Materials
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2022
·Vol. 15
·期 10
·3546
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IF 3.748
Xiangyu Ge,Zhiyuan Chai,Qiuyu Shi,Yanfei Liu,Jiawei Tang,Wenzhong Wang
In this study, graphene oxide (GO) nanoflakes and lithium salt (LiPF6) were utilized as lubrication additives in ether bond−containing dihydric alcohol aqueous solutions (DA(aq)) to improve lubrication performances. The apparent friction reduction and superlubricity were realized at the Si3N4/sapphire interface. The conditions and laws for superlubricity realization have been concluded. The underlying mechanism was the synergy effect of GO and LiPF6. It was proven that a GO adsorption layer was formed at the interface, which caused the shearing interface to transfer from solid asperities to GO interlayers (weak interlayer interactions), resulting in friction reduction and superlubricity realization. In addition to the GO adsorption layer, a boundary layer containing phosphates and fluorides was formed by tribochemical reactions of LiPF6and was conducive to low friction. Additionally, a fluid layer contributed to friction reduction as well. This work proved that GO−family materials are promising for friction reduction, and provided new insights into realizing liquid superlubricity at macroscale by combining GO with other materials.Keywords:superlubricity;graphene oxide;LiPF6;friction reduction
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
npj 2D Materials and Applications
·
2021
·Vol. 5
·期 1
·1-12
·
IF 11.106
Ren Xiaoyong,Yang Xiao,Xie Guoxin,He Feng,Wang Rong,Zhang Chenhui,Guo Dan,Luo Jianbin
Superlubricity has recently raised an increasing interest owing to its great potential in energy saving and environmental benefits. Yet how to obtain stable superlubricity under an ultrahigh contact pressure (>1 GPa) still remains a challenge. Here, we demonstrate that robust liquid superlubricity can be realized even under a contact pressure of 1193 MPa by lubrication with partially oxidized black phosphorus (oBP) nanosheets. The analysis indicates that the oBP nanosheets that absorb large amounts of water molecules are retained at the friction interface and transform the friction pairs interface to that between the oBP nanosheets. Molecular dynamics simulation demonstrates that water molecules could be retained at the friction interface even under the ultrahigh contact pressure owing to the abundant P=O and P–OH bonds formed on the oBP nanosheet surfaces, contributing to the achievement of stable superlubricity under the ultrahigh contact pressure. This work has the potential of introducing the liquid superlubricity concept in diverse industrial applications involving high-contact-pressure operating conditions.
研究领域:
材料科学
·
摩擦学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Tianyi Han,Shuang Yi,Chenhui Zhang,Jinjin Li,Xinchun Chen,Jianbin Luo,Xavier Banquy
Hypothesis Superlubricity is known to dramatically reduce frictional energy consumption and to improve service life of mechanical devices and biological systems. However, reduction of wear during the running-in period of friction pairs, especially under high contact pressures, still remains an unresolved issue affecting all machines. Experiments Here the lubrication , adsorption, and conformational properties of hydrated ions and polyethylene glycol (PEG) mixtures were evaluated at different mass fractions and concentrations of PEG and salts by ball-on-disc tribometer , ζ -potential, quartz crystal microbalance with dissipation (QCM-D), and dynamic light scatting (DLS) analyses. Findings These mixtures exhibited superlubricity between Si 3 N 4 and sapphire surfaces in a wide range of concentrations and ions valency. Interestingly, a running-in phase shorter than 1 min and low wear rate of 1.85 μm 3 /(N·m) were observed at contact pressures up to 555 MPa, significantly higher to earlier findings. PEG chains retain random coils filling the bulk of the interfacial film without strongly adsorbing on the interfaces but significantly increasing the viscosity of lubricating film, thereby favoring hydrodynamic lubrication . Hydrated ions are strongly adsorbed on the negatively charged ceramic surfaces, ensuring a sustained hydration effect maintaining superlubricity. The outstanding lubrication characteristics of the PEG/ions mixtures were attributed to the synergistic action of hydration and hydrodynamic lubrication, which appears as a promising avenue for developing new green lubricants and has implications for industrial and biological applications.
研究领域:
材料科学
·
生物工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Yangqin Liu,Lei Chen,Lin Liu,Pengfei Shi,Junhui Sun,Yang Wang,Linmao Qian
Reducing wear and even achieving superlubrication in industrial applications using simple yet effective methodologies has been a longstanding research objective. In this study, we propose a convenient approach by employing a combination of carboxylated graphene (Gr-COOH) coating with glycerol as lubricants. Compared to the non-lubricated state, this strategy enabled the achievement of superlubrication with an exceptionally low friction coefficient of 0.002, while simultaneously reducing wear volume of substrate by 4 orders of magnitude, and the wear of the counterpart balls are nearly zero. The transfer of Gr-COOH to the ball surface led to the formation of a low shear resistance interface with the Gr-COOH present on the substrate. Nanoscopic experiments with atomic force microscopy revealed that the substrate surface lubricated by this method exhibited more hydrophilic properties. The formation of a featured hydrophilic interface enables the persistence of glycerol molecules in the contact region for an extended duration, thereby facilitating continuous elastohydrodynamic lubrication. This proposed lubrication methodology holds broad utilization potential as a wear-reduction strategy across various industrial fields.
研究领域:
材料科学
·
摩擦学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Wei Wang,Guoxin Xie,Jianbin Luo
Superlubricity is defined as a sliding regime in which friction, or the resistance to sliding of two relatively moving surfaces, almost vanishes. From a practical point of view, the development and use of new materials that can enable superlubricity (coefficient of friction, COF < 0.01) in moving mechanical systems will have huge positive impact on energy-saving and emission reduction. In this work, the use of a new two-dimensional material, black phosphorus (BP) as a high-performance water-based lubricant additive that can significantly reduce friction and achieve superlubricity has been explored. A lowest COF value of 0.0006 ever measured by an application-orientated ball-on-plate tribometer has been found. Robust superlubricity in the aqueous solution with ultrafine BP nanosheets modified by NaOH (BP-OH) has been observed for a wide range of additive concentrations, contact pressures, and sliding velocities owing to the very low shear resistance of the water layer retained by BP-OH nanosheets. This finding has the potential of opening up a new approach to dramatically reduce or even eliminate friction by using BP nanomaterials as lubricant additives.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Jianfeng Li,Wei Cao,Jinjin Li,Ming Ma
Hypothesis Achievement of superlubricity is an effective method to reduce friction and wear, which has a prominent influence on the operational efficiency and lifetime of a device. However, some burning issues still remain to be solved for the practical applications of superlubricity, such as the poor load-bearing capacity, especially in liquid superlubricity. Therefore, exploring an effective method to enhance the superlubricity performance is essential to accelerate the application of superlubricity. Experiments The friction properties between two different self-assembled monolayers (SAMs)—a perfluorocarbon SAM and a hydrocarbon SAM—and graphite in water were explored and compared by atomic force microscopy (AFM). Findings Enhanced superlubricity performance due to the fluorination was observed. Specifically, we observed an approximately 85% reduction of the friction coefficient after fluorination, and superlubricity was achieved with extremely low friction coefficient of 0.0003. Moreover, 2.4-fold greater load-bearing capacity of the superlubricity was obtained after fluorination. The molecular origin of the superlubricity enhancement by fluorination was revealed by molecular dynamics (MD) simulations, indicating that the greater load-bearing capacity of the perfluorocarbon SAM was ascribed to the enhanced interaction between the water and SAM by fluorination to form a more robust layered water structure confined in the contact zone, which played a pivotal role in the superlubricity.
研究领域:
材料科学
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表面科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
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2020
·
IF 0
Xiaoyong Ren,Xiao Yang,Guoxin Xie,Jianbin Luo
In this study, black phosphorus quantum dots (BPQDs) have been successfully prepared at a low cost and high yield by the liquid-based high-energy ball milling method. The obtained BPQDs with an average lateral size of 6.5 ± 3 nm and a thickness of 3.4 ± 2.6 nm dispersed stably in ethylene glycol (EG). A robust macroscale superlubricity state (μ, 0.002) was achieved under a high contact pressure of 336 MPa via the lubrication of BPQDs-EG aqueous suspension (BPQDs-EGaq) at the Si3N4/sapphire frictional interface. The wear rate lubricated by BPQDs-EGaq suspension account for 5.96% of that lubricated by EG aqueous solution (EGaq), demonstrating the improvement in the antiwear property with the addition of BPQDs. The rolling effect of BPQDs and the low shear stress between the BPQDs interlamination played important roles in the improvement in the antiwear property. The oxidative products of BPQDs (PxOy) contributed to the effective realization of macroscale superlubricity. This work realized macroscale superlubricity at a high contact pressure by combining the BPQDs with special liquid molecules and provided the great potential in industrial applications.
研究领域:
材料科学
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摩擦学
✓ 已验证
产品关联
DOI
CARBON
·
2019
·
IF 7.466
Xiangyu Ge,Jinjin Li,Hongdong Wang,Chenhui Zhang,Yuhong Liu,Jianbin Luo
The liquid-superlubricity state has rarely been studied under an average contact pressure exceeding 300 MPa at the macroscale . In this work, a robust macroscale liquid-superlubricity state (μ ≈ 0.005) under an extreme pressure of 600 MPa was reported, which was enabled by the combination of graphene-oxide (GO) nanosheets with an ionic liquid (IL) between the frictional pairs of Si 3 N 4 /sapphire. The analysis indicated that a composite boundary layer (formed by IL) at the interface contributed to the excellent antiwear performance, thereby providing a lubricating condition under extreme pressure. Notably, GO nanosheets were directly observed to adsorb on worn surfaces, thereby proving the transformation of the shear interface from Si 3 N 4 /sapphire into GO/GO nanosheets. The extreme pressure property and extremely low shear stress between the interlayers of GO nanosheets contributed to the achievement of superlubricity. Therefore, the synergistic effect between GO nanosheets and IL played a dominant role in achieving liquid-superlubricity under extreme pressure at the macroscale. This study provided a novel method to achieve liquid-superlubricity under extreme conditions—by the synergistic effect of 2D materials and liquid molecules—accelerating the achievement of liquid-superlubricity in industrial applications.
研究领域:
材料科学
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摩擦学
✓ 已验证
产品关联
DOI
高影响因子
Friction
·
2022
·Vol. 11
·期 7
·1138-1149
·
IF 4.924
Liu Wenrui,Wang Hongdong,Liu Yuhong
Polyalkylene glycol (PAG) aqueous solutions have recently been demonstrated to exhibit an ultralow friction coefficient (COF, μ < 0.01). However, the prolonged running-in period and low bearing capacity have limited its widespread application. In this study, we determined that the running-in period can be decreased by more than 75% when the pH value of the lubricant is controlled at 3 by introducing various acid solutions. Additionally, less time was required to realize stable superlubricity with inorganic acid at lower pH values. This was mainly attributed to the acceleration effect of hydrogen ions around the contact region. In case of PAG aqueous solution with organic acid, the wear loss between sliding solid surfaces was reduced, and thus the bearing pressure during the superlubricity period was significantly improved from approximately 30 to 160 MPa. Furthermore, the organic acid molecules were considered to form strong hydrogen bonds with PAG macromolecules and solid surfaces. This in turn strengthened the structure of the adsorption layers. The unique effect of different acids in aqueous polymer lubrication can potentially significantly aid in advancing the study of polymer tribology and broadening industrial applications.
研究领域:
材料科学
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表面工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Nano
·
2022
·
IF 13.364
K. Wang,L. Liu,Y. Liu,J. Luo
Macroscale superlubricity is a new field that can greatly reduce energy consumption due to friction, which accounts for approximately 30% of human nonrenewable energy. However, prior research on liquid superlubricity mostly involved low contact pressures (<600 MPa). Here, we evaluated the lubrication and adsorption properties of ionic liquid alcohol solutions (ILs (as) ) with different alkyl chain lengths and monovalent anions between Si 3 N 4 and sapphire surfaces. Robust macroscale superlubricity and ultrahigh load capacity exceeding 1 GPa were obtained by protective adsorption layer caused by tribochemical reactions. Zeta potential measurements and simulation analysis revealed that the ceramic interfaces were enriched with numerous ionic liquid (IL) anions, preventing the direct collision of the asperities of the friction pairs. The relatively low sliding energy barrier and extremely strong electrostatic repulsion developed between these asperities enhanced the superlubricity and ultrahigh load capacity. Meanwhile, long alkyl chains and tetrafluoroborate anions more easily met the hydrodynamic boundary conditions at the solid–liquid interface, and the formation of low energy consumption channels through the smooth potential energy fluctuation surface generated extremely low shear stress. Such macroscale lubrication provides a novel method of achieving extremely high contact pressure in ILs (as) , which could enable liquid superlubricity in practical industrial applications.
研究领域:
材料科学
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表面工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·Vol. 34
·期 30
·2316036
·
IF 18.5
Dongxiang Zhu,Jie Zhang,Panpan Li,Zhan Li,Hongxuan Li,Xiaohong Liu,Tianbao Ma,Li Ji,Huidi Zhou,Jianmin Chen
Superlubricity, a cutting-edge concept, has the potential to drive the Fourth Industrial Revolution giving its near-zero energy consumption, but the challenge is how to achieve it in humid air with chemical activity and at macroscale surfaces with unavoidable defects. Here, a novel principle involving the amorphous/crystalline friction pair based on the cognition that tribochemical interaction sites originate from grain boundary defect locations is proposed to achieve macroscale superlubricity in humid air. The absence of grain boundaries in amorphous diamond-like carbon (DLC) significantly reduces chemical interaction during the sliding process. This is supported by experimental observations of priority oxidation at the grain boundaries. Results indicate DLC versus MoS 2 friction pair has weakened chemical interaction and less humid insensitivity compared to the MoS 2 versus MoS 2 pair, even increasing the contact area. Theoretical simulation suggests that DLC versus MoS 2 pair eliminates the cross-linking of friction interlayers induced by the enrichment of H 2 O molecules at MoS 2 defects. The robust superlubricity is achieved for the typical friction pair of DLC versus MoS 2 in air (RH≤25%) at macroscopic contact pressure (1.1 GPa) with friction coefficient in 10 −3 magnitude and extra-long anti-wear life (more than 2 × 10 5 cycles), which is of significance for the industrialization of superlubricity.
研究领域:
材料科学
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摩擦学
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表面工程
✓ 已验证
产品关联
DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2024
·
IF 6.1
Yongfeng Yang,Rui Zhang,Shaowen Dong,Xiaoyang Ma,Jinjin Li
In this study, a stable macroscopic superlubricity state (COF about 0.005) after a short running-in period of 5 s under an ultra-high contact pressure of 1.45 GPa was achieved with the lubrication of polyacrylic acid modified Fe 3 O 4 nanoparticles as additives at the Si 3 N 4 /sapphire interface. The realization of superlubricity can be attributed to the detachment of polyacrylic acid molecules on the modified Fe 3 O 4 nanoparticles surface, which induced the tribochemical reaction between the polyacrylic acid molecules and friction surfaces, generating a tribofilm to prevent the direct contact of the friction pair and provide a low shear strength to reduce friction. The extremely low friction and wear induced by polyacrylic acid modified Fe 3 O 4 nanoparticles may contribute to the development of high-performance lubrication systems.
研究领域:
材料科学
·
摩擦学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）