Lipophilic graphene quantum dot lubricating oil additive prepared by one-pot method and application of lipophilic graphene quantum dot lubricating oil additive

Abstract

The invention relates to the technical field of preparation of graphene quantum dot nano materials, in particular to a lipophilic graphene quantum dot lubricating oil additive prepared by a one-pot method and application thereof. The specific preparation method comprises the following steps: S1, heating and carbonizing a carbon source; s2, adding an oily modifier into S1, reacting for a period of time, and then cooling to room temperature; s3, putting the base oil into a reaction kettle, adding the material obtained in the step S2 into the reaction kettle, and stirring and mixing; s4, adding a dispersing agent into the reaction kettle in S3, and stirring and mixing; and S5, filtering the material obtained in the step S4, circulating for multiple times by adopting ultrahigh-pressure equipment, and discharging to obtain the graphene quantum dot lubricating oil additive. Wherein the oily modifier further comprises a modified silane coupling agent, and by modifying vinyl trimethoxy silane, the purposes of enhancing the dispersibility of the graphene quantum dots and inhibiting oxidative decay of the lubricating oil are finally achieved.

Description

Technical Field

[0001] The invention relates to the technical field of graphene quantum dot nano material preparation, in particular to a one-pot method for preparing an oleophilic graphene quantum dot lubricating oil additive and application thereof. Background Art

[0003] In recent years, graphene as a lubricant additive or directly as a graphene lubricant has been a hot research direction for companies or universities. Graphene has an ultra-low friction coefficient and excellent physical properties, which can greatly improve the performance of lubricants, especially in some extreme working conditions, and can solve many difficult problems. However, graphene as a lubricant additive material cannot currently pass the US API standard. Its black color alone does not meet the requirements for lubricant clarity and transparency. We cannot break the standard at present, and the only thing we can do is to upgrade the technology. Therefore, how to change the color of graphene has always been a difficult problem.

[0004] On the other hand, with the rapid development of quantum dot technology, there are also related reports on the use of graphene quantum dots as lubricant additives. The literature basically starts from graphene quantum dots, makes graphene quantum dots oleophilic through functional modification, and then adds them to base oil to prepare lubricant additives or lubricants. However, the inventor believes that this method has the defects of complex process, low yield and great difficulty in industrialization.

[0005] Considering that the oleophilic soluble graphene quantum dots have a particle size of only 3 to 10 nm and a flake thickness of only 1 to 3 nm, adding them to lubricating oil will basically not change its color and other basic properties, and can also significantly improve its anti-friction and wear performance; therefore, adding a small amount of graphene quantum dot additives is expected to meet the US API standards and achieve a new material overtaking in the lubricating oil industry.

[0006] Based on this, an efficient and industrializable graphene quantum dot lubricant additive needs to be developed urgently. Summary of the invention

[0007] The object of the present invention is to provide a one-pot method for preparing an oleophilic graphene quantum dot lubricant additive and its application, so as to solve the problems raised in the above background technology.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A one-pot method is used to prepare an oleophilic graphene quantum dot lubricant additive, and the preparation method comprises the following steps:

[0010] S1: Weigh a certain amount of carbon source and place it in a reactor, and heat it to 150-250°C until the carbon source is carbonized;

[0011] S2: Weigh a certain amount of oil modifier and add it to the reactor in S1. After reacting for 1 to 3 hours, terminate the reaction and cool to room temperature.

[0012] S3: Weigh a certain amount of base oil and place it in a reactor, add the material obtained in S2, and stir to mix;

[0013] S4: Weigh a certain amount of dispersant, add it to the reactor in S3, and stir to mix;

[0014] S5: filtering the material obtained in S4, and then circulating it for 8 to 15 times using ultra-high pressure equipment to discharge the material to obtain a graphene quantum dot lubricant additive.

[0015] Furthermore, the carbon source includes but is not limited to a combination of one or more of glucose, sucrose, and citric acid.

[0016] Furthermore, the carbon source is preferably glucose.

[0017] Furthermore, the oil modifier includes, but is not limited to, one or more combinations of oleylamine, N-tetradecylamine, N-pentadecylamine, N-hexadecylamine, and polyetheramine.

[0018] Furthermore, the oily modifier also includes a modified silane coupling agent; preferably, the oily amine and the modified silane coupling agent are mixed in a ratio of 1:1.

[0019] Furthermore, the preparation method of the modified silane coupling agent is as follows: (1) adding vinyl trimethoxysilane, DL-cysteine ​​and a photoinitiator into a reaction container, stirring and mixing, irradiating with ultraviolet light of 350 to 370 nm for 1 to 20 minutes, washing with carbon tetrachloride, and separating to obtain a product I; (2) adding N-phenyl-p-phenylenediamine and the product I into anhydrous ethanol, stirring and mixing, and then adding a condensing agent and 4-dimethylaminopyridine, stirring and reacting at 0 to 30° C. for 6 to 48 hours, terminating the reaction, and finally separating and purifying to obtain a modified silane coupling agent.

[0020] Furthermore, the raw materials for preparing the modified silane coupling agent include the following components: by weight, 5 to 10 parts of vinyltrimethoxysilane, 5 to 10 parts of DL-cysteine, 4 to 8 parts of N-phenyl-p-phenylenediamine, 4 to 8 parts of condensation agent, 4 to 8 parts of 4-dimethylaminopyridine, and 0.05 to 0.2 parts of photoinitiator.

[0021] The purpose of the oil modifier is to promote the dispersion of graphene quantum dots and avoid their agglomeration. In order to achieve better lipophilicity of graphene quantum dots, the present invention is designed to add a silane coupling agent to modify the carbonized material, thereby achieving the effect of promoting the dispersion of graphene quantum dots. However, it is also considered that the lubricating oil will continue to oxidize and decay during use. At that time, the peroxides and oxidative condensates produced by the decay will further have an antagonistic effect on the graphene quantum dots, thereby aggravating the deterioration of the performance of the lubricating oil. Therefore, in the present invention, DL-cysteine ​​is finally used to perform UV click grafting modification on vinyltrimethoxysilane to introduce amino and carboxyl groups; wherein the carboxyl group is further amidated and grafted with N-phenyl-p-phenylenediamine to prepare a modified silane coupling agent. The amino groups on the modified silane coupling agent can be grafted and adsorbed with the active groups on the graphene quantum dots, which can greatly promote the dispersion of the graphene quantum dots. At the same time, N-phenyl-p-phenylenediamine is grafted on the modified silane coupling agent, and this structure can react with free radicals in the lubricating oil in the subsequent reaction to achieve the effect of scavenging free radicals, that is, it can inhibit the oxidative decay of the lubricating oil to a certain extent, effectively avoiding the antagonistic effect of peroxides and oxidative condensation products produced by the decay on the graphene quantum dots, and ultimately achieving the purpose of extending the life of the lubricating oil.

[0022] Furthermore, the base oil includes, but is not limited to, a combination of one or more of Class II hydrogenated base oil, Class III hydrogenated base oil, PAO base oil, and ester base oil.

[0023] Furthermore, the base oil is preferably a combination of three types of hydrogenated base oil and ester base oil mixed in a ratio of 4:1.

[0024] Furthermore, the dispersant includes but is not limited to any one of alkylphenol salts, alkylsulfonates, alkylsalicylates, succinimide ashless dispersants, and ester ashless dispersants.

[0025] Furthermore, the dispersant is preferably a succinimide ashless dispersant, specifically polyisobutylene succinimide.

[0026] Furthermore, the mesh size of the filter used for the filtration is 200 to 500 meshes.

[0027] Furthermore, the ultra-high pressure equipment is an ultra-high pressure microfluidizer, and its pressure is greater than 45000psi.

[0028] Compared with the prior art, the present application has the following beneficial effects:

[0029] (1) The present invention innovatively prepares a novel graphene quantum dot lubricant additive through a one-pot method, and the preparation process is simple and has the characteristics of high industrial feasibility;

[0030] (2) The graphene quantum dot lubricant additive prepared by the present invention ensures the dispersibility of graphene quantum dots, and can also inhibit the oxidation decay of lubricating oil, thereby extending the service life of lubricating oil;

[0031] (3) The graphene quantum dot lubricant additive prepared by the present invention is a brand-new technical field, which is expected to break the technical blockade of foreign lubricant additive giants and achieve overtaking. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0033] Figure 1 is a transmission electron microscope image of graphene quantum dots in the graphene quantum dot lubricant additive in Example 1;

[0034] Figure 2 is an atomic force microscope image of graphene quantum dots in the graphene quantum dot lubricant additive in Example 1;

[0035] Figure 3 is a stability comparison chart of the graphene quantum dot lubricating oil additive prepared in Example 1 and Comparative Example 1;

[0036] Figure 4 is a stability comparison chart of the graphene quantum dot lubricating oil additive prepared in Example 1 and Comparative Example 2;

[0037] Figure 5 is a stability comparison chart of the graphene quantum dot lubricating oil additive prepared in Example 1 and Comparative Example 3;

[0038] Figure 6 This is a test chart of the compatibility and stability of graphene quantum dot lubricant additives with various brands of lubricants;

[0039] Figure 7 This is a three-dimensional topography of Castrol sp 0W-40 + 5% graphene quantum dot lubricant additive undergoing wear testing;

[0040] Figure 8 This is a three-dimensional topography of Shell sp 0W-40 undergoing wear testing;

[0041] Fig. 9 This is a three-dimensional topography of Castrol sp 0W-40 undergoing wear testing;

[0042] Fig.10 This is a three-dimensional topography of the wear test of Mobil sp 0W-40; in, Figure 3 to Figure 5In the figure, the graphene quantum dot lubricant additive corresponding to Example 1 is the test tube on the left, and the graphene quantum dot lubricant additive corresponding to Comparative Examples 1 to 3 is the test tube on the right; Figure 6 In the picture, the cup on the left corresponds to Shell sp0W-40+5% graphene quantum dot lubricant additive; the cup in the middle corresponds to Castrol sp0W-40+5% graphene quantum dot lubricant additive; the cup on the right corresponds to Mobil sp0W-40+5% graphene quantum dot lubricant additive. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] In the following examples, all raw materials and equipment sources are as follows:

[0045] Glucose, purity 99%, was purchased from Xi'an Qiyue Biotechnology Co., Ltd.;

[0046] Oleylamine with a purity of 99% and N-tetradecylamine with a purity of 99% were purchased from Shandong Rongyuan New Materials Technology Co., Ltd.;

[0047] Vinyl trimethoxysilane purity 99%, DL-cysteine ​​purity 99%, photoinitiator model: IHT-PI432, N-phenyl-p-phenylenediamine purity 99%, CAS number: 101-54-2, N,N'-dicyclohexylcarbodiimide purity 99%, 4-dimethylaminopyridine purity 99%, all purchased from Shanghai Jinjinle Industrial Co., Ltd.;

[0048] The type III hydrogenated base oil was 150N, with a purity of 99% of di-n-caprylate adipate, purchased from Formosa Petrochemical Corporation;

[0049] Polyisobutylene succinimide with a purity of 99% and polyisobutylene succinate with a purity of 99% were purchased from Wuxi Nanfang Petroleum Additives Company;

[0050] Ultrahigh pressure microfluidizer model: Production 4000 series, purchased from Noze Fluid Technology (Shanghai) Co., Ltd.;

[0051] Atomic force microscope model: multimode8, purchased from Bruker, Germany;

[0052] Transmission electron microscope model: JEM-2100, purchased from JEOL Ltd.

[0053] Preliminary test: Preparation of modified silane coupling agent: (1) Add 800 g of vinyl trimethoxysilane, 800 g of DL-cysteine ​​and 10 g of photoinitiator into a reaction container, stir and mix, and then irradiate with 350 nm ultraviolet light for 15 min. Finally, wash with carbon tetrachloride and separate to obtain product I; (2) Add 600 g of N-phenyl-p-phenylenediamine and product I into anhydrous ethanol, stir and mix, then add 600 g of N,N'-dicyclohexylcarboximide and 600 g of 4-dimethylaminopyridine, stir and react at 20°C for 24 h, and finally separate and purify to obtain a modified silane coupling agent.

[0054] Example 1: One-pot preparation of oleophilic graphene quantum dot lubricant additive:

[0055] S1: Weigh 300 g of glucose and place it in a reactor, and electrically heat it to 180°C until the carbon source is carbonized;

[0056] S2: Weigh 443 g of oily modifier (oleylamine and modified silane coupling agent mixed in a mass ratio of 1:1), add it to the reactor in S1, react for 1.5 h, terminate the reaction, and cool to room temperature;

[0057] S3: Weigh 99.257 kg of base oil (150N type III hydrogenated base oil and di-n-decyl adipate mixed in a mass ratio of 4:1) and place it in a reactor, add the material obtained in S2, and stir and mix at a speed of 450 r / min for 30 min;

[0058] S4: Weigh 100 g of polyisobutylene succinimide, add it to the reactor in S3, and stir and mix at a speed of 450 r / min for 30 min;

[0059] S5: The material obtained in S4 is filtered (the filter mesh is 300 mesh), and then an ultra-high pressure microfluidizer is used for 10 cycles at a processing pressure of 50,000 psi to obtain a graphene quantum dot lubricant additive.

[0060] Based on Example 1, Examples 2 to 4 are set, as shown below:

[0061] Example 2: Example 2 is based on Example 1, with the following modifications: the oleylamine in the oiliness modifier is replaced by N-tetradecylamine, and the other processes remain unchanged, specifically:

[0062] One-pot preparation of oleophilic graphene quantum dots lubricant additives:

[0063] S1: Weigh 300 g of glucose and place it in a reactor, and electrically heat it to 180°C until the carbon source is carbonized;

[0064] S2: Weigh 443g of oil modifier (N-tetradecylamine and modified silane coupling agent mixed in a mass ratio of 1:1) and add it to the reactor in S1. After reacting for 1.5h, terminate the reaction and cool to room temperature;

[0065] S3: Weigh 99.257 kg of base oil (150N type III hydrogenated base oil and di-n-decyl adipate mixed in a mass ratio of 4:1) and place it in a reactor, add the material obtained in S2, and stir and mix at a speed of 450 r / min for 30 min;

[0066] S4: Weigh 100 g of polyisobutylene succinimide, add it to the reactor in S3, and stir and mix at a speed of 450 r / min for 30 min;

[0067] S5: The material obtained in S4 is filtered (the filter mesh is 300 mesh), and then an ultra-high pressure microfluidizer is used for 10 cycles at a processing pressure of 50,000 psi to obtain a graphene quantum dot lubricant additive.

[0068] Example 3: Example 3 is based on Example 1, with the following modifications: the base oil only uses 150N type III hydrogenated base oil, and the other processes remain unchanged, specifically:

[0069] One-pot preparation of oleophilic graphene quantum dots lubricant additives:

[0070] S1: Weigh 300 g of glucose and place it in a reactor, and electrically heat it to 180°C until the carbon source is carbonized;

[0071] S2: Weigh 443 g of oily modifier (oleylamine and modified silane coupling agent mixed in a mass ratio of 1:1), add it to the reactor in S1, react for 1.5 h, terminate the reaction, and cool to room temperature;

[0072] S3: Weigh 99.257 kg of 150N type III hydrogenated base oil, place it in a reactor, add the material obtained in S2, and stir and mix at a speed of 450 r / min for 30 min;

[0073] S4: Weigh 100 g of polyisobutylene succinimide, add it to the reactor in S3, and stir and mix at a speed of 450 r / min for 30 min;

[0074] S5: The material obtained in S4 is filtered (the filter mesh is 300 mesh), and then an ultra-high pressure microfluidizer is used for 10 cycles at a processing pressure of 50,000 psi to obtain a graphene quantum dot lubricant additive.

[0075] Example 4: Example 4 is based on Example 1, with the following modifications: the dispersant is replaced by an ester ashless dispersant, specifically polyisobutylene succinate, and the rest remains unchanged, specifically:

[0076] One-pot preparation of oleophilic graphene quantum dots lubricant additives:

[0077] S1: Weigh 300 g of glucose and place it in a reactor, and electrically heat it to 180°C until the carbon source is carbonized;

[0078] S2: Weigh 443 g of oily modifier (oleylamine and modified silane coupling agent mixed in a mass ratio of 1:1), add it to the reactor in S1, react for 1.5 h, terminate the reaction, and cool to room temperature;

[0079] S3: Weigh 99.257 kg of base oil (150N type III hydrogenated base oil and di-n-decyl adipate mixed in a mass ratio of 4:1) and place it in a reactor, add the material obtained in S2, and stir and mix at a speed of 450 r / min for 30 min;

[0080] S4: Weigh 100 g of polyisobutylene succinate, add it to the reactor in S3, and stir and mix at a speed of 450 r / min for 30 min;

[0081] S5: The material obtained in S4 is filtered (the filter mesh is 300 mesh), and then an ultra-high pressure microfluidizer is used for 10 cycles at a processing pressure of 50,000 psi to obtain a graphene quantum dot lubricant additive.

[0082] Based on Example 1, comparative examples 1 to 3 are set, as shown below:

[0083] Comparative Example 1: Comparative Example 1 is based on Example 1, with the following modifications: no ultrahigh pressure microfluidizer treatment is used, and other processes remain unchanged, specifically:

[0084] One-pot preparation of oleophilic graphene quantum dots lubricant additives:

[0085] S1: Weigh 300 g of glucose and place it in a reactor, and electrically heat it to 180°C until the carbon source is carbonized;

[0086] S2: Weigh 443 g of oily modifier (oleylamine and modified silane coupling agent mixed in a mass ratio of 1:1), add it to the reactor in S1, react for 1.5 h, terminate the reaction, and cool to room temperature;

[0087] S3: Weigh 99.257 kg of base oil (150N type III hydrogenated base oil and di-n-decyl adipate mixed in a mass ratio of 4:1) and place it in a reactor, add the material obtained in S2, and stir and mix at a speed of 450 r / min for 30 min;

[0088] S4: Weigh 100 g of polyisobutylene succinate, add it to the reactor in S3, and stir and mix at a speed of 450 r / min for 30 min;

[0089] S5: filtering the material obtained in S4 (the filter mesh is 300 meshes), discharging the material, and obtaining a graphene quantum dot lubricating oil additive.

[0090] Comparative Example 2: Comparative Example 2 is based on Example 1, with the following adjustments: the oily modifier only uses a modified silane coupling agent, and the other processes remain unchanged, specifically:

[0091] One-pot preparation of oleophilic graphene quantum dots lubricant additives:

[0092] S1: Weigh 300 g of glucose and place it in a reactor, and electrically heat it to 180°C until the carbon source is carbonized;

[0093] S2: Weigh 443 g of modified silane coupling agent and add it to the reactor in S1. After reacting for 1.5 h, terminate the reaction and cool to room temperature;

[0094] S3: Weigh 99.257 kg of base oil (150N type III hydrogenated base oil and di-n-decyl adipate mixed in a mass ratio of 4:1) and place it in a reactor, add the material obtained in S2, and stir and mix at a speed of 450 r / min for 30 min;

[0095] S4: Weigh 100 g of polyisobutylene succinimide, add it to the reactor in S3, and stir and mix at a speed of 450 r / min for 30 min;

[0096] S5: The material obtained in S4 is filtered (the filter mesh is 300 mesh), and then an ultra-high pressure microfluidizer is used for 10 cycles at a processing pressure of 50,000 psi to obtain a graphene quantum dot lubricant additive.

[0097] Comparative Example 3: Comparative Example 3 is based on Example 1, with the following adjustments: the oiliness modifier is only oleylamine, and the other processes remain unchanged, specifically:

[0098] One-pot preparation of oleophilic graphene quantum dots lubricant additives:

[0099] S1: Weigh 300 g of glucose and place it in a reactor, and electrically heat it to 180°C until the carbon source is carbonized;

[0100] S2: Weigh 443 g of oleylamine and add it to the reactor in S1. After reacting for 1.5 h, terminate the reaction and cool to room temperature;

[0101] S3: Weigh 99.257 kg of base oil (150N type III hydrogenated base oil and di-n-decyl adipate mixed in a mass ratio of 4:1) and place it in a reactor, add the material obtained in S2, and stir and mix at a speed of 450 r / min for 30 min;

[0102] S4: Weigh 100 g of polyisobutylene succinimide, add it to the reactor in S3, and stir and mix at a speed of 450 r / min for 30 min;

[0103] S5: The material obtained in S4 is filtered (the filter mesh is 300 mesh), and then an ultra-high pressure microfluidizer is used for 10 cycles at a processing pressure of 50,000 psi to obtain a graphene quantum dot lubricant additive.

[0104] Performance test: The graphene quantum dot lubricant additives prepared in the examples and comparative examples were subjected to stability tests: The specific test methods are as follows:

[0105] Stability test of graphene quantum dot lubricant additive: The graphene quantum dot lubricant additive prepared in the embodiment and the comparative example was centrifuged at a speed of 5000 r / min for 10 min, and the state of the graphene quantum dot lubricant additive corresponding to each example was directly observed; the specific results are shown in Table 1 below:

[0106] Table 1

[0107] Examples state Example 1 No material precipitation Example 2 Trace amount of substances precipitated Example 3 Trace amount of substances precipitated Example 4 Trace amount of substances precipitated Comparative Example 1 Obvious precipitation of substances Comparative Example 2 Obvious precipitation of substances Comparative Example 3 Obvious precipitation of substances

[0108] Result analysis: From the data in Table 1 above, it can be seen that Example 1 is the best example; by selecting oleylamine and modified silane coupling agent as oil modifiers, three types of hydrogenated base oils and di-n-decyl adipate as base oils, polyisobutylene succinimide as dispersant, and ultra-high pressure microfluidization treatment, the dispersion of graphene quantum dots can be promoted and the stability performance can be made better.

[0109] Since Example 1 is the best example, the graphene quantum dot lubricant additive prepared in Example 1 was further tested using a high-power transmission electron microscope and an atomic force microscope. Figure 1 , Figure 2 As shown; and it is detected that the lateral size of the graphene quantum dots prepared by the present invention is about 3nm and the thickness is about 1.5nm.

[0110] According to the above test results, the graphene quantum dot lubricant additive prepared in Example 1 was further added to various brands of lubricants on the market to conduct compatibility stability tests and anti-wear performance tests. The specific test methods are as follows:

[0111] (1) Stability test: After adding the graphene quantum dot lubricant additive to each brand of lubricant (the amount of graphene quantum dot lubricant additive added was 5% of the volume of the lubricant), the lubricant of each brand was centrifuged at 5000 r / min for 30 min, and the state of each brand of lubricant was directly observed (e.g. Figure 6 The specific results are shown in Table 2;

[0112] (2) Anti-wear performance test: The anti-wear performance of each brand of lubricant was tested separately, and then according to the results, the graphene quantum dot lubricant additive was added to the lubricant with the worst anti-wear performance (the addition amount of the graphene quantum dot lubricant additive was 5% of the volume of the lubricant), and the mixture was stirred and mixed at a speed of 450 r / min to obtain the corresponding lubricant product. According to the test standard of ASTMD6425-19, the friction coefficient was tested under the conditions of test temperature of 50°C, test load of 300N, test frequency of 50Hz, and test stroke of 1mm; the specific test data are shown in Table 3;

[0113] Table 2

[0114]

[0115] Result analysis: From the results in Table 2 above, it can be seen that the graphene quantum dot lubricant additive prepared by the present invention exhibits excellent compatibility stability in various lubricants.

[0116] Table 3

[0117]

[0118] Result analysis: From the data in Table 3 above, it can be seen that Castrol sp 0W-40 has the highest friction coefficient (i.e., the worst performance) among the above lubricants. Therefore, the graphene quantum dot lubricant additive is added thereto. The friction coefficient of the lubricant (Castrol sp 0W-40 + 5% graphene quantum dot lubricant additive) is almost better than that of other benchmark brands in each time period, and the average friction coefficient, minimum friction coefficient, 90-minute friction coefficient and 120-minute friction coefficient are all the smallest; among them, the average friction coefficient is 13.95% lower than that of Shell sp 0W-40, 15.91% lower than that of Castrol sp 0W-40, and 9.76% lower than that of Mobil sp0W-40.

[0119] The three-dimensional morphology of the test disc also shows that the wear of the friction surface during the test of the above four samples is that the wear scar depth of Castrol sp 0W-40 + 5% graphene quantum dot lubricant additive is the shallowest, which is 0.85μm; the wear scar depths of Shell sp 0W-40, Castrol sp 0W-40, and Mobil sp 0W-40 without adding graphene quantum dot lubricant additive are 1.404μm, 6.577μm, and 1.708μm respectively. Figures 7-10 shown.

[0120] In summary, the present invention prepares a graphene quantum dot lubricant additive with excellent compatibility and dispersibility.

[0121] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0122] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. One-pot method for preparing oleophilic graphene quantum dot lubricant additive, characterized in that: The preparation method comprises the following steps: S1: placing a carbon source in a reaction kettle and heating it to 150-250°C until the carbon source is carbonized; S2: Add the oil modifier to the reactor in S1, react for 1 to 3 hours, terminate the reaction, and cool to room temperature; S3: placing the base oil in a reactor, adding the material obtained in S2 thereto, and stirring and mixing; S4: adding the dispersant to the reactor in S3 and stirring to mix; S5: filtering the material obtained in S4, and then circulating it for 8 to 15 times using ultra-high pressure equipment to discharge the material to obtain a graphene quantum dot lubricant additive.

2. The one-pot method for preparing an oleophilic graphene quantum dot lubricant additive according to claim 1, characterized in that: In S1, the carbon source includes one or more combinations of glucose, sucrose, and citric acid.

3. The one-pot method for preparing an oleophilic graphene quantum dot lubricant additive according to claim 1, characterized in that: In S2, the oiliness modifier includes one or more combinations of oleylamine, N-tetradecylamine, N-pentadecylamine, N-hexadecylamine, and polyetheramine.

4. The one-pot method for preparing an oleophilic graphene quantum dot lubricant additive according to claim 1, characterized in that: In S3, the base oil includes a combination of one or more of type II hydrogenated base oil, type III hydrogenated base oil, PAO base oil, and ester base oil.

5. The one-pot method for preparing an oleophilic graphene quantum dot lubricant additive according to claim 4, characterized in that: The base oil is preferably a combination of three types of hydrogenated base oil and ester base oil mixed in a ratio of 4:

1.

6. The one-pot method for preparing an oleophilic graphene quantum dot lubricant additive according to claim 1, characterized in that: In S4, the dispersant includes any one of alkylphenol salts, alkylsulfonates, alkylsalicylates, succinimide ashless dispersants, and ester ashless dispersants.

7. The one-pot method for preparing an oleophilic graphene quantum dot lubricant additive according to claim 1, characterized in that: In S5, the mesh size of the filter used for the filtration is 200-500 meshes; the ultra-high pressure equipment uses an ultra-high pressure micro-jet homogenizer, and its pressure is greater than 45000psi.

8. The one-pot method for preparing an oleophilic graphene quantum dot lubricant additive according to claim 3, characterized in that: The oily modifier also includes a modified silane coupling agent.

9. The one-pot method for preparing an oleophilic graphene quantum dot lubricant additive according to claim 8, characterized in that: The preparation method of the modified silane coupling agent comprises: (1) adding vinyl trimethoxysilane, DL-cysteine ​​and a photoinitiator into a reaction container, stirring and mixing, irradiating with ultraviolet light of 350 to 370 nm for 1 to 20 minutes, washing and separating to obtain a product I; (2) adding N-phenyl-p-phenylenediamine and the product I into anhydrous ethanol, stirring and mixing, then adding a condensing agent and 4-dimethylaminopyridine, stirring and reacting at 0 to 30° C. for 6 to 48 hours, terminating the reaction, and finally separating and purifying to obtain a modified silane coupling agent; Among them, the raw materials for preparing the modified silane coupling agent include the following components: by weight, 5 to 10 parts of vinyltrimethoxysilane, 5 to 10 parts of DL-cysteine, 4 to 8 parts of N-phenyl-p-phenylenediamine, 4 to 8 parts of condensation agent, 4 to 8 parts of 4-dimethylaminopyridine, and 0.05 to 0.2 parts of photoinitiator.

10. Use of the one-pot method for preparing oleophilic graphene quantum dot lubricant additive according to any one of claims 1 to 9, characterized in that: Graphene quantum dot lubricant additives are introduced into lubricating oil to improve the performance of the lubricating oil.

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