▎ 摘　　要

A novel thin composite film, which contained both ionic liquids (ILs) and graphene, was fabricated successfully on silicon substrate using a dip-coating method. The formation and surface properties of the films were analyzed using scanning electron microscopy (SEM) and multifunctional X-ray photoelectron spectroscopy. A ball-on-plate tribometer was used to evaluate the influence of graphene content on the microtribological performance of the thin composite films. The results showed that compared to the single IL film deposited directly on the silicon surface, the as-prepared IL-graphene (IL-G) film showed improved friction reduction properties, which was attributed to the synergistic effect of IL and graphene. The composite IL-G film also exhibited decreasing wear resistance compared to the single IL film. We postulate that this is due to the fact that IL films become more discontinuous with the incorporation of graphene powder. This was verified by SEM imaging, which showed that the film was not continuous enough to prevent direct contact between the steel ball counterpart and Si surface.