Black phosphorus-based composite material as well as preparation method and application thereof

Abstract

The invention discloses a black phosphorus-based composite material as well as a preparation method and application thereof, and relates to the technical field of black phosphorus materials. The black phosphorus-based composite material is prepared from the following raw materials: black phosphorus, nano ferroferric oxide and dopamine hydrochloride. The dopamine hydrochloride is subjected to in-situ polymerization to form polydopamine. The obtained black phosphorus-based composite material has a low friction coefficient and an excellent lubricating effect, can be used for preparing a lubricant, for example, as a lubricating additive in lubricating oil or lubricating grease, effectively improves the friction performance of the lubricant, improves the lubricating effect of the lubricant, and is suitable for lubrication of mechanical parts.

Description

Technical Field

[0001] The present invention relates to the technical field of black phosphorus materials, and in particular to a black phosphorus-based composite material and a preparation method and application thereof. Background Art

[0002] With the development of modern industrial technology, the application of mechanical equipment in various industries has become more and more extensive. However, the problem of mechanical friction and wear has always plagued the use and maintenance of mechanical equipment, not only resulting in a large amount of energy waste and environmental pollution, but also reducing the service life of the equipment. Therefore, how to reduce mechanical friction and wear and improve the lubrication effect between mechanical parts has become a major issue that urgently needs to be solved in the current mechanical engineering field. Although traditional grease lubrication can reduce friction and wear to a certain extent, its lubrication effect will be seriously affected under extreme environments, resulting in rupture or extrusion of the lubricating film, a decrease in lubrication effect, and direct contact of the friction interface. Therefore, the requirements for lubricating additives in grease lubrication are getting higher and higher. In order to obtain excellent lubricating additives, researchers are constantly exploring new nano-composite lubricating materials. However, the existing preparation methods of nano-composite lubricating materials often have problems such as harsh reaction conditions and unstable product performance, which limits the application scope and effect of nano-composite lubricating materials. Summary of the Invention

[0003] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art. To this end, the present invention provides a black phosphorus-based composite material. The composite material is formed by using black phosphorus, ferroferric oxide particles, and dopamine hydrochloride as the main raw materials. The composite material has excellent friction performance, stable performance, and mild reaction conditions.

[0004] The second aspect of the present invention is to provide a method for preparing a black phosphorus-based composite material.

[0005] A third aspect of the present invention is to provide a lubricant.

[0006] A fourth aspect of the present invention provides a use of a lubricant.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: A first aspect of the present invention provides a black phosphorus-based composite material, wherein raw materials for preparing the black phosphorus-based composite material include black phosphorus, nano-ferroferric oxide and dopamine hydrochloride; the dopamine hydrochloride is in situ polymerized to form polydopamine.

[0008] Black phosphorus (BP), a novel two-dimensional material with a unique layered structure and reducible properties, offers excellent lubrication performance, outstanding recyclability, and environmental friendliness as a water-based lubricant additive. Nano-sized ferroferric oxide (Fe3O4) particles possess a large surface area, high catalytic activity, and a spherical structure that easily forms a ball-bearing effect. Polydopamine (PDA) exhibits excellent adhesion and compatibility with organic molecules. The present invention combines these three materials: PDA improves the composite's dispersibility in lubricating oils, BP enhances the lubricant's friction and wear characteristics, and ferroferric oxide provides catalytically active sites. During the lubrication process, it catalyzes the formation of a carbon film containing bonds such as PC, C=N, and COP on the surfaces of the grinding pair, enhancing lubrication effectiveness. At the same time, when subjected to friction, the excellent reducing property of black phosphorus forms amorphous carbon, spherical structure oxides, etc. on the surface of the grinding pair, which helps to reduce the friction coefficient, and polydopamine strengthens the interface bonding between the lubricant and the matrix and imparts self-repairing function. The three cooperate with each other to form a multi-level, multifunctional composite lubrication system at the friction interface, so that the black phosphorus-based composite material of the present invention has excellent friction performance and superior lubrication effect.

[0009] Specifically, the black phosphorus-based composite material contains black phosphorus, nano-ferroferric oxide and polydopamine.

[0010] In some embodiments, the average particle size of the nano-ferrosoferric oxide is 10-50 nm.

[0011] In some specific embodiments, the average particle size of the nano-trimer tetraoxide is 10-30 nm.

[0012] In some embodiments, the mass ratio of the black phosphorus to the nano-ferroferric oxide is 1:(0.01-0.03). For example, the mass ratio of the black phosphorus to the nano-ferroferric oxide is 1:0.01, 1:0.015, 1:0.02, 1:0.025, or 1:0.03.

[0013] In some specific embodiments, the mass ratio of the black phosphorus to the nano-ferroferric oxide is 1:(0.015~0.025).

[0014] In the present invention, nano-ferroferric oxide can catalyze black phosphorus and polydopamine to form a carbon film containing bonds such as PC and C=N to improve the lubrication effect. When the amount of ferroferric oxide is small, the catalytic activity is low and the improvement of the lubrication effect is limited. When the amount of ferroferric oxide is large, the ferroferric oxide is easy to aggregate to form particles during the friction process, which damages the grinding pair and reduces the friction and lubrication effect.

[0015] In some embodiments, the mass ratio of the black phosphorus to the dopamine hydrochloride is 1:(2-3). For example, the mass ratio of the black phosphorus to the dopamine hydrochloride can be 1:2, 1:2.3, 1:2.5, 1:2.8 or 1:3.

[0016] The second aspect of the present invention provides a method for preparing the black phosphorus-based composite material according to the first aspect of the present invention, comprising the following steps: The black phosphorus and ferroferric oxide are mixed in water for a first reaction; The mixture obtained from the first mixing reaction and dopamine hydrochloride are mixed in water for a second mixing reaction.

[0017] In some embodiments, the preparation method comprises the following steps: Mixing and dispersing black phosphorus and nano-ferroferric oxide in water to obtain a first mixed solution; subjecting the first mixed solution to ultrasonic treatment and then performing a first reaction to obtain a first reaction solution; and subjecting the first reaction solution to solid-liquid separation to obtain a precipitate; The precipitate is mixed with dopamine hydrochloride in water to obtain a second mixed liquid, and a second reaction is performed to obtain a second reaction liquid; the second reaction liquid is subjected to solid-liquid separation to obtain the black phosphorus-based composite material.

[0018] In some embodiments, the pH of the first mixed solution and / or the second mixed solution is adjusted to 7.5 to 9. For example, the pH is 7.5, 8, 8.5 or 9.

[0019] In some embodiments, the pH of the first mixed solution and / or the second mixed solution is adjusted to 8-9.

[0020] Black phosphorus is easily oxidized in air, water or acidic solution, and alkaline conditions inhibit excessive oxidation of phosphorus atoms. Under alkaline conditions, only a small amount of black phosphorus is oxidized, and at the same time, a complex chemical reaction occurs with ferroferric oxide and water, eventually forming P=O, POP, Fe-OP and FeP x The structure is conducive to the loading of nano-ferroferric oxide on the surface of black phosphorus.

[0021] In the second mixed solution, the pH is adjusted to an appropriate range, and during the reaction, dopamine self-polymerizes in an alkaline environment to cause it to polymerize in situ on the surface of the precipitate, thereby grafting polydopamine on the surface of the precipitate.

[0022] Specifically, the pH of the first mixed solution and / or the second mixed solution is adjusted using sodium hydroxide.

[0023] In some embodiments, the ultrasonic treatment conditions of the first mixed solution meet at least one of the following a) to b): a) Ultrasonic power is 100~200W; b) Ultrasound time is 1~3h.

[0024] Specifically, the ultrasonic power can be any value within the range of 100~200W, such as 100W, 120W, 140W, 150W, 160W, 180W or 200W, or any other range within this range, such as 120~180W, 140~160W.

[0025] Likewise, the ultrasound time may be 1 h, 1.5 h, 2 h, 2.5 h or 3 h.

[0026] In some specific embodiments, the ultrasound time is 1.5 to 2.5 hours.

[0027] Ultrasonic treatment helps disperse the reactants evenly, initiates a preliminary reaction, and promotes interaction between black phosphorus and nano-ferroferric oxide particles. When the ultrasonic treatment time and power are insufficient, the nano-ferroferric oxide loading effect is poor. However, when the ultrasonic treatment time is long and the power is high, the black scale is easily oxidized, which reduces the performance of the black phosphorus-based composite material.

[0028] In some embodiments, the first reaction and / or the second reaction is performed under heating in an oil bath.

[0029] In some embodiments, the first reaction and / or the second reaction are carried out under stirring conditions. Specifically, the stirring speed can be a conventional speed, or 3500-4500 r / min, to ensure sufficient contact and reaction of the reaction materials.

[0030] In some embodiments, the reaction temperature of the first reaction is 100-150° C. Specifically, the reaction temperature of the first reaction (i.e., the first mixing reaction) can be 100° C., 110° C., 120° C., 130° C., 140° C., or 150° C., or other ranges thereof, such as 110-150° C., or 120-150° C.

[0031] In some specific embodiments, the reaction temperature of the first reaction is 110-130°C.

[0032] In some embodiments, the reaction time of the first reaction is 1 to 3 hours.

[0033] In some embodiments, the reaction temperature of the second reaction is 40-80° C. It should be understood that the reaction temperature of the second reaction, i.e., the second mixing reaction, can be 40° C., 50° C., 60° C., 70° C., or 80° C.

[0034] In some specific embodiments, the reaction temperature of the second reaction is 50-70°C.

[0035] In some embodiments, the reaction time of the second reaction is 10 to 15 hours.

[0036] In some embodiments, the solid-liquid separation is performed by centrifugation.

[0037] In some embodiments, the solid-liquid separation of the first reaction liquid is performed by low-speed centrifugation followed by high-speed centrifugation; the low-speed centrifugation is performed at a speed of 700-900 r / min for 3-5 hours; the high-speed centrifugation is performed at a speed of 3500-4500 r / min for 3-5 hours. Large particles are removed during low-speed centrifugation, and a uniformly sized precipitate is obtained after high-speed centrifugation.

[0038] In some specific embodiments, the first reaction liquid and the second reaction liquid further comprise a drying step after solid-liquid separation, wherein the drying temperature is 60-80° C. A suitable drying temperature helps to prevent oxidation or agglomeration of the product during the drying process.

[0039] Specifically, after the solid-liquid separation of the first reaction liquid, the drying time is 5 to 7 hours; after the solid-liquid separation of the second reaction liquid, the drying time is 10 to 15 hours.

[0040] In some embodiments, Tris HCl is further added to the second mixed solution as a buffer.

[0041] The third aspect of the present invention provides a lubricant, which includes the black phosphorus-based composite material described in the first aspect of the present invention, or the black phosphorus-based composite material prepared by the preparation method described in the second aspect of the present invention.

[0042] Specifically, the lubricant refers to lubricating oil or lubricating grease. The lubricant includes a lubricating additive, and the lubricating additive is the black phosphorus-based composite material of the present invention.

[0043] In some specific embodiments, the mass content of the black phosphorus-based composite material in the lubricant is 0.1-0.5%, for example, 0.1%, 0.2%, 0.3% or 0.5%.

[0044] The fourth aspect of the present invention provides a use of the lubricant described in the third aspect of the present invention in lubricating mechanical parts.

[0045] Compared with the prior art, the present invention has the following beneficial effects: 1) The present invention provides a black phosphorus-based composite material, which uses black phosphorus, ferroferric oxide particles and dopamine hydrochloride as main raw materials to form a black phosphorus, ferroferric oxide and polydopamine composite material, wherein the ferroferric oxide can provide catalytic active sites. During the lubrication grinding process, the black phosphorus and polydopamine are catalyzed to form a carbon film containing bonds such as PC and C=N on the surface of the grinding pair, thereby reducing the friction coefficient and improving the lubrication effect, so that the obtained black phosphorus-based composite material has excellent friction performance.

[0046] 2) The preparation method of the black phosphorus-based composite material of the present invention has simple steps and mild reaction conditions. The obtained black phosphorus-based composite material has stable performance, excellent friction properties, good lubrication effect, and is suitable for industrial production.

[0047] 3) The black phosphorus-based composite material of the present invention has a low friction coefficient and excellent lubrication effect. It can be used to prepare lubricants, for example, as a lubricating additive in lubricating oil or grease, effectively improving the friction performance of the lubricant and enhancing its lubrication effect. It is suitable for the lubrication of mechanical parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a flow chart for preparing the black phosphorus-based composite material in Example 1 of the present invention.

[0049] Figure 2 This is an SEM image of the black phosphorus-based composite material of Example 1 of the present invention.

[0050] Figure 3 These are the friction curves of Application Example 1 of the present invention and Comparative Application Examples 1 and 2.

[0051] Figure 4 The wear scar diagrams of Application Example 1 of the present invention and Comparative Application Examples 1 and 2 are shown; wherein, Figure 4 Figures (a), (b), and (c) are the wear scar images of comparative application example 1, comparative application example 2, and application example 1, respectively.

[0052] Figure 5 These are the friction curves of Application Example 2 of the present invention and Comparative Application Examples 3 and 4.

[0053] Figure 6 The wear scar diagrams of Application Example 2 of the present invention and Comparative Application Examples 3 and 4 are shown; wherein, Figure 6 Figures (a), (b), and (c) are the wear scar images of comparative application example 3, comparative application example 4, and application example 2, respectively. DETAILED DESCRIPTION

[0054] The present invention is further described in detail below using specific examples. Unless otherwise specified, the raw materials, reagents, and apparatus used in the examples and comparative examples are available from conventional commercial sources or by conventional methods. Unless otherwise specified, all experimental or testing methods are conventional in the art.

[0055] The following describes the detailed description in conjunction with specific embodiments and application examples.

[0056] Example 1 A black phosphorus-based composite material, the raw materials of which include black phosphorus, nano-ferroferric oxide and dopamine hydrochloride, and the preparation process is as follows: Figure 1 The specific steps are as follows: S1. Add 200 mg of black phosphorus powder and 4 mg of nano-Fe₃O₄ particles (average particle size 20 nm) to 200 mL of deionized water to form a uniform mixed solution. Adjust the pH of the mixed solution to 8.5 using sodium hydroxide (NaOH). S2. The pH-adjusted mixed solution in step S1 was placed in a cell crusher and subjected to ultrasonic treatment at an ultrasonic power of 150W for 2h. S3. The solution after ultrasonic treatment in step S2 was moved to an oil bath, the reaction temperature was set to 120°C, and the reaction was stirred for 2h to ensure sufficient contact and reaction of the reactants; S4. After the reaction in step S3, the precipitate was collected by centrifugation, first centrifuged at 800 r / min for 4 h to remove large particles, and then centrifuged at 4000 r / min for 4 h to obtain a precipitate; S5. The precipitate collected in step S4 was vacuum dried at 70 ° C for 6h; S6. The powder obtained after drying in step S5 was redissolved in 200 mL of deionized water, and then 400 mg of Tris HCl was added as a buffer, followed by 500 mg of dopamine hydrochloride, and the pH of the system was adjusted to 8.5 with NaOH to obtain a mixed solution; S7. The mixture obtained in step S6 was moved to an oil bath, the reaction temperature was set to 60 ° C, and the reaction was stirred at 4000 r / min for 12h to ensure sufficient contact and reaction of the reactants; S8. After the reaction in step S7 is completed, the precipitate is collected by centrifugation and the surface of the precipitate is washed with anhydrous ethanol to ensure the purity of the precipitate. After vacuum drying at 70°C for 12 hours, a black phosphorus-based composite material (denoted as BP / Fe3O4-PDA) is obtained.

[0057] The scanning electron microscope (SEM) image of the black phosphorus-based composite material obtained in Example 1 is as follows: Figure 2 shown.

[0058] Application Example 1 The black phosphorus-based composite material in Example 1 was added as a lubricating additive to pure soybean oil, and the mixture was mixed to obtain a lubricant. The mass content of the black phosphorus-based composite material in the lubricant was 0.1 wt %.

[0059] Application Example 2 The black phosphorus-based composite material in Example 1 was added as a lubricating additive to conventional commercially available HP-P high-temperature lithium-based grease, and the mixture was mixed to obtain a lubricant. The mass content of the black phosphorus-based composite material in the lubricant was 0.1 wt %.

[0060] Comparative Application Example 1 Pure soybean oil without adding any black phosphorus or black phosphorus-based composite materials is directly used as lubricant.

[0061] Comparative Application Example 2 Black phosphorus powder (BP) was added as a lubricating additive to pure soybean oil to obtain a lubricant. The mass content of black phosphorus in the lubricant was 0.2 wt%.

[0062] Comparative Application Example 3 Pure grease (conventional commercially available HP-P high-temperature lithium-based grease) without adding black phosphorus and black phosphorus-based composite materials is directly used as the lubricant. The grease used is the same as that in Application Example 2.

[0063] Comparative Application Example 4 Black phosphorus powder (BP) was added as a lubricating additive to conventional commercially available grease to obtain a lubricant. The grease used was the same as that in Application Example 2. The mass content of black phosphorus in the lubricant was 0.2 wt%.

[0064] Result detection The lubricating properties of the lubricants used in Application Examples 1-2 and Comparative Examples 1-4 were tested using a ball-on-disc rotational tribometer (UMT-TriboLab, Bruker Corporation, USA). To ensure the accuracy of the average friction coefficient, each set of friction tests was repeated three times, and the average value was calculated. The test conditions were as follows: a temperature of 24-25°C, a friction pair consisting of a 6mm diameter GCr15 (AISI 52100) steel ball and a 304 stainless steel (ASTM 304) disc with surface roughnesses of 14.5μm and 0.25μm, respectively. Before each experiment, approximately 20μL of lubricant was added using a dropper. The tribometer parameters were set to: a load of 5-20N and a rotation speed of 200r / min.

[0065] The test results are as follows Figures 3 to 6 .

[0066] Figure 3 and Figure 4The friction curves and wear scar diagrams of application example 1 and comparative application examples 1-2 are shown respectively. Figure 3 and Figure 4 It can be seen that the friction curve of the lubricant added with the black phosphorus-based composite material (BP / Fe3O4-PDA) in Application Example 1 is relatively stable, without obvious fluctuations, and its overall friction coefficient is significantly lower than the friction coefficient of the lubricant when pure soybean oil and black phosphorus (BP) are used as additives. Compared with pure soybean oil, when the lubricant prepared using the BP / Fe3O4-PDA of the present invention as an additive is used, the average friction coefficient and wear scar width are reduced by approximately 46% and 48%, respectively. Figure 4 The SEM image of the wear scar width proves that the lubricant prepared by using the black phosphorus-based composite material of the present invention as a lubricating additive has certain advantages in improving the lubrication performance.

[0067] Figure 5 The friction curves of Application Example 2 of the present invention and Comparative Application Examples 3 and 4 are shown; Figure 6 The wear scar diagrams of Application Example 2 of the present invention and Comparative Application Examples 3 and 4 are shown in FIG. Figure 5 The test results show that the average friction coefficient of the black phosphorus composite material of Example 1 of the present invention when used as a grease-based additive is the lowest, which is significantly lower than that of pure grease and black phosphorus as an additive. This shows that the black phosphorus composite material of the present invention also has significant advantages in improving the lubricating properties of grease. Figure 6 Compared with the wear scar widths of the greases, the black phosphorus composite material of Example 1 has the narrowest wear scar width. A narrower wear scar width indicates lower wear between the friction pairs. This shows that the black phosphorus-based composite material of the present invention has a superior effect in improving lubricant performance as a grease additive.

[0068] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A black phosphorus-based composite material, characterized in that: The raw materials for preparing the black phosphorus-based composite material include black phosphorus, nano-ferroferric oxide and dopamine hydrochloride; the dopamine hydrochloride is polymerized in situ to form polydopamine.

2. The black phosphorus-based composite material according to claim 1, characterized in that The average particle size of the nano-ferroferric oxide is 10-50 nm; And / or, the mass ratio of the black phosphorus to the nano-ferroferric oxide is 1:(0.01-0.03).

3. The black phosphorus-based composite material according to claim 1 or 2, characterized in that The mass ratio of the black phosphorus to the dopamine hydrochloride is 1:(2-3).

4. A method for preparing the black phosphorus-based composite material according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: The black phosphorus and ferroferric oxide are mixed in water for a first reaction; The mixture obtained from the first mixing reaction and dopamine hydrochloride are mixed in water for a second mixing reaction.

5. The preparation method according to claim 4, characterized in that The preparation method comprises the following steps: Mixing and dispersing black phosphorus and nano-ferroferric oxide in water to obtain a first mixed solution; subjecting the first mixed solution to ultrasonic treatment and then performing a first reaction to obtain a first reaction solution; and subjecting the first reaction solution to solid-liquid separation to obtain a precipitate; The precipitate is mixed with dopamine hydrochloride in water to obtain a second mixed liquid, and a second reaction is performed to obtain a second reaction liquid; the second reaction liquid is subjected to solid-liquid separation to obtain the black phosphorus-based composite material.

6. The preparation method according to claim 5, characterized in that The pH of the first mixed solution and / or the second mixed solution is adjusted to 7.5-9.

7. The preparation method according to claim 5, characterized in that The ultrasonic treatment conditions of the first mixed solution meet at least one of the following a) to b): a) Ultrasonic power is 100~200W; b) Ultrasound time is 1~3h.

8. The preparation method according to claim 5, characterized in that The first reaction and / or the second reaction are carried out under heating in an oil bath; And / or, the reaction temperature of the first reaction is 100-150°C; And / or, the reaction temperature of the second reaction is 40-80°C.

9. A lubricant, characterized in that: The lubricant comprises the black phosphorus-based composite material according to any one of claims 1 to 3, or the black phosphorus-based composite material prepared by the preparation method according to any one of claims 4 to 8.

10. Use of the lubricant according to claim 9 in lubricating mechanical parts.

Images