Prediction of material properties of single walled carbon nanotube using MD simulations

Carbon nanotubes have various unique properties beneficial for use in various electronic devices such as quantum wires, optical switchers, nano-transistors etc. Theoretical and experimental attempts were made in past decade to predict material properties of CNTs. In the present work, calculations of fundamental mechanical material properties of a single walled carbon nanotube (SWCNT) were performed using molecular dynamics simulations via Material Studio by Accelrys Inc. As the lattice size is decreased to achieve the actual known density of SWCNT to be 2.4 gm/cm³, the shape of SWCNT get distorted after energy minimization. A simple but effective technique of extrapolation was adapted to overcome this problem of SWCNT distortion. The lattice size was increased (and hence the density was decreased) in the increments of 20% by volume starting with the minimum size of lattice where the shape of SWCNT remains unchanged after energy minimization. Property calculations were performed at each increment and plotted against the density. Young's modulus and Poisson's ratio was calculated by extrapolating the density to the actual value of 2.4 gm/cm³, and was found to match well with the available experimental data.