Torsional failure of water-filled carbon nanotubes

The failure behavior of water-filled carbon nanotubes under the torsional moment is investigated by molecular dynamics simulations. The computational results indicate that the shear modulus can be slightly increased but the critical buckling angle can be greatly enhanced by the water filling as compared to the empty carbon nanotubes. The enhancement in the critical buckling angle is almost comparable to that induced by the copper filling. However, the critical failure angle of carbon nanotubes decreases with the increase in the packing density of water, and it is reduced by about 50% when the water density reaches 1.2g/cm(3). Moreover, the researches on the defective water-filled carbon nanotubes reveal that the torsional property of the carbon nanotubes can be influenced by the density and distribution of the Stone-Wales defects. The present findings can provide a theoretical guidance for the stability assessment of nanochannels and the potential application for the drug delivery and release.