JOURNAL OF MOLECULAR LIQUIDS
·
2023
·
IF 6
Haocheng Wang,Yi Li,Songwei Zhang,Qinglun Che,Litian Hu,Jianjun Zhang
Although carbon dots (CDs) have attracted much attention due to their excellent lubricity and high load-carrying capacity as lubricant additives, the deficiency of easy agglomeration and the feature of solid state still restrict the application of CDs in the field of lubrication engineering. In order to break through the above limitations, novel liquid CD materials, carbon dot-based ionic liquids (CDILs), were synthesized via ionic modification of CDs with organic ammonium cations endowing new functions as novel liquid lubricants, which demonstrates that CDILs provide better lubrication performance than classical ILs ([BMIM][BF 4 ]) and at room and high temperature (30 °C and 100 °C). More importantly, the newly synthesized [N888H][CDs] containing tertiary ammonium cations with long alkyl chains exhibits the best lubrication performance. The resultant analyses give direct evidence that CD anions play a surprising role in improving the lubricity and protecting the steel/steel friction pairs, growing robust tribofilm with abundant CDs on the worn surfaces. Hence, it can not only offer fundamental insights into the formation of the tribofilm, but also provide a method for modifying CDs to promote their lubricity as liquid lubricants.
研究领域:
材料科学
·
润滑工程
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2023
·
IF 3.9
Shaonan Du,Chenhui Zhang,Zhi Luo
In this article, five kinds of 1,3-diketones and their chelates with different molecular structures were prepared, and their tribological properties were tested. The experimental results show that the running-in time and friction coefficient of the friction pairs lubricated by 1,3-diketones containing a benzene ring increased with the increase of the carbon chain length. In addition, only the friction pair lubricated by 1-(4-ethylphenyl)-butane-1,3-dione (0201) and 1-(4-ethylphenyl)-nonane-1,3-dione (0206) could achieve stable superlubricity. When the benzene ring was replaced with a carbon six-membered ring, it was found that although the friction pair lubricated by this lubricant could achieve superlubricity, the wear of the friction pair was severe, and obvious abrasive wear occurred. In addition, the lubricants prepared by mixing 1,3-diketones and the corresponding chelates in a ratio of 4:6 had greatly improved lubricating properties compared to 1,3-diketones. Through X-ray photoelectron spectroscopy (XPS) analysis of the surface of the friction pair after the test and Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) analyses of 1,3-diketones before and after the experiment, we found that the necessary conditions for the friction pair lubricated by 1,3-diketone to achieve superlubricity were formation of tribochemical adsorption films and the presence of chelates in solution.
研究领域:
材料科学
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化学工程
·
机械工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2025
·
IF 3.9
Junting Dong,Guoliang Zhang,Fucong Liu,Houjun Qi,Kan Xing
COF-5 is an excellent choice as a lubricant additive due to its high specific surface area and regular layer stacking structure. In this paper, the porous covalent organic frameworks of the COF-5 nanomaterial were successfully synthesized as a lubricant additive via a method of sonochemical synthesis. Pure [BMIM][SCN] (BS) was used as the base oil, and the tribological properties of the COF-5-BS composite lubricant were evaluated by using a ball-on-disk wear tester. The results were demonstrated that the wear volume of BS with the addition of 0.1 wt % COF-5 was reduced by 46.64% as compared to that of the pure BS, and the corrosion on the friction interface was effectively inhibited by the addition of COF-5 nanomaterial. This phenomenon was ascribed to COF-5 with a large specific surface area, being adsorbed onto the friction interface, which could repair the wear-induced pits and prevent the direct contact between the metal substrate and the corrosive medium. The tribological properties of the COF-5-BS composite lubricant could be efficiently regulated under the applied electric current. The results of intelligent electric current-controlled friction were indicated that the average coefficients of friction (COF) under the current stimulation of 30 mA with on/off cycling were reduced by 12.05% as compared to that of a continuous current operated for 1 h. Moreover, the wear volume and depth were reduced by 11.69% and 8.75%, respectively. That is because the short duration of current regulation could enhance the rapid formation of a lubricant film composed of BS liquid and COF-5 nanosheets on the friction interface. Meanwhile, the temperature on the interface would not be high to produce the failure of lubricating film, resulting in an excellent low friction coefficient and excellent antifriction property.
研究领域:
材料科学
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摩擦学
·
表面工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2022
·
IF 4.331
Xiangli Wen,Pengpeng Bai,Yonggang Meng,Liran Ma,Yu Tian
Ceramic friction pairs lubricated with chlorinated-phenyl and methyl-terminated silicone oil (CPSO) systems have potential applications in the aerospace industry. In this study, the effects of the running-in process and temperature on the lubricating performance of CPSO were investigated. The superlubricity of Si3N4/sapphire lubricated with CPSO was realized at >190 °C after H+-ion running-in. The mechanism of this high-temperature superlubricity was investigated by determining the stable adsorption configurations and adsorption energies of CPSO on different surfaces using density functional theory calculations. Compared with that on the Si3N4 surface, the adsorption capacity of CPSO on the hydroxylated SiO2 surface generated by H+-ion running-in increased, whereas the steric hindrance decreased. The viscosity–temperature curve of CPSO was measured, wherein the viscosity and pressure–viscosity coefficient of CPSO considerably decreased with increasing temperature, leading to high-temperature superlubricity in a wide speed/load range. This is the first paper to report oil-based superlubricity at temperatures of 190 °C, or even higher-temperature conditions. Furthermore, it provides guidance for the use of ceramic–CPSO systems in high-temperature conditions, including in the aerospace industry.
研究领域:
材料科学
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摩擦学
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航空航天工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TRIBOLOGY INTERNATIONAL
·
2024
·
IF 6.1
Qiang Gao,Qingyao Li,Wenhao Chen,Wenpeng Wang,Zixiang Wu,Zhuopei Zhang,Yong Wan,Yange Feng,Daoai Wang
The wear of friction pairs, especially under current-carrying conditions, significantly reduces equipment performance and service life due to electric arc erosion. This study employs laser surface texturing on copper blocks to create microporous structures, with polyaniline grease synthesized in situ based on these microscale reactors to reduce material wear and arc erosion. Results demonstrate that this method effectively fills the microporous with grease, ensuring grease supply under starved lubrication and long-term stable operation of friction pairs. The textured sample with a diameter of 140 µm at 6 A exhibits a 74.3 % reduction in coefficient of friction, 2.7 times less wear, extremely low arc erosion, and an electrical contact resistance of only 2.5 mΩ, maintaining stable tribological performance even after 21,600 cycles.
研究领域:
材料科学
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摩擦学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
TRIBOLOGY LETTERS
·
2025
·Vol. 73
·期 2
·1-15
·
IF 3.3
Zhang Xiaosheng,He Xuexue,Ma Chong,Kong Xiaowei,Li Gangsen,Qiao Li,Zhang Yanfei,Li Kangwei,Ma Jingyi,Zheng Yuewei,Liu Lei
Developing and utilizing high-extreme pressure (EP) performance solid lubricants has become imperative to meet the lubrication requirements for harsh operating conditions. Based on the action mechanism of rare earth on alloys, the influence of material corrugated layered crystal structure, and sulfur content on lubrication properties at the atomic and molecular levels, layered rare earth sulfates have become a new type of high EP performance solid lubricants. Herein, we prepared layered rare earth sulfate materials (RE 2 (OH) 4 SO 4 ·nH 2 O, RE = La/Sm/Ce, i.e., RES, LaS, SmS, CeS, respectively) using a mild hydrothermal method for controlled particle size and morphology. To evaluate its applicability, we tested the new solid lubricants against high load, high temperature, long-term, different friction pair materials, and fretting. Overall, the RES samples exhibited excellent lubricating behavior when added to polyurea grease, better than MoS 2 . By adding layered lanthanum sulfate, samarium sulfate, and cerium sulfate, the seizure loads can reach up to 1400, 1300, and 1300 N, respectively. Microscopic analysis of the friction pairs confirmed that the lubricating films formed on the worn surface during friction. Excitingly, the RES materials exhibited excellent synergistic effects on EP performance and corrosion resistance. Thus, these materials have broad application prospects as lubricants. Graphical
研究领域:
材料科学
·
机械工程
·
摩擦学
·
无机化学
·
纳米技术
✓ 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）