Uniform radial expansion/contraction of carbon nanotubes and their transverse elastic moduli

Carbon nanotubes have very high potential for applications in nano-electromechanical devices, nano-optomechanical systems and nano-composites. However, their full exploitation depends upon knowledge of their mechanical, electrical and thermal properties. Several analytical, experimental, molecular mechanics (MM) and molecular dynamics simulations have been performed to study their deformations under axial loads. Here a novel MM simulation technique has been developed to study uniform radial expansion/contraction of a single wall carbon nanotube (SWCNT). Radial deformations of a SWCNT are achieved by considering a double wall carbon nanotube (DWCNT) with the SWCNT as one of its walls and moving radially through the same distance all atoms of the other wall of the DWCNT thereby causing a pseudo-pressure through changes in the cumulative van der Waals forces which deform the desired wall. These results are used to find through-the-thickness elastic moduli (Young's modulus in the radial direction, E_r, and Poisson's ratio, ν_rθ) of the SWCNT.