Synergistic lubricating effect of graphene/ionic liquid composite material used as an additive

• Published in: Friction Vol. 9; no. 6; pp. 1568 - 1579
• Main Authors: Liu, Lincong, Zhou, Ming, Mo, Youtang, Bai, Pengpeng, Wei, Qilin, Jin, Long, You, Shengli, Wang, Mingyue, Li, Liangchuan, Chen, Xin, Li, Xiao, Tian, Yu
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01-12-2021; Springer Nature B.V
• Subjects: Coefficient of friction; Composite materials; Corrosion and Coatings; Engineering; Graphene; Ionic liquids; Ions; Lubricating oils; Lubricating properties; Mechanical Engineering; Nanotechnology; Oil additives; Physical Chemistry; Research Article; Rubbing; Surfaces and Interfaces; Thin Films; Tribology; Wear; protective films; ionic liquid (IL); grapheme (G); synergistic lubrication; out-of-plane puckering mechanism
• ISSN: 2223-7690; 2223-7704
• DOI: 10.1007/s40544-020-0442-8

We prepared a graphene/ionic liquid (G/IL) composite material by the hybridization of G and an IL for use as a lubricating oil additive. The friction coefficient and wear volume of a base oil containing 0.04 wt% of the G/IL composite was reduced by 45% and 90%, respectively. Furthermore, the base oil containing the G/IL composite exhibited better lubricating properties than the base oil containing G, IL, or a mixture of IL and G at the same mass fraction. A synergistic lubrication mechanism was also revealed. The G/IL composite was adsorbed and deposited on the wear surface, forming a more ordered protective film and a unique tribochemical reaction film during rubbing. Therefore, the G/IL composite exhibited the synergistic lubricating effects of G and IL, which significantly improved the lubricating performance of the base oil. This study also suggested a way to limit the out-of-plane puckering of G at the macroscale.