Tris-based protic ionic liquids with multiple adsorption effects enabling excellent anti-wear and anti-corrosion performances

Molecular additives have garnered widespread attention in the fields of lubrication and corrosion protection due to their designable interfacial film-forming efficiency. Herein, three protic ionic liquids (PILs) with the same cation but different anions have been designed and synthesized. Their physicochemical properties, tribological properties and anti-corrosion properties were systematically investigated. Results demonstrated that under dynamic steel-on-steel friction conditions, the PILs can maximally reduce the running-in period, friction coefficient, and wear rate by 90 %, 40 %, and 97 %, respectively, compared to the commercial ionic liquid, BMIMPF 6 . Under static copper corrosion conditions, the PILs efficiently adsorb onto the copper surface and formed a dense oxide layer on its surface, thus achieving excellent corrosion protection for the copper substrates. Molecular dynamics (MD) simulation results indicate that the exceptional lubricity of PILs is due to its ability to rapidly adsorb onto the metal surface through multiple interaction sites on both its anionic and cationic components, thereby reducing the running-in period and swiftly establishing a lubricating film. This study provides insights into the development of molecular additives featuring multiple adsorption sites, with potential applications in the fields of tribology and corrosion engineering.