Liñeira del Río, José ManuelFernandes, Carlos M.C.G.Gonçalves, David E.P.Seabra, Jorge H.O.2024-12-102024-12-102024-02-16Liñeira del Río, J.M.; Fernandes, C.M.C.G.; Gonçalves, D.E.P.; Seabra, J.H.O. Synergistic Effects of Functionalized WS2 and SiO2 Nanoparticles and a Phosphonium Ionic Liquid as Hybrid Additives of Low-Viscosity Lubricants. Lubricants 2024, 12, 58. https://doi.org/10.3390/ lubricants12020058https://hdl.handle.net/10347/38063This research shows the antifriction and antiwear synergies between a phosphonium ionic liquid (IL) and f-WS2 and f-SiO2 nanoparticles (NPs) as additives of a base oil with low viscosity (PAO6). Mass concentrations of 0.1 wt% nanoadditives and 1% IL were selected to formulate the nanolubricants. Pure sliding and rolling–sliding friction tests were performed at 120 °C, finding great friction reductions in comparison with the PAO6 base oil, specifically for the double hybrid nanolubricant (PAO6 + 1 wt% IL + 0.1 wt% f-WS2 + 0.1 wt% f-SiO2). Regarding the wear produced, the greatest antiwear behavior was also achieved for the double hybrid nanolubricant (width reduction of 48% and worn area decrease of 84%). Furthermore, by means of Raman microscopy and roughness examination of the worn surfaces, it can be proposed that the lubrication mechanism of doubled hybrid nanolubricants could be supported by the adsorbed tribofilm (IL and f-WS2) as well as the mending effects (f-WS2 and f-SiO2).eng© 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) licensehttp://creativecommons.org/licenses/by/4.0/Ionic liquidsNanoparticlesFrictionWearjournal article10.3390/lubricants12020058open access