▎ 摘　　要

NOVELTY - Method for preparing modified graphene, involves (i) providing graphene with an unsaturated carbon six-membered ring, adding the graphene to a reaction kettle and ultrasonically processing the graphene, and (ii) completely melting the graphene, dripping a surface modifier in the reaction kettle, refluxing, subjecting the graphene to addition reaction with the surface modifier, so that the unsaturated carbon six-membered ring is connected with a long-chain carboxyl group having 8-22C, and purifying to obtain the finished product. The surface modifier comprises a first carboxyl compound and a second carboxyl compound. USE - The modified graphene is used in lubricating oil for lubricating mechanical structures (all claimed). ADVANTAGE - The modified graphene improves the dispersibility of graphene in an oily solvent. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a modified graphene comprising a graphene having an unsaturated carbon six-membered ring, where the unsaturated carbon six-membered ring has a long-chain carboxyl group having 8-22C; and (2) a lubricating oil comprising a base oil, and 0.04-0.08 %mass modified graphene, which is uniformly dispersed in the base oil.