阅读说明：本技术 一种石墨烯机油抗磨剂及其制备方法 (Graphene engine oil antiwear agent and preparation method thereof ) 是由 冯岩 夏明� 于 2019-11-25 设计创作，主要内容包括：本发明公开了一种石墨烯机油抗磨剂及其制备方法,包括以下步骤：将氧化石墨烯溶解在甲苯中,超声分散形成氧化石墨烯分散液；将叠氮化钠和三聚氰酰氯溶解在甲苯中,形成反应液；将反应液加入到氧化石墨烯分散液中,进行二次超声分散形成混合液；将混合液加入到反应釜中进行溶剂热反应,制备氮化碳改性的石墨烯复合材料；离心、洗涤,即得所述石墨烯机油抗磨剂。本发明以氧化石墨烯为主要原料,通过溶剂热方法在氧化石墨烯层间原位聚合合成氮化碳纳米管,通过氮化碳纳米管改性的石墨烯具有更好的抗磨性能和分散性。(The invention discloses a graphene engine oil antiwear agent and a preparation method thereof, and the preparation method comprises the following steps: dissolving graphene oxide in toluene, and performing ultrasonic dispersion to form a graphene oxide dispersion liquid; dissolving sodium azide and cyanuric chloride in toluene to form a reaction solution; adding the reaction solution into the graphene oxide dispersion solution, and performing secondary ultrasonic dispersion to form a mixed solution; adding the mixed solution into a reaction kettle to perform a solvothermal reaction to prepare a carbon nitride modified graphene composite material; centrifuging and washing to obtain the graphene engine oil antiwear agent. The graphene oxide is used as a main raw material, the carbon nitride nanotube is synthesized by in-situ polymerization between the graphene oxide layers through a solvothermal method, and the graphene modified by the carbon nitride nanotube has better wear resistance and dispersibility.)

1. A preparation method of a graphene engine oil antiwear agent is characterized by comprising the following steps:

dissolving graphene oxide in toluene, and performing ultrasonic dispersion to form a graphene oxide dispersion liquid;

dissolving sodium azide and cyanuric chloride in toluene to form a reaction solution;

adding the reaction solution into the graphene oxide dispersion solution, and performing secondary ultrasonic dispersion to form a mixed solution;

adding the mixed solution into a reaction kettle to perform a solvothermal reaction to prepare a carbon nitride modified graphene composite material;

centrifuging and washing to obtain the graphene engine oil antiwear agent.

2. The preparation method of the graphene engine oil antiwear agent according to claim 1, wherein the concentration of the graphene oxide dispersion liquid is 0.10-0.16 mg/mL.

3. The preparation method of the graphene engine oil antiwear agent according to claim 2, wherein the concentration of sodium azide in the reaction liquid is 40-50 mg/mL, and the concentration of cyanuric chloride is 40-45 mg/mL.

4. The preparation method of the graphene engine oil antiwear agent according to claim 1, wherein the reaction conditions of the solvothermal reaction are as follows: the reaction temperature is 200-230 ℃, and the reaction time is 12-18 h.

5. The preparation method of the graphene engine oil antiwear agent according to claim 1, wherein the ultrasonic dispersion conditions are as follows: the ultrasonic power is 150-200 w, and the ultrasonic time is 30-60 min.

6. The preparation method of the graphene engine oil antiwear agent according to claim 1, wherein the secondary ultrasonic dispersion conditions are as follows: the ultrasonic power is 150-200 w, and the ultrasonic time is 5-10 min.

7. The graphene engine oil antiwear agent prepared by the preparation method of the graphene engine oil antiwear agent according to any one of claims 1 to 6, wherein the graphene engine oil antiwear agent is prepared by modifying multilayer graphene oxide through carbon nitride nanotubes.

8. The graphene engine oil antiwear agent of claim 7, wherein the diameter of the carbon nitride nanotube is 40-80 nm, and the wall thickness is 20-40 nm.

9. The graphene engine oil antiwear agent according to claim 7, wherein the multilayer graphene oxide is prepared by a hummers method, and the number of layers is 10-50.

Technical Field

The invention relates to the technical field of lubricating oil,

particularly, the invention relates to a graphene engine oil antiwear agent and a preparation method thereof.

Background

The antiwear agent is an engine oil (lubricating oil) additive, can reduce the abrasion of an engine, increase the power of the engine, prolong the service life of the engine oil, save fuel and improve power. Commonly used antiwear agents include sulfur type antiwear agents, phosphorus type antiwear agents, sulfur and phosphorus type antiwear agents, halogen type antiwear agents, organic metal type antiwear agents, and boron type antiwear agents.

Graphene is a novel antiwear agent researched in recent years, is a two-dimensional crystal stripped from a graphite material and composed of carbon atoms, and is the thinnest and highest-strength material in the nature at present. Graphene is used as an anti-wear agent, the graphene nano material can play a role of a pressure-bearing framework in lubricating oil by utilizing the specific physical and chemical properties of the graphene nano material, and the graphene can partially permeate into the surface of a friction metal to change the surface structure of the metal, so that the hardness of the metal is changed, and the anti-wear property of the metal is further improved; and the graphene which does not permeate into the metal surface is filled in the concave-convex part of the friction surface, so that the bearing area of the friction surface is increased, the friction coefficient can be reduced, and the bearing capacity of the metal surface is improved. However, graphene is easy to agglomerate and precipitate and difficult to disperse uniformly in the using process.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a graphene engine oil antiwear agent and a preparation method thereof.

In order to solve the problems, the invention adopts the following technical scheme:

a preparation method of a graphene engine oil antiwear agent comprises the following steps:

dissolving graphene oxide in toluene, and performing ultrasonic dispersion to form a graphene oxide dispersion liquid;

dissolving sodium azide and cyanuric chloride in toluene to form a reaction solution;

adding the reaction solution into the graphene oxide dispersion solution, and performing secondary ultrasonic dispersion to form a mixed solution;

adding the mixed solution into a reaction kettle to perform a solvothermal reaction to prepare a carbon nitride modified graphene composite material;

centrifuging and washing to obtain the graphene engine oil antiwear agent.

Preferably, the concentration of the graphene oxide dispersion liquid is 0.10-0.16 mg/mL.

Preferably, the concentration of the sodium azide in the reaction liquid is 40-50 mg/mL, and the concentration of the cyanuric chloride is 40-45 mg/mL.

Preferably, the reaction conditions of the solvothermal reaction are: the reaction temperature is 200-230 ℃, and the reaction time is 12-18 h.

Preferably, the ultrasonic dispersion conditions are: the ultrasonic power is 150-200 w, and the ultrasonic time is 30-60 min.

Preferably, the secondary ultrasonic dispersion conditions are as follows: the ultrasonic power is 150-200 w, and the ultrasonic time is 5-10 min.

The invention also provides the graphene engine oil antiwear agent prepared by the preparation method of the graphene engine oil antiwear agent, and the graphene engine oil antiwear agent is prepared by modifying multilayer graphene oxide through carbon nitride nanotubes.

Preferably, the diameter of the carbon nitride nanotube is 40-80 nm, and the wall thickness is 20-40 nm.

Preferably, the multilayer graphene oxide is prepared by a hummers method, and the number of layers is 10-50.

Compared with the prior art, the invention has the technical effects that:

according to the invention, graphene oxide is used as a main raw material, and a carbon nitride nanotube is synthesized by in-situ polymerization between graphene oxide layers through a solvothermal method, so that on one hand, the carbon nitride nanotube can act in synergy with graphene to play a role in wear resistance and enhance the wear resistance of a graphene material; on the other hand, the carbon nitride in the shape of a nano tube plays a role in supporting layers between graphene layers, prevents the graphene layers and the layers from stacking and agglomerating to cause precipitation, and improves the dispersibility of the graphene material as an antiwear agent.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The embodiment of the invention provides a graphene engine oil antiwear agent and a preparation method thereof, wherein the preparation method comprises the following steps:

(1) dissolving graphene oxide in toluene, and performing ultrasonic dispersion to form a graphene oxide dispersion liquid;

(2) dissolving sodium azide and cyanuric chloride in toluene to form a reaction solution;

(3) adding the reaction solution into the graphene oxide dispersion solution, and performing secondary ultrasonic dispersion to form a mixed solution;

(4) adding the mixed solution into a reaction kettle to perform a solvothermal reaction to prepare a carbon nitride modified graphene composite material;

(5) centrifuging and washing to obtain the graphene engine oil antiwear agent.

The multilayer graphene oxide in the step (1) is prepared by a hummers method, and the number of layers is 10-50. The friction coefficient of the 10-50 layers of graphene is smaller than that of single-layer graphene, and the cost is lower than that of a single layer; the graphene with more than 50 layers is easy to stack and agglomerate between layers, and the stability is poor. The graphene oxide has better solubility in toluene, the graphene oxide can be promoted to be dissolved in the toluene and generate interlayer peeling through ultrasonic dispersion, and the ultrasonic dispersion conditions are as follows: the ultrasonic power is 150-200 w, and the ultrasonic time is 30-60 min. Preferably, the concentration of the prepared graphene oxide dispersion liquid is 0.10-0.16 mg/mL.

The amount of the sodium azide and the cyanuric chloride in the step (2) is correspondingly adjusted according to the amount of the graphene oxide in the step (1), and preferably, the concentration of the sodium azide in the reaction solution is 40-50 mg/mL, and the concentration of the cyanuric chloride is 40-45 mg/mL.

In the step (3), the time for the secondary ultrasonic dispersion is not suitable to be too long, and the ultrasonic time is too long, which may damage the lamellar structure of the graphene oxide and cause lamellar fragmentation, preferably, the conditions for the secondary ultrasonic dispersion are as follows: the ultrasonic power is 150-200 w, and the ultrasonic time is 5-10 min.

Controlling the temperature and time of the solvothermal reaction in the step (4) is a key step for preparing the carbon nitride modified graphene composite material, and preferably, the reaction conditions of the solvothermal reaction are as follows: the reaction temperature is 200-230 ℃, and the reaction time is 12-18 h. After preorder ultrasonic treatment, graphene oxide lamella layers are well stripped, the interlayer spacing is increased, sodium azide and cyanuric chloride molecules are diffused among the graphene oxide lamella layers in a toluene solvent, in-situ polymerization reaction is carried out among the graphene oxide lamella layers to generate nanotube-shaped carbon nitride, and the diameter of the carbon nitride nanotube is 40-80 nm and the wall thickness is 20-40 nm determined by an SEM (scanning electron microscope). The carbon nitride has the characteristics of ultrahigh hardness and high temperature resistance, the graphene composite material modified by the nanotube-shaped carbon nitride has a better anti-wear effect, and in addition, the nanotube-shaped carbon nitride plays a role in supporting between layers of graphene, so that the phenomenon of precipitation caused by stacking and agglomeration between the graphene layers can be prevented, and the dispersibility of the graphene material as an anti-wear agent is improved.

In the step (5), the prepared carbon nitride modified graphene composite material can be washed by using solvents such as methanol, acetonitrile, ether and the like, and finally, the graphene engine oil antiwear agent is prepared by washing with pure water and freeze drying.

The following is a further description with reference to specific examples.