CN108641783B - A kind of CeO2/FGO nano lubricating oil additive and bionic preparation method - Google Patents

Abstract

The invention relates to a bionic preparation method of a cerium dioxide/fluorinated-graphene oxide lubricating oil additive, belonging to the field of nano composite materials and self-lubricating materials. According to the invention, fluorinated-oxidized graphene self-prepared by a hydrothermal method is used as a raw material, and dopamine hydrochloride is used for biomimetic modification of the fluorinated-oxidized graphene. And polydopamine/fluorinated-graphene oxide and Ce (NO) prepared by the method₃)₃·6H₂And O is taken as a raw material, ultrasonically dispersed in a mixed solution of ethanol and water, and the cerium dioxide/polydopamine/fluorinated-graphene oxide nano lubricating oil additive is prepared in situ by one step through a hydrothermal method. The results of tribology tests show that the cerium dioxide/polydopamine/fluorinated-graphene oxide nano composite material prepared by the method has excellent wear-resistant and antifriction effects and is an ideal nano lubricating oil additive.

Description

A kind of CeO2/FGO nano lubricating oil additive and bionic preparation method

technical field

The invention relates to a biomimetic preparation method for a ceria/fluorinated-graphene oxide lubricating oil additive, in particular to a method for preparing a ceria/polydopamine/fluorinated-graphene oxide nanocomposite lubricating oil additive by a hydrothermal method , which belongs to the field of nanocomposite materials and self-lubricating materials.

Background technique

At present, based on the large-scale use of machinery and equipment, the world is facing major challenges of environmental pollution, resource and energy shortages. At the same time, with the advancement and development of technology, to a large extent, most of the properties of modern lubricating oils no longer depend on the original basic properties of crude oil, but are more inclined to and depend on the properties of the lubricating additives used. Traditional lubricating oils containing S, P, Cl and other series of additives can no longer meet the lubricating performance under extreme pressure and high speed conditions, and these series of additives are non-decomposable, cause serious pollution to the environment, and do not meet the requirements of environmental protection. In the 1990s, nanoscience and technology gradually emerged in the scientific research community, and nanotribology also received extensive research and development. More and more reports show that researchers uniformly disperse nanomaterials in base oil, which can effectively improve its anti-friction and wear performance, and also have excellent performance that other traditional lubricants do not have, and a variety of nanocomposite materials. The reasonable combination of , will also show more excellent performance.

In recent years, compared with the extensive research on graphene and graphene oxide by researchers, less research has been done on fluorinated graphene oxide (FGO). Fluorinated-graphene oxide not only maintains the physical and chemical properties of graphene oxide, but at the same time, the introduction of fluoride ions reduces the surface energy of the material, makes it resistant to high temperatures, has stable chemical properties, and has characteristics similar to PTFE. Rare earth elements and their related compounds have attracted extensive attention in tribological research. Compared with metal nanoparticles, rare earth compounds are not easily oxidized and have better tribological properties in marine, aerospace and other environments. Cerium oxide has a high melting point and good heat resistance, which can improve the high temperature resistance and extreme pressure resistance of the matrix. It is often used as an extreme pressure, anti-wear and anti-friction lubricant additive.

At present, there are few reports on the biomimetic preparation method and application of ceria/fluorinated-graphene oxide nano-lubricating oil additive. Chinese patent (CN102716734A) a kind of preparation method of cerium oxide/graphene oxide nanocomposite material uses cerium salt, sodium acetate, urea and graphite oxide as raw materials to prepare cerium oxide/graphene oxide composite material, put graphite oxide and graphite oxide in the container Water, the graphite oxide is formed into a suspension in water by ultrasonic, and then cerium salt, sodium acetate and urea are put into the container, the cerium salt, sodium acetate and urea put in are dissolved in water, and then the container is put into the container with reflux. The reaction is carried out in the reactor of the device. Chinese Patent (CN103611523A) A preparation method of a highly dispersed layered nano-ceria/graphene composite material is prepared by using graphite oxide, inorganic raw materials and dimethylformamide (DMF) solution, using acrylamide as an additive and hydrazine hydrate as a reducing agent The cerium dioxide/graphene composites were prepared by water bath reaction.

The present invention is inspired by the living habits of a marine organism mussel from the field of bionics. Mussels in the ocean often secrete a substance through the byssus, which can show very strong adhesion in alkaline seawater, so that mussels can easily adhere to any surface (especially reefs) or boat). This substance is dopamine. Dopamine is a protein that can spontaneously polymerize in an alkaline environment in the presence of oxygen and can adhere tightly to almost all solid surfaces. More importantly, the polydopamine formed by polymerization contains abundant phenolic hydroxyl and amino groups, which can adsorb a large amount of metal ions through electrostatic force.

To sum up, the prior art has a complicated preparation process, more organic solvents are required, and an oxidant is often used, which pollutes the environment. In addition, the obtained ceria particles have poor dispersibility on fluorinated-graphene oxide and serious particle agglomeration, thus greatly reducing their anti-wear and friction-reducing effects as lubricating oil additives.

In view of the above defects, it is necessary to provide a preparation method which is simple in operation, low in cost, excellent in anti-wear and anti-friction properties, and is economical and environmentally friendly.

SUMMARY OF THE INVENTION

The object of the present invention is to solve the problems of large environmental pollution, complicated preparation method, uneven dispersion of cerium oxide nanoparticles on the fluorinated-graphene oxide sheet, and poor anti-wear and anti-friction effect in the existing lubricating oil additives, and provide a A simple and easy-to-implement method for biomimetic preparation of ceria/fluorinated-graphene oxide nano-lubricating oil additives.

The invention utilizes the polymerization characteristics of dopamine to coat the surface of fluorinated-graphene oxide with an extremely thin polydopamine layer. Polydopamine is rich in phenolic hydroxyl and amino groups. These organic groups can adsorb Ce ^{3 +} in large quantities through electrostatic force, which promotes the formation of cerium dioxide (CeO ₂ ) particles on the surface of fluorinated graphene oxide. Uniform distribution and uniform size of nanoparticles.

The technical scheme adopted in the present invention uses polydopamine-modified fluorinated-graphene oxide as a raw material, and then utilizes a hydrothermal reaction to further prepare a ceria/fluorinated-graphene oxide nano lubricating oil additive. The specific steps are:

(1) Preparation of polydopa/fluorinated-graphene oxide: ultrasonically disperse fluorinated-graphene oxide in tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution to obtain a fluorinated 0.25 mg/ml concentration -graphene oxide dispersion liquid; slowly add dopamine hydrochloride in the above-mentioned fluorinated-graphene oxide dispersion liquid, control the concentration of dopamine hydrochloride to be 0.5～2.0mg/ml, after magnetic stirring, the obtained product is centrifuged with no After washing with water ethanol and distilled water, freeze-drying was performed to obtain polydopamine/fluorinated-graphene oxide.

(2) ultrasonically dispersing polydopamine/fluorinated-graphene oxide in a mixed solution of ethanol and water to obtain a dispersion having a concentration of 1 mg/ml.

(3) Take Ce(NO ₃ ) ₃ ·6H ₂ O and disperse it in a mixed solution of ethanol and water by ultrasonic; under the condition of magnetic stirring, drop the Ce(NO ₃ ) ₃ ·6H ₂ O solution into the polydopamine/fluorine at a uniform speed The mixed solution 1 is obtained in the TiO-graphene oxide dispersion liquid, and after the magnetic stirring is completed, NaOH is added to the mixed solution 1 to obtain the mixed solution 2.

(4) The mixed solution 2 obtained in step (3) is transferred to the hydrothermal reactor, and after 12 hours of reaction at 140-180°C, the reactor is naturally cooled to room temperature.

(5) The product obtained after the cooling of the above-mentioned hydrothermal reaction, after centrifugal separation, is washed with dehydrated alcohol and distilled water and then freeze-dried to obtain ceria/polydopamine/fluorinated-graphene oxide.

In step (1), the fluorinated-graphene oxide is prepared by a hydrothermal method.

In step (1), the pH value of the tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution is between 7 and 10.

In step (1), the magnetic stirring time is 12h.

In steps (2) and (3), in the mixed solution of ethanol and water, the volume ratio of ethanol to water is 1:1.

In step (3), the mass ratio of Ce( _NO3 ) _3.6H2O to polydopamine/fluorinated _- graphene oxide is 0.215-1.550, and the molar ratio of Ce(NO3)3.6H2O to _NaOH is 3. :1.

In step (3), magnetic stirring was performed for 1 hour.

In the invention, dopamine is used to modify the surface of the fluorinated-graphene oxide, so that the ceria nanoparticles are evenly distributed on the fluorinated-graphene oxide; the nano ceria particles are prepared by a hydrothermal method, and the growth process and the growth process of the ceria are effectively controlled. Particle distribution, ceria particle size distribution is 3-5nm. The preparation method of the invention is simple and feasible, the preparation process is safe and pollution-free, the raw materials are environmentally friendly, and no oxidant is required, and the prepared ceria/polydopamine/fluorinated-graphene oxide material has excellent tribological properties as a lubricant additive.

Description of drawings

Fig. 1 is the TEM photograph of fluorinated-graphene oxide prepared in Example 3 of the present invention.

Fig. 2 is the TEM photo of polydopamine/fluorinated-graphene oxide prepared by Example 3 of the present invention, it can be seen that a very thin polydopamine layer is coated on the surface of fluorinated-graphene oxide, so fluorination-oxidation The graphene surface is rougher and more wrinkled.

3 is a TEM photograph of ceria/polydopamine/fluorinated-graphene oxide prepared in Example 3 of the present invention, and it can be seen that ceria nanoparticles are uniformly distributed on the surface of the composite material.

4 is a high _- resolution TEM photo of CeO in ceria/polydopamine/fluorinated-graphene oxide prepared by Example 3 of the present invention. It can be seen that the ceria nanoparticles are in a hexagonal structure with uniform particle size. The particle size distribution is 3-5nm.

Figure 5 is a graph showing the comparison of friction coefficients of pure GO, nano-CeO ₂ crystals, nano-CeO ₂ /FGO composites and ceria/polydopamine/fluorinated-graphene oxide nanocomposites. By comparison, it can be seen that, relative to pure GO, nano _- CeO2 crystals, nano _- CeO2/FGO composites, ceria/polydopamine/fluorinated-graphene oxide nanocomposites have the lowest friction coefficient and the highest friction reduction performance. Excellent.

Figure 6. Comparison of wear scar widths of pure GO, nano-CeO ₂ crystals, nano-CeO ₂ /FGO composites and ceria/polydopamine/fluorinated-graphene oxide nanocomposites. By comparison, it can be seen that, relative to pure GO, nano _- CeO2 crystals, nano _- CeO2/FGO composites, ceria/polydopamine/fluorinated-graphene oxide nanocomposites have the lowest wear scar width, wear resistance The best.

Detailed ways

The following will further illustrate the content of the present invention in conjunction with specific embodiments, but these embodiments do not limit the protection scope of the present invention.

Example 1

Take 75mg of fluorinated-graphene oxide and ultrasonically disperse it in a mixed solution of 37.5ml of ethanol and water (the volume ratio of ethanol to water is 1:1), and ultrasonically to a homogeneous solution; take 0.0775g of Ce(NO ₃ ) ₃ ·6H ₂ O was ultrasonically dispersed in 37.5 ml of a mixed solution of ethanol and water (the volume ratio of ethanol to water was 1:1); under the condition of magnetic stirring, the Ce(NO ₃ ) ₃ ·6H ₂ O solution was dropped into the fluorinated- In the graphene oxide solution, magnetic stirring was carried out for one hour; after stirring, 0.0214g NaOH was taken, and the above-mentioned mixed solution was added; the above-mentioned precursor solution was transferred to 100 milliliters of hydrothermal reactors, and after 12 hours of reaction at 140 ° C, the reaction The kettle is naturally cooled to room temperature; the product obtained after cooling is subjected to centrifugal separation, washed with absolute ethanol and distilled water, and then freeze-dried. The friction coefficient and wear scar width properties of the composite material prepared in Example 1 correspond to the nano-CeO ₂ /FGO composite material in Fig. 5 and Fig. 6 .

Example 2

Ultrasonic dispersion of fluorinated-graphene oxide in 200ml of tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (PH=8.5) to obtain a fluorinated-graphene oxide dispersion liquid with a concentration of 0.25mg/ml; in the above-mentioned fluorine 0.1 g of dopamine hydrochloride was slowly added to the 20%-graphene oxide dispersion, and magnetic stirring was performed for 12 hours; the obtained product was centrifuged and washed with absolute ethanol and distilled water, and then freeze-dried to obtain polydopamine/fluorinated-graphene oxide. . Disperse 75mg of polydopamine/fluorinated-graphene oxide in a mixed solution of 37.5ml of ethanol and water, and ultrasonicate to a homogeneous solution; take 0.0775g of Ce(NO ₃ ) ₃ ·6H ₂ O and disperse it in a mixture of 37.5ml of ethanol and water by ultrasonic. In the mixed solution; under the condition of magnetic stirring, drop the Ce(NO ₃ ) ₃ ·6H ₂ O solution into the fluorinated-graphene oxide solution at a constant speed, and magnetically stir for one hour; after stirring, take 0.0214g NaOH, add the above mixed solution; transfer the above-mentioned precursor solution to a 100 ml hydrothermal reactor, react at 160°C for 12 hours, and then cool the reactor to room temperature naturally; the product obtained after cooling is centrifuged and washed with absolute ethanol and distilled water After freeze drying. Compared with pure GO, nano _- CeO2 crystals, nano _- CeO2/FGO composites, ceria/polydopamine/fluorinated-graphene oxide nanocomposites have the lowest wear scar width, the most excellent wear resistance, and the lowest friction coefficient, the best anti-friction performance.

Example 3

Ultrasonic dispersion of fluorinated-graphene oxide in 200ml of tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (PH=8.5) to obtain a fluorinated-graphene oxide dispersion liquid with a concentration of 0.25mg/ml; in the above-mentioned fluorine 0.4g of dopamine hydrochloride was slowly added to the 20%-graphene oxide dispersion, and magnetic stirring was performed for 12 hours; the obtained product was centrifuged and washed with absolute ethanol and distilled water, and then freeze-dried to obtain polydopamine/fluorinated-graphene oxide. . Get 75mg polydopamine/fluorinated-graphene oxide and be dispersed in the mixed solution of 37.5ml ethanol and water (the volume ratio of ethanol and water is 1:1), ultrasonication to homogeneous solution; Get 0.0775g Ce(NO ₃ ) ₃ · 6H ₂ O was ultrasonically dispersed in a mixed solution of 37.5 ml of ethanol and water; under the condition of magnetic stirring, the Ce(NO ₃ ) ₃ ·6H ₂ O solution was dropped into the fluorinated-graphene oxide solution at a constant speed, and the magnetic stirring was carried out for one hour. After stirring, get 0.0214g NaOH, add above-mentioned mixed solution; The above-mentioned precursor solution is transferred in the hydrothermal reactor of 100 milliliters, after 12 hours of reaction at 140 ℃, the reactor is naturally cooled to room temperature; The product was centrifuged, washed with absolute ethanol and distilled water, and freeze-dried.

The fluorinated-graphene oxide TEM photo prepared in Example 3 is shown in Figure 1; the polydopamine/fluorinated-graphene oxide TEM photo prepared in Example 3 is shown in Figure 2; Figure 3 and Figure 4 are the results of Example 3. TEM images of the as-prepared ceria/polydopamine/fluorinated-graphene oxide and high _- resolution TEM images of CeO2 in the composite. Figure 5 and Figure 6 are the comparison diagrams of the friction coefficient and wear scar width of the ceria/polydopamine/fluorinated-graphene oxide nanocomposite prepared in Example 3 and pure GO, nano-CeO ₂ crystal, and CeO ₂ /FGO composite material .

Example 4

The self-made (prepared by hydrothermal method) fluorinated-graphene oxide is ultrasonically dispersed in 200ml of tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (PH=8.5) to obtain a concentration of 0.25mg/ml of fluorinated- Graphene oxide dispersion liquid; Slowly add 0.2g dopamine hydrochloride in above-mentioned fluorination-graphene oxide dispersion liquid, magnetic stirring for 12 hours; The product obtained is centrifuged with dehydrated alcohol, washed with distilled water and freeze-dried to obtain Polydopamine/Fluorinated-Graphene Oxide. Get 75mg polydopamine/fluorinated-graphene oxide and be dispersed in the mixed solution of 37.5ml ethanol and water (the volume ratio of ethanol and water is 1:1), ultrasonication to homogeneous solution; get 0.1163g Ce(NO ₃ ) ₃ · 6H ₂ O was ultrasonically dispersed in a mixed solution of 37.5 ml of ethanol and water; under the condition of magnetic stirring, the Ce(NO ₃ ) ₃ ·6H ₂ O solution was dropped into the fluorinated-graphene oxide solution at a constant speed, and the magnetic stirring was carried out for one hour After stirring, get 0.0321g NaOH, add above-mentioned mixed solution; The above-mentioned precursor solution is transferred in the hydrothermal reactor of 100 milliliters, after 12 hours of reaction at 160 ℃, the reactor is naturally cooled to room temperature; The obtained after cooling The product was centrifuged, washed with absolute ethanol and distilled water, and freeze-dried. Compared with pure GO, nano _- CeO2 crystals, nano _- CeO2/FGO composites, ceria/polydopamine/fluorinated-graphene oxide nanocomposites have the lowest wear scar width, the most excellent wear resistance, and the lowest friction coefficient, the best anti-friction performance.

Example 5

The self-made (prepared by hydrothermal method) fluorinated-graphene oxide is ultrasonically dispersed in 200ml of tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (PH=8.5) to obtain a concentration of 0.25mg/ml of fluorinated- Graphene oxide dispersion liquid; Slowly add 0.3g of dopamine hydrochloride in above-mentioned fluorination-graphene oxide dispersion liquid, magnetic stirring for 12 hours; The product obtained is centrifuged with dehydrated alcohol, washed with distilled water and then freeze-dried to obtain Polydopamine/Fluorinated-Graphene Oxide. Get 75mg polydopamine/fluorinated-graphene oxide and be dispersed in the mixed solution of 37.5ml ethanol and water (the volume ratio of ethanol and water is 1:1), ultrasonication to homogeneous solution; get 0.0581g Ce(NO ₃ ) ₃ · 6H ₂ O was ultrasonically dispersed in a mixed solution of 37.5 ml of ethanol and water; under the condition of magnetic stirring, the Ce(NO ₃ ) ₃ ·6H ₂ O solution was dropped into the fluorinated-graphene oxide solution at a constant speed, and the magnetic stirring was carried out for one hour After stirring, get 0.0161g NaOH, add above-mentioned mixed solution; The above-mentioned precursor solution is transferred in the hydrothermal reactor of 100 milliliters, after 12 hours of reaction at 180 ℃, the reactor is naturally cooled to room temperature; The product is centrifuged, washed with absolute ethanol and distilled water, and freeze-dried. Compared with pure GO, nano _- CeO2 crystals, nano _- CeO2/FGO composites, ceria/polydopamine/fluorinated-graphene oxide nanocomposites have the lowest wear scar width, the most excellent wear resistance, and the lowest friction coefficient, the best anti-friction performance.

Example 6

The self-made (prepared by hydrothermal method) fluorinated-graphene oxide is ultrasonically dispersed in 200ml of tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (PH=8.5) to obtain a concentration of 0.25mg/ml of fluorinated- Graphene oxide dispersion liquid; Slowly add 0.4g dopamine hydrochloride in above-mentioned fluorination-graphene oxide dispersion liquid, magnetic stirring for 12 hours; The product obtained is centrifuged with dehydrated alcohol, washed with distilled water and freeze-dried to obtain Polydopamine/Fluorinated-Graphene Oxide. Get 75mg of polydopamine/fluorinated-graphene oxide and be dispersed in the mixed solution of 37.5ml of ethanol and water (the volume ratio of ethanol and water is 1:1), ultrasonically to a homogeneous solution; get 0.0775g Ce(NO ₃ ) ₃ · 6H ₂ O was ultrasonically dispersed in a mixed solution of 37.5 ml of ethanol and water; under the condition of magnetic stirring, the Ce(NO ₃ ) ₃ ·6H ₂ O solution was dropped into the fluorinated-graphene oxide solution at a constant speed, and the magnetic stirring was carried out for one hour After stirring, get 0.0214g NaOH, add above-mentioned mixed solution; The above-mentioned precursor solution is transferred in the hydrothermal reactor of 100 milliliters, after 12 hours of reaction at 160 ℃, the reactor is naturally cooled to room temperature; The obtained after cooling The product was centrifuged, washed with absolute ethanol and distilled water, and freeze-dried. Compared with pure GO, nano _- CeO2 crystals, nano _- CeO2/FGO composites, ceria/polydopamine/fluorinated-graphene oxide nanocomposites have the lowest wear scar width, the most excellent wear resistance, and the lowest friction coefficient, the best anti-friction performance.

Example 7

The self-made (prepared by hydrothermal method) fluorinated-graphene oxide is ultrasonically dispersed in 200ml of tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution (PH=8.5) to obtain a concentration of 0.25mg/ml of fluorinated- Graphene oxide dispersion liquid; Slowly add 0.4g dopamine hydrochloride in above-mentioned fluorination-graphene oxide dispersion liquid, magnetic stirring for 12 hours; The product obtained is centrifuged with dehydrated alcohol, washed with distilled water and freeze-dried to obtain Polydopamine/Fluorinated-Graphene Oxide. Get 75mg of polydopamine/fluorinated-graphene oxide and be dispersed in the mixed solution of 37.5ml of ethanol and water (the volume ratio of ethanol and water is 1:1), ultrasonically to a homogeneous solution; get 0.0775g Ce(NO ₃ ) ₃ · 6H ₂ O was ultrasonically dispersed in a mixed solution of 37.5 ml of ethanol and water; under the condition of magnetic stirring, the Ce(NO ₃ ) ₃ ·6H ₂ O solution was dropped into the fluorinated-graphene oxide solution at a constant speed, and the magnetic stirring was carried out for one hour After stirring, get 0.0214g NaOH, add above-mentioned mixed solution; The above-mentioned precursor solution is transferred in the hydrothermal reactor of 100 milliliters, after 12 hours of reaction at 180 ℃, the reactor is naturally cooled to room temperature; the obtained after cooling The product is centrifuged, washed with absolute ethanol and distilled water, and freeze-dried. Compared with pure GO, nano _- CeO2 crystals, nano _- CeO2/FGO composites, ceria/polydopamine/fluorinated-graphene oxide nanocomposites have the lowest wear scar width, the most excellent wear resistance, and the lowest friction coefficient, the best anti-friction performance.

The ceria/polydopamine/fluorinated-graphene oxide nanocomposite lubricating oil additive prepared by the present invention is subjected to a friction and wear experiment, and the specific process and experimental conditions are as follows:

The friction performance analysis of various experimental materials is based on the MS-T3000 tribological experimental machine produced by China Lanzhou Huafeng Technology Co., Ltd. The conditions for the friction and wear test to determine the tribological performance of the sample are: the rotation speed is 300r/min, The load is 10N, and the time lasts for 30min. The friction ball used in the experiment is made of GCr15 bearing steel, the hardness is 62HRC, the diameter of the steel ball is 4mm, and the material of the steel sheet is 45# steel. The radius of rotation is 3mm.

Claims (8)

1. a CeO ₂ /FGO nanometer lubricating oil additive, is characterized in that: described nanometer lubricating oil additive is made up of the fluorinated-graphene oxide modified by nano-ceria, dopamine; fluorinated-graphene oxide is carried out by dopamine. Surface modification; on the dopamine-modified fluorinated-graphene oxide, the nano-ceria particles are uniformly dispersed, the particles are hexagonal, and the particle size is distributed in 3-5nm; the nano-lubricating oil additive has excellent anti-wear and friction-reducing properties performance. 2. the preparation method of a kind of CeO ₂ /FGO nano lubricating oil additive as claimed in claim 1, is characterized in that, concrete steps are: (1) Preparation of polydopamine/fluorinated-graphene oxide: ultrasonically dispersed fluorinated-graphene oxide in tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution to obtain fluorinated-graphene oxide with a concentration of 0.25 mg/ml Graphene oxide dispersion liquid; slowly add dopamine hydrochloride in the above-mentioned fluorination-graphene oxide dispersion liquid, control the concentration of dopamine hydrochloride to be 0.5～2.0mg/ml, after magnetic stirring, the obtained product is centrifuged with anhydrous After washing with ethanol and distilled water, freeze drying to obtain polydopamine/fluorinated-graphene oxide; (2) ultrasonically dispersing polydopamine/fluorinated-graphene oxide in a mixed solution of ethanol and water to obtain a dispersion having a concentration of 1 mg/ml; (3) Take Ce(NO ₃ ) ₃ ·6H ₂ O and disperse it in a mixed solution of ethanol and water by ultrasonic; under the condition of magnetic stirring, drop the Ce(NO ₃ ) ₃ ·6H ₂ O solution into the polydopamine/fluorine at a uniform speed The mixed solution 1 is obtained in the TiO-graphene oxide dispersion liquid, and after the magnetic stirring is completed, NaOH is added to the mixed solution 1 to obtain the mixed solution 2; (4) the mixed solution 2 obtained in step (3) is transferred to the hydrothermal reactor, and after 12 hours of reaction at 140-180 ° C, the reactor is naturally cooled to room temperature; (5) The product obtained after the cooling of the above-mentioned hydrothermal reaction, after centrifugal separation, is washed with dehydrated alcohol and distilled water and then freeze-dried to obtain ceria/polydopamine/fluorinated-graphene oxide. 3. the preparation method of a kind of CeO ₂ /FGO nano lubricating oil additive as claimed in claim 2, is characterized in that, in step (1), described fluorination-graphene oxide is prepared by adopting hydrothermal method; In step (1), the pH value of the tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution is between 7 and 10; in step (1), the time of magnetic stirring is 12h. 4. the preparation method of a kind of CeO ₂ /FGO nano lubricating oil additive as claimed in claim 2, is characterized in that, in step (1), control the concentration of dopamine hydrochloride to be 2.0mg/ml. 5. the preparation method of a kind of CeO ₂ /FGO nano lubricating oil additive as claimed in claim 2, is characterized in that, in step (2) and (3), in the mixed solution of ethanol and water, the volume of ethanol and water The ratio is 1:1. 6. the preparation method of a kind of CeO ₂ /FGO nano lubricating oil additive as claimed in claim 2 is characterized in that, in step (3), Ce(NO ₃ ) ₃ .6H ₂ O and polydopamine/fluorinated- The mass ratio of graphene oxide is 0.215-1.550, and the molar ratio of Ce(NO ₃ ) ₃ ·6H ₂ O to NaOH is 3:1. 7. the preparation method of a kind of CeO ₂ /FGO nano lubricating oil additive as claimed in claim 6, is characterized in that, in step (3), Ce(NO ₃ ) ₃ .6H ₂ O and polydopamine/fluorinated- The mass ratio of graphene oxide is 1.0333:1. 8 . The method for preparing a CeO ₂ /FGO nano-lubricating oil additive according to claim 2 , wherein in step (3), magnetic stirring is performed for 1 hour. 9 .

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