▎ 摘　　要

The main goal of this work is to study the tribological properties of nanolubricants formed by trimethylolpropane trioleate (TMPTO) or a polyalphaolefin (PAO 40) base oils with reduced graphene oxide sheets (rGO). This reduction was carried out in order to have a good stability of the nanoadditives in the fluids. For this aim, rGO nanopowders were prepared by thermal reduction of graphene oxide (GO) powders using KOH/ethanol as reducing agent. Tribological behavior of nanolubricants based on TMPTO and on PAO 40 oils with 0.05, 0.10, 025 and 0.50 wt% of rGO was evaluated. The tribological tests were carried out with a tribometer operating in ball on disk configuration and rotational mode under a working load of 20 N at room temperature. In order to analyze the wear track through the width, depth and cross-section area of the scar, a 3D optical profilometer was used. The best antifriction performance was found for 0.25 wt% rGO nanodispersions, with a 24% and a 20% enhancement for the PAO 40 and the TMPTO base oils, respectively. Moreover, for this last nanodispersion, a reduction of 24% in the wear track width was obtained. (C) 2018 Elsevier B.V. All rights reserved.