title: Thermal-gradient-induced interaction energy ramp and actuation of relative axial motion in short-sleeved double-walled carbon nanotubes.
abstract: We investigate the phenomenon of actuation of relative linear motion in double-walled carbon nanotubes (DWNTs) resulting from a temperature gradient. Molecular dynamics simulations of DWNTs with short outer tube reveal that the outer tube is driven towards the cold end of the long inner tube. It is also found that the terminal velocity of the sleeve roughly depends linearly on the applied thermal gradient. We calculate the inter-tube interaction energy surface which is revealed to have a gradient depending upon the applied thermal gradient. Consequently, it is proposed that the origin of the thermophoretic motion of the outer tube may be attributed partially to the existence of such an energy gradient. A simple analytical model is presented accounting for the gradient in energy profile as well as the effect of biased thermal noise. It is shown that the proposed model predicts the dynamical behaviour of the long-time performance reasonably well.
authors: School of Materials Science and Engineering, Nanyang Technological University, Singapore.
authors: Prathamesh M
authors: PM
authors: Shenai
authors: Zhiping
authors: Z
authors: Xu
authors: Yang
authors: Y
authors: Zhao