Thermal conductivity of single-walled carbon nanotubes under torsional deformation

Abstract

Molecular dynamics simulations were performed to evaluate the thermal conductivity of torsional single-walled carbon nanotubes (CNTs). We found that torsional deformation decreases the thermal conductivity of an isolated CNT as well as that of bundled ones, while tensile strain has no effect. A large decrease in thermal conductivity was observed when the torsion angle exceeded a certain threshold. In addition, the decrement in thermal conductivity of the isolated CNT was larger than that of the bundled ones. To gain a better understanding of the thermal conductivity reduction, the cross section and the energy spectrum of the torsional CNTs were also investigated. The eccentricity of the cross section of CNTs was strongly correlated with the thermal conductivity reduction. The energy spectrum suggested that the reduction in phonon relaxation time caused by torsional deformation leads to a decrement in thermal conductivity.