Tribological properties of physically modified fluorinated graphene and soluble starch hybrid as water-based lubricating additive system

In this study, a hybrid additive system of soluble starch (SS) and physically modified fluorinated graphene (FG) with excellent friction-reduction and anti-wear properties was designed to meet the future demand for water-based lubrication. The modified FG nanosheets with amphiphilicity were obtained from the high-speed shear exfoliation of fluorinated graphite with surfactants. The modified FG significantly improves the load-bearing and boundary lubrication performances of the water-based lubricant via forming boundary lubricating film, while SS further enhances the friction-reduction and boundary film formation performances, especially during the running-in period. At the best ratio (0.3 wt% FG and 0.6 wt% SS), the hybrid lubricant synergistically reduces the corresponding friction coefficient and wear rate by around 90%.