Lubrication effectiveness investigation on the friendly capped MoS2 nanoparticles

The compatibility and effectiveness of nanoparticles with the existing additives in formulated oil are still unclear. In the present study, some lubricant additives were selected to modify nanoparticles to obtain friendly capped nano-MoS2. Various polyisobutyleneamine succinimide (PIBS) concentrations were applied to investigate the lubrication effectiveness of capped nano-MoS2. The results showed that the reduction in COF and wear volume of friendly capped nanoparticles without PIBS reached about 35% and 75% in comparison with those of the base oil respectively. However, the average coefficient of friction and wear volume loss of nano oil increased with PIBS concentration in the range of 0.05%-1%. By scanning electron microscope, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy analysis, it is identified that ( i) MoS2 tribofilm was formed on the wear track for the oil with nano-MoS2 and (ii) wear scar was smooth for nano-MoS2 with low PIBS concentration and without PIBS, while it showed plowing wear when containing high PIBS concentration. Copyright (C) 2016 John Wiley & Sons, Ltd.