Tribological properties of molybdenum disulfide nanosheets by monolayer restacking process as additive in liquid paraffin

Molybdenum disulfide nanosheets were prepared by monolayer restacking process. Results of transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and scanning electron microscopy (SEM) showed that the obtained MoS2 nanosheets had a thickness about 30–70 nm. The tribological properties of the so-prepared MoS2 nanosheets were investigated on a MQ-800 four-ball tribometer. The results showed the base oil with MoS2 nanosheets had better friction reduction, wear resistance and extreme pressure than those with commercial micro-MoS2. The good tribological properties of MoS2 nanosheets were mainly ascribed to the surface effect and the dimension effect of nanoparticles. Moreover, the formation of MoO3 and FeSO4 complex film on the rubbed surface also played an important role in friction reduction and wear resistance.