Abstract
Utilizing fuels blended with nanofluid particles may enhance fuel delivery and combustion in engines. However, the underlying tribochemistry related to fuel delivery when using nanofluids remains unclear. In this study, we investigate fuel lubricity over low-sulfur diesel (D100), diesel fuel containing 10 wt% ethanol (DE10), and DE10 blended with 50 to 200 ppm surface modified graphene oxide (mGO), i.e., G50, G100, and G200. The fuel lubricity experiment shows that as compared to D100, the DE10 fuel produced 50% larger wear volumes on rubbed balls, while lubrication with the G200 fuel reduced wear by 6%. The tribochemical reaction kinetic model developed in this work unravels the lubrication mechanism. The blended mGO reduces direct metal-to-metal contacts, produces graphitic tribofilms on wear tracks, and serves as tribo-active sources to grow frictional products.