Mechanical properties of CNTs with S-W defects

Abstract

Although single-walled carbon nanotubes (SWCNTs) are found to have remarkable mechanical properties, a substantial variation in performance data is reported in the literature. These discrepancies may be attributed to the presence of nanoscale defects, among other factors. In this thesis, the effects of Stone-Wales (SW) defects on the mechanical properties of composites reinforced with SWCNTs are studied using molecular dynamics (MD) simulations. In particular, the effects of Stone-Wales defects on the mechanical properties of SWCNTs and their composites (polyethylene reinforced with SWCNTs) are studied. MD results obtained in the current thesis were corroborated against analytical and atomistic finite element (AFE) results. Our simulations showed that the longitudinal Young’s modulus of individual single-walled carbon nanotubes is dependent on the tube structure, the diameter of the nanotube, and the number of Stone-Wales defects. In the present study MD result is compared with FE result. The FE results show good agreement with MD predictions for defect-free SWCNTs, although the accuracy of the AFE results declines for defective nanotubes with diameters less than 9.5 Angstroms.