Synergistic lubrication of a porous MoS₂-POSS nanohybrid

A porous MoS₂-polyhedral oligomeric silsesquioxane (POSS) nanohybrid was prepared from octavinyl-POSS nanoparticles and MoS₂ nanosheets for the first time, the structure and composition of which were confirmed by X-ray powder diffraction (XRD), Fourier-transform infrared spectra (FTIR), scanning electron microscopy (SEM), energy dispersive spectra (EDS) and thermal gravimetric analysis (TGA). As a comparison, MoS₂ nanosheets, octavinyl-POSS and MoS₂-POSS nanohybrid were used as lubricating additives for liquid paraffin (LP), which decreased the friction coefficients of LP by 7.8% (MoS₂), 14.1% (octavinyl-POSS), and 18.8% (MoS₂-POSS). Compared with MoS₂ and octavinyl-POSS, the MoS₂-POSS nanohybrid can be dispersed in organic solvents more homogeneously without adscititious dispersants or surfactants due to its better organic compatibilities. SEM and EDS analyses indicate that a synergistic frictional effect is responsible for the improved friction-reduction and anti-wear behavior.