CN112940825B - Application of silicon phosphide quantum dots as lubricating oil additive, lubricating oil and preparation method and application thereof - Google Patents

Abstract

The invention relates to the technical field of lubricating oil additives, in particular to application of silicon phosphide quantum dots as a lubricating oil additive, lubricating oil and a preparation method and application thereof. The invention provides an application of a silicon phosphide quantum dot as a lubricating oil additive. The invention provides lubricating oil which comprises silicon phosphide quantum dots and base oil. The results of the examples show that the lubricating oil provided by the invention has excellent wear-reducing and wear-resisting properties relative to base oil, the friction coefficient is reduced by 18%, and the wear-resisting spot diameter is reduced by 63.5%.

Description

Application of silicon phosphide quantum dots as lubricating oil additive, a kind of lubricating oil and its preparation method and application

technical field

The invention relates to the technical field of lubricating oil additives, in particular to the application of silicon phosphide quantum dots as lubricating oil additives, a lubricating oil and a preparation method and application thereof.

Background technique

With the development of production technology, the vigorous development of engines, agricultural machinery equipment and micro-electromechanical systems, the requirements for lubricating oil are also getting higher and higher. Lubricating oil is a substance that acts on the mechanical friction part, and is mainly used for lubrication, cooling and sealing. In addition, in industrial production, lubricating oil can also clean the friction part and prevent pollution. In order to improve the lubricating effect of the lubricating oil, lubricating additives are usually contained in the lubricating oil, which can greatly improve the lubricating performance and anti-friction performance of the lubricating oil. The exploration of new lubricating additives has always been an important measure to solve the problem of high-quality lubricating additives.

In recent years, two-dimensional materials can be used as a new type of solid lubricant and as an excellent lubricant additive because of the covalent bonds in the layers and the van der Waals force between the layers. Additive hot spot material. However, the existing 2D materials still have certain problems, such as the zero band gap of graphene, easy agglomeration, and the failure of molybdenum disulfide (MoS ₂ ) due to deliquescence in a humid environment, which limits its use. Therefore, it is urgent to explore the application of new two-dimensional materials as lubricant additives.

SUMMARY OF THE INVENTION

In view of this, the present invention provides the application of silicon phosphide quantum dots as lubricating oil additives, a kind of lubricating oil and its preparation method and application. The lubricating oil provided by the present invention uses SiP quantum dots as lubricating oil additives, in lubricating oil The dispersion of the lubricating oil is good, so that the anti-wear and anti-wear performance of the lubricating oil is significantly improved, and the average friction coefficient is 0.064 to 0.072.

For achieving the above object, the present invention provides the following scheme:

The present invention provides the application of SiP quantum dots as lubricating oil additives.

Preferably, the average particle size of the SiP quantum dots is 8-15 nm, and the average thickness is 1-3 nm; the mass percentage of the SiP quantum dots in the lubricating oil is 0.01-0.1%.

The present invention provides a lubricating oil comprising SiP quantum dots and base oil.

Preferably, the average particle size of the SiP quantum dots is 8-15 nm, and the average thickness is 1-3 nm; the mass percentage of the SiP quantum dots in the lubricating oil is 0.01-0.1%.

Preferably, the base oil is polyethylene glycol base oil, polyether base oil or synthetic ester base oil.

Preferably, the preparation method of the SiP quantum dots includes the following steps:

After mixing the SiP powder and the polar organic solvent, ultrasonic peeling, stirring, solid-liquid separation and drying of the supernatant are sequentially performed to obtain the SiP quantum dots;

The average particle size of the SiP powder is 1-100 μm, and the average thickness is 500-2000 nm;

The SiP quantum dots have an average particle size of 8-15 nm and an average thickness of 1-3 nm.

Preferably, the polar organic solvent includes one or more of acetone, absolute ethanol, dimethyl sulfoxide, N-methylpyrrolidone and dimethylformamide.

The power of the ultrasonic peeling is 1000-1500W, the frequency of the ultrasonic peeling is 20-30 kHz, and the time of the ultrasonic peeling is 2-10h;

The stirring speed is 500～1000rpm, and the stirring time is 2～10h;

The solid-liquid separation method is centrifugation; the centrifugal speed is 3000-10000 r/min, and the centrifugation time is 30-100 min.

The present invention provides the preparation method of the lubricating oil described in the above technical scheme, comprising the following steps:

The SiP quantum dots and the base oil are mixed and sonicated to obtain the lubricating oil.

Preferably, the power of the ultrasonic is 1000-1500 W, and the ultrasonic time is 3-10 h.

The present invention provides the application of the lubricating oil described in the above technical solution or the lubricating oil obtained by the preparation method described in the above technical solution in friction pairs such as metal-metal, metal-polymer, and metal-ceramic.

The present invention has achieved the following technical effects with respect to the prior art:

The present invention provides the application of SiP quantum dots as lubricating oil additives. In the present invention, the SiP quantum dots have a layered structure, there is a nano-level interlayer spacing between the layers, and there is covalent bond force in the layers. There is van der Waals force between layers, and the interlayer force is weak, which makes it easier for SiP quantum dot layers to slide between layers; and its structural elements are interconnected twisted five-membered rings and six-membered rings, showing In-plane anisotropy, this ring structure can eliminate edge dangling bonds, make SiP quantum dots have excellent stability, and improve the moisture resistance of SiP quantum dots. Using SiP quantum dots as lubricating oil additives to achieve good dispersion of SiP quantum dots in lubricating oil, the obtained lubricating oil product has excellent anti-friction and anti-wear performance, stable structure and strong bearing capacity.

The present invention provides a lubricating oil comprising SiP quantum dots and base oil. The results of the examples show that the average friction coefficient of the lubricating oil provided by the present invention is 0.064-0.072.

Description of drawings

1 is an atomic force microscope image of the SiP quantum dots prepared in Example 1 of the present invention;

2 is a thickness distribution diagram of SiP quantum dots prepared in Example 1 of the present invention;

Fig. 3 is the particle size statistics diagram of SiP quantum dots prepared in Example 1 of the present invention;

4 is a friction coefficient curve and a wear spot diagram of the lubricating oil obtained when the SiP quantum dots prepared in Example 1 of the present invention are used as additives;

5 is a friction coefficient curve and a wear spot diagram of the lubricating oil obtained when the SiP quantum dots prepared in Example 2 of the present invention are used as additives;

6 is a friction coefficient curve and a wear spot diagram of the lubricating oil obtained when the SiP quantum dots prepared in Example 3 of the present invention are used as additives;

7 is a friction coefficient curve and a wear spot diagram of the lubricating oil obtained when the SiP quantum dots prepared in Example 4 of the present invention are used as additives;

Fig. 8 is the friction coefficient curve and the wear spot diagram of the lubricating oil obtained when the SiP quantum dots prepared in Example 5 of the present invention are used as additives;

9 is a friction coefficient curve and a wear spot diagram of the lubricating oil obtained when the SiP quantum dots prepared in Example 6 of the present invention are used as additives;

10 is a friction coefficient curve and a wear spot diagram of the lubricating oil obtained when the SiP quantum dots prepared in Example 7 of the present invention are used as additives;

11 is a friction coefficient curve and a wear spot diagram of the lubricating oil obtained when the SiP quantum dots prepared in Example 8 of the present invention are used as additives;

FIG. 12 is the friction coefficient curve and wear scar chart of the base oil PEG-400.

Detailed ways

The present invention provides the application of SiP quantum dots as lubricating oil additives.

In the present invention, the average particle size of the SiP quantum dots is preferably 8-15 nm, more preferably 9.5-13 nm, more preferably 12 nm; the average thickness is preferably 1-3 nm, more preferably 1.5-2 nm; the SiP The mass percentage of the quantum dots in the lubricating oil is 0.01-0.1%, preferably 0.03-0.08%, and more preferably 0.05-0.06%.

The SiP quantum dots provided by the present invention have a layered structure, and the interlayer force is weak; and has excellent stability and in-plane anisotropy. The SiP quantum dots are used as lubricating oil additives. It has good dispersibility, and the obtained lubricating oil has excellent anti-wear and anti-wear properties.

The present invention also provides a lubricating oil comprising SiP quantum dots and base oil.

In the present invention, the mass percentage of the SiP quantum dots in the lubricating oil is preferably 0.01-0.1 wt%, more preferably 0.03-0.08%, and more preferably 0.05-0.06%.

In the present invention, the SiP quantum dots are preferably obtained by preparation; the preparation method of the IV-V group two-dimensional compound quantum dots preferably includes the following steps:

After mixing the SiP powder and the polar organic solvent, ultrasonic peeling, stirring, solid-liquid separation and drying of the supernatant are sequentially performed to obtain the SiP quantum dots;

The average particle size of the SiP powder is 1-100 μm, and the average thickness is 500-2000 nm

The SiP quantum dots have an average particle size of 8-15 nm and an average thickness of 1-3 nm.

In the present invention, the average particle size of the SiP powder is preferably 1-100 μm, more preferably 40-70 μm; the average thickness is preferably 500-2000 nm, more preferably 800-1500 nm, the average particle size of the SiP quantum dots The diameter is preferably 8 to 15 nm, more preferably 9.5 to 13 nm, and more preferably 12 nm; the average thickness is preferably 1 to 3 nm, further preferably 1.5 to 2 nm. The present invention has no special requirements on the source of the SiP powder, and can use commercially available products or laboratory preparations.

In the present invention, the SiP powder is preferably obtained by preparation, and the preparation method of the SiP powder preferably includes the following steps: grinding a SiP single crystal to obtain the SiP powder.

In the present invention, the SiP single crystal is preferably 5-10 mm×1 mm×1 mm, and the SiP single crystal is preferably based on the literature “Controllable seeded flux growth and optoelectronic properties of bulk o-SiP crystals” (Li C, Wang S , Zhang X, et al CrystEngComm) by the experimental method described in the preparation. In the embodiment of the present invention, the preparation method of the SiP single crystal is as follows: the raw materials are batched according to the molar ratio of Si:P:Sn to 1:1:5, fully mixed, and then transferred to a quartz tube. , after the quartz tube is evacuated to 5×10 ^-3 Pa with a molecular pump, sealed with a hydrogen-oxygen flame, placed in the synthesis furnace, and the temperature is controlled by an FP23 temperature control table. The temperature control procedure is as follows: Initial temperature At room temperature, the temperature was raised to 723K and kept at a constant temperature for 36h, then heated to 973K after 36h, then heated to 1423K after 48h, then cooled to 873K after 500h, and cooled to room temperature. The sintered sample was soaked in dilute hydrochloric acid with a ratio of concentrated hydrochloric acid to water of 1:1 to remove Sn in the sample, washed with ethanol and dried at 333K to obtain the SiP single crystal. In the present invention, the grinding time is preferably 10-30 min, and the grinding is preferably an agate mortar, which can be manually ground.

In the present invention, the polar organic solvent preferably includes one or more of acetone, absolute ethanol, dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP) and dimethylformamide (DMF). Various, more preferably acetone, absolute ethanol, dimethyl sulfoxide, N-methylpyrrolidone or dimethylformamide; when the polar organic solvent preferably includes acetone, absolute ethanol, dimethyl sulfoxide , N-methylpyrrolidone and two or more kinds of dimethylformamide, the present invention has no special requirements for the mass ratio of the above-mentioned specific substances, and any ratio can be used. The present invention has no special requirements on the source of the polar organic solvent, and a commercially available product can be used.

In the present invention, the mass-volume ratio of the SiP and the polar organic solvent is preferably 0.01-0.1 g: 10-50 mL, and the present invention has no special requirements for the specific operation process of mixing the SiP powder and the polar organic solvent.

After mixing the SiP powder and the polar organic solvent, the present invention also preferably includes performing preliminary ultrasound on the dispersion obtained after mixing, and the power of the preliminary ultrasound is preferably 150-300W, more preferably 180-250W, most preferably 150-300W. Preferably it is 210-245W; the time of the preliminary ultrasonic is preferably 1-3h, more preferably 1.5-2h. The present invention has no special requirements on the equipment for the preliminary ultrasound, and an ultrasound equipment well-known to those skilled in the art can be used. In the embodiment of the present invention, the equipment for the preliminary ultrasonic wave is an ultrasonic cleaning machine.

In the present invention, the SiP powder is more uniformly dispersed in the polar organic solvent through preliminary ultrasonic waves.

After the dispersion is obtained, the present invention performs ultrasonic peeling of the dispersion, the power of the ultrasonic peeling is preferably 1000-1500W, more preferably 1200-1350W, the frequency of the ultrasonic peeling is preferably 20-30kHz, and more preferably 23-28 kHz, the ultrasonic peeling time is preferably 2-10 h, more preferably 4-8 h. The present invention has no special requirements for the ultrasonic peeling equipment, and an ultrasonic equipment well known to those skilled in the art may be used. In the embodiment of the present invention, the ultrasonic peeling equipment is an ultrasonic disruptor.

In the present invention, the stirring speed is preferably 500-1000 rpm, more preferably 650-800 rpm, and the stirring time is preferably 2-10 h, more preferably 3.5-7.8 h. There are no special requirements. In the embodiment of the present invention, the stirring mode is preferably magnetic stirring.

In the present invention, the solid-liquid separation method is preferably centrifugation; the centrifugal speed is preferably 3000-10000 r/min, more preferably 4500-8900 r/min; the centrifugation time is preferably 30-100 min.

After the solid-liquid separation is completed, the present invention preferably dries the supernatant liquid, and the supernatant liquid is preferably 2/3-4/5 of the liquid volume after the solid-liquid separation, and the drying temperature is preferably 80-150 °C. ℃, the drying time is preferably 2h, and the drying is preferably carried out in a drying oven.

In the present invention, the lubricating oil further includes base oil. In the present invention, the base oil is preferably polyethylene glycol base oil, polyether base oil or synthetic ester base oil, more preferably polyethylene glycol base oil, liquid paraffin or polyalphaolefin (PAO), In the embodiment of the present invention, the base oil is preferably PEG-400, PEG-800, liquid paraffin, polyalphaolefin (PAO). The present invention has no special requirements on the source of the base oil, and a commercially available product can be used.

In the present invention, the mass percentage of the SiP quantum dots in the lubricating oil is 0.01-0.1%, preferably 0.03-0.08%, more preferably 0.05-0.06%.

The present invention provides the preparation method of the lubricating oil described in the above technical scheme, comprising the following steps:

The SiP quantum dots and the base oil are mixed and sonicated to obtain the lubricating oil.

The present invention has no special requirements on the specific operation process of the mixing.

In the present invention, the power of the ultrasonic wave is preferably 1000-1500W, more preferably 1150-1350W; the ultrasonic time is preferably 3-10h, more preferably 4.5-8.5h.

The present invention provides the application of the lubricating oil described in the above technical solution or the lubricating oil obtained by the preparation method described in the above technical solution in friction pairs such as metal-metal, metal-polymer, and metal-ceramic.

In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with the embodiments, but the content of the present invention is not limited to the following embodiments.

Example 1

The raw materials were prepared according to the molar ratio of Si:P:Sn to 1:1:5, mixed well, and then transferred to a quartz tube. After the quartz tube was evacuated to 5×10 ^-3 Pa with a molecular pump, hydrogen The oxygen flame is sealed, the quartz tube is placed in the synthesis furnace, and the FP23 temperature control table is used to control the temperature. The temperature control program is as follows: the initial temperature is room temperature, the temperature is raised to 723K, and the temperature is kept constant for 36h, then the temperature is raised to 973K after 36h, and then It was heated to 1423K after 48h, then cooled to 873K after 500h, and cooled to room temperature. The sintered sample was soaked in dilute hydrochloric acid with a ratio of concentrated hydrochloric acid to water of 1:1 to remove Sn in the sample, washed with ethanol and dried at 333K to obtain the SiP single crystal. In the present invention, the grinding time is preferably 10-30 min, and the grinding is preferably an agate mortar, which can be manually ground.

The SiP single crystal was ground with an agate mortar for 10 minutes to obtain SiP powder (particle size was 50 μm, thickness was 500 nm), and then the SiP powder was mixed with acetone (the mass-volume ratio of the two was 0.1 g: 50 mL). Ultrasonic cleaning machine, for preliminary ultrasonic dispersion, the treatment time is 1h, and then the SiP powder is subjected to liquid-phase ultrasonic peeling with a power of 1000W and a frequency of 20kHz, and the ultrasonic peeling time is 2h; SiP acetone dispersion is obtained;

Transfer the obtained SiP acetone dispersion into a beaker, conduct magnetic stirring for 2 hours, and stir at a rate of 500 rpm. Finally, centrifuge at a centrifugal speed of 3000 r/min for 60 minutes, and take 2/3 of the liquid volume after solid-liquid separation as the supernatant. The obtained supernatant was dried (the drying temperature was 80 °C, and the drying time was 2 h) to obtain SiP quantum dots;

The SiP quantum dots and the PEG-400 base oil were mixed, and the 1200W ultrasonic breaker was used to ultrasonicate for 3 hours to obtain a lubricating oil containing SiP quantum dots with a mass fraction of 0.03%.

FIG. 1 is an atomic force microscope image of the SiP quantum dots prepared in the present embodiment, and it can be concluded from FIG. 1 that the SiP quantum dots prepared in the present embodiment are in a dispersed state and have a uniform particle size;

Fig. 2 is a thickness distribution diagram of the SiP quantum dots prepared in the present embodiment, wherein the ordinate is the thickness size of the SiP quantum dots, and the abscissa is the size of the lateral arrangement of several SiP quantum dots. The thickness of the SiP quantum dots prepared in this example is less than 3 nm; FIG. 3 is a statistical graph of the average particle size of the SiP quantum dots prepared in this example, and the average size of the particle size is 12.4 nm.

Example 2

The SiP single crystal was ground in an agate mortar for 15 minutes to obtain SiP powder (50 μm in particle size and 2000 nm in thickness), and then the SiP powder and NMP were mixed (the mass-to-volume ratio of the two was 0.01 g: 10 mL). Ultrasonic cleaning machine, carry out preliminary ultrasonic dispersion, the treatment time is 1h, and then the SiP powder is subjected to liquid-phase ultrasonic peeling with a power of 1200W and a frequency of 50kHz, and the ultrasonic peeling time is 3h; The NMP dispersion of SiP is obtained;

Transfer the obtained SiP NMP dispersion into a beaker, conduct magnetic stirring for 3 hours, and stir at a rate of 600 rpm. Finally, centrifuge at a centrifugal speed of 3000 r/min for 60 min, and take 2/3 of the liquid volume after solid-liquid separation as the supernatant. The obtained supernatant is dried (the drying temperature is 100 °C, and the drying time is 2 h) to obtain SiP quantum dots;

The SiP quantum dots and the PEG-400 base oil were mixed, and the 1500W ultrasonic breaker was used to ultrasonicate for 3 hours to obtain a lubricating oil containing SiP quantum dots with a mass fraction of 0.05%.

Example 3

The SiP single crystal was ground with an agate mortar for 20 min to obtain SiP powder (particle size was 50 μm, thickness was 800 nm), and then the SiP powder and DMF were mixed (the mass-volume ratio of the two was 0.05 g: 50 mL), and a 250 W Ultrasonic cleaning machine, carry out preliminary ultrasonic dispersion, the treatment time is 3h, and then the SiP powder is subjected to liquid-phase ultrasonic peeling with a power of 1300W and a frequency of 40kHz, and the ultrasonic peeling time is 2h; The DMF dispersion of SiP is obtained;

Transfer the obtained DMF dispersion of SiP into a beaker, conduct magnetic stirring for 5h, the stirring speed is 800rpm, and finally centrifuge at a centrifugal speed of 5000r/min for 60min, and take 2/3 of the liquid volume after solid-liquid separation as the supernatant The obtained supernatant is dried (the drying temperature is 120 °C, and the drying time is 2 h) to obtain SiP quantum dots;

The SiP quantum dots and PEG-400 base oil were mixed, and the 1500W ultrasonic breaker was used to ultrasonicate for 3 hours to obtain a lubricating oil containing SiP quantum dots with a mass fraction of 0.03%.

Example 4

The SiP single crystal was ground with an agate mortar for 20 minutes to obtain SiP powder (particle size was 50 μm, thickness was 1500 nm), and then the SiP powder was mixed with DMSO, and a 300W ultrasonic cleaner was used for preliminary ultrasonic dispersion. The treatment time was 3h, and then use an ultrasonic breaker with a power of 1500W and a frequency of 40kHz to carry out liquid-phase ultrasonic peeling of the SiP powder, and the ultrasonic peeling time is 5h; the DMSO dispersion of SiP is obtained;

Transfer the obtained SiP DMSO dispersion into a beaker, conduct magnetic stirring for 5h, the stirring speed is 800rpm, and finally centrifuge at a centrifugal speed of 6000r/min for 60min, and take 2/3 of the liquid volume after solid-liquid separation as the supernatant The obtained supernatant is dried (the drying temperature is 120 °C, and the drying time is 2 h) to obtain SiP quantum dots;

The SiP quantum dots and the PEG-400 base oil were mixed, and sonicated by a 1500W ultrasonic disruptor for 3 hours to obtain a lubricating oil containing SiP quantum dots with a mass fraction of 0.07%.

Example 5

The SiP single crystal was ground in an agate mortar for 20 min to obtain SiP powder (50 μm in particle size and 1000 nm in thickness), and then the SiP powder was mixed with absolute ethanol (the mass-volume ratio of the two was 0.1 g: 50 mL), and the A 220W ultrasonic cleaning machine was used for preliminary ultrasonic dispersion, and the treatment time was 3h. Then, the SiP powder was subjected to liquid-phase ultrasonic peeling with a power of 1100W and a frequency of 40kHz. The ultrasonic peeling time was 5h; the anhydrous SiP was obtained. Ethanol dispersion;

Transfer the obtained SiP anhydrous ethanol dispersion into a beaker, conduct magnetic stirring for 5h, the stirring speed is 800rpm, and finally centrifuge at a centrifugal speed of 7000r/min for 60min, take 2/3 of the liquid volume after solid-liquid separation as The supernatant is dried (the drying temperature is 120° C., and the drying time is 2 h) to obtain SiP quantum dots;

The SiP quantum dots and the PEG-400 base oil were mixed, and sonicated by a 1400W ultrasonic disruptor for 3 hours to obtain a lubricating oil containing SiP quantum dots with a mass fraction of 0.06%.

Example 6

The SiP single crystal was ground in an agate mortar for 30 min to obtain SiP powder (particle size was 80 μm, thickness was 1800 nm), and then the SiP powder was mixed with acetone (the mass-volume ratio of the two was 0.05 g: 25 mL). Ultrasonic cleaning machine, for preliminary ultrasonic dispersion, the treatment time is 1h, and then the SiP powder is subjected to liquid-phase ultrasonic peeling with a power of 1600W and a frequency of 20kHz, and the ultrasonic peeling time is 2h; SiP acetone dispersion is obtained;

Transfer the obtained SiP acetone dispersion into a beaker, conduct magnetic stirring for 7 hours, and stir at a rate of 500 rpm. Finally, centrifuge at a centrifugal speed of 3000 r/min for 60 minutes, and take 2/3 of the liquid volume after solid-liquid separation as the supernatant. The obtained supernatant is dried (the drying temperature is 80 °C, and the drying time is 2 h) to obtain SiP quantum dots;

The SiP quantum dots and the PEG-400 base oil were mixed, and the 1700W ultrasonic breaker was used to ultrasonicate for 3 hours to obtain a lubricating oil containing SiP quantum dots with a mass fraction of 0.02%.

Example 7

The SiP single crystal was ground with an agate mortar for 30 min to obtain SiP powder (particle size was 50 μm, thickness was 1500 nm), and then SiP powder and NMP were mixed (the mass-volume ratio of the two was 0.1 g: 50 mL), and a 270 W Ultrasonic cleaning machine, for preliminary ultrasonic dispersion, the treatment time is 6h, and then the SiP powder is subjected to liquid-phase ultrasonic peeling with a power of 1700W and a frequency of 20kHz, and the ultrasonic peeling time is 3h; SiP NMP dispersion is obtained;

Transfer the obtained NMP dispersion of SiP into a beaker, conduct magnetic stirring for 5h, the stirring speed is 800rpm, and finally centrifuge at a centrifugal speed of 8000r/min for 60min, and take 2/3 of the liquid volume after solid-liquid separation as the supernatant The obtained supernatant is dried (the drying temperature is 80 °C, and the drying time is 2 h) to obtain SiP quantum dots;

The SiP quantum dots and the PEG-400 base oil were mixed, and the 1500W ultrasonic breaker was used to sonicate for 3 hours to obtain a lubricating oil containing SiP quantum dots with a mass fraction of 0.09%.

Example 8

The SiP single crystal was ground in an agate mortar for 20 min to obtain SiP powder (50 μm in particle size and 500 nm in thickness), and then the SiP powder and NMF were mixed (the mass-to-volume ratio of the two was 0.1 g: 50 mL). Ultrasonic cleaning machine for preliminary ultrasonic dispersion, the treatment time is 3h, and then the SiP powder is subjected to liquid-phase ultrasonic peeling with a power of 1300W and a frequency of 20kHz, and the ultrasonic peeling time is 2h; SiP NMF dispersion is obtained;

Transfer the obtained SiP NMF dispersion into a beaker, conduct magnetic stirring for 5 hours, and stir at a rate of 800 rpm. Finally, centrifuge at a centrifugal speed of 5000 r/min for 60 min, and take 2/3 of the liquid volume after solid-liquid separation as the supernatant. The obtained supernatant is dried (the drying temperature is 80 °C, and the drying time is 2 h) to obtain SiP quantum dots;

The SiP quantum dots and PEG-400 base oil were mixed, and the 1500W ultrasonic breaker was used to ultrasonicate for 3 hours to obtain a lubricating oil containing SiP quantum dots with a mass fraction of 0.03%.

Test Example 1

The lubricating oil and PEG-400 base oil prepared in Examples 1 to 8 were subjected to friction and wear test. The test method was as follows: a four-ball friction tester was used, the test time was 30 min, and the load was 200 kgf. is 12.7mm. The friction coefficient and wear scar obtained from the test are shown in Figures 4 to 12 (wherein Figures 4 to 11 are the friction coefficient and wear scar diagram of the lubricating oils described in Examples 1 to 8 in turn, and Figure 12 is the friction coefficient of the PEG-400 base oil. and wear scar diagram), the specific friction coefficient and wear scar size are shown in Table 1. From the results in Table 1 and Figures 4 to 12, it can be concluded that compared with the PEG-400 base oil, the lubricating oils prepared in Examples 1 to 8 have excellent anti-wear and anti-wear properties, the average friction coefficient is 0.064 to 0.072, and the friction coefficient is 0.064 to 0.072. The spot size was significantly smaller.

Friction and wear test data of lubricating oil prepared by table 1PEG-400 and Examples 1-8

In the present invention, specific examples are used to illustrate the principles and implementations of the present invention, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention; There will be changes in the specific implementation manner and application scope of the idea of the invention. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (8)

1. The application of the SiP quantum dots as the lubricating oil additive is characterized in that the average particle size of the SiP quantum dots is 8-15 nm, and the average thickness of the SiP quantum dots is 1-3 nm; the mass percentage of the SiP quantum dots in the lubricating oil is 0.01-0.1%.
2. 2. A lubricating oil, comprising SiP quantum dots and a base oil; the average particle size of the SiP quantum dots is 8-15 nm, and the average thickness of the SiP quantum dots is 1-3 nm; the mass percentage of the SiP quantum dots in the lubricating oil is 0.01-0.1%.
3. 3. The lubricating oil of claim 2, wherein the base oil is a polyethylene glycol base oil, a polyether base oil, or a synthetic ester base oil.
4. 4. The lubricating oil of claim 2, wherein the preparation method of the SiP quantum dots comprises the following steps:

   mixing SiP powder and a polar organic solvent, and then sequentially carrying out ultrasonic stripping, stirring, solid-liquid separation and supernatant fluid drying to obtain the SiP quantum dots;

   the average particle size of the SiP powder is 1-100 mu m, and the average thickness of the SiP powder is 500-2000 nm;

   the average particle size of the SiP quantum dots is 8-15 nm, and the average thickness of the SiP quantum dots is 1-3 nm.
5. 5. The lubricating oil of claim 4, wherein the polar organic solvent comprises one or more of acetone, absolute ethanol, dimethyl sulfoxide, N-methylpyrrolidone, and dimethylformamide;

   the power of ultrasonic stripping is 1000-1500W, the frequency of ultrasonic stripping is 20-30 kHz, and the time of ultrasonic stripping is 2-10 h;

   the stirring speed is 500-1000 rpm, and the stirring time is 2-10 hours;

   the solid-liquid separation mode is centrifugation; the centrifugation speed is 3000-10000 r/min, and the centrifugation time is 30-100 min.
6. 6. A method for preparing the lubricating oil according to any one of claims 2 to 5, characterized by comprising the steps of:

   and mixing the SiP quantum dots with base oil, and performing ultrasonic treatment to obtain the lubricating oil.
7. 7. The preparation method of claim 6, wherein the power of the ultrasound is 1000-1500W, and the time of the ultrasound is 3-10 h.
8. 8. The lubricating oil according to any one of claims 2 to 5 or the lubricating oil obtained by the preparation method according to claim 6 or 7 is used in friction pairs such as metal-metal, metal-polymer, metal-ceramic and the like.

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