Utilization of biodiesel soot particles as additives for improved aqueous lubrication

Biodiesel soot particles (BSPs) and first heat-treated and then acid-treated BSPs (T-BSPs) were employed as lubricant additives for GCr15 steel/316 austenitic stainless steel contacts in aqueous media. Their tribological performances and mechanisms were tested. The result shows that T-BSPs exhibited better lubricating performances than BSPs in aqueous media. Moreover, it is proved that both BSPs and T-BSPs could enter the friction surfaces and prevent the direct steel–steel contact. In addition, T-BSPs exhibited better dispersion in water, which aided uniform adsorption on the friction surfaces, resulting in better friction-reducing and antiwear performances.