Spontaneous cross linking of small-diameter single-walled carbon nanotubes

We report surprising findings of spontaneous cross-linking of small-diameter zigzag single-walled carbon nanotubes, with no applied external pressure, using ab initio density functional theory. Sunstantial differences in the cross-linking reactivity of zigzag and armchair single-walled carbon nanotubes are revealed by the calculations. The cross linking creates 2D sheetlike network structures of highly deformed nanotubes linked with covalent C-C bonds. The cross-linking process can be directed by H-2 chemisorption.