Bisurfactant-functionalized TiO2 nanoparticles as additives of the lubricating oil

In this work, TiO 2 nanoparticles modified with octadecylamine and dodecyl mercaptan (DDM/ODA@PDA@TiO 2 NPs) are uesd to improve the tribological properties of the white oil. The DDM/ODA@PDA@TiO 2 NPs which are simply prepared by mussel inspired chemistry and the Michael addition reaction can be facilely dispersed in the white base oil. Tribological measurements showed that the dispersion of the white oil containing 3 wt% DDM/ODA@PDA@TiO 2 NPs displays significant reductions in the friction coefficient and wear scar diameter at room temperature and 75°C. Further XPS investigation shows that the favourable tribological properties of DDM/ODA@PDA@TiO 2 NPs are ascribed to the synergistic effect of tribofilm (Fe 2 O 3 , Fe 3 O 4 , FeS 2 , FeS and FeSO 4 ) and TiO 2 nanofluids.