The reactivity of defects at the sidewalls of single-walled carbon nanotubes: The Stone-Wales defect

The reactivity of 5/7/7/5 (Stone-Wales, SW) defects is compared to that of the pristine sidewalls of (5,5) and (10,0) carbon nanotubes (CNTs) using density functional theory (PBE). Infinite tube models (periodic boundary conditions) are used to investigate the reaction energy for CH2 addition to the ten [5,6], [5,7], [6,7], and [7,7] C-C junctions resulting from SW rotations of the two unique bonds in (5,5) and (10,0) CNTs. In all cases, at least one of the junctions associated with the SW defects is more highly reactive than the pristine tubes. The orientation of these junctions with respect to the tube axis mainly determines the exothermicity. The [7,7] junctions are not the most reactive sites in SW defects of (5,5) and (10,0) CNTs.