Mechanism of Multilayer Graphene/Ionic Liquid Synergistic Regulation of Interface State under Current‐Carrying Friction

Abstract

Herein, improving the conductivity of the lubricant itself is the main idea behind current‐conductive lubricant designs. However, as per previous studies, the interface state has a more dominant influence on the interface conductivity than the conductivity of the lubricant. Therefore, improving the interface state is a more direct and effective way to improve the interface conductivity. In this study, improving the interface state is the primary idea underlying the design of a conductive lubricant. Multilayer graphene/ionic liquid (MG/IL) composites with excellent interfacial adsorption properties are prepared using IL non‐covalently modified graphene. Subsequently, corresponding conductive greases are synthesized using MG, IL, and MG/IL as additives. The lubricating and conductive properties of these greases are characterized by performing current‐carrying friction tests. In the results, it is shown that when MG/IL is used as an additive, the grease exhibits excellent lubricating performance and the lowest average contact resistance. This finding is primarily attributed to the MG and IL in MG/IL acting synergistically to improve the interface state significantly, which decreases the contact resistance and increases the conductivity of the friction interface. In this work, a novel idea is provided for the design of conductive lubricants.