论文标题
在石墨烯晶界上滑动：迈向宏观尺度的一步
Sliding Over Graphene Grain Boundaries: A Step Towards Macroscale Superlubricity
论文作者
论文摘要
鉴于朝宏观的石墨接触型宏观润滑性的竞赛，晶界对其摩擦特性的影响变得至关重要。在这里，我们阐明了沿典型的晶界表征拓扑缺陷的独特摩擦机制，这些差异可能从几乎平坦到高度瓦楞纸，具体取决于边界不合适的角度。我们发现，晶界的摩擦能量耗散可以源于沿表面的可压缩性的变化，在缺陷（UN）屈曲事件中产生的热量以及在不可逆的屈曲过程中弹性能量存储。这些可能导致平均摩擦对正常载荷的非典型非单调依赖性。本研究中获得的知识构成了朝着实现宏观石墨接触中高级润滑性的重要一步。
In light of the race towards macroscale superlubricity of graphitic contacts, the effect of grain boundaries on their frictional properties becomes of central importance. Here, we elucidate the unique frictional mechanisms characterizing topological defects along typical grain boundaries that can vary from being nearly flat to highly corrugated, depending on the boundary misfit angle. We find that frictional energy dissipation over grain boundaries can originate from variations of compressibility along the surface, heat produced during defect (un)buckling events, and elastic energy storage in irreversible buckling processes. These may lead to atypical non-monotonic dependence of the averaged friction on the normal load. The knowledge gained in the present study constitutes an important step towards the realization of superlubricity in macroscopic graphitic contacts.
