Theoretical variations in the Young’s modulus of single-walled carbon nanotubes with tuberadius and temperature: a molecular dynamics study

Abstract

This study uses molecular dynamics simulations to investigate the intrinsic thermalvibrations of a single-walled carbon nanotube (SWNT) modelled as a clamped cantilever.Using an elastic model defined in terms of the tube length, the tube radius and the tubetemperature, the standard deviation of the vibrational amplitude of the tube’s free end iscalculated and the Young’s modulus of the SWNT evaluated. The numerical results revealthat the value of the Young’s modulus is independent of the tube length, butdecreases with increasing tube radius. At large tube radii, the Young’s modulusvalue approaches the in-plane modulus of graphene, which can be regarded asan SWNT of infinitely large radius. The results also indicate that the Young’smodulus is insensitive to changes in the tube temperature at temperatures of lessthan approximately 1100 K, but decreases significantly at higher temperatures.