论文标题
物理纳米管的摩擦：滚动还是滑动？
Friction of Physisorbed Nanotubes: Rolling or Sliding?
论文作者
论文摘要
理论上，基于最先进的原子间力场的模拟，从理论上询问了在石墨烯上沉积在石墨烯上的碳和H-BN纳米管（NTS）的结构和运动。结果表明，任何典型的圆柱体对面近似基本上都是不准确的。 NT倾向于在与基板的界面上平坦，然后在驾驶时，它们可以根据其大小和与基板的相对取向滚动或滑动。在外延相位的方向中，我们发现滚动始终是运动的主要机理，产生了与壁数线性生长的动力学摩擦，进而导致前所未有的超线性缩放与接触区域。 30度的未对准会引起超润滑作用，从而使滑动良好。通过在大型多壁管中出现的刻面侧面解释了未对准NTS的滚动到滑动的过渡，这是导致旋转刚度增加的。修改几何条件提供了一种在这个独特的摩擦学系统中严重调整摩擦特性的额外手段。
The structure and motion of carbon and h-BN nanotubes (NTs) deposited on graphene is inquired theoretically by simulations based on state-of-the-art interatomic force fields. Results show that any typical cylinder-over-surface approximation is essentially inaccurate. NTs tend to flatten at the interface with the substrate and upon driving they can either roll or slide depending on their size and on their relative orientation with the substrate. In the epitaxially aligned orientation we find that rolling is always the main mechanism of motion, producing a kinetic friction linearly growing with the number of walls, in turn causing an unprecedented supra-linear scaling with the contact area. A 30 degrees misalignment raises superlubric effects, making sliding favorable against rolling. The resulting rolling-to-sliding transition in misaligned NTs is explained in terms of the faceting appearing in large multi-wall tubes, which is responsible for the increased rotational stiffness. Modifying the geometrical conditions provides an additional means of drastically tailoring the frictional properties in this unique tribological system.
