It was found using the density functional theory that vacancy-COOH pairs with a strong covalent bond are energetically favorable on the zigzag nanotube
sidewall after acid treatment, and the electrical conductivity would be enhanced .
An armchair ribbon can be thought of as essentially an unrolled zigzag nanotube
."We proposed an electronic spin-filter device using nonmagnetic materials.
Figure 5 shows the calculated force-strain relationships for armchair and zigzag nanotube fibers.
Same as the Young's moduli , the in-plane stiffness for both armchair and zigzag nanotubes decrease with decreasing tube diameter and approach the predicted graphite value when the tube diameter is increased.
But in the nanotubes, it had been predicted that the formation energies for divacancies in armchair nanotubes are higher than in zigzag nanotubes
. In addition, for the 585 divacancies in CNTs, the formation energies of divacancies strongly depend on the orientation of the divacancy with respect to the tube axis .
We choose a junction between two zigzag nanotubes
, namely, the (8, 0)/(14, 0) case.