Supplementary information files for "Graphene oxide as an additive in aqueous lubricants for electric drive units: Synthesis, preparation, and tribological performance"

Supplementary files for article "Graphene oxide as an additive in aqueous lubricants for electric drive units: Synthesis, preparation, and tribological performance"This study investigates the tribological performance of graphene oxide (GO) nanosheets as additives in deionized (DI) water. Four different water-based lubricants were prepared, including supernatant and redispersed solutions, both with and without surfactant. GO supernatant had a significantly lower particle size compared to GO redispersed at all pH levels. The results show that in the absence of a surfactant, the addition of 0.06 wt% GO nanosheets led to maximum of 54 % reduction in the average coefficient of friction (COF). The introduction of surfactant further enhanced this effect, reducing the COF by up to 84 %, compared to DI water. The wear track width was also decreased by up to 353.8 %.<br><br>©The Author(s), CC BY 4.0