Despite the unparalleled mechanical properties of C nanotubes, experiments have revealed large scattering which could be attributed to structural defects. How two neighboring defects may interact and influence the mechanical properties of C nanotubes was still unclear. Here, interactions between a Stone-Wales (SW) defect pair in axially loaded single-walled C nanotubes were systematically studied using molecular mechanics. The defect-defect interaction was quantified by the bond with the highest energy, E, which varies in magnitude with respect to the inter-defect distance, D. Defect pairs, corresponding to combinations of two types of SW defects (namely, the SW defect of A and B modes) with a different relative orientation angle, ϕ, embedded in single-walled C nanotubes of different size and chirality were studied. It was shown from the results that, in general, E varies according to defect pair, and converges to a constant at large D. It was found that the magnitude of E was regulated by the type of defect pair, and the profile of E versus D was modulated by ϕ. In addition, E was also influenced by the tube size and chirality. From all of the cases studied, the largest indifference length, D0, beyond which two neighboring defects did not feel the existence of each other, was found to be approximately 30  

On Defect Interactions in Axially Loaded Single-Walled Carbon Nanotubes. A.M.A.Huq, K.L.Goh, Z.R.Zhou, K.Liao: Journal of Applied Physics, 2008, 103[5], 054306