High extreme pressure type molybdenum disulfide-black phosphorus composite lithium-based lubricating grease and preparation method thereof

Abstract

The invention discloses high-extreme-pressure molybdenum disulfide-black phosphorus composite lithium-based lubricating grease and a preparation method thereof, and belongs to the technical field of lubricating materials. The composite lithium-based lubricating grease comprises the following components in percentage by mass: 70-85% of lubricating grease base oil, 10-20% of a thickening agent, 0.5-5% of a molybdenum disulfide-black phosphorus composite material and 1-5% of other functional additives. According to the invention, black phosphorus grows in situ on molybdenum disulfide nanosheets through a chemical vapor transport method, and a strongly-coupled heterojunction structure is constructed. The structure fundamentally overcomes the defects of weak interface bonding and easy phase separation of a traditional physical mixing method, and realizes stable and efficient synergistic lubrication between molybdenum disulfide and black phosphorus. Experimental data prove that the prepared lubricating grease is excellent in friction performance, and an accelerated aging test further verifies the long-term stability of the lubricating grease: after the product is stored for 65 days, the friction coefficient change rate is less than 7%, the wear scar diameter change rate is less than 11%, and the performance durability is obviously superior to that of a physical mixed sample.

Description

Technical Field

[0001] This invention belongs to the field of lubricating materials technology, specifically relating to a high extreme pressure molybdenum disulfide-black phosphorus composite lithium-based grease and its preparation method. Background Technology

[0002] Two-dimensional layered materials are widely used as solid lubricant additives due to their unique layered structure and easy interlayer slip properties. Among them, molybdenum disulfide has a hexagonal layered structure, with strong covalent bonds within its molecular layers and weak van der Waals forces connecting the layers. This allows interlayer slip to occur even under low shear stress, resulting in excellent lubrication performance. However, molybdenum disulfide alone is prone to oxidation under extreme conditions such as high temperature and high load, leading to a sharp decline in lubrication performance, and its load-bearing capacity is limited.

[0003] Black phosphorus (BP), as an emerging two-dimensional material, possesses a unique two-dimensional layered structure and excellent thermodynamic stability, attracting widespread attention in the lubrication field in recent years. Black phosphorus nanosheets not only exhibit ideal mechanical properties but can also produce synergistic effects with other lubricating materials, further enhancing lubrication performance. However, black phosphorus is extremely sensitive to environment and humidity, easily oxidizing to form phosphorus oxides, leading to a decline in lubrication performance. This characteristic severely restricts its practical application in the lubrication field.

[0004] Currently, traditional methods for composite molybdenum disulfide and black phosphorus mainly employ physical mixing or liquid-phase methods. Physical mixing suffers from weak interfacial bonding and easy phase separation, failing to achieve sustained synergy between the two materials under extreme pressure and heavy load conditions. Liquid-phase methods, such as solvothermal methods, easily lead to oxidation and hydrolysis of black phosphorus during the composite process, reducing its performance. For example, existing technologies provide solid-liquid composite microcapsules whose core material contains a lubricant and a two-dimensional material (including one or more of graphene, molybdenum disulfide, tungsten disulfide, boron nitride, and black phosphorus). These microcapsules exhibit excellent lubrication performance under large contact areas and high loads. However, this method still employs physical mixing and fails to address the issue of strong interfacial bonding between the two two-dimensional materials.

[0005] Therefore, developing a novel extreme pressure heavy-duty composite grease that can achieve a strong composite of molybdenum disulfide and black phosphorus, fully utilize their synergistic lubrication effect, and has good environmental stability has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The first objective of this invention is to provide a molybdenum disulfide-black phosphorus composite material, and the second objective of this invention is to provide a high extreme pressure molybdenum disulfide-black phosphorus composite lithium-based grease and its preparation method.

[0007] The primary objective of this invention is achieved as follows: a molybdenum disulfide-black phosphorus composite material is formed by in-situ growth of black phosphorus on the surface of molybdenum disulfide nanosheets via chemical vapor transport. The preparation method involves placing molybdenum disulfide nanosheets in the low-temperature growth zone of a quartz ampoule, mixing red phosphorus with a tin-iodine flux, and then placing the mixture in the high-temperature source zone of the quartz ampoule, followed by evacuation to a vacuum level of 1×10⁻⁶. -3 After being sealed below Pa, the mixture is placed in a dual-temperature zone furnace and reacted for 20-28 hours to obtain a black powder, wherein the high-temperature zone temperature is 600-650℃ and the low-temperature zone temperature is 480-520℃. The obtained black powder is washed with CS2 solvent and then vacuum dried at 60℃ to obtain a molybdenum disulfide-black phosphorus composite material. The mass ratio of molybdenum disulfide nanosheets to red phosphorus is 1:0.4-0.6; the mass ratio of red phosphorus to tin-iodine flux is 8-12:1.

[0008] The second objective of this invention is achieved by providing a high extreme pressure molybdenum disulfide-black phosphorus composite lithium-based grease based on the aforementioned molybdenum disulfide-black phosphorus composite material, comprising the following components by mass fraction: 70-85% grease base oil, 10-20% thickener, 0.5-5% molybdenum disulfide-black phosphorus composite material, and 1-5% other functional additives.

[0009] The method for preparing the high extreme pressure molybdenum disulfide-black phosphorus composite lithium-based grease involves mixing and stirring a base oil and a thickener at 75-85°C for 1-2 hours to form a uniform paste; adding molybdenum disulfide-black phosphorus composite material and other functional additives to the paste; and then subjecting the paste to high-speed shear dispersion and ultrasonic homogenization treatments to obtain the grease composition.

[0010] The beneficial effects of this invention are as follows: This invention utilizes a chemical vapor transport method to grow black phosphorus in situ on molybdenum disulfide nanosheets, constructing a strongly coupled heterojunction structure. This structure fundamentally solves the defects of traditional physical mixing methods, namely "weak interfacial bonding and easy phase separation," achieving stable and efficient synergistic lubrication between molybdenum disulfide and black phosphorus. Performance test data fully validates the advantages of this heterojunction: the coefficient of friction remains stable in the low range of 0.073-0.079, and the PB value is between 1432-1570 N. These significant improvements in key indicators demonstrate that this structure can form a more robust and durable protective film at the friction interface, thereby greatly enhancing reliability and durability under extreme pressure and heavy load conditions. Furthermore, this heterojunction structure significantly improves the long-term stability of the grease. Accelerated aging tests show that after 65 days of storage, the coefficient of friction change rate is <7%, and the wear scar diameter change rate is <11%, demonstrating performance durability far superior to physically mixed samples. This effectively suppresses performance degradation during storage, providing a reliable solution to the industry problem of insufficient long-term stability of black phosphorus-based lubricating materials.

[0011] In summary, the composite grease provided by this invention far surpasses traditional physical mixing products in terms of extreme pressure anti-wear performance and long-term stability. It successfully breaks through the technical bottleneck of interfacial bonding and synergistic stability of two-dimensional materials in composite lubricants, and shows great application potential in harsh lubrication conditions in metallurgy, machinery and other industrial fields. Attached Figure Description

[0012] Figure 1 The image shows an electron microscope image of the MoS2 nanosheets prepared in Example 1. Detailed Implementation

[0013] The present invention will be further described below with reference to embodiments, but this is not intended to limit the present invention in any way. Any modifications or substitutions made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0014] This invention provides a molybdenum disulfide-black phosphorus composite material, which is formed by in-situ growth of black phosphorus on the surface of molybdenum disulfide nanosheets via chemical vapor transport. The preparation method involves placing molybdenum disulfide nanosheets in the low-temperature growth zone of a quartz ampoule, mixing red phosphorus with a tin-iodine flux, and then placing the mixture in the high-temperature source zone of the quartz ampoule, followed by evacuation to a vacuum level of 1×10⁻⁶. - 3 After being sealed below Pa, the mixture is placed in a dual-temperature zone furnace and reacted for 20-28 hours to obtain a black powder, wherein the high-temperature zone temperature is 600-650℃ and the low-temperature zone temperature is 480-520℃. The obtained black powder is washed with CS2 solvent and then vacuum dried at 60℃ to obtain a molybdenum disulfide-black phosphorus composite material. The mass ratio of molybdenum disulfide nanosheets to red phosphorus is 1:0.4-0.6; the mass ratio of red phosphorus to tin-iodine flux is 8-12:1.

[0015] The molybdenum disulfide nanosheets were obtained by exfoliating bulk molybdenum disulfide using a lithium-ion intercalation method.

[0016] The present invention also provides a high extreme pressure molybdenum disulfide-black phosphorus composite lithium-based grease based on the aforementioned composite material, which contains the following components in mass fraction: 70-85% grease base oil, 10-20% thickener, 0.5-5% molybdenum disulfide-black phosphorus composite material and 1-5% other functional additives.

[0017] The mass fraction of the molybdenum disulfide-black phosphorus composite material is 2%.

[0018] The thickener is a composite lithium-based thickener.

[0019] The base oil is PAO10 base oil.

[0020] The other functional additives include one or more of antioxidants, rust inhibitors, and metal passivators.

[0021] The present invention further provides a method for preparing the high extreme pressure molybdenum disulfide-black phosphorus composite lithium-based grease. The method involves mixing and stirring a base oil and a thickener at 75-85°C for 1-2 hours to form a uniform paste; adding molybdenum disulfide-black phosphorus composite material and other functional additives to the paste; and then subjecting the paste to high-speed shear dispersion and ultrasonic homogenization treatments to obtain the grease composition.

[0022] The high-speed shearing rotation speed is 3000-5000 rpm, and the time is 30-60 minutes; the ultrasonic homogenization treatment power is 400W, the working mode is 2 seconds working / 2 seconds intermittent, and the total duration is 30 minutes.

[0023] To verify the long-term structural stability and performance retention of the molybdenum disulfide / black phosphorus composite grease prepared in this invention, a systematic accelerated aging test was designed, and the specific method is as follows: Experimental group: MoS2 / BP composite grease prepared in Examples 1-12 (prepared by CVT method) Control group: Physically mixed MoS2 / BP grease prepared in comparative examples 1-3 Oxidation stability was tested according to ASTM D942 standard, and damp heat aging conditions were added: the test was conducted in an environmental test chamber at (85±2)℃ and (85±5)% relative humidity. The friction coefficient, wear scar diameter, and PB value were tested at 0 and 65 days respectively.

[0024] Example 1

[0025] 1. Preparation of MoS2 nanosheets: Molybdenum disulfide nanosheets were prepared by lithium-ion intercalation: 10 g of bulk molybdenum disulfide was reacted with 100 mL of n-butyllithium / hexane solution (1.6 M) under argon protection for 48 hours; after filtration, the nanosheets were washed with hexane to obtain lithium-intercalated molybdenum disulfide; the lithium-intercalated molybdenum disulfide was dispersed in 500 mL of deionized water and sonicated (400 W, 4 hours) for exfoliation; the unexfoliated thick sheets were removed by gradient centrifugation (2000 rpm, 20 min), and the supernatant was collected; the precipitate was collected by further high-speed centrifugation (12000 rpm, 30 min), and vacuum dried to obtain molybdenum disulfide nanosheets.

[0026] 2. MoS2 / BP composite material was prepared using the CVT method. The preparation method is as follows: 1g of the above-prepared molybdenum disulfide nanosheets were placed in the low-temperature growth zone of a quartz ampoule (20cm long, 2.5cm in diameter); 0.4g of red phosphorus and 0.05g of tin-iodine flux were mixed and placed in the high-temperature source zone of the quartz ampoule; the ampoule was connected to a high-vacuum system and evacuated to 1×10⁻⁶. -3After Pa, the ampoule was sealed; it was then placed in a dual-temperature zone tube furnace, with the high-temperature zone set to 620℃ and the low-temperature zone to 500℃, with a heating rate of 2℃ / min, and reacted for 24 hours; after the program ended, it was allowed to cool naturally to room temperature, and the ampoule was broken in an argon-protected glove box to collect the gray-black powder from the growth zone; it was washed three times with CS2 solvent to remove unreacted phosphorus and byproducts, and then vacuum dried at 60℃ for 12 hours to obtain the MoS2 / BP composite material.

[0027] 3. Preparation of composite grease: Based on PAO10 base oil (84.5wt%) and composite lithium-based thickener (12wt%), the prepared MoS2 / BP composite material (2wt%) is added, along with diphenylamine (0.5wt%) and barium petroleum sulfonate (1wt%). First, the base oil and thickener are mixed and stirred at 80℃ for 1 hour to form a uniform paste. Then, the MoS2 / BP composite material and additives (diphenylamine and barium petroleum sulfonate) are added, and the mixture is initially dispersed by high-speed shearing (5000rpm, 30 minutes). Then, it is homogenized by ultrasonic cell disruptor (400W, 2 seconds working / 2 seconds intermittent, total duration 30 minutes) to obtain the final composite grease product.

[0028] Example 2

[0029] 1. Preparation of MoS2 nanosheets: Molybdenum disulfide nanosheets were prepared by lithium-ion intercalation: 10 g of bulk molybdenum disulfide was reacted with 100 mL of n-butyllithium / hexane solution (1.6 M) under argon protection for 48 hours; after filtration, the nanosheets were washed with hexane to obtain lithium-intercalated molybdenum disulfide; the lithium-intercalated molybdenum disulfide was dispersed in 500 mL of deionized water and sonicated (400 W, 4 hours) for exfoliation; the unexfoliated thick sheets were removed by gradient centrifugation (2000 rpm, 20 min), and the supernatant was collected; the precipitate was collected by further high-speed centrifugation (12000 rpm, 30 min), and vacuum dried to obtain molybdenum disulfide nanosheets.

[0030] 2. MoS2 / BP composite material was prepared using the CVT method. The preparation method is as follows: 1g of the above-prepared molybdenum disulfide nanosheets were placed in the low-temperature growth zone of a quartz ampoule (20cm long, 2.5cm in diameter); 0.5g of red phosphorus and 0.05g of tin-iodine flux were mixed and placed in the high-temperature source zone of the quartz ampoule; the ampoule was connected to a high-vacuum system and evacuated to 1×10⁻⁶. -3 After Pa, the ampoule was sealed; it was then placed in a dual-temperature zone tube furnace, with the high-temperature zone set to 620℃ and the low-temperature zone to 500℃, with a heating rate of 2℃ / min, and reacted for 24 hours; after the program ended, it was allowed to cool naturally to room temperature, and the ampoule was broken in an argon-protected glove box to collect the gray-black powder from the growth zone; it was washed three times with CS2 solvent to remove unreacted phosphorus and byproducts, and then vacuum dried at 60℃ for 12 hours to obtain the MoS2 / BP composite material.

[0031] 3. Preparation of composite grease: Based on PAO10 base oil (84.5wt%) and composite lithium-based thickener (12wt%), the prepared MoS2 / BP composite material (2wt%) is added, along with diphenylamine (0.5wt%) and barium petroleum sulfonate (1wt%). First, the base oil and thickener are mixed and stirred at 80℃ for 1 hour to form a uniform paste. Then, the MoS2 / BP composite material and additives (diphenylamine and barium petroleum sulfonate) are added, and the mixture is initially dispersed by high-speed shearing (5000rpm, 30 minutes). Then, it is homogenized by ultrasonic cell disruptor (400W, 2 seconds working / 2 seconds intermittent, total duration 30 minutes) to obtain the final composite grease product.

[0032] Example 3

[0033] 1. Preparation of MoS2 nanosheets: Molybdenum disulfide nanosheets were prepared by lithium-ion intercalation: 10 g of bulk molybdenum disulfide was reacted with 100 mL of n-butyllithium / hexane solution (1.6 M) under argon protection for 48 hours; after filtration, the nanosheets were washed with hexane to obtain lithium-intercalated molybdenum disulfide; the lithium-intercalated molybdenum disulfide was dispersed in 500 mL of deionized water and sonicated (400 W, 4 hours) for exfoliation; the unexfoliated thick sheets were removed by gradient centrifugation (2000 rpm, 20 min), and the supernatant was collected; the precipitate was collected by further high-speed centrifugation (12000 rpm, 30 min), and vacuum dried to obtain molybdenum disulfide nanosheets.

[0034] 2. MoS2 / BP composite material was prepared using the CVT method. The preparation method is as follows: 1g of the above-prepared molybdenum disulfide nanosheets were placed in the low-temperature growth zone of a quartz ampoule (20cm long, 2.5cm in diameter); 0.55g of red phosphorus and 0.05g of tin-iodine flux were mixed and placed in the high-temperature source zone of the quartz ampoule; the ampoule was connected to a high-vacuum system and evacuated to 1×10⁻⁶. -3 After Pa, the ampoule was sealed; it was then placed in a dual-temperature zone tube furnace, with the high-temperature zone set to 620℃ and the low-temperature zone to 500℃, with a heating rate of 2℃ / min, and reacted for 24 hours; after the program ended, it was allowed to cool naturally to room temperature, and the ampoule was broken in an argon-protected glove box to collect the gray-black powder from the growth zone; it was washed three times with CS2 solvent to remove unreacted phosphorus and byproducts, and then vacuum dried at 60℃ for 12 hours to obtain the MoS2 / BP composite material.

[0035] 3. Preparation of composite grease: Based on PAO10 base oil (84.5wt%) and composite lithium-based thickener (12wt%), the prepared MoS2 / BP composite material (2wt%) is added, along with diphenylamine (0.5wt%) and barium petroleum sulfonate (1wt%). First, the base oil and thickener are mixed and stirred at 80℃ for 1 hour to form a uniform paste. Then, the MoS2 / BP composite material and additives (diphenylamine and barium petroleum sulfonate) are added, and the mixture is initially dispersed by high-speed shearing (5000rpm, 30 minutes). Then, it is homogenized by ultrasonic cell disruptor (400W, 2 seconds working / 2 seconds intermittent, total duration 30 minutes) to obtain the final composite grease product.

[0036] Example 4

[0037] 1. Preparation of MoS2 nanosheets: Molybdenum disulfide nanosheets were prepared by lithium-ion intercalation: 10 g of bulk molybdenum disulfide was reacted with 100 mL of n-butyllithium / hexane solution (1.6 M) under argon protection for 48 hours; after filtration, the nanosheets were washed with hexane to obtain lithium-intercalated molybdenum disulfide; the lithium-intercalated molybdenum disulfide was dispersed in 500 mL of deionized water and sonicated (400 W, 4 hours) for exfoliation; the unexfoliated thick sheets were removed by gradient centrifugation (2000 rpm, 20 min), and the supernatant was collected; the precipitate was collected by further high-speed centrifugation (12000 rpm, 30 min), and vacuum dried to obtain molybdenum disulfide nanosheets.

[0038] 2. MoS2 / BP composite material was prepared using the CVT method. The preparation method is as follows: 1g of the above-prepared molybdenum disulfide nanosheets were placed in the low-temperature growth zone of a quartz ampoule (20cm long, 2.5cm in diameter); 0.6g of red phosphorus and 0.05g of tin-iodine flux were mixed and placed in the high-temperature source zone of the quartz ampoule; the ampoule was connected to a high-vacuum system and evacuated to 1×10⁻⁶. -3 After Pa, the ampoule was sealed; it was then placed in a dual-temperature zone tube furnace, with the high-temperature zone set to 620℃ and the low-temperature zone to 500℃, with a heating rate of 2℃ / min, and reacted for 24 hours; after the program ended, it was allowed to cool naturally to room temperature, and the ampoule was broken in an argon-protected glove box to collect the gray-black powder from the growth zone; it was washed three times with CS2 solvent to remove unreacted phosphorus and byproducts, and then vacuum dried at 60℃ for 12 hours to obtain the MoS2 / BP composite material.

[0039] 3. Preparation of composite grease: Based on PAO10 base oil (84.5wt%) and composite lithium-based thickener (12wt%), the prepared MoS2 / BP composite material (2wt%) is added, along with diphenylamine (0.5wt%) and barium petroleum sulfonate (1wt%). First, the base oil and thickener are mixed and stirred at 80℃ for 1 hour to form a uniform paste. Then, the MoS2 / BP composite material and additives (diphenylamine and barium petroleum sulfonate) are added, and the mixture is initially dispersed by high-speed shearing (5000rpm, 30 minutes). Then, it is homogenized by ultrasonic cell disruptor (400W, 2 seconds working / 2 seconds intermittent, total duration 30 minutes) to obtain the final composite grease product.

[0040] Example 5

[0041] 1. Preparation of MoS2 nanosheets: Molybdenum disulfide nanosheets were prepared by lithium-ion intercalation: 10 g of bulk molybdenum disulfide was reacted with 100 mL of n-butyllithium / hexane solution (1.6 M) under argon protection for 48 hours; after filtration, the nanosheets were washed with hexane to obtain lithium-intercalated molybdenum disulfide; the lithium-intercalated molybdenum disulfide was dispersed in 500 mL of deionized water and sonicated (400 W, 4 hours) for exfoliation; the unexfoliated thick sheets were removed by gradient centrifugation (2000 rpm, 20 min), and the supernatant was collected; the precipitate was collected by further high-speed centrifugation (12000 rpm, 30 min), and vacuum dried to obtain molybdenum disulfide nanosheets.

[0042] 2. MoS2 / BP composite material was prepared using the CVT method. The preparation method is as follows: 1g of the above-prepared molybdenum disulfide nanosheets were placed in the low-temperature growth zone of a quartz ampoule (20cm long, 2.5cm in diameter); 0.5g of red phosphorus and 0.05g of tin-iodine flux were mixed and placed in the high-temperature source zone of the quartz ampoule; the ampoule was connected to a high-vacuum system and evacuated to 1×10⁻⁶. -3 After Pa, the ampoule was sealed; it was then placed in a dual-temperature zone tube furnace, with the high-temperature zone set to 600℃ and the low-temperature zone to 480℃, with a heating rate of 2℃ / min, and reacted for 24 hours; after the program ended, it was allowed to cool naturally to room temperature, and the ampoule was broken in an argon-protected glove box to collect the gray-black powder from the growth zone; it was washed three times with CS2 solvent to remove unreacted phosphorus and byproducts, and then vacuum dried at 60℃ for 12 hours to obtain the MoS2 / BP composite material.

[0043] 3. Preparation of composite grease: Based on PAO10 base oil (84.5wt%) and composite lithium-based thickener (12wt%), the prepared MoS2 / BP composite material (2wt%) is added, along with diphenylamine (0.5wt%) and barium petroleum sulfonate (1wt%). First, the base oil and thickener are mixed and stirred at 80℃ for 1 hour to form a uniform paste. Then, the MoS2 / BP composite material and additives (diphenylamine and barium petroleum sulfonate) are added, and the mixture is initially dispersed by high-speed shearing (5000rpm, 30 minutes). Then, it is homogenized by ultrasonic cell disruptor (400W, 2 seconds working / 2 seconds intermittent, total duration 30 minutes) to obtain the final composite grease product.

[0044] Example 6

[0045] 1. Preparation of MoS2 nanosheets: Molybdenum disulfide nanosheets were prepared by lithium-ion intercalation: 10 g of bulk molybdenum disulfide was reacted with 100 mL of n-butyllithium / hexane solution (1.6 M) under argon protection for 48 hours; after filtration, the nanosheets were washed with hexane to obtain lithium-intercalated molybdenum disulfide; the lithium-intercalated molybdenum disulfide was dispersed in 500 mL of deionized water and sonicated (400 W, 4 hours) for exfoliation; the unexfoliated thick sheets were removed by gradient centrifugation (2000 rpm, 20 min), and the supernatant was collected; the precipitate was collected by further high-speed centrifugation (12000 rpm, 30 min), and vacuum dried to obtain molybdenum disulfide nanosheets.

[0046] 2. MoS2 / BP composite material was prepared by CVT method as follows: 1g of the prepared molybdenum disulfide nanosheets were placed in the low-temperature growth zone of a quartz ampoule (20cm long, 2.5cm in diameter); 0.5g of red phosphorus and 0.05g of tin-iodine flux were mixed and placed in the high-temperature source zone of the quartz ampoule; the ampoule was connected to a high vacuum system, evacuated to 1×10-3 Pa, and then sealed; the ampoule was placed in a dual-temperature zone tube furnace, with the high-temperature zone temperature set to 650℃ and the low-temperature zone temperature to 520℃, the heating rate set to 2℃ / min, and the reaction was carried out for 24 hours; after the program was completed, the ampoule was naturally cooled to room temperature, and the ampoule was broken in an argon-protected glove box to collect the gray-black powder from the growth zone; the ampoule was washed three times with CS2 solvent to remove unreacted phosphorus and byproducts, and then dried under vacuum at 60℃ for 12 hours to obtain the MoS2 / BP composite material.

[0047] 3. Preparation of composite grease: Based on PAO10 base oil (84.5wt%) and composite lithium-based thickener (12wt%), the prepared MoS2 / BP composite material (2wt%) is added, along with diphenylamine (0.5wt%) and barium petroleum sulfonate (1wt%). First, the base oil and thickener are mixed and stirred at 80℃ for 1 hour to form a uniform paste. Then, the MoS2 / BP composite material and additives (diphenylamine and barium petroleum sulfonate) are added, and the mixture is initially dispersed by high-speed shearing (5000rpm, 30 minutes). Then, it is homogenized by ultrasonic cell disruptor (400W, 2 seconds working / 2 seconds intermittent, total duration 30 minutes) to obtain the final composite grease product.

[0048] Example 7

[0049] The difference between this embodiment and Embodiment 1 is that the composite grease is prepared as follows: it is based on PAO10 base oil (70wt%) and composite lithium-based thickener (20wt%); the prepared MoS2 / BP composite material (5wt%) is added, and diphenylamine and barium petroleum sulfonate (total 5wt%) are added.

[0050] Example 8

[0051] The difference between this embodiment and Embodiment 1 is that the composite grease is prepared as follows: it is based on PAO10 base oil (80wt%) and composite lithium-based thickener (10wt%); the prepared MoS2 / BP composite material (5wt%) is added, and diphenylamine and barium petroleum sulfonate (total 5wt%) are added.

[0052] Example 9

[0053] The difference between this embodiment and Example 1 is that the composite grease is prepared as follows: it is based on PAO10 base oil (80wt%) and composite lithium-based thickener (15wt%); the prepared MoS2 / BP composite material (0.5wt%) is added, and diphenylamine and barium petroleum sulfonate (total 4.5wt%) are added.

[0054] Example 10

[0055] The difference between this embodiment and Example 1 is that the composite grease is prepared as follows: it is based on PAO10 base oil (85wt%) and composite lithium-based thickener (10wt%); the prepared MoS2 / BP composite material (0.5wt%) is added, and diphenylamine and barium petroleum sulfonate (total 4.5wt%) are added.

[0056] Example 11

[0057] The difference between this embodiment and Example 1 is that the composite grease is prepared as follows: it is based on PAO10 base oil (75wt%) and composite lithium-based thickener (20wt%); the prepared MoS2 / BP composite material (2wt%) is added, and diphenylamine and barium petroleum sulfonate (total 3wt%) are added.

[0058] Example 12

[0059] The difference between this embodiment and Example 1 is that the composite grease is prepared as follows: it is based on PAO10 base oil (85wt%) and composite lithium-based thickener (10wt%); the prepared MoS2 / BP composite material (2wt%) is added, and diphenylamine and barium petroleum sulfonate (total 3wt%) are added.

[0060] Comparative Example 1 The base oil was made from PAO10 base oil (84.5 wt%) and a complex lithium-based thickener (12 wt%). Diphenylamine (0.5 wt%) and barium petroleum sulfonate (1 wt%) were added. First, the base oil and thickener were mixed and stirred at 80°C for 1 hour to form a uniform paste. Then, diphenylamine (0.5 wt%) and barium petroleum sulfonate were added. The mixture was first initially dispersed by high-speed shearing (5000 rpm, 30 minutes). Then, it was homogenized by ultrasonic cell disruptor (400W, 2 seconds working / 2 seconds intermittent, total duration 30 minutes) to obtain the base ester.

[0061] Comparative Example 2 In this comparative example, a step-dispersion strategy was used to perform a composite process of molybdenum disulfide nanosheets in the base lipid system of Comparative Example 1.

[0062] The base grease from Comparative Example 1 was placed in a high-speed dispersion vessel. 2 wt% molybdenum disulfide nanosheets were added in portions at 10-minute intervals while stirring at 500 rpm. After all the powder was added, it was initially dispersed by high-speed shearing (5000 rpm, 30 minutes); then homogenized using an ultrasonic cell disruptor (400W, 2 seconds on, 2 seconds off, total 30 minutes) to obtain the final composite grease product.

[0063] Comparative Example 3 2.4 parts of molybdenum disulfide nanosheets and 0.6 parts of black phosphorus nanosheets were premixed in an argon-protected glove box (water and oxygen content <0.1ppm), and then placed in a three-dimensional mixer with 2.0 parts of polyisobutylene succinimide dispersant. The mixture was dry-mixed for 120 minutes at a 45° angle and a speed of 60 rpm to obtain physically mixed MoS2 / BP powder. Next, the base grease from Comparative Example 1 was placed in a high-speed dispersion vessel, and the physically mixed MoS2 / BP powder (2wt% of the total grease mass) was added in portions at a stirring speed of 500 rpm, with 10-minute intervals between additions. After all the powder was added, the following treatments were performed sequentially: first, preliminary dispersion by high-speed shearing (5000 rpm, 30 minutes); then, homogenization by ultrasonic cell disruptor (400W, 2 seconds working / 2 seconds intermittent, total duration 30 minutes) to obtain the final composite grease product.

[0064] Performance testing of composite greases prepared in Experimental Example 1, Examples 1-12 and Comparative Examples 1-3 1. Lubricating grease friction performance testing The tribological properties of the greases in Examples 1-12 and Comparative Examples 1-3 were tested according to the national standard GB / T 3142-2019 (Determination of Lubricant Carrying Capacity). The results are shown in Table 1.

[0065] Table 1. Tribological test data of the greases in Comparative Examples 1-3 and Examples 1-12

[0066] Results Analysis: A comprehensive evaluation of the performance data of all samples shows that Examples 1-12 are significantly superior to Comparative Examples 1-3 in terms of tribological performance. The friction coefficients of the examples are consistently low, ranging from 0.073 to 0.079, and the wear scar diameters are concentrated in a small range of 0.38-0.41 mm. This fully demonstrates that the MoS2 / BP composite lubrication structure constructed in this invention can form a more stable and denser protective film at the friction interface, thereby simultaneously achieving excellent friction reduction and anti-wear effects. Their maximum non-seize load (PB value) is between 1432-1570 N, far exceeding that of Comparative Example 3; simultaneously, their sintering load (PD value) all reach over 3090 N, with some examples even reaching 3924 N. This significant leap indicates that the grease of this invention has an excellent ability to maintain the integrity of the lubricating film under extreme operating conditions, greatly improving the reliability and safety of equipment operation.

[0067] 2. Grease stability test To verify the long-term structural stability and performance retention of the molybdenum disulfide / black phosphorus composite grease prepared in this invention, a systematic accelerated aging test was designed, and the specific method is as follows: Experimental group: MoS2 / BP composite grease prepared in Examples 1-12 (prepared by CVT method) Control group: Physically mixed MoS2 / BP grease prepared in comparative examples 1-3 Oxidation stability was tested according to ASTM D942 standard, and damp heat aging conditions were added: the test was conducted in an environmental test chamber at (85±2)℃ and (85±5)% relative humidity. The friction coefficient, wear scar diameter, and PB value were tested at 0 and 65 days.

[0068] The stability of the greases in Examples 1-12 and Comparative Examples 1-3 was tested, and the results are shown in Tables 2, 3, and 4.

[0069] Table 2. Friction coefficient accelerated aging test data

[0070] Table 3. Accelerated aging test data on wear scar diameter

[0071] Table 4. Accelerated aging test data for PB value

[0072] Results Analysis: As shown in Tables 2-4, Examples 1-12 exhibited superior performance stability, with all key indicators showing lower rates of change than Comparative Examples 1-3. Specifically, the rate of change in friction coefficient was <7%, the rate of change in wear scar diameter was <11%, and the PB value retention rate was >90%. In contrast, Comparative Examples 1-3 showed a rate of change in friction coefficient >27%, a rate of change in wear scar diameter >29%, and a PB value retention rate <83.5%.

[0073] In summary, based on the test results and comparative analysis, the following conclusions are drawn: 1. The grease prepared by this invention exhibits excellent tribological properties, significantly superior to the base grease of Comparative Example 1, the pure molybdenum disulfide additive of Comparative Example 2, and the physical mixture of Comparative Example 3. The core of its performance improvement lies in the stable and dense lubricating protective film formed on the friction surface by the CVT method. 2. In terms of extreme pressure performance, the grease of this invention exhibits excellent load-bearing capacity, proving that the heterojunction structure can still maintain complete lubrication function under extreme pressure conditions, and can effectively inhibit wear and sintering of metal surfaces; 3. System comparison shows that the CVT method has an essential advantage over the weak van der Waals force bonding of physical mixing, realizing the efficient synergy between the interlayer slip characteristics of molybdenum disulfide and the high-strength support characteristics of black phosphorus, forming a high-strength composite lubricating film with self-healing function. 4. The results of Examples 1-12 show that the grease of the present invention maintains excellent performance stability under different process parameters, providing reliable technical support for subsequent industrial production, and has broad application prospects in high-end equipment fields such as heavy machinery and aerospace.

Claims

1. A molybdenum disulfide-black phosphorus composite material, characterized in that, The composite material is formed by in-situ growth of black phosphorus on the surface of molybdenum disulfide nanosheets via chemical vapor transport. The preparation method involves placing molybdenum disulfide nanosheets in the low-temperature growth zone of a quartz ampoule, mixing red phosphorus with a tin-iodine flux, and then placing the mixture in the high-temperature source zone of the quartz ampoule, followed by evacuation to 1×10⁻⁶. -3 After being sealed below Pa, the mixture is placed in a dual-temperature zone furnace and reacted for 20-28 hours to obtain a black powder, wherein the high-temperature zone temperature is 600-650℃ and the low-temperature zone temperature is 480-520℃. The obtained black powder is washed with CS2 solvent and then vacuum dried at 60-65℃ to obtain a molybdenum disulfide-black phosphorus composite material. The mass ratio of molybdenum disulfide nanosheets to red phosphorus is 1:0.4-0.6; the mass ratio of red phosphorus to tin-iodine flux is 8-12:

1.

2. The molybdenum disulfide-black phosphorus composite material according to claim 1, characterized in that, The molybdenum disulfide nanosheets were obtained by exfoliating bulk molybdenum disulfide using a lithium-ion intercalation method.

3. A high extreme pressure molybdenum disulfide-black phosphorus composite lithium-based grease based on the composite material described in claim 1, characterized in that, It contains the following components by mass fraction: 70-85% lubricating grease base oil, 10-20% thickener, 0.5-5% molybdenum disulfide-black phosphorus composite material, and 1-5% other functional additives.

4. The high extreme pressure molybdenum disulfide-black phosphorus composite lithium-based grease according to claim 3, characterized in that, The mass fraction of the molybdenum disulfide-black phosphorus composite material is 2%.

5. The high extreme pressure molybdenum disulfide-black phosphorus composite lithium-based grease according to claim 3, characterized in that, The thickener is a composite lithium-based thickener.

6. The high extreme pressure molybdenum disulfide-black phosphorus composite lithium-based grease according to claim 3, characterized in that, The base oil is PAO10 base oil.

7. The high extreme pressure molybdenum disulfide-black phosphorus composite lithium-based grease according to claim 3, characterized in that, The other functional additives include one or more of antioxidants, rust inhibitors, and metal passivators.

8. A method for preparing the high extreme pressure molybdenum disulfide-black phosphorus composite lithium-based grease according to any one of claims 3-7, characterized in that, The base oil and thickener are mixed and stirred at 75-85℃ for 1-2 hours to form a uniform paste; molybdenum disulfide-black phosphorus composite material and other functional additives are added to the paste, and then subjected to high-speed shear dispersion and ultrasonic homogenization treatment in sequence to obtain the lubricating grease composition.

9. The preparation method of the high extreme pressure molybdenum disulfide-black phosphorus composite lithium-based grease according to claim 8, characterized in that, The high-speed shearing rotation speed is 3000-5000 rpm, and the time is 30-60 minutes; the ultrasonic homogenization treatment power is 400W, the working mode is 2 seconds working / 2 seconds intermittent, and the total duration is 30 minutes.

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