阅读说明：本技术 一种具有自清洁能力的二氧化钛-氧化石墨烯润滑油纳米添加剂的制备方法和应用 (Preparation method and application of titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capacity ) 是由 王惠 王泽娟 马生华 白晋波 于 2021-01-25 设计创作，主要内容包括：一种具有自清洁能力的二氧化钛-氧化石墨烯润滑油纳米添加剂的制备方法和应用,它涉及一种润滑油纳米添加剂的制备方法和应用。本发明的目的是要解决现有润滑油的添加剂不具有自清洁功能和使用不当易发生意外情况的问题。方法：一、制备二氧化钛-氧化石墨烯纳米复合物；二、分散。具有自清洁能力的二氧化钛-氧化石墨烯润滑油纳米添加剂作为润滑油的添加剂使用。具有自清洁能力的二氧化钛-氧化石墨烯润滑油纳米添加剂作为光热转换材料使用。具有自清洁能力的二氧化钛-氧化石墨烯润滑油纳米添加剂作为自清洁材料使用。本发明可获得一种具有自清洁能力的二氧化钛-氧化石墨烯润滑油纳米添加剂。(A preparation method and application of a titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability relate to a preparation method and application of a lubricating oil nano additive. The invention aims to solve the problems that the existing lubricating oil additive does not have a self-cleaning function and is easy to cause accidents when being used improperly. The method comprises the following steps: firstly, preparing a titanium dioxide-graphene oxide nano composite; secondly, dispersing. The titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability is used as an additive of lubricating oil. The titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability is used as a photo-thermal conversion material. The titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability is used as a self-cleaning material. The invention can obtain the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability.)

1. A preparation method of a titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability is characterized in that the preparation method of the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability is completed according to the following steps:

firstly, preparing a titanium dioxide-graphene oxide nano composite:

firstly, adding graphene oxide into absolute ethyl alcohol, then ultrasonically dispersing under the ice bath condition, stirring again, and finally adding deionized water, tetrabutyl titanate, polyvinylpyrrolidone, lauric acid, oleic acid, sorbitan oleate and stearic acid under the magnetic stirring condition to obtain a mixed solution;

secondly, the mixed solution is filled into a zirconia ball tank, and ball milling is carried out in a forward rotation manner, ball milling is stopped, and then ball milling is carried out in a reverse rotation manner;

thirdly, recycling the first step to obtain a reaction product I; alternately cleaning the reaction product I by using absolute ethyl alcohol and deionized water, freeze-drying, and finally grinding to obtain a titanium dioxide-graphene oxide nano compound;

secondly, dispersing:

dispersing a titanium dioxide-graphene oxide nano compound into n-hexane, performing ultrasonic dispersion, adding octadecyltrimethoxysilane, and continuing ultrasonic treatment to obtain a reaction product II;

and secondly, washing the reaction product II by using n-heptane, washing by using absolute ethyl alcohol, and then carrying out vacuum drying to obtain the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability.

2. The method for preparing titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability as claimed in claim 1, wherein the volume ratio of the mass of the graphene oxide to the absolute ethyl alcohol in the first step (r) is (0.06-0.25 g): 60-200 mL); the volume ratio of the mass of the deionized water to the absolute ethyl alcohol in the first step is (0.3 g-0.5 g) to (60 mL-200 mL); the volume ratio of the mass of the tetrabutyl titanate to the absolute ethyl alcohol in the first step is (1.3-4 g): 60-200 mL; the volume ratio of the mass of the polyvinylpyrrolidone in the first step to the volume of the absolute ethyl alcohol is (4 g-6 g): 60 mL-200 mL; the volume ratio of the mass of the lauric acid to the absolute ethyl alcohol in the first step is (0.1-0.5 g): 60-200 mL; the volume ratio of the mass of the oleic acid to the absolute ethyl alcohol in the first step is (0.18-0.54 g): 60-200 mL; the volume ratio of the mass of the sorbitan oleate to the volume of the absolute ethyl alcohol in the first step is (0.06-0.18 g) to (60-200 mL); the volume ratio of the mass of the stearic acid to the absolute ethyl alcohol in the first step is (2 g-6 g) to (60 mL-200 mL).

3. The preparation method of the titanium dioxide-graphene oxide lubricating oil nano additive with the self-cleaning capability according to claim 1, wherein the rotating speed of the forward rotation ball milling in the first step is 400 r/min-500 r/min; the rotating speed of the reverse ball milling in the first step is 400 r/min-500 r/min; the temperature of the freeze drying in the step one is-40 ℃ to-55 ℃, and the time of the freeze drying is 20h to 24 h.

4. The method for preparing titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability as claimed in claim 1, wherein the ratio of the mass of the titanium dioxide-graphene oxide nano composite to the volume of n-hexane in the second (r) step is (0.08 g-0.25 g): 30 mL-100 mL); the volume ratio of the octadecyl trimethoxy silane to the normal hexane in the second step is (0.1-2) to (30-100); the temperature of the vacuum drying in the second step is 60-70 ℃, and the time of the vacuum drying is 4-24 h.

5. The method for preparing the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning capability as claimed in claim 1, 2, 3 or 4, characterized in that the method for preparing the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning capability is completed by the following steps:

firstly, preparing a titanium dioxide-graphene oxide nano composite:

firstly, adding graphene oxide into absolute ethyl alcohol, then ultrasonically dispersing for 0.5-1 h under the ice bath condition, then stirring for 5-15 min under the stirring speed of 500-800 r/min, and finally adding deionized water, tetrabutyl titanate, polyvinylpyrrolidone, lauric acid, oleic acid, sorbitan oleate and stearic acid under the magnetic stirring condition of 400-800 r/min to obtain a mixed solution;

secondly, the mixed solution is put into a zirconia ball tank, firstly ball milling is carried out for 0.5 to 0.6h in a forward rotation manner, ball milling is stopped for 5 to 15min, and then ball milling is carried out for 0.5 to 0.6h in a reverse rotation manner;

thirdly, circulating the first step for 8 to 10 times to obtain a reaction product I; alternately cleaning the reaction product I by using absolute ethyl alcohol and deionized water, freeze-drying, and finally grinding to obtain a titanium dioxide-graphene oxide nano compound;

secondly, dispersing:

dispersing a titanium dioxide-graphene oxide nano compound into n-hexane, performing ultrasonic dispersion for 10-30 min, adding octadecyltrimethoxysilane, and continuing ultrasonic treatment for 0.2-1 h to obtain a reaction product II;

and secondly, washing the reaction product II for 1 to 2 times by using n-heptane, washing the reaction product II for 2 to 3 times by using absolute ethyl alcohol, and then carrying out vacuum drying to obtain the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability.

6. The use of the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability prepared by the preparation method according to claim 1, characterized in that the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability is used as an additive of lubricating oil.

7. The use of the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability according to claim 6, characterized in that the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability is used as an additive of lubricating oil by the steps of: adding the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability into lubricating oil, and performing ultrasonic dispersion to obtain lubricating oil dispersed with the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability;

the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability accounts for 0.1-0.2% of the lubricating oil by mass;

the power of the ultrasonic dispersion is 500W-1000W, and the time of the ultrasonic dispersion is 0.2 h-1 h.

8. The use of the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability according to claim 6, characterized in that the lubricating oil is 150N base oil.

9. The use of the self-cleaning titanium dioxide-graphene oxide lubricating oil nano-additive prepared by the preparation method according to claim 1, wherein the self-cleaning titanium dioxide-graphene oxide lubricating oil nano-additive is used as a photothermal conversion material.

10. The use of the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability prepared by the preparation method according to claim 1, characterized in that the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability is used as a self-cleaning material.

Technical Field

The invention relates to a preparation method and application of a lubricating oil nano additive.

Background

In modern society life, the application and consumption of lubricating oil in various industries of society are very large, so the performance of the lubricating oil is the key of research of people, and in order to improve the friction lubricating performance of the lubricating oil and better maintain various large-scale machine equipment and prolong the service life, researchers add various additives into base oil to improve the practical application of the lubricating oil and reduce the friction and abrasion among various devices. The lubricating oil mainly comprises base oil and various additives, the performance of the general base oil in the aspect of lubricating friction is lower, the additives in the lubricating oil mainly play a role in friction reduction and wear resistance in device equipment, and the action mechanisms mainly comprise three types: (1) entering a friction pair contact area; (2) forming a friction film and a transfer film; (3) adsorbing peaks and valleys on the surface of the friction pair.

In recent years, researches on various two-dimensional materials and composite materials thereof in lubricating friction are also active. The graphene oxide and the titanium dioxide are both two-dimensional materials, the graphene oxide belongs to an ultrathin lamellar structure, the two materials still have the lamellar structure after being compounded, and the lamellar structure can well enter the surface of the friction pair and form a friction film on the surface of the friction pair, so that a physical protective film can be well formed, and the two sliding surfaces are prevented from being directly contacted, thereby reducing friction and abrasion, and the titanium dioxide also has the wear resistance, the friction reducing performance, the self-repairing performance and the excellent mechanical property. The dispersion stability of the additive material in the base oil largely determines the strength of the lubricating performance of the lubricating oil, and therefore, the nano additive material with poor dispersibility in the base oil is effectively subjected to surface modification to form a colloid capable of forming stable dispersion in the base oil. The surface modification method, namely physical modification and chemical modification, can eliminate partial defects on the surface of the nano particles, so that the nano particles can be uniformly dispersed in the base oil, and the friction and lubrication performance is correspondingly improved.

Most of the lubricating oil has great promotion effect on the development of human production and life, but improper use and various accidents can cause the lubricating oil to cause certain harm to human beings, such as the leakage of the lubricating oil in various instruments and the leakage of crude oil on the sea. If these leaked lubricating oils could be self-cleaned, human input would be reduced significantly. On the sea, the most direct energy source capable of being utilized is solar energy, so that a titanium dioxide-graphene oxide novel lubricating oil nano additive composite material with self-cleaning capability is designed based on the above conditions.

Disclosure of Invention

The invention aims to solve the problems that the existing additive of the lubricating oil has no self-cleaning function and is easy to cause accidents due to improper use, and provides a preparation method and application of a titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability.

A preparation method of a titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability is completed according to the following steps:

firstly, preparing a titanium dioxide-graphene oxide nano composite:

firstly, adding graphene oxide into absolute ethyl alcohol, then ultrasonically dispersing under the ice bath condition, stirring again, and finally adding deionized water, tetrabutyl titanate, polyvinylpyrrolidone, lauric acid, oleic acid, sorbitan oleate and stearic acid under the magnetic stirring condition to obtain a mixed solution;

secondly, the mixed solution is filled into a zirconia ball tank, and ball milling is carried out in a forward rotation manner, ball milling is stopped, and then ball milling is carried out in a reverse rotation manner;

thirdly, recycling the first step to obtain a reaction product I; alternately cleaning the reaction product I by using absolute ethyl alcohol and deionized water, freeze-drying, and finally grinding to obtain a titanium dioxide-graphene oxide nano compound;

secondly, dispersing:

dispersing a titanium dioxide-graphene oxide nano compound into n-hexane, performing ultrasonic dispersion, adding octadecyltrimethoxysilane, and continuing ultrasonic treatment to obtain a reaction product II;

and secondly, washing the reaction product II by using n-heptane, washing by using absolute ethyl alcohol, and then carrying out vacuum drying to obtain the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability.

The invention has the advantages that:

firstly, the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability is prepared by a mechanical high-energy ball milling method, the additive not only can play a role in anti-wear and anti-friction lubricating performance in lubricating oil, but also has self-degradation capability under a photo-thermal condition, and has certain reality;

secondly, the friction coefficient of the base oil added with the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability prepared by the invention is about 0.042, and is obviously reduced compared with the friction coefficient of 0.09 of 150N of the base oil.

The invention can obtain the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability.

Drawings

FIG. 1 is a graph showing the relationship between friction coefficient and friction time, in which FIG. 1 is a graph showing the relationship between friction coefficient and friction time of a steel ball in base oil 150N in example II, and FIG. 2 is a graph showing the relationship between friction coefficient and friction time of a steel ball in base oil 150N to which a titanium dioxide-graphene oxide lubricating oil nano-additive having self-cleaning ability prepared in example I is added in example II;

FIG. 2 is a diagram of the wear marks of three steel balls in the base oil 150N after the end of the second embodiment;

FIG. 3 is a diagram of the wear marks of three steel balls in the base oil 150N to which the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability prepared in the first embodiment is added after the second embodiment is finished;

FIG. 4 shows the evaporation rate in one sunlight, wherein 1 is pure water, 2 is a graphene oxide solution, and 3 is a titanium dioxide-graphene oxide lubricating oil nano-additive solution with self-cleaning capability prepared in the first embodiment;

FIG. 5 shows the top maximum temperature and the bottom maximum temperature of a solar photothermal device in a titanium dioxide-graphene oxide lubricating oil nano-additive solution with self-cleaning capability prepared in the first embodiment, wherein 1 is the top maximum temperature, and 2 is the bottom maximum temperature;

fig. 6 is a graph showing the change of surface temperature with time in the titania-graphene oxide lubricating oil nano-additive solution with self-cleaning ability prepared in the first embodiment of the solar photothermal device.

Detailed Description

Modifications and substitutions to methods, procedures, or conditions of the invention may be made without departing from the spirit of the invention.

The first embodiment is as follows: the embodiment is a preparation method of a titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability, which is completed by the following steps:

firstly, preparing a titanium dioxide-graphene oxide nano composite:

firstly, adding graphene oxide into absolute ethyl alcohol, then ultrasonically dispersing under the ice bath condition, stirring again, and finally adding deionized water, tetrabutyl titanate, polyvinylpyrrolidone, lauric acid, oleic acid, sorbitan oleate and stearic acid under the magnetic stirring condition to obtain a mixed solution;

secondly, the mixed solution is filled into a zirconia ball tank, and ball milling is carried out in a forward rotation manner, ball milling is stopped, and then ball milling is carried out in a reverse rotation manner;

thirdly, recycling the first step to obtain a reaction product I; alternately cleaning the reaction product I by using absolute ethyl alcohol and deionized water, freeze-drying, and finally grinding to obtain a titanium dioxide-graphene oxide nano compound;

secondly, dispersing:

dispersing a titanium dioxide-graphene oxide nano compound into n-hexane, performing ultrasonic dispersion, adding octadecyltrimethoxysilane, and continuing ultrasonic treatment to obtain a reaction product II;

and secondly, washing the reaction product II by using n-heptane, washing by using absolute ethyl alcohol, and then carrying out vacuum drying to obtain the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability.

The advantages of this embodiment:

the titanium dioxide-graphene oxide lubricating oil nano additive with the self-cleaning capability is prepared by a mechanical high-energy ball milling method, can play a role in wear-resistant and friction-reducing lubricating properties in lubricating oil, has the self-degradation capability under a photo-thermal condition, and has certain actual performance;

secondly, the friction coefficient of the base oil added with the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability prepared by the embodiment is about 0.042, and is obviously reduced compared with the friction coefficient of 0.09 of 150N of the base oil.

The embodiment can obtain the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability.

The second embodiment is as follows: the present embodiment differs from the present embodiment in that: the volume ratio of the mass of the graphene oxide to the absolute ethyl alcohol in the first step is (0.06-0.25 g): 60-200 mL; the volume ratio of the mass of the deionized water to the absolute ethyl alcohol in the first step is (0.3 g-0.5 g) to (60 mL-200 mL); the volume ratio of the mass of the tetrabutyl titanate to the absolute ethyl alcohol in the first step is (1.3-4 g): 60-200 mL; the volume ratio of the mass of the polyvinylpyrrolidone in the first step to the volume of the absolute ethyl alcohol is (4 g-6 g): 60 mL-200 mL; the volume ratio of the mass of the lauric acid to the absolute ethyl alcohol in the first step is (0.1-0.5 g): 60-200 mL; the volume ratio of the mass of the oleic acid to the absolute ethyl alcohol in the first step is (0.18-0.54 g): 60-200 mL; the volume ratio of the mass of the sorbitan oleate to the volume of the absolute ethyl alcohol in the first step is (0.06-0.18 g) to (60-200 mL); the volume ratio of the mass of the stearic acid to the absolute ethyl alcohol in the first step is (2 g-6 g) to (60 mL-200 mL). Other steps are the same as in the first embodiment.

The third concrete implementation mode: the present embodiment differs from the first or second embodiment in that: the rotating speed of the corotation ball milling in the first step is 400 r/min-500 r/min; the rotating speed of the reverse ball milling in the first step is 400 r/min-500 r/min; the temperature of the freeze drying in the step one is-40 ℃ to-55 ℃, and the time of the freeze drying is 20h to 24 h. The other steps are the same as in the first or second embodiment.

The fourth concrete implementation mode: the difference between this embodiment and one of the first to third embodiments is as follows: the mass ratio of the titanium dioxide-graphene oxide nano composite to the volume ratio of the n-hexane in the second step is (0.08-0.25 g): 30-100 mL; the volume ratio of the octadecyl trimethoxy silane to the normal hexane in the second step is (0.1-2) to (30-100); the temperature of the vacuum drying in the second step is 60-70 ℃, and the time of the vacuum drying is 4-24 h. The other steps are the same as those in the first to third embodiments.

The fifth concrete implementation mode: the difference between this embodiment and one of the first to fourth embodiments is: the preparation method of the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability is completed according to the following steps:

firstly, preparing a titanium dioxide-graphene oxide nano composite:

firstly, adding graphene oxide into absolute ethyl alcohol, then ultrasonically dispersing for 0.5-1 h under the ice bath condition, then stirring for 5-15 min under the stirring speed of 500-800 r/min, and finally adding deionized water, tetrabutyl titanate, polyvinylpyrrolidone, lauric acid, oleic acid, sorbitan oleate and stearic acid under the magnetic stirring condition of 400-800 r/min to obtain a mixed solution;

secondly, the mixed solution is put into a zirconia ball tank, firstly ball milling is carried out for 0.5 to 0.6h in a forward rotation manner, ball milling is stopped for 5 to 15min, and then ball milling is carried out for 0.5 to 0.6h in a reverse rotation manner;

thirdly, circulating the first step for 8 to 10 times to obtain a reaction product I; alternately cleaning the reaction product I by using absolute ethyl alcohol and deionized water, freeze-drying, and finally grinding to obtain a titanium dioxide-graphene oxide nano compound;

secondly, dispersing:

dispersing a titanium dioxide-graphene oxide nano compound into n-hexane, performing ultrasonic dispersion for 10-30 min, adding octadecyltrimethoxysilane, and continuing ultrasonic treatment for 0.2-1 h to obtain a reaction product II;

and secondly, washing the reaction product II for 1 to 2 times by using n-heptane, washing the reaction product II for 2 to 3 times by using absolute ethyl alcohol, and then carrying out vacuum drying to obtain the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability. The other steps are the same as those in the first to fourth embodiments.

The sixth specific implementation mode: the embodiment is that the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability is used as an additive of lubricating oil.

The seventh embodiment: the present embodiment differs from the sixth embodiment in that: the use of the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability as the additive of the lubricating oil comprises the following steps: adding the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability into lubricating oil, and performing ultrasonic dispersion to obtain lubricating oil dispersed with the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability;

the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability accounts for 0.1-0.2% of the lubricating oil by mass;

the power of the ultrasonic dispersion is 500W-1000W, and the time of the ultrasonic dispersion is 0.2 h-1 h. The other steps are the same as in the sixth embodiment.

The specific implementation mode is eight: the difference between this embodiment and one of the first to seventh embodiments is: the lubricating oil is 150N base oil. The other steps are the same as those in the first to seventh embodiments.

The specific implementation method nine: the present embodiment is: the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability is used as a photo-thermal conversion material.

The detailed implementation mode is ten: the present embodiment is: the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability is used as a self-cleaning material.

The following examples were used to demonstrate the beneficial effects of the present invention:

the first embodiment is as follows: a preparation method of a titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability is completed according to the following steps:

firstly, preparing a titanium dioxide-graphene oxide nano composite:

firstly, adding graphene oxide into absolute ethyl alcohol, performing ultrasonic dispersion for 1h under the ice bath condition, stirring for 10min under the stirring speed of 500r/min, and finally adding deionized water, tetrabutyl titanate, polyvinylpyrrolidone, lauric acid, oleic acid, sorbitan oleate and stearic acid under the magnetic stirring condition of 800r/min to obtain a mixed solution;

the volume ratio of the mass of the graphene oxide to the absolute ethyl alcohol in the first step is 0.12g:100 mL;

the volume ratio of the mass of the deionized water to the absolute ethyl alcohol in the first step is 0.4g:100 mL;

the volume ratio of the mass of the tetrabutyl titanate to the absolute ethyl alcohol in the first step is 2g:100 mL;

the volume ratio of the mass of the polyvinylpyrrolidone in the first step to the absolute ethyl alcohol is 5g:100 mL;

the volume ratio of the mass of the lauric acid to the absolute ethyl alcohol in the first step is 0.25g to 100 mL;

the volume ratio of the mass of the oleic acid to the absolute ethyl alcohol in the first step is 0.27g:100 mL;

the volume ratio of the mass of the sorbitan oleate to the volume of the absolute ethyl alcohol in the first step is 0.09g to 100 mL;

the volume ratio of the mass of the stearic acid to the absolute ethyl alcohol in the first step is 3g:100 mL;

secondly, the mixed solution is filled into a zirconia ball tank, firstly, the ball milling is carried out for 0.5h in a forward rotation mode, the ball milling is stopped for 10min, and then the ball milling is carried out for 0.5h in a reverse rotation mode;

the rotating speed of the corotation ball milling in the first step is 400 r/min;

the rotating speed of the reverse ball milling in the first step is 500 r/min;

thirdly, circulating the first step and the second step for 8 times to obtain a reaction product I; alternately cleaning the reaction product I by using absolute ethyl alcohol and deionized water, freeze-drying, and finally grinding to obtain a titanium dioxide-graphene oxide nano compound;

the temperature of the freeze drying in the step one is-45 ℃, and the time of the freeze drying is 20 hours;

secondly, dispersing:

dispersing a titanium dioxide-graphene oxide nano compound into n-hexane, performing ultrasonic dispersion for 20min, adding octadecyl trimethoxy silane, and continuing performing ultrasonic treatment for 0.5h to obtain a reaction product II;

the volume ratio of the mass of the titanium dioxide-graphene oxide nano compound to the normal hexane in the second step is 0.2g:60 mL;

the volume ratio of the octadecyl trimethoxy silane to the normal hexane in the second step is 0.15: 70;

washing the reaction product II with n-heptane for 2 times, washing with absolute ethyl alcohol for 2 times, and performing vacuum drying to obtain the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability;

and the temperature of the vacuum drying in the second step is 65 ℃, and the time of the vacuum drying is 10 hours.

Example two: example one application test of the prepared titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability:

MRS-10A four-ball friction tester (purchased from Jincheng technologies, Inc. of Jinan) is adopted to research the lubricating properties of 150N base oil and 150N base oil added with the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability prepared in the first embodiment; all friction tests were carried out at standard temperature, load 392N, speed 1200r/min for 1 hour; the steel ball used in the experiment is GCr15 bearing steel with the diameter of 12.7mm, and the hardness is 61-65 HRC. All test devices were ultrasonically cleaned prior to installation, then washed with absolute ethanol and finally dried in an oven; the data of the friction coefficient is directly and automatically recorded by a tribology instrument; the abrasion performance of the steel ball is judged according to the friction coefficient and the abrasion scar of the steel ball after the friction test. The wear scar values were obtained from photographs taken with an KEYENCE VK-X200 microscope to an accuracy of 0.01 mm. At least three tests with standard deviations of less than 5% were carried out on each material under the same experimental conditions. The wear scars on the ball surface were observed with a digital microscope (RH-2000, Hirox, China Co., Ltd.);

the preparation method of the base oil 150N added with the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability prepared in the first embodiment comprises the following steps: adding the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability into lubricating oil, and then performing ultrasonic dispersion for 0.5h under the ultrasonic dispersion power of 800W to obtain lubricating oil dispersed with the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability; the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability accounts for 0.1 percent of the base oil by mass percent;

FIG. 1 is a graph showing the relationship between friction coefficient and friction time, in which FIG. 1 is a graph showing the relationship between friction coefficient and friction time of a steel ball in base oil 150N in example II, and FIG. 2 is a graph showing the relationship between friction coefficient and friction time of a steel ball in base oil 150N to which a titanium dioxide-graphene oxide lubricating oil nano-additive having self-cleaning ability prepared in example I is added in example II;

as can be seen from fig. 1, the friction coefficient of the base oil to which the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability prepared in the first embodiment is added is about 0.042, which is obviously lower than the friction coefficient of the base oil of 0.09N, so that the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability prepared in the first embodiment has a certain antifriction property.

Table 1 shows the wear scar diameters of the steel balls after the second example is completed, wherein the titanium dioxide-graphene oxide lubricating oil nano-additives with self-cleaning ability are added to the first group, the second group and the third group, and the mass fraction of the titanium dioxide-graphene oxide lubricating oil nano-additives with self-cleaning ability in the base oil 150N is 0.1%.

As can be seen from Table 1, the average wear-leveling diameters of the three steel balls added with the base oil 150N are 785.3 μm, and the average wear-leveling diameters of the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability prepared in the first embodiment are 403.8 μm, 412.2 μm and 419.1 μm, which are reduced by 360 μm to 390 μm compared with the wear-leveling diameter of the base oil 150N, so that the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability prepared in the first embodiment has very significant anti-wear performance.

FIG. 2 is a diagram of the wear marks of three steel balls in the base oil 150N after the end of the second embodiment;

FIG. 3 is a diagram of the wear marks of three steel balls in the base oil 150N to which the titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability prepared in the first embodiment is added after the second embodiment is finished;

from the wear patterns 2-3, it can be seen that the wear on the wear pattern of the 150N base oil is relatively serious, and the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability prepared in the first embodiment is relatively weak in wear, so that the additive plays a role in friction reduction and wear resistance.

Example three: example one self-cleaning test of the prepared titanium dioxide-graphene oxide lubricating oil nano-additive with self-cleaning ability:

(1) photothermal conversion capability of the material:

under 1 standard sunlight, the evaporation rate of pure water is measured by a photo-thermal system to be 0.37kg m^-2h^-1The evaporation rate of the graphene oxide solution is 1.16kg m^-2h^-1Wherein the mass fraction of the graphene oxide solution is 0.2%;

example one prepared titanium dioxide-graphene oxide lubricating oil nano-additive solution with self-cleaning ability has an evaporation rate of 1.35kg m^-2h^-1Wherein the mass fraction of the titanium dioxide-graphene oxide lubricating oil nano additive solution with self-cleaning capability prepared in the first embodiment is 1.25 percent; the evaporation rates of the three liquids under 1 standard sunlight are shown in fig. 4;

FIG. 4 shows the evaporation rate in one sunlight, wherein 1 is pure water, 2 is a graphene oxide solution, and 3 is a titanium dioxide-graphene oxide lubricating oil nano-additive solution with self-cleaning capability prepared in the first embodiment;

FIG. 5 shows the top maximum temperature and the bottom maximum temperature of a solar photothermal device in a titanium dioxide-graphene oxide lubricating oil nano-additive solution with self-cleaning capability prepared in the first embodiment, wherein 1 is the top maximum temperature, and 2 is the bottom maximum temperature;

as can be seen from fig. 5, the top maximum temperature of the solar photothermal device: 44.6 ℃, bottom maximum temperature: 23.2 ℃, indicating that the photothermal structure exhibits strong advantages in photothermal management, since the upper surface minimum temperature is 16.4 ℃, raised by 28.2 ℃; the lowest temperature of the lower surface is 18.0 ℃, and is only increased by 5.2 ℃ compared with the initial temperature, so that the solar photothermal device has certain advantages in the aspect of thermal management, the obtained material has certain photothermal capacity, and the photothermal degradation capacity of the oil-polluted water is tested by simulating oil in the follow-up process.

Fig. 6 is a graph showing the change of surface temperature with time in the titania-graphene oxide lubricating oil nano-additive solution with self-cleaning ability prepared in the first embodiment of the solar photothermal device.

(2) Photothermal conversion capability of the material:

0.01g to 0.05g of the titanium dioxide-graphene oxide lubricating oil nano additive with self-cleaning capability prepared in the first embodiment is added into 150N of lubricating oil base oil, then 100mL to 200mL of deionized water is added, the mixture is uniformly stirred, and an experiment is carried out under a photo-thermal system. The control experiment was run under the same conditions with the same volume of water only for subsequent comparison.

Through multiple experiments, the oil content in water is obviously reduced by observing, the mass of the solution before and after the experiment is weighed by a balance, and compared with a contrast experiment, the mass of the solution of the lubricating oil added with the nano additive is reduced by 5-20 g compared with the mass of pure water, so that the material has self-cleaning capability.