▎ 摘　　要

NOVELTY - Preparation of functionalized graphene powder comprises soaking graphite material as electrode in aqueous cationic surfactant solution as electrolyte solution to peel off graphite material and obtain electrolyte solution in which graphene powder is dispersed. USE - Method for preparing functionalized graphene powder used in preparing composite lubricating oil for mechanical parts (claimed). ADVANTAGE - The method modifies graphene material to obtain cationic surface activity which improves its lubricating property and dispersion stability. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) composite lubricating oil comprising 87.45-95.965 pts. wt. base oil, 0.025-2.5 pts. wt. functionalized graphene powder, 3-7 pts. wt., preferably 5 pts. wt. dispersant, 0.01-0.05 pt. wt., preferably 0.02 pt. wt. antifoaming agent, and 1-3 pts. wt., preferably 1.5 pts. wt. microemulsion aid; and (2) preparation of composite lubricating oil comprising mixing one part base oil with dispersant and antifoaming agent at 3000-5000 revolutions/minute (rpm) for 15-30 minutes to obtain component (i), mixing remaining base oil with functionalized graphene powder and microemulsion aid at 50000-8000 rpm for 10-20 minutes, and homogenizing at 60-80 degrees C and 40-60 MPa to obtain component (ii); and mixing component (i) and component (ii) at 3000-5000 rpm for 40-60 minutes, and kneading mixture. The base oil is mineral base oil, synthetic base oil, and/or bio-base oils. The dispersant is monoalkenyl succinimide. The anti-foaming agent is dimethyl silicone oil. The microemulsion aid is propylene glycol.