Lubrication Properties of the Ionic Liquid Dodecyl-3 Methylimidazolium bis(trifluoromethylsulfonyl)imide

Abstract

The ionic liquid (IL) dodecyl-3 methylimidazolium bis(trifluoromethylsulfonyl)imide was tested as neat lubricant and as additive (at 1 and 4 wt%) in a polar oil (diester). Tribological tests were performed using a reciprocating configuration for 90 min at 30 and 70 N, 10 Hz, 4 mm stroke length, and at room temperature and 100 °C. Wear volume and surface–IL interaction were determined by confocal microscopy, SEM, and XPS. The main findings were: Neat ionic liquid showed the best tribological behavior; the IL-containing mixtures had similar behavior than the base oil at the lower load; meanwhile, the mixture with 4 wt% of IL outperformed the antiwear behavior of the neat base oil at the higher load; surface–IL chemical interaction was found mainly at 100 °C.