Design and Characterization of Lubricants Based on Functionalized Nanoparticles

Abstract

The main objective of this PhD thesis is to design and characterize efficient nanolubricants based on three polyalphaolefins (PAOs) and nanoparticles (NPs) of metal oxides or ceramics coated with organic acids for wind turbine gearboxes and electric transmissions of electric vehicles. First, preliminary tests and an in-depth literature survey on the time stability and tribological behavior of nanodispersions containing chemically modified nanoadditives were performed. Then, the thermophysical and tribological properties of PAO nanolubricants containing coated NPs (ZnO-OA, TiO2-OA, or SiO2-SA) were evaluated; in addition, possible tribological mechanisms were analyzed by confocal Raman microscopy. All the coated NPs studied improve the tribological behavior of their base oil, being the best the SiO2-SA NPs.