Abstract:Graphene oxide(GO) has numerous oxygencontaining groups in its structure,which could be used as the active sites for chemical modification.Octanethiol-GO was prepared by modifying GO with octanethiol,and its structure characterization was carried out by FTIR,XRD,XPS and TGA.The tribological properties of the mixgreases with GO and octanethiol-GO as additives was tested by a fourball machine (according to ASTM D2596-15) and a noncontact 3D surface interferometer.The results show that GO can slightly decrease the friction coefficient and wear rate of base grease.Octanethiol-GO can obviously improve the lubricating property of base grease,which can decrease the friction coefficient by 11.7%,and decrease the wear rate by 31.5%.Mechanism test shows that during friction process,GO particles will adsorb on the contacting surface,and the active sulfur element in the modified GO grease will react with steel balls to generate iron sulfide,which will reduce the friction and wear of steel balls and improve the tribological properties of grease effectively.