Elastic moduli of multi-walled carbon nanotubes and the effect of van der Waals forces

This paper reports a study of the elastic behavior of multi-walled carbon nanotubes (MWCNTs). The nested individual layers of an MWCNT are treated as single-walled frame-like structures and simulated by the molecular structural mechanics method. The interlayer van der Waals forces are represented by Lennard-Jones potential and simulated by a nonlinear truss rod model. The computational results show that the Young's moduli and shear moduli of MWCNTs are in the ranges of 1.05 +/- 0.05 and 0.40 +/- 0.05 TPa, respectively. Results indicate that the tube diameter, tube chirality and number of tube layers have some noticeable effects on the elastic properties of MWCNTs. Furthermore, it has been demonstrated that the inner layers of an MWCNT can be effectively deformed only through the direct application of tensile or shear forces, not through van der Waals interactions. (C) 2003 Elsevier Ltd. All rights reserved.