Benzotriazole as the additive for ionic liquid lubricant: One pathway towards actual application of ionic liquids

In this paper, we report on the first tribological evaluation of the room temperature ionic liquids (RTILs) compatible lubricant additive. Benzotriazole (BTA) was chosen for study in that it shows good miscibility with imidazole ionic liquids because of similar molecular structure. BTA can greatly improve the tribological behaviors of ionic liquids carrying hexafluorophosphate anions for Steel/Cu-Sn alloy sliding pair mainly because of the alleviation of corrosion. The worn surface of the bronze was investigated by X-ray photoelectron spectroscopy (XPS), which revealed complex tribochemical reactions during the sliding process. A protective film comprised of [Cu(-C₆H₅N₃)] and Cu₂O is formed. Strong interaction between benzotriazole and the surface of Cu alloy was proposed to account for the excellent anti-wear and anti-corrosion improvement capability.