Mechanical properties of single-walled carbon nanotubes with vacancy defects: A computational approach.

Carbon nanotubes (CNTs) have revolutionized modern composites offering unique properties and strength with less weight. CNTs themselves possess remarkable electrical, optical, mechanical, thermal, and tribological properties which have been appreciated as ideal fibers for nanocomposite structures. These features may be different when comparing a pristine CNT with defects. To explore this, armchair and zigzag single-walled CNTs containing 2.5% vacancy defects have been modeled and studied. The studies have been performed using molecular dynamics (MD) simulation technique with Condensed-phase Optimized Molecular Potentials for Atomistic Simulation Studies (COMPASS) force field to predict the mechanical properties. The obtained values corroborated well with previous literature. The results revealed the reduction in young's modulus of the armchair and zigzag CNTs with vacancy defects when compared with pristine CNTs are of about 8.08%, 8.65%, and shear modulus 5.9%, and 7.52%, respectively. The investigation shows the trend of reduction in predicted young's modulus values with increase in CNTs radius and increases in shear modulus for same. In addition, the influence of single vacancy (SV) defects has also been studied and discussed. [ABSTRACT FROM AUTHOR]