▎ 摘　　要

Imidazolyl dinitrile amine salt was used as a high-quality alternative to intercalation agent and modifier for achieving the exfoliation of graphite into modified graphene via the assistance in low applied voltage. Asprepared modified-graphene was divided into three samples with different size through centrifugation. Surface/interface techniques and analysis ensure the successful preparation and high-density modification of graphene. The modified graphene could steadily disperse in polyethylene glycol 200 (PEG200) and improve the tribological behaviors, especially thinner and smaller modified-graphene with lower friction and wear (reduce by 16% and 25.9%, respectively). Such significant lubrication function comes from modified-graphene and asformed protective layer on the mating interfaces. Moreover, the additive was transformed into an overlapping and ordered-sheet structure under the interfacial interaction.