▎ 摘　　要

NOVELTY - Surface-modified graphene-based lubricating oil additive comprises 0.002-1 mass% surface-modified graphene, where graphene surface is modified by bile acid or its derivative. USE - Surface-modified graphene-based lubricating oil additive used for commercial vehicle lubricating oil to prepare surface-modified graphene-based lubricating oil (claimed). ADVANTAGE - The preparation of surface-modified graphene-based lubricating oil additive is simple and easy and suitable for large-scale industrial implementation and has high repeatability. The surface-modified graphene-based lubricating oil additive has good dispersibility and anti-friction property, increases lubricity of lubricating oil and reduces engine wear and tear. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) preparation of surface-modified graphene-based lubricating oil additive comprising preparing graphene, dispersing in water to prepare diluted solution, adding bile acid or its derivative aqueous solution, dropwise adding reducing agent, reacting and obtaining the product; and (2) preparation of surface-modified graphene-based lubricating oil comprising adding 0.002-1 mass% (based on the mass of lubricating oil) surface-modified graphene-based lubricating oil additive to lubricating oil, and stirring to obtain the product.