▎ 摘　　要

NOVELTY - Producing graphene oxide comprises (a) forming an amide bond between a carboxy group distributed at edge of graphene oxide (GO) and an amino group of ethylenediamine to synthesize an amino-GO material, and (b) performing nucleophilic substitution reaction between the amino-GO material and alkyl chloride, where chlorine functions as a good leaving group to form an alkyl-functionalized oxidized graphene (FGO). USE - The graphene oxide is useful to produce oil-based lubricant (claimed). ADVANTAGE - The graphene oxide improves abrasion resistance by reducing friction coefficient of 5.88% and wear track width of 3.8% compared to conventional polyalphaolefin oil under ball-on-disk rubbing despite very low concentration of 0.02 weight. The oil-based lubricant has long-term dispersion stability due to van der Waals interaction between alkyl chain of alkylamine and alkyl chain of lubricating oil. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing oil-based lubricant, comprising (i) preparing graphene oxide by performing steps (a) and (b), and (ii) dispersing the alkyl-FGO in oil having predetermined wt.% concentration, preferably 0.01-0.03 wt.%.