Nanographite lubricating oil and preparation method thereof

Abstract

The present application relates to the technical field of lubricating oil, and particularly relates to a nano-graphite lubricating oil and a preparation method thereof. Specifically, the nano-graphite lubricating oil is composed of PAO and nano-graphite, wherein the nano-graphite is composed of graphene modified CeO2 nanosheet and MoS2 graphdiyne composite; the mass percentage of the graphene modified CeO2 nanosheet in the nano-graphite lubricating oil is 1% to 3%, the mass percentage of the MoS2 graphdiyne composite is 1% to 3%, and the rest is PAO. In the present application, the graphene modified CeO2 nanosheet and the MoS2 graphdiyne composite are combined with PAO to form a nano-graphite lubricating oil formula, which helps to reduce the energy consumption of mechanical equipment, improve the operation efficiency and reliability of the mechanical equipment, and prolong the service life of the mechanical equipment.

Description

Technical Field

[0001] This invention relates to the field of lubricating oil technology, and in particular to a nano-graphite lubricating oil and its preparation method. Background Technology

[0002] In recent years, with the rapid development of industry, the challenges faced by moving parts of mechanical equipment under complex working conditions such as high stress and high load have become increasingly severe. Among these challenges, friction and wear between moving parts has become one of the key factors leading to the failure of materials and mechanical equipment. Against this backdrop, reducing friction and wear between moving parts and optimizing lubrication performance have risen to the level of strategic issues concerning the improvement of industrial competitiveness and resource conservation.

[0003] Recently, the application of advanced carbon materials in the field of tribology has attracted much attention, especially graphite and its composites, which have driven a new wave of research on carbon-based materials in tribology due to their superior performance. Graphite's unique layered structure endows it with excellent self-lubricating properties, making it outstanding in reducing friction and wear. At the same time, it has the ability to relieve contact stress and wear to a certain extent, as well as the self-healing function of automatically repairing minor damage during friction.

[0004] Although graphene has good oleophilicity in lubricating oils, its tendency to agglomerate and precipitate remains a major challenge for its use as a lubricating oil additive. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a nano-graphite lubricating oil and its preparation method.

[0006] This invention is achieved through the following technical solution:

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

[0008] Furthermore, the graphene-modified CeO2 nanosheets have a mass percentage of 1%, the MoS2 graphyne composite has a mass percentage of 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 sonicated 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 p-aminobenzoic acid-modified CeO2 nanosheets were added. The mixture was stirred for 3 h, centrifuged to obtain a precipitate, and then vacuum dried at 60 degrees Celsius to obtain graphene-modified CeO2 nanosheets.

[0012] Furthermore, the method for preparing the CeO2 nanosheets is as follows:

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

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

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

[0016] Furthermore, the synthesis method of the MoS2 graphdiyne composite is as follows:

[0017] 1 g of MoS2 nanoflowers and 0.2 g of hexynylbenzene were mixed and dissolved in 20 mL of pyridine. The mixture was 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 reflux for 18 h, the reaction system was cooled to room temperature. The precipitate was washed several times with DMF and ethanol and then dried under vacuum at 60 °C to obtain the MoS2 graphdiyne composite.

[0018] Furthermore, the method for preparing the MoS2 nanoflowers is as follows:

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

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

[0021] This invention also provides a method for preparing nano-graphite lubricating oil, characterized by comprising the following steps: sequentially adding graphene-modified CeO2 nanosheets and MoS2 graphylene composite to PAO-4, heating, and then ultrasonically dispersing for 0.5 h to obtain nano-graphite lubricating oil. The heating temperature is 40℃.

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

[0023] This invention innovatively combines graphene-modified CeO2 nanosheets and a MoS2 graphylene composite with PAO to form a nano-graphite lubricant formulation. This unique material combination can exert a synergistic effect under different operating conditions, providing superior lubrication performance. During lubrication, the graphene-modified CeO2 nanosheets and the MoS2 graphylene composite can form a uniform and stable lubricating film on the friction surface, effectively isolating the direct contact of the friction pairs, thereby 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 the service life of the equipment. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation on the embodiments of the present invention.

[0025] Figure 1 Macroscopic view of the copper sheet after performing three corrosion tests;

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

[0027] Figure 3 This is a SEM image of the MoS2 graphyne composite. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0029] In this invention, PAO-4 has a flash point of 224°C, a viscosity index of 124, and a kinematic viscosity (Ries) of 3.9 at 100°C.

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

[0031] Dissolve 5 mmol Ce(NO3)3·6H2O and 0.5 g PVP (polyvinylpyrrolidone) in 20 mL of ethylene glycol to obtain solution A;

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

[0033] Solution B was slowly added to solution A and stirred for 20 min. The mixed solution was heated to 180 degrees Celsius and sonicated for 6 h. After the reaction was completed, the solution was naturally cooled to room temperature, centrifuged, and the precipitate was washed with ethanol at least 3 times. The precipitate was then 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 sonicated 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 p-aminobenzoic acid-modified CeO2 nanosheets were added. The mixture was stirred for 3 h, centrifuged to obtain a precipitate, and then vacuum dried at 60 degrees Celsius to obtain graphene-modified CeO2 nanosheets.

[0036] Synthesis of MoS2-graphyne composite in this invention:

[0037] 1 g of MoS2 nanoflowers and 0.2 g of hexynylbenzene were mixed and dissolved in 20 mL of pyridine. The mixture was 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 reflux for 18 h, the reaction system was cooled to room temperature. The precipitate was washed several times with DMF and ethanol and then dried under vacuum at 60 °C to obtain the MoS2 graphdiyne composite.

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

[0039] Example 1

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

[0041] The preparation method of nano-graphite lubricating oil is as follows: graphene-modified CeO2 nanosheets and MoS2 graphylene composite are added to PAO-4 in sequence, and ultrasonically dispersed at 40℃ for 0.5 h to obtain nano-graphite lubricating oil.

[0042] Example 2

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

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

[0045] Example 3

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

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

[0048] Example 4

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

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

[0051] Example 5

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

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

[0054] Comparative Example 1

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

[0056] The preparation method of nano-graphite lubricating oil is as follows: graphene-modified CeO2 nanosheets are added to PAO-4 and ultrasonically dispersed at 40℃ for 0.5 h to obtain nano-graphite lubricating oil.

[0057] Comparative Example 2

[0058] A nano-graphite lubricant, wherein the mass percentage of MoS2 graphdiyne composite is 1% and the balance is PAO-4.

[0059] The preparation method of nano-graphite lubricating oil is as follows: MoS2-graphynylene composite is added to PAO-4 and ultrasonically dispersed at 40℃ for 0.5 h to obtain nano-graphite lubricating oil.

[0060] Test Example 1

[0061] According to GB / T 5096, firstly, the copper sheet is sanded and polished, and the surface of the copper sheet is cleaned and wiped. The mass of the copper sheet is then weighed. Next, 50 mL of the lubricating oil from the examples and comparative examples is placed in small test tubes. The polished copper sheet is then immersed in the oil sample to be tested. The test tube is sealed with a cork stopper with an air vent and placed in a constant temperature water bath at 100±1℃ for 3 hours. After the test, the copper sheet is removed and repeatedly cleaned with petroleum ether and alcohol. Finally, the corrosion level is determined by comparing the sample with a standard colorimetric card.

[0062] The conditions for the friction test were: a load of 10 N and a steel disc rotation speed of 300 r / min.

[0063] Table 1 Performance Tests.

[0064] Corrosion level Average coefficient of friction 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 nano-graphite is added to the base oil PAO-4, either graphene-modified CeO2 nanosheets or MoS2 graphylene composite, it exhibits excellent anti-corrosion performance, whether added in combination or individually. When the two are used in combination, especially when the mass ratio of the two is 1:3, the friction performance is even better.

[0066] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment 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 within the scope of protection of the present invention.

Claims

1. A nanographite lubricating oil, characterized by, The nano-graphite is composed of graphene modified CeO2 nanosheet and MoS2 graphdiyne composite; the mass percentage of the graphene modified CeO2 nanosheet in the nano-graphite lubricating oil is 1-3%, the mass percentage of the MoS2 graphdiyne composite is 1-3%, and the rest is PAO. The synthesis method of the MoS2 graphdiyne composite is as follows: 1g of MoS2 nanoflower and 0.2g of hexaalkynylbenzene are mixed and dissolved in 20ml of pyridine, then slowly added into a three-necked flask containing 40ml of pyridine and copper foil, and the whole process is carried out under an argon (Ar) atmosphere; after refluxing for 18h, the reaction system is cooled to room temperature, the precipitate is washed with DMF and ethanol for several times, and then vacuum dried at 60°C to obtain the MoS2 graphdiyne composite.

2. The nanographite lubricating oil as claimed in claim 1, wherein, The mass percentage of the graphene modified CeO2 nanosheet is 1%, the mass percentage of the MoS2 graphdiyne composite is 3%, and the rest is PAO.

3. The nanographite lubricating oil as claimed in claim 1, wherein, The preparation method of the graphene modified CeO2 nanosheet is as follows: 0.3g of CeO2 nanosheet is dispersed in 20ml of ethanol and ultrasonically treated for 0.5h; then 0.2g of p-aminobenzoic acid is added and stirred for 3h, centrifuged, and the precipitate is dried at 60°C to obtain p-aminobenzoic acid modified CeO2 nanosheet; 0.05g of graphene is dispersed in 50ml of ethanol, then 6g of p-aminobenzoic acid modified CeO2 nanosheet is added and stirred for 3h, centrifuged to obtain the precipitate, and vacuum dried at 60°C to obtain the graphene modified CeO2 nanosheet.

4. The nanographite lubricating oil as claimed in claim 1, wherein, The preparation method of the CeO2 nanosheet is as follows: 5mmol of Ce(NO3)3·6H2O and 0.5g of PVP are dissolved in 20ml of ethylene glycol to obtain solution A; 7.5mmol of urea and 0.5g of PVP are dissolved in 15ml of ethylene glycol to obtain solution B; solution B is slowly added into solution A and stirred for 20min; the mixed solution is heated to 180°C and ultrasonically reacted for 6h; after the reaction is completed, it is naturally cooled to room temperature, centrifuged, the precipitate is washed with ethanol for at least 3 times, and the precipitate is vacuum dried at 65°C overnight to obtain the CeO2 nanosheet.

5. The nanographite lubricating oil as claimed in claim 1, wherein, The PAO is selected from one or more of PAO-2, PAO-4, PAO-6, PAO-10, PAO-40, PAO-100 or PAO-135.

6. The nanographite lubricating oil as claimed in claim 5, wherein, The PAO is selected from PAO-4, and the flash point is 224°C.

7. The method for preparing the nano-graphite lubricating oil as described in claim 6, characterized in that, The method comprises the following steps: The graphene modified CeO2 nanosheet and the MoS2 graphdiyne composite are sequentially added into PAO-4, heated, and ultrasonically dispersed for 0.5h to obtain the nano-graphite lubricating oil.

8. The method of claim 7, wherein the nanographite lubricating oil is prepared by the steps of: The heating temperature is 40°C. ​

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