of 224°C.

9. The method for preparing nano-graphite lubricating oil according to any one of claims 1 to 6, characterized in that: The following steps are involved: Graphene-modified CeO2 nanosheets and MoS2 graphyne complexes were added to PAO-4 in sequence, heated, and ultrasonically dispersed for 0.5 h to obtain nanographite lubricating oil.

10. The method for preparing nano-graphite lubricating oil according to claim 9, wherein: The heating temperature is 40°C.

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