The effects of carbon nanotube chirality, Stone-Wales defects and defect orientation on the radial collapse and elasticity of single-walled carbon nanotubes were investigated using molecular mechanics and molecular dynamics simulations. It was found that the collapse pressure of the armchair single-walled carbon nanotube was 13.75 times higher than that of the zig-zag single-walled carbon nanotubes. Moreover, the armchair single-walled carbon nanotubes with Stone-Wales defects was easier to collapse compared to the intrinsic armchair single-walled carbon nanotubes, while the zig-zag single-walled carbon nanotubes with Stone-Wales defects was more difficult to collapse compared to the intrinsic zig-zag single-walled carbon nanotubes; the SW2 defect made the collapse pressure of single-walled carbon nanotubes (10,10) decrease by 11.0%, while the SW4 defect made the collapse pressure of single-walled carbon nanotubes (17,0) increased by 100.0%. A model for single-walled carbon nanotubes deformed in the radial direction according to the projection of the C-C bond along the bending direction was introduced. The model was validated for defect-free single-walled carbon nanotubes and was then used to study the radial collapse of single-walled carbon nanotubes with Stone-Wales defects. The effect of chirality and Stone-Wales defect on the radial collapse of single-walled carbon nanotubes could be understood by the model. The strong sensitivity of radial collapse of single-walled carbon nanotubes to chirality and Stone-Wales defect could provide some guidance for high load structural applications of single-walled carbon nanotubes.

Radial Collapse of Carbon Nanotubes without and with Stone-Wales Defects under Hydrostatic Pressure. C.C.Ling, Q.Z.Xue, L.Y.Chu, N.N.Jing, X.Y.Zhou: RSC Advances, 2012, 2[32], 12182-9