Long-term sustainability and decreasing amount of fossil oil reserves require a partial
or complete transformation of traditional lubricating oils. The use of silica nanoparticles
as a lubricant additive has a huge tribological potential, which has already been
discussed in numerous articles. Nanosized silica shows excellent results in reducing
friction and preventing wear, but they quickly aggregate and settle after homogenization
in oils. For long-term stable dispersion of lubricating oils containing nanoceramics,
the surface of the particles was modified with ethyl oleate. The surface modification,
the ethyl oleate applied to the surface of the nanosilica, was confirmed by Fourier-transform
infrared spectroscopy. Group III based lubricating oil was prepared using the surface-modified
nanosilica. The particle size of the nanoparticles in the lubricating oil dispersion
was examined by dynamic light scattering. Oscillating tribometer measurements were
performed with different concentrations (0.1; 0.2; 0.3 wt%) of nanolubricants. Based
on the tribological results, the friction coefficient of the surface-modified nanosilica
is more stable, its wear is 15% lower compared to the reference. There is no significant
change in the magnitude of the friction coefficient. It can be concluded that the
ethyl oleate surface modification method may be suitable for tribological investigations
of the acting mechanisms of nanoparticles.
