High-wear-resistance lubricating grease based on quantum dot rolling ball effect as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of lubricating additives, and particularly relates to high-wear-resistance lubricating grease based on a quantum dot rolling ball effect as well as a preparation method and application of the high-wear-resistance lubricating grease. According to the invention, polybasic acid or a bio-based raw material and polyol are used as raw materials for esterification reaction, and ester base oil is independently researched and developed; then ester base oil and quantum dots are compounded, the quantum dots are selected from O-CDS quantum dots, aminated O-CDS dots, phosphate grafted O-CDS quantum dots or O-CDS quantum dots coated with oxidized ascorbic acid, and the high-wear-resistance lubricating grease based on the quantum dot rolling ball effect is obtained. The quantum dots have good compatibility with the ester base oil and are uniformly dispersed in the ester base oil, the preparation cost is low, the ester base oil is prepared without an organic solvent, and the technical defects of lubricating grease in the prior art are overcome.

Description

Technical Field

[0001] This invention belongs to the field of lubricant additive technology, specifically to high anti-wear grease based on quantum dot rolling ball effect, its preparation method and application. Background Technology

[0002] As a key functional material in mechanical systems, lubricating grease significantly extends equipment life and improves energy efficiency by reducing direct contact and wear between friction pairs. Traditional lubricating greases mostly use mineral oil or synthetic oil as base oil and add solid lubricants (such as molybdenum disulfide, graphite, and polytetrafluoroethylene) or organic anti-wear agents (such as ZDDP) to improve tribological properties. However, these additives have the following limitations: dispersibility problems: solid particles (such as molybdenum disulfide) are prone to agglomeration, resulting in an uneven lubricating film, especially under high temperature and high shear conditions, performance deteriorates; insufficient chemical stability: organic additives (such as ZDDP) are prone to decomposition in high temperature or oxidizing environments, producing harmful byproducts; poor environmental compatibility: some sulfur- and phosphorus-containing additives pose potential hazards to the ecological environment.

[0003] In recent years, carbon-based nanomaterials (such as graphene, carbon nanotubes, and carbon quantum dots) have become a research hotspot in lubricant additives due to their high specific surface area, excellent chemical stability, and functionalizability. Among them, carbon quantum dots (CDs), with their nanoscale size (<10nm) and abundant surface functional groups (-OH, -COOH, -NH2), exhibit unique physical adsorption and synergistic lubrication potential with tribochemical reactions. However, the application of carbon quantum dots in current technologies still faces the following bottlenecks: poor compatibility with base oils: carbon quantum dots tend to settle in the oil phase, requiring complex surface modification or dispersants; high preparation process cost: most studies use chemical oxidation methods to synthesize carbon quantum dots, resulting in low yields and requiring the use of strong acids and bases.

[0004] In addition, for example, the prior art application number CN113582748A, entitled "A Carbon Quantum Dot Grease and Its Preparation Method", discloses the following technical solution: mineral oil is used as the base oil, and nitrogen-doped carbon quantum dots (N-CDs) with surface modification are added as a lubricating additive with a concentration range of 0.05wt%~0.2wt%. The N-CDs are synthesized by hydrothermal method and modified with silane coupling agent (KH550) to improve dispersibility. The friction coefficient of carbon quantum dot grease is reduced by about 40%, and the wear depth is reduced by 50%. However, it has the following defects: (1) Base oil depends on external purchase: it does not involve the independent synthesis of base oil, which leads to limited formulation flexibility and cost control; (2) Insufficient dispersion stability: it depends on silane coupling agent modification, and the quantum dots may still agglomerate after long-term storage; (3) Single function: it only relies on the physical rolling ball effect of quantum dots and does not utilize the chemical lubrication potential of its surface functional groups; (4) Environmental defects: hydrothermal synthesis requires a large amount of organic solvents, which does not conform to the trend of green chemistry.

[0005] It is evident that existing technologies for lubricating greases based on carbon-based nanomaterials still suffer from the aforementioned problems, affecting their application. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a high-wear-resistant grease based on the quantum dot rolling ball effect, its preparation method, and its applications. This invention uses polybasic acids or bio-based raw materials and polyols as raw materials to conduct an esterification reaction, independently developing an ester-based base oil. Then, the ester-based base oil is compounded with quantum dots, selected from O-CDS quantum dots, aminated O-CDS quantum dots, phosphate-grafted O-CDS quantum dots, or oxidized ascorbic acid-coated O-CDS quantum dots, to obtain a high-wear-resistant grease based on the quantum dot rolling ball effect. The quantum dots of this invention exhibit good compatibility with the ester-based base oil, achieving uniform dispersion within the ester-based base oil, and have low preparation costs. Furthermore, the preparation of the ester-based base oil in this invention does not require organic solvents, overcoming the technical defects of existing grease technologies.

[0007] To address the aforementioned problems in the prior art, the present invention adopts the following technical solution: This invention provides a method for preparing a high-wear-resistant grease based on the quantum dot rolling ball effect, comprising the following steps: Ester-based oils are obtained by esterification reactions using polybasic acids or bio-based raw materials and polyols. Quantum dots, ester-based oils, thickeners, and antioxidants are then mixed to obtain a high-wear-resistant grease based on the quantum dot rolling ball effect.

[0008] The mass percentages of ester base oil, quantum dots, thickener and antioxidant are 80%~90%, 0.02%~0.08%, 7%~17% and 1%~5%, respectively, and the sum of the mass percentages of the four is 100%.

[0009] Alternatively, polybasic acids or bio-based raw materials, polyols and quantum dots can be mixed and then subjected to esterification under catalysis to obtain an ester-based base oil intermediate; the ester-based base oil intermediate, thickener and antioxidant can be mixed to obtain a high-wear-resistant grease based on the quantum dot rolling ball effect.

[0010] Among them, the mass percentage of quantum dots in the ester-based base oil intermediate is 0.02%~0.08%; the mass percentages of the ester-based base oil intermediate, thickener and antioxidant are 80%~90%, 7%~17% and 1%~5% respectively, and the sum of the mass percentages of the three is 100%.

[0011] The quantum dots are selected from O-CDS quantum dots, aminated O-CDS quantum dots, phosphate-grafted O-CDS quantum dots, or oxidized ascorbic acid-coated O-CDS quantum dots.

[0012] Preferably, the molar ratio of polybasic acid or bio-based raw material to polyol is 3~5:1~2.

[0013] Preferably, the bio-based raw material is selected from soybean oil derivatives, methyl palmitate, or methyl ricinoleate.

[0014] Preferably, the polyacids are bisaccharide, sebacic acid, azelaic acid, maleic anhydride, or terephthalic acid.

[0015] Preferably, the polyol is selected from glycerol, pentaerythritol, neopentyl glycol, trimethylolpropane, sorbitol, or polyethylene glycol.

[0016] Preferably, the esterification reaction conditions are: stirring at 100℃~125℃ for 4h~6.5h.

[0017] Preferably, the amination of O-CDS dots is prepared according to the following steps: citric acid and glutathione are mixed and heated at 210±10℃ for 15-17 minutes, then oleylamine is added, and heating is continued for 3-5 minutes to obtain O-CDS quantum dots; the O-CDS quantum dots are mixed with (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide in PBS buffer and stirred for 2 hours±20 minutes to activate -COOH and form an active ester. Then the active ester is mixed with ethylenediamine and stirred at room temperature for 12 hours±20 minutes to carry out an amino grafting reaction to obtain amination of O-CDS dots.

[0018] Preferably, phosphate-grafted O-CDS quantum dots are prepared according to the following steps: citric acid and glutathione are mixed and heated at 210±10℃ for 15-17 min, then oleylamine is added, and heating continues for 3-5 min to obtain O-CDS quantum dots; the O-CDS quantum dots are dispersed, and then a phosphorylation reagent is added dropwise under an ice bath, followed by a grafting reaction at 80℃±5℃ for 6 h±20 min under an inert atmosphere to obtain phosphate-grafted O-CDS quantum dots; wherein the phosphorylation reagent is selected from phosphorus oxychloride or sodium dihydrogen phosphate.

[0019] Preferably, the oxidized ascorbic acid-coated O-CDS quantum dots are prepared according to the following steps: citric acid and glutathione are mixed and heated at 210±10℃ for 15min~17min, then oleylamine is added, and heating is continued for 3min~5min to obtain O-CDS quantum dots; the O-CDS quantum dots are mixed with ascorbic acid and stirred at 80℃±5℃ for 2h±20min, first coating the O-CDS quantum dots with ascorbic acid, then adding H2O2 dropwise, and continuing the reaction for 1h±20min, oxidizing the ascorbic acid with H2O2 to obtain oxidized ascorbic acid-coated O-CDS quantum dots.

[0020] This invention also protects the high-wear-resistant grease based on the quantum dot rolling ball effect prepared by the above preparation method.

[0021] This invention also protects the application of high-wear-resistant grease based on quantum dot rolling ball effect in the preparation of grease additives.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention first provides a fully self-prepared ester base oil, which is obtained by esterification reaction of bio-based raw materials or polybasic acid and polyol. The prepared ester base oil has both low viscosity (45 cSt at 40℃) and high oxidation stability (PDSC induction period >180min). Then, the ester base oil is mixed with O-CDS quantum dots to prepare a high anti-wear grease based on the quantum dot rolling ball effect.

[0023] This invention provides a high-wear-resistant grease based on the quantum dot rolling ball effect, which achieves physical lubrication. In terms of physical lubrication, quantum dots reduce the contact area through the "rolling ball effect".

[0024] This invention solves the core problems of poor dispersibility, single function, and insufficient environmental compatibility of existing greases by independently preparing ester base oils and quantum dots, and innovatively utilizing the synergistic effect of the two, thus providing a new approach for the development of high-performance and environmentally friendly greases.

[0025] 2. The high-wear grease based on the quantum dot rolling ball effect of this invention reduces the coefficient of friction by 51.2% (vs. 40% of the prior art CN113582748A) with an addition of 0.1wt% O-CDS quantum dots; the wear depth is reduced by 61.6%, and there is no wear failure (verified by the ASTM D2266 standard for introducing an online monitoring system in the mixing stage).

[0026] 3. The oxygen-containing functional groups on the surface of quantum dots in this invention can capture free radicals and inhibit the oxidation reaction of ester base oils, so that the high anti-wear grease based on the quantum dot rolling ball effect has long-term stability. After accelerated oxidation test (150℃, 72h), the friction coefficient fluctuation is <5%, which is far superior to traditional additives (friction coefficient fluctuation >15%), such as molybdenum disulfide, which is a layered solid lubricant that relies on physical adsorption and is easily oxidized and fails at high temperatures; another example is zinc dialkyl dithiophosphate (ZDDP), an organic anti-wear agent that reduces friction through chemical reaction film, but the decomposition products pollute the environment.

[0027] 4. The process of this invention is green and environmentally friendly, specifically in that: solvent-free synthesis and bio-based raw materials reduce the carbon footprint; the process of this invention achieves cost control, specifically in that: the integrated preparation process reduces intermediate steps, and the total cost is reduced by 30% compared with CN113582748A. Attached Figure Description

[0028] Figure 1 The figures are comparison charts of friction coefficients; (a) is a comparison chart of the friction coefficients of the greases of Examples 1, 20-22, Comparative Examples 1-3, and dry friction; (b) is a comparison chart of the friction coefficients of the greases of Examples 1, 20-22, and Comparative Examples 1-2; and (c) is a bar chart of the friction coefficients of the greases of Examples 1, 20-22, and Comparative Examples 1-2.

[0029] Figure 2 Figure 1 shows a comparison of the wear area of ​​the greases used in Examples 1, 20-22, Comparative Examples 1-3, and dry friction. Figure 2 shows a comparison of the wear area of ​​the greases used in Examples 1, 20-22, and Comparative Examples 1-2.

[0030] Figure 3 The images are scanning electron microscope images and energy-dispersive X-ray spectra obtained from dry friction.

[0031] Figure 4 The images shown are scanning electron microscope (SEM) images and energy-dispersive X-ray spectra of the grease after friction, as shown in Comparative Example 1.

[0032] Figure 5 The images shown are the scanning electron microscope (SEM) image and energy-dispersive X-ray spectra of the grease after friction in Comparative Example 2.

[0033] Figure 6 The images shown are scanning electron microscope (SEM) images and energy dispersive X-ray spectra of the high-wear-resistant grease based on the O-CDS quantum dot rolling ball effect after friction in Example 20.

[0034] Figure 7 The images shown are scanning electron microscope (SEM) images and energy dispersive X-ray spectra of the high-wear-resistant grease based on the O-CDS quantum dot rolling ball effect after friction in Example 21.

[0035] Figure 8 The images shown are scanning electron microscope (SEM) images and energy dispersive X-ray spectra of the high-wear-resistant grease based on the O-CDS quantum dot rolling ball effect after friction in Example 1.

[0036] Figure 9 The images shown are scanning electron microscope (SEM) images and energy dispersive X-ray spectra of the high-wear-resistant grease based on the O-CDS quantum dot rolling ball effect after friction in Example 22.

[0037] Figure 10 The images shown are the scanning electron microscope (SEM) image and energy-dispersive X-ray spectra of Comparative Example 3 after grease friction.

[0038] Figures 3-10 In the figures, a are all scanning electron microscope (SEM) images, and b are all energy-dispersive X-ray spectroscopy (EDS) images. Detailed Implementation

[0039] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods.

[0040] Compared with the prior art, the advantages of the present invention are given below, as shown in Table 1: Table 1. Advantages of high-wear grease based on O-CDS quantum dot rolling ball effect Compared with the carbon quantum dot grease disclosed in application number CN113582748A, its defects are: it relies on silane coupling agent for dispersion, and after long-term storage, the carbon quantum dots agglomerate, and the friction reduction performance is only 40%; the present invention has stable suspension without dispersant (Zeta potential -35mV), and the friction reduction performance is improved to 51.2%.

[0041] The bio-based grease disclosed in US application number US20210071121A1 has the following drawbacks: the base oil viscosity is too high (80 cSt) and the low-temperature fluidity is poor (pour point -10°C); the ester base oil synthesized in this invention has a viscosity of 45 cSt and a pour point of -25°C, making it suitable for a wide temperature range of operating conditions.

[0042] Compared to the graphene grease published in Tribology International in 2020, although it reduces friction by 40%, it is more expensive (graphene unit price $500 / g).

[0043] Compared to the ionic liquid additives published in Wear 2021, its coefficient of friction is reduced by 35%, but it corrodes metal surfaces (acid value > 1.0 mg KOH / g).

[0044] The comparative results show that the present invention overcomes the technical defects of existing lubricating greases based on carbon-based nanomaterials.

[0045] The following section describes the preparation of O-CDS quantum dots at different temperatures and the study of their morphology to obtain the O-CDS quantum dots with the best performance.

[0046] Preparation of O-CDS quantum dots at 200℃: 1.75g ​​citric acid and 0.35g glutathione were mixed and heated at 200℃ for 17min. Then 0.75mL oleylamine was added and the mixture was heated for another 3min to obtain O-CDS pyrolysis solution. The O-CDS pyrolysis solution was cooled to room temperature, centrifuged, and washed three times with anhydrous ethanol to obtain O-CDS-200 quantum dots.

[0047] Preparation of O-CDS quantum dots at 210℃: 1.75g ​​citric acid and 0.35g glutathione were mixed and heated at 210℃ for 17min. Then 0.75mL oleylamine was added and the mixture was heated for another 3min to obtain O-CDS pyrolysis solution. The O-CDS pyrolysis solution was cooled to room temperature, centrifuged, and washed three times with anhydrous ethanol to obtain O-CDS-210 quantum dots.

[0048] Preparation of O-CDS quantum dots at 220℃: 1.75g ​​citric acid and 0.35g glutathione were mixed and heated at 220℃ for 17min. Then 0.75mL oleylamine was added and the mixture was heated for another 3min to obtain O-CDS pyrolysis solution. The O-CDS pyrolysis solution was cooled to room temperature, centrifuged, and washed three times with anhydrous ethanol to obtain O-CDS-220 quantum dots.

[0049] O-CDS-200 quantum dots contain uncarbonized precursors (citric acid and glutathione), indicating incomplete pyrolysis; O-CDS-210 quantum dots have a particle size of 5±0.8 nm, surface functional groups (-OH, -COOH, -NH2), a fluorescence emission peak at 450 nm (excitation wavelength 365 nm), and a yield >85%; O-CDS-220 quantum dots contain pyrolyzed carbon particles, indicating excessive pyrolysis. Comparatively, O-CDS quantum dots obtained through pyrolysis at 210 °C exhibit the best performance. In the embodiments of this invention, in those without O-CDS quantum dots, O-CDS-210 quantum dots were used to prepare a high-wear-resistant grease based on the O-CDS quantum dot rolling ball effect. The specific research methods and results are shown below: Example 1 The preparation method of high anti-wear grease based on O-CDS quantum dot rolling ball effect includes the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0050] Ester base oil: Kinematic viscosity at 40°C: 45 cSt, Oxidation stability (PDSC induction period): >180 min, Pour point: -25°C.

[0051] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following ingredients by weight percentage: 85.94 wt% ester base oil, 12 wt% lithium soap, 0.06 wt% O-CDS quantum dots, and 2 wt% antioxidant.

[0052] O-CDS quantum dots were dispersed in anhydrous ethanol and ultrasonically treated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50 °C for 12 h. Then, lithium soap (thickener) and diphenylamine (antioxidant) were added and stirred for another 2 h to obtain a high-wear-resistant grease based on the rolling ball effect of O-CDS quantum dots. Stable suspension of O-CDS quantum dots without dispersant was achieved by ultrasonic dispersion and mechanical stirring.

[0053] To expand the range of bio-based raw materials, improve formulation flexibility, and adapt to different application scenarios (such as low-temperature or high-temperature conditions), this invention has been optimized through Example 2, and other bio-based raw materials (such as soybean oil derivatives and methyl palmitate) can be used to replace methyl castor oil.

[0054] Example 2 The preparation method of high anti-wear grease based on O-CDS quantum dot rolling ball effect involves the condensation polymerization of polybasic acids (such as adipic acid) and polyols (such as glycerol) to generate a synthetic ester, adjusting the molar ratio, and optimizing the viscosity and pour point. The method includes the following steps: S1. Preparation of ester base oil: Adipic acid and glycerol are mixed in a molar ratio of 3:1, and then 1 wt% sodium methoxide is added as a catalyst. The mixture is stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction is completed, the mixture is cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0055] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following components by weight percentage: 85.9 wt% ester base oil, 12 wt% lithium soap, 0.1 wt% O-CDS quantum dots, and 2 wt% antioxidant.

[0056] O-CDS quantum dots were dispersed in anhydrous ethanol and ultrasonically treated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50°C for 12 h. Then, lithium soap (thickener) and diphenylamine (antioxidant) were added and stirred for another 2 h to obtain a high-wear-resistant grease based on the rolling ball effect of O-CDS quantum dots.

[0057] In order to reduce energy consumption, improve environmental protection, and avoid the impact of alkaline catalyst residue on subsequent processes, the present invention has optimized Examples 3 and 4.

[0058] Example 3 A method for preparing high-wear-resistant grease based on the O-CDS quantum dot rolling ball effect, using a solid acid catalyst (such as zirconium oxide sulfate) instead of sodium methoxide, can reduce the reaction temperature to 100℃ and shorten the reaction time to 4 hours, including the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% zirconium sulfate was added as a catalyst. The mixture was stirred at 100°C for 4 h to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst to obtain the ester base oil.

[0059] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following components by weight percentage: 85.9 wt% ester base oil, 12 wt% lithium soap, 0.1 wt% O-CDS quantum dots, and 2 wt% antioxidant.

[0060] O-CDS quantum dots were dispersed in anhydrous ethanol and ultrasonically treated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50°C for 12 h. Then, lithium soap (thickener) and diphenylamine (antioxidant) were added and stirred for another 2 h to obtain a high-wear-resistant grease based on the rolling ball effect of O-CDS quantum dots.

[0061] Example 4 A method for preparing high-wear anti-wear grease based on the O-CDS quantum dot rolling ball effect involves esterification under vacuum to reduce byproduct formation and improve the purity of ester base oils, achieving an acid value <0.1 mg KOH / g. The method includes the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1 and stirred at 120°C for 6 hours under vacuum to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst to obtain the ester base oil.

[0062] Ester base oil: Kinematic viscosity at 40°C: 45 cSt, Oxidation stability (PDSC induction period): >180 min, Pour point: -25°C.

[0063] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following components by weight percentage: 85.9 wt% ester base oil, 12 wt% lithium soap, 0.1 wt% O-CDS quantum dots, and 2 wt% antioxidant.

[0064] O-CDS quantum dots were dispersed in anhydrous ethanol and ultrasonically treated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50°C for 12 h. Then, lithium soap (thickener) and diphenylamine (antioxidant) were added and stirred for another 2 h to obtain a high-wear-resistant grease based on the rolling ball effect of O-CDS quantum dots.

[0065] To improve preparation efficiency, reduce energy consumption, and enhance the controllability of O-CDS quantum dot surface functional groups, this invention optimized Examples 5 and 6.

[0066] Example 5 A method for preparing high-wear anti-wear grease based on the O-CDS quantum dot rolling ball effect employs microwave-assisted pyrolysis, shortening the reaction time to 5 minutes and resulting in a narrower O-CDS quantum dot particle size distribution of 4±0.5 nm. The method includes the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0067] Preparation of S2 and O-CDS quantum dots: 1.75g ​​citric acid, 0.35g glutathione and 0.75mL oleylamine were mixed, microwaved for 5min, cooled to room temperature, centrifuged, and washed 3 times with anhydrous ethanol to obtain O-CDS quantum dots.

[0068] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following components by weight percentage: 85.9 wt% ester base oil, 12 wt% lithium soap, 0.1 wt% O-CDS quantum dots, and 2 wt% antioxidant.

[0069] O-CDS quantum dots were dispersed in anhydrous ethanol and ultrasonically treated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50°C for 12 h. Then, lithium soap (thickener) and diphenylamine (antioxidant) were added and stirred for another 2 h to obtain a high-wear-resistant grease based on the rolling ball effect of O-CDS quantum dots.

[0070] Example 6 A method for preparing high-wear anti-wear grease based on the rolling ball effect of O-CDS quantum dots involves introducing an inert gas (such as argon) during the pyrolysis process of O-CDS quantum dots to suppress oxidation side reactions and increase the yield of O-CDS quantum dots to 90%. The method includes the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0071] S2, Preparation of O-CDS quantum dots: 1.75g ​​citric acid and 0.35g glutathione were mixed and heated at 210℃ for 17min under an inert atmosphere. Then 0.75mL oleylamine was added and the mixture was heated for another 3min to obtain O-CDS pyrolysis solution. The O-CDS pyrolysis solution was cooled to room temperature, centrifuged, and washed three times with anhydrous ethanol to obtain O-CDS quantum dots.

[0072] S3. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following components by weight percentage: 85.9 wt% ester base oil, 12 wt% lithium soap, 0.1 wt% O-CDS quantum dots, and 2 wt% antioxidant.

[0073] O-CDS quantum dots were dispersed in anhydrous ethanol and ultrasonically treated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50°C for 12 h. Then, lithium soap (thickener) and diphenylamine (antioxidant) were added and stirred for another 2 h to obtain a high-wear-resistant grease based on the rolling ball effect of O-CDS quantum dots.

[0074] In order to adapt to extreme working conditions (such as high-speed bearings or heavy-duty gears) and extend the service life of high anti-wear grease based on O-CDS quantum dot rolling ball effect, the present invention has optimized Examples 7 and 8.

[0075] Example 7 A method for preparing high-wear grease based on the O-CDS quantum dot rolling ball effect, using calcium soap or complex lithium-calcium soap instead of single lithium soap, and adjusting the thickener ratio to 10wt%, improves the high-temperature stability of the high-wear grease based on the O-CDS quantum dot rolling ball effect, with a dropping point >250℃, including the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0076] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following components by weight percentage: 85.9 wt% ester base oil, 10 wt% complex lithium calcium soap, 0.1 wt% O-CDS quantum dots, and 4 wt% antioxidant.

[0077] O-CDS quantum dots were dispersed in anhydrous ethanol and ultrasonically treated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50°C for 12 h. Then, a thickener, a complex lithium calcium soap, and an antioxidant, diphenylamine, were added, and stirring was continued for 2 h to obtain a high-wear-resistant grease based on the rolling ball effect of O-CDS quantum dots.

[0078] Example 8 A method for preparing high-wear-resistant grease based on the O-CDS quantum dot rolling ball effect involves introducing 8 wt% polyurea thickener to form a composite thickening system, enhancing shear resistance. The consistency change after 100,000 shear cycles is <10%. The method includes the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0079] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following ingredients by weight percentage: 82.9 wt% ester base oil, 7 wt% lithium soap, 8 wt% polyurea thickener, 0.1 wt% O-CDS quantum dots, and 2 wt% antioxidant.

[0080] O-CDS quantum dots were dispersed in anhydrous ethanol and ultrasonically treated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50°C for 12 h. Then, lithium soap, polyurea thickener, and diphenylamine antioxidant were added, and stirring was continued for 2 h to obtain a high anti-wear grease based on the O-CDS quantum dot rolling ball effect.

[0081] In order to further improve the overall performance (resulting in a friction coefficient reduction of >55%) and adapt to the lubrication requirements of multiple mechanisms, the present invention has optimized Examples 9 and 10.

[0082] Example 9 A method for preparing a high-wear-resistant grease based on the rolling ball effect of O-CDS quantum dots involves compounding O-CDS quantum dots (0.1 wt%) with tungsten disulfide nanosheets (0.05 wt%). The grease reduces friction synergistically through physical rolling balls and a layered structure, and includes the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0083] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following ingredients by weight percentage: 85wt% ester base oil, 12wt% lithium soap (main thickener, providing structural stability), 0.1wt% O-CDS quantum dots (core anti-wear agent, rolling ball effect), 0.05wt% tungsten disulfide nanosheets (synergistic anti-wear and extreme pressure enhancement), 2wt% antioxidant (diphenylamine, inhibiting oxidative aging), 0.5wt% molybdenum disulfide (extreme pressure agent, improving high load performance), 0.3wt% barium petroleum sulfonate (rust inhibitor, preventing metal corrosion), and 0.05wt% polymethyl methacrylate (optimizing low-temperature fluidity).

[0084] O-CDS quantum dots, tungsten disulfide nanosheets, and molybdenum disulfide were dispersed in anhydrous ethanol and ultrasonically treated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50 °C for 12 h. Then, lithium soap, diphenylamine, barium petroleum sulfonate, and polymethyl methacrylate were added, and stirring was continued for 2 h to obtain a high-wear-resistant grease based on the O-CDS quantum dot rolling ball effect.

[0085] Example 10 A method for preparing high-wear grease based on the rolling ball effect of O-CDS quantum dots involves adding 1 wt% ionic liquid, such as 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, to enhance the dispersibility of O-CDS quantum dots through its polarity, thereby further improving the overall performance. The method includes the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0086] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following components by weight percentage: 85.9 wt% ester base oil, 11 wt% lithium soap, 0.1 wt% O-CDS quantum dots, 2 wt% antioxidant, and 1 wt% ionic liquid.

[0087] O-CDS quantum dots were dispersed in anhydrous ethanol containing 1 wt% 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt. The mixture was ultrasonically treated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50 °C for 12 h. Then, lithium soap (a thickener) and diphenylamine (an antioxidant) were added, and stirring was continued for 2 h to obtain a high-wear-resistant grease based on the rolling ball effect of O-CDS quantum dots.

[0088] To avoid potential damage to the O-CDS quantum dot structure by ultrasound and to reduce process complexity, the present invention has optimized Examples 11 and 12.

[0089] Example 11 A method for preparing high-wear-resistant grease based on the O-CDS quantum dot rolling ball effect uses a high-pressure homogenizer (150 MPa, 3 cycles) instead of ultrasonic dispersion to achieve a more uniform distribution of O-CDS quantum dots (particle size distribution standard deviation <0.3 nm), including the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0090] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following components by weight percentage: 85.9 wt% ester base oil, 12 wt% lithium soap, 0.1 wt% O-CDS quantum dots, and 2 wt% antioxidant.

[0091] The O-CDS quantum dots were circulated and pressed three times at a pressure of 150 MPa using a high-pressure homogenizer. Then, they were added to an ester base oil and heated and stirred at 50°C for 12 hours. Thickener lithium soap and antioxidant diphenylamine were then added, and stirring was continued for 2 hours to obtain a high-wear-resistant grease based on the O-CDS quantum dot rolling ball effect.

[0092] Example 12 A method for preparing a high-wear-resistant grease based on the rolling ball effect of O-CDS quantum dots involves adding a small amount of surfactant (such as Span 80, 0.5wt%) during the dispersion process to improve the long-term storage stability (Zeta potential -40mV) of O-CDS quantum dots. The method includes the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0093] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following by weight percentages: 85.9 wt% ester base oil, 12 wt% lithium soap, 0.1 wt% O-CDS quantum dots, 1.5 wt% antioxidant, and 0.5 wt% Span 80.

[0094] O-CDS quantum dots were dispersed in anhydrous ethanol containing 0.5 wt% Span 80 to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50°C for 12 h. Then, lithium soap (thickener) and diphenylamine (antioxidant) were added and stirred for another 2 h to obtain a high-wear grease based on the rolling ball effect of O-CDS quantum dots.

[0095] In order to dynamically adjust the lubrication film structure and adapt to varying operating conditions (such as mechanical systems with frequent start-stop cycles), the present invention has optimized Examples 13 and 14.

[0096] Example 13 A method for preparing a high-wear-resistant grease based on the rolling ball effect of O-CDS quantum dots coated with oxidized ascorbic acid enhances its rolling performance by controlling the morphology of O-CDS quantum dots (such as core-shell structure or rod-like structure), and the coefficient of friction can be further reduced to 0.095. The method includes the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0097] S2. Preparation of O-CDS quantum dots coated with oxidized ascorbic acid: 0.1 g of O-CDS quantum dots were dispersed in 50 mL of water, and 0.5 g of ascorbic acid was added. The mixture was stirred at 80 °C for 2 h to coat the O-CDS quantum dots with ascorbic acid. Then, H2O2 (30% by volume, 1 mL) was added dropwise, and the reaction was continued for 1 h to oxidize the ascorbic acid to generate a -COOH / -OH shell. The mixture was then purified by dialysis (MWCO 1000 Da) and freeze-dried to obtain O-CDS quantum dots coated with oxidized ascorbic acid.

[0098] S3. Preparation of high-wear grease based on the rolling ball effect of O-CDS quantum dots coated with oxidized ascorbic acid: Weigh the following ingredients by weight percentage: 85.9 wt% ester base oil, 12 wt% lithium soap, 0.1 wt% oxidized ascorbic acid-coated O-CDS quantum dots, and 2 wt% antioxidant.

[0099] O-CDS quantum dots coated with oxidized ascorbic acid were dispersed in anhydrous ethanol and sonicated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50 °C for 12 h. Then, lithium soap as a thickener and diphenylamine as an antioxidant were added and stirred for another 2 h to obtain a high-wear grease based on the rolling ball effect of O-CDS quantum dots coated with oxidized ascorbic acid.

[0100] Example 14 A method for preparing high-wear anti-wear grease based on the O-CDS quantum dot rolling ball effect involves introducing magnetic nanoparticles (such as Fe3O4, 0.05wt%) and directionally arranging O-CDS quantum dots under the action of an external magnetic field to form an ordered lubricating film. The method includes the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0101] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following components by weight percentage: 85.9 wt% ester base oil, 12 wt% lithium soap, 0.05 wt% O-CDS quantum dots, 2 wt% antioxidant, and 0.05 wt% Fe3O4.

[0102] O-CDS quantum dots and 0.05wt% Fe3O4 were dispersed in anhydrous ethanol and ultrasonically treated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50℃ for 12 h. Then, lithium soap as a thickener and diphenylamine as an antioxidant were added and stirred for another 2 h to obtain a high anti-wear grease based on the rolling ball effect of O-CDS quantum dots.

[0103] To enhance chemical bonding strength and improve lubricant film durability, the present invention has optimized Examples 15 and 16.

[0104] Example 15 A method for preparing a high-wear-resistant grease based on the phosphate ester grafted O-CDS quantum dot rolling ball effect involves grafting phosphate ester groups (-PO4) onto the surface of O-CDS quantum dots to form a phosphate lubricating film on the metal surface, thereby improving anti-wear performance (wear track depth reduction >65%). The method includes the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0105] S2, Preparation of phosphate-grafted O-CDS quantum dots: O-CDS quantum dots were dispersed in DMSO and sonicated for 30 min. Then, POCl3 (1 mL) was added dropwise under an ice bath. After the addition was complete, the temperature was raised to 80 °C under nitrogen protection and reacted for 6 h. After the reaction was completed, the temperature was cooled to room temperature, and unreacted reagents were removed by dialyzing (MWCO 1000 Da). The mixture was then freeze-dried to obtain phosphate-grafted O-CDS quantum dots.

[0106] S3. Preparation of high-wear-resistant grease based on phosphate ester grafted O-CDS quantum dot rolling ball effect: Weigh the following components by weight percentage: 85.9 wt% ester base oil, 12 wt% lithium soap, 0.1 wt% phosphate-grafted O-CDS quantum dots, and 2 wt% antioxidant.

[0107] Phosphate-grafted O-CDS quantum dots were dispersed in anhydrous ethanol and sonicated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50 °C for 12 h. Then, lithium soap (thickener) and diphenylamine (antioxidant) were added and stirred for another 2 h to obtain a high-wear-resistant grease based on the spherical effect of phosphate-grafted O-CDS quantum dots.

[0108] Example 16 A method for preparing high-wear grease based on the rolling ball effect of amination-based O-CDS quantum dots utilizes the coordination of amino groups (-NH2) on the surface of O-CDS quantum dots with the metal oxide layer to form a self-healing lubricating film (XPS verification of N-Fe bond formation), including the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0109] S2, Preparation of amination O-CDS sites: O-CDS (0.1 g) was dispersed in 10 mL of PBS buffer (pH=6.0), then 50 mg of (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and 30 mg of N-hydroxysuccinimide were added, and the mixture was stirred at room temperature for 2 h to activate the -COOH group to form an active ester. Then ethylenediamine (1 mL) was added, and the mixture was reacted at room temperature for 12 h to perform amino grafting. After the grafting was completed, unreacted reagents were removed by dialysis (MWCO 1000 Da), and the mixture was freeze-dried to obtain the amination O-CDS.

[0110] S3. Preparation of high-wear grease based on the rolling ball effect of amminated O-CDS: Weigh the following components by weight percentage: 85.9 wt% ester base oil, 12 wt% lithium soap, 0.1 wt% amination O-CDS point, and 2 wt% antioxidant.

[0111] The ammoniated O-CDS points were dispersed in anhydrous ethanol and ultrasonically treated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50°C for 12 h. Then, the thickener lithium soap and the antioxidant diphenylamine were added and stirred for another 2 h to obtain a high anti-wear grease based on the rolling ball effect of the ammoniated O-CDS points.

[0112] Example 17 A method for preparing high-wear anti-wear grease based on the rolling ball effect of O-CDS quantum dots involves first preparing O-CDS quantum dots, then co-participating them in an esterification reaction with methyl ricinoleate and pentaerythritol to achieve in-situ dispersion of O-CDS quantum dots, including the following steps: S1. Methyl ricinoleate, pentaerythritol and O-CDS quantum dots are mixed with a molar ratio of methyl ricinoleate to pentaerythritol of 4:1. Then, 1 wt% sodium methoxide is added as a catalyst and stirred at 120°C for 6 h to carry out the esterification reaction. After the reaction is completed, the mixture is cooled to room temperature and filtered to remove the catalyst to obtain an ester-based base oil intermediate. The mass percentage of O-CDS quantum dots in the ester-based base oil intermediate is 0.1 wt%.

[0113] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following components by weight percentage: 86 wt% ester base oil, 12 wt% lithium soap, and 2 wt% antioxidant; Thickener lithium soap and antioxidant diphenylamine were added to the ester-based base oil intermediate and stirred for 2 hours to obtain a high-wear grease based on the O-CDS quantum dot rolling ball effect.

[0114] Example 18 The preparation method of high-anti-wear grease based on the O-CDS quantum dot rolling ball effect introduces an online monitoring system (such as near-infrared spectroscopy) during the mixing stage of the high-anti-wear grease based on the O-CDS quantum dot rolling ball effect to adjust the component ratio in real time and ensure batch consistency (deviation <2%), including the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0115] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following components by weight percentage: 85.9 wt% ester base oil, 12 wt% lithium soap, 0.1 wt% O-CDS quantum dots, and 2 wt% antioxidant.

[0116] O-CDS quantum dots were dispersed in anhydrous ethanol and ultrasonically treated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil, and an online monitoring system was introduced during the mixing stage. The mixture was heated and stirred at 50°C for 12 h. Then, lithium soap (thickener) and diphenylamine (antioxidant) were added, and stirring was continued for 2 h to obtain a high-wear-resistant grease based on the rolling ball effect of O-CDS quantum dots.

[0117] Example 19 The preparation method of the high-wear grease based on the O-CDS quantum dot rolling ball effect is the same as the preparation steps in Example 1, except that 0.1 wt% of O-CDS quantum dots are replaced with 0.05 wt% of O-CDS quantum dots, including the following steps: S1. Preparation of ester base oil: Methyl ricinoleate and pentaerythritol were mixed in a molar ratio of 4:1, and then 1 wt% sodium methoxide was added as a catalyst. The mixture was stirred at 120°C for 6 hours to carry out the esterification reaction. After the reaction was completed, the mixture was cooled to room temperature and filtered to remove the catalyst, thus obtaining the ester base oil.

[0118] S2. Preparation of high-wear-resistant grease based on O-CDS quantum dot rolling ball effect: Weigh the following ingredients by weight percentage: 85wt% ester base oil (lubricant and carrier), 12wt% lithium soap (main thickener), 0.05wt% O-CDS quantum dots (core anti-wear agent), 2wt% antioxidant (inhibits oxidative aging), 0.8wt% molybdenum disulfide (extreme pressure enhancer), and 0.15wt% barium petroleum sulfonate (rust inhibitor and corrosion protection).

[0119] O-CDS quantum dots were dispersed in anhydrous ethanol and sonicated for 30 min to obtain a dispersion. The dispersion was added to an ester base oil and heated and stirred at 50 °C for 12 h. Lithium soap, diphenylamine, molybdenum disulfide and barium petroleum sulfonate were then added and stirred for another 2 h to obtain a high-wear-resistant grease based on the rolling ball effect of O-CDS quantum dots.

[0120] Example 20 The preparation steps are the same as in Example 1, except that the mass percentage of O-CDS quantum dots is replaced from 0.06wt% to 0.02wt%, and the mass percentage of ester base oil is replaced from 85.94wt% to 85.98wt%.

[0121] Example 21 The preparation steps are the same as in Example 1, except that the mass percentage of O-CDS quantum dots is replaced from 0.06wt% to 0.04wt%, and the mass percentage of ester base oil is replaced from 85.94wt% to 85.96wt%.

[0122] Example 22 The preparation steps are the same as in Example 1, except that the mass percentage of O-CDS quantum dots is replaced from 0.06wt% to 0.08wt%, and the mass percentage of ester base oil is replaced from 85.94wt% to 85.92wt%.

[0123] Comparative Example 1 The preparation steps are the same as in Example 1, except that the mass percentage of O-CDS quantum dots is replaced by 0 instead of 0.06wt%, and the mass percentage of ester base oil is replaced by 86wt% instead of 85.94wt%.

[0124] Comparative Example 2 The preparation steps are the same as in Example 1, except that the mass percentage of O-CDS quantum dots is replaced from 0.06wt% to 0.01wt%, and the mass percentage of ester base oil is replaced from 85.94wt% to 85.99wt%.

[0125] Comparative Example 3 The preparation steps are the same as in Example 1, except that the mass percentage of O-CDS quantum dots is replaced from 0.06wt% to 0.1wt%, and the mass percentage of ester base oil is replaced from 85.94wt% to 85.9wt%.

[0126] The following section verifies the high-wear-resistance grease based on the O-CDS quantum dot rolling ball effect of this invention. Viscosity testing was performed using an apparent viscometer, according to ASTM D1092. High oxidation stability was determined using PDSC differential pressure scanning calorimetry, simulating high-temperature, high-pressure, and oxygen-rich environments to measure its oxidation induction period, according to ASTM D6186. Other test methods and conclusions are detailed below:

[0127] Figure 1 The optimal addition amount of O-CDS quantum dots was determined. The results showed that the optimal addition amount of O-CDS quantum dots was 0.06 wt% (balancing reaction efficiency and lubrication performance); when the O-CDS quantum dots were greater than or equal to 0.1 wt%, the dispersibility decreased.

[0128] To obtain the three-dimensional morphology of the worn surface of the sample after tribological experiments, Figure 2The results of confocal microscopy (CLSM) showed that adding O-CDS quantum dots in the range of 0.02wt% to 0.08wt% could significantly reduce the wear rate and the width of the wear tracks, with the lowest wear rate at 0.06wt%.

[0129] Surface elemental distribution was analyzed using energy-dispersive X-ray spectroscopy (EDS). Figures 3-10 The results showed that there was a clear distribution of Fe, O, and C elements in each group on the wear trajectory, indicating the formation of a friction film. Compared with the dry friction group, the oxygen content on the surface of the examples and comparative examples was significantly reduced, proving that the degree of oxidation was reduced.

[0130] Microstructural features were observed using scanning electron microscopy (SEM). Figures 3-10 The results showed that the worn surface of the grease without added quantum dots exhibited numerous unevenness and grooves, with a wear mark width of 476.16 μm, indicating severe adhesive wear. The wear trajectory of the high-anti-wear grease based on the O-CDS quantum dot rolling ball effect was investigated, revealing that metal adhesion almost disappeared and the wear mark width decreased.

[0131] Embodiment 1 of this invention, based on the O-CDS quantum dot rolling ball effect, also includes a study of technical implementation cases and application scenarios for the high-wear grease, specifically: (1) Industrial application cases: Case 1: The lifespan of the drive motor bearing for new energy vehicles has been extended to 2000 hours (compared to 1200 hours for traditional grease).

[0132] Case 2: The high-speed gear of the wind turbine gearbox did not solidify during the -30°C low-temperature start-up test, and the coefficient of friction remained stable at 0.11.

[0133] (2) Extreme operating condition test: High temperature test: continuous operation at 180°C for 50 hours, friction coefficient fluctuation <5% (traditional grease fluctuation >20%).

[0134] High load test: Under a 5N load, the wear depth is 7.2μm (15.8μm for conventional grease).

[0135] This invention presents a study on the commercialization potential and market analysis of a high-wear-resistant grease based on the O-CDS quantum dot rolling ball effect, specifically as follows: 1. Target Market: Sub-sectors: High-end equipment manufacturing (wind power, high-speed rail), new energy vehicles, and aerospace lubrication systems.

[0136] Market size: The global high-performance grease market is projected to reach $1.25 billion by 2025, with a CAGR of 6.8% (Source: Grand View Research).

[0137] 2. Competitive Advantages: Cost advantage: The integrated preparation process reduces the total cost by 30%, and the mass production cost of O-CDS quantum dots is less than $50 / g.

[0138] Environmental certifications: Compliant with EU REACH regulations (no harmful solvents) and US USDA bio-based product certification (bio-based content >80%).

[0139] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims and their equivalents, this invention also intends to include these modifications and variations. The above-described embodiments are merely preferred embodiments for fully illustrating the invention, and their scope of protection is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on this invention are all within the scope of protection of this invention, which is defined by the claims.

Claims

1. A method for preparing a high-wear-resistant grease based on the quantum dot rolling ball effect, characterized in that, Includes the following steps: Esterification reaction is carried out using polybasic acids or bio-based raw materials and polyols to obtain ester base oils; quantum dots, ester base oils, thickeners and antioxidants are mixed to obtain high anti-wear grease based on the quantum dot rolling ball effect; The mass percentages of ester base oil, quantum dots, thickener, and antioxidant are 80%~90%, 0.02%~0.08%, 7%~17%, and 1%~5%, respectively, and the sum of the mass percentages of the four is 100%. Alternatively, polybasic acids or bio-based raw materials, polyols and quantum dots are mixed and then esterified under catalysis to obtain an ester-based base oil intermediate; the ester-based base oil intermediate, thickener and antioxidant are mixed to obtain a high anti-wear grease based on the quantum dot rolling ball effect. In the ester-based base oil intermediate, the mass percentage of quantum dots is 0.02%~0.08%; the mass percentages of the ester-based base oil intermediate, thickener, and antioxidant are 80%~90%, 7%~17%, and 1%~5%, respectively, and the sum of the mass percentages of the three is 100%. The quantum dots are selected from O-CDS quantum dots, aminated O-CDS quantum dots, phosphate-grafted O-CDS quantum dots, or oxidized ascorbic acid-coated O-CDS quantum dots.

2. The method for preparing high-wear-resistant grease based on quantum dot rolling ball effect according to claim 1, characterized in that, The bio-based raw materials are selected from soybean oil derivatives, methyl palmitate, or methyl castor oil.

3. The method for preparing high-wear-resistant grease based on quantum dot rolling ball effect according to claim 1, characterized in that, For polybasic acids, choose diacid, sebacic acid, azelaic acid, maleic anhydride, or terephthalic acid.

4. The method for preparing high-wear-resistant grease based on quantum dot rolling ball effect according to claim 1, characterized in that, The polyol is selected from glycerol, pentaerythritol, neopentyl glycol, trimethylolpropane, sorbitol, or polyethylene glycol.

5. The method for preparing the high-wear-resistant grease based on quantum dot rolling ball effect according to claim 1, characterized in that, The esterification reaction conditions are: stirring at 100℃~125℃ for 4h~6.5h.

6. The method for preparing high-wear-resistant grease based on quantum dot rolling ball effect according to claim 1, characterized in that, Amination of O-CDS points is prepared according to the following steps: Citric acid and glutathione were mixed and heated at 210±10℃ for 15min~17min, then oleylamine was added and the mixture was heated for another 3min~5min to obtain O-CDS quantum dots. The O-CDS quantum dots were first activated with (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide to form an active ester. Then, the active ester was mixed with ethylenediamine and subjected to an amino grafting reaction to obtain aminated O-CDS dots.

7. The method for preparing high-wear-resistant grease based on quantum dot rolling ball effect according to claim 1, characterized in that, Phosphate-grafted O-CDS quantum dots were prepared according to the following steps: Citric acid and glutathione were mixed and heated at 210±10℃ for 15min~17min, then oleylamine was added and the mixture was heated for another 3min~5min to obtain O-CDS quantum dots. O-CDS quantum dots were dispersed, then phosphorylation reagent was added dropwise, and a grafting reaction was carried out under an inert atmosphere to obtain phosphate-grafted O-CDS quantum dots.

8. The method for preparing high-wear-resistant grease based on quantum dot rolling ball effect according to claim 1, characterized in that, Oxidized ascorbic acid-coated O-CDS quantum dots were prepared according to the following steps: Citric acid and glutathione were mixed and heated at 210±10℃ for 15min~17min, then oleylamine was added and the mixture was heated for another 3min~5min to obtain O-CDS quantum dots. After mixing O-CDS quantum dots with ascorbic acid, the O-CDS quantum dots are first coated with ascorbic acid, and then H2O2 is added dropwise to oxidize the ascorbic acid, thus obtaining O-CDS quantum dots coated with oxidized ascorbic acid.

9. A high-wear-resistant grease based on the quantum dot rolling ball effect prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the high anti-wear grease based on quantum dot rolling ball effect as described in claim 8 in the preparation of grease additives.

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