Graphene Nanoparticles for Ultralow Friction at Extremely High Pressures and Temperatures

This study uses the molecular dynamics approach to design
graphene
nanoparticles from the graphene sheets seeded randomly and investigates
their lubricity. These nanoparticles are found to provide stable lubrication
at extremely high pressure and temperature of up to 15 GPa and 2000
K, respectively. From the influences of both nanoparticle and graphene,
the friction between the diamond slab and the nanoparticles shows
ultralow values of the friction coefficient of 0.0034–0.0162
under 1–15 GPa and 300 K and 0.0065–0.0338 under 300–2000
K and 1 or 10 GPa. Providing stable lubrication and ultralow friction
under these conditions is the large advantage of graphene nanoparticles.

本研究采用分子动力学（molecular dynamics）方法，基于随机生成的石墨烯片构建石墨烯纳米颗粒，并探究其润滑特性。研究发现，此类石墨烯纳米颗粒可在分别高达15吉帕斯卡（GPa）与2000开尔文（K）的极端高压高温环境下实现稳定润滑。结合纳米颗粒与石墨烯的协同作用，金刚石平板与纳米颗粒间的摩擦系数呈现超低数值：在1~15 GPa、300 K工况下，摩擦系数范围为0.0034~0.0162；在300~2000 K、1或10 GPa工况下，摩擦系数范围为0.0065~0.0338。在上述极端工况下实现稳定润滑与超低摩擦，正是此类石墨烯纳米颗粒的显著优势。