Institute of Spectroscopy, Russian Academy of Science, Fizicheskaya Street 5, Troitsk, Moscow Region 142190, Russia.
J Chem Phys. 2013 Jan 14;138(2):024703. doi: 10.1063/1.4774083.
Interwall interaction energies of double-walled nanotubes with long inner and short outer walls are calculated as functions of coordinates describing relative rotation and displacement of the walls using van der Waals corrected density functional theory. The magnitude of corrugation and the shape of the potential energy relief are found to be very sensitive to changes of the shorter wall length at subnanometer scale and atomic structure of the edges if at least one of the walls is chiral. Threshold forces required to start relative motion of the short walls and temperatures at which the transition between diffusive and free motion of the short walls takes place are estimated. The edges are also shown to provide a considerable contribution to the barrier to relative rotation of commensurate nonchiral walls. For such walls, temperatures of orientational melting, i.e., the crossover from rotational diffusion to free relative rotation, are estimated. The possibility to produce nanotube-based bolt∕nut pairs and nanobearings is discussed.
使用范德华修正密度泛函理论，将双壁纳米管的内管长、外管短的互壁相互作用能作为描述壁相对旋转和相对位移的坐标的函数进行计算。如果至少有一个壁是手性的，那么波纹的幅度和位能缓解的形状对短壁长度在亚纳米尺度和边缘原子结构的变化非常敏感。估计了开始短壁相对运动所需的阈值力以及短壁在扩散和自由运动之间发生转变的温度。结果表明，边缘对同构非手性壁相对旋转的势垒也有很大的贡献。对于这种壁，估计了取向熔化的温度，即从旋转扩散到自由相对旋转的转变温度。讨论了基于纳米管的螺栓/螺母对和纳米轴承的制造可能性。
