Self-assembly of sidewall functionalized single-walled carbon nanotubes investigated by scanning tunneling microscopy

The thiol and thiophene sidewall functionalized single-walled carbon nanotubes have been investigated by scanning tunneling microscopy. By exploiting the well-established Au-S chemistry, the thiol- and thiophene-modified nanotubes were self-assembled and anchored on bare gold surfaces as well as inserted into hexanethiol self-assembled monolayers. The positions of functional groups on the nanotube sidewall are revealed during imaging. From these measurements we have determined the size and spatial distribution of the sulfur-functionalized sidechains along the nanotube sidewalls.