▎ 摘　　要

NOVELTY - Modified graphene oxide is prepared by using graphene oxide as a raw material and modifying the surface of graphene oxide with long-chain aliphatic amine and/or silane coupling agent. USE - Modified graphene oxide is useful as a friction modifier in engine lubricating oil (claimed). ADVANTAGE - The modified graphene oxide reduces abrasion of engine so that automobile engine oil drain intervals is prolonged from 5000-50000 km, and can save 7-10% fuel. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) the preparation method of the modified graphene oxide, which involves (a) dissolving long-chain fatty amine in ethanol, (b) uniformly mixing, (c) pouring the mixture into graphene oxide-containing aqueous solution, (d) heating, (e) naturally cooling to room temperature, (f) filtering the reaction solids, (g) washing the solid with ethanol and (h) drying to obtain modified graphene oxide; and (2) an engine lubricating oil, which comprises 1-2.2 wt.% friction modifier, 0.5-1.1 wt.% metal cleaner, 0.2-1.2 wt.% metal corrosion inhibitor, 2-2.5 wt.% antioxidant, 0.05-0.1 wt.% defoaming agent, 1-1.2 wt.% dispersing agent, 8-10 wt.% viscosity index improver, 8-10 wt.% synthetic ester base oil and balance of hydrogenation base oil, where the friction modifier comprises the modified graphene oxide.