Self-dispersed molybdenum disulfide quantum dot/graphene crumpled ball as efficient high temperature lubricant additive

Abstract

Inorganic nanoparticles have been proved as powerful lubricant additives at elevated temperature. However, the tribological properties are inevitably impaired due to poor dispersion and insufficient high temperature resistance of organic matter modified nanoparticles. Here, we prepare a self-dispersed molybdenum disulfide quantum dot/graphene crumpled ball (MGCB) comprising molybdenum disulfide quantum dot uniformly interspersed on the wrinkled graphene ball. The crumpled ball composite possesses excellent dispersity in polyalkylene glycol base oil without depending on surface modifiers. Compared with the conventional phosphate esters lubricant, our results indicate MGCB could vastly improve the lubrication performance of polyalkylene glycol with an extremely low concentration (0.05 wt%) at elevated temperature (150 °C), showing a friction reduction of 47% and a wear reduction of 30% compared with the conventional phosphate esters lubricant (tricresyl phosphate, TCP). This is because crumpled ball potentiates synergistic lubrication effect within the boundary lubrication. Overall, we envision our designed self-dispersed MGCB has significant potential in tribological application at elevated temperature.