Study of graphene-family nanomaterials as grease additives for electroregulated friction

Graphene (GN)-family materials show significant potential as electroregulated lubrication additives because of their tunable properties under electrical stimuli. However, a comprehensive comparison of their performance under such conditions is lacking, limiting their broader industrial adoption. This study explores the electroregulated friction behavior of GN, graphene oxide (GO), and fluorinated graphene (FG) nanosheets as grease additives. The results indicate that compared with the GO and FG additives, the GN additive demonstrated good antifriction and antiwear performance under constant negative electrical stimulation. It also demonstrates good stability and repeatability in friction regulation under varying electrical conditions, which is attributed to its deposition on contact surfaces, enhancing lubrication. Furthermore, the direction of electrical stimulation affects the oxidation (or defect) level of GN, with reduced oxidation levels (fewer defects) correlated with lower friction. These findings deepen the understanding of graphene-family materials and provide a basis for designing advanced nanoadditives with enhanced electroregulated performance.