tailieunhanh - Báo cáo hóa học: " Radial Corrugations of Multi-Walled Carbon Nanotubes Driven by Inter-Wall Nonbonding Interactions"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Radial Corrugations of Multi-Walled Carbon Nanotubes Driven by Inter-Wall Nonbonding Interactions | Huang et al. Nanoscale Res Lett 2011 6 53 http content 6 1 53 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Radial Corrugations of Multi-Walled Carbon Nanotubes Driven by Inter-Wall Nonbonding Interactions Xu Huang Wentao Liang Sulin Zhang Abstract We perform large-scale quasi-continuum simulations to determine the stable cross-sectional configurations of free-standing multi-walled carbon nanotubes MWCNTs . We show that at an inter-wall spacing larger than the equilibrium distance set by the inter-wall van der Waals vdW interactions the initial circular cross-sections of the MWCNTs are transformed into symmetric polygonal shapes or asymmetric water-drop-like shapes. Our simulations also show that removing several innermost walls causes even more drastic cross-sectional polygonization of the MWCNTs. The predicted cross-sectional configurations agree with prior experimental observations. We attribute the radial corrugations to the compressive stresses induced by the excessive inter-wall vdW energy release of the MWCNTs. The stable cross-sectional configurations provide fundamental guidance to the design of single MWCNT-based devices and shed lights on the mechanical control of electrical properties. Introduction The unique combination of mechanical electronic and biochemical properties of carbon nanotubes CNTs has found a wide range of applications as building blocks in micro nano -electro-mechanical systems MEMS NEMS 1-6 . It has been experimentally demonstrated that mechanical deformation of CNTs is generally coupled with significant changes in the electronic and magnetic properties 4 7 8 . In addition the structural stability of CNT-based devices has become a major concern in their applications. These have motivated continuing experimental 9-11 and numerical studies 12-20 on the stable morphologies of CNTs. Because of their extremely large in-plane rigidity compared to their out-of-plane bending rigidity 21 .