Double hybrid lubricant additives consisting of a phosphonium ionic liquid and graphene nanoplatelets/hexagonal boron nitride nanoparticles
Khodor I. Nasser, José M. Liñeira del Río, Fátima Mariño, Enriqueta R. López, Josefa Fernández
Abstract
Tribological performance of polyalphaolefin 32, PAO, is investigated by adding two nanomaterials (graphene nanoplatelets, GnP, and hexagonal boron nitride nanoparticles, h-BN) and an ionic liquid ([P6,6,6,14][DEHP], IL1, [P2,4,4,4][DEP], IL2, or [P6,6,6,14][(iC8)2PO2], IL3). Designed double hybrid nanodispersions are PAO/1 wt% ILX/0.05 wt% GnP/0.1 wt% h-BN (X = 1, 2 or 3). The best anti-friction behavior corresponds to PAO/IL3/GnP/h-BN (40% reduction compared to that achieved with PAO). Anti-wear behavior is similar for the three double hybrid nanodispersions. Roughness of the worn surface tested with PAO is higher than that obtained for each of the nanodispersions. Tribo-film formation and repair effect on worn surfaces due to ILs and nanoparticles are revealed. Some positive synergies were found between each IL and GnP/h-BN as hybrid PAO additives.