Multiscale investigation of electrically induced friction modulation and interfacial dynamics of ionic liquids with varying chain lengths

Ionic liquids (ILs), as novel electric-controlled lubricants, can regulate their tribological behavior under electrified sliding. This study systematically investigates the tribological properties and interface adsorption dynamics of ILs with different chain lengths under electric field control, combining macroscopic experiments and molecular dynamics simulations. Compared to the base lubricant, longer-chain ILs form more stable tribofilms at the electrified interface, reducing the friction coefficient and wear volume by 33.13 % and 79.61 %, respectively. The −COO – group plays a dominant role in tribofilm formation and alters the dynamic migration of ILs. The applied electric field weakens the hydrogen bonding between ILs and the base lubricant, promotes ILs accumulation at the electrified interface, and effectively reduces shear stress.