Efficiency of C 60 incorporation in and release from single-wall carbon nanotubes depending on their diameters

Abstract

We show that the efficiency of incorporating C 60 in single-wall carbon nanotubes (SWCNTs) and that of the incorporated C 60’s release from the SWCNTs depend on the SWCNT diameter. Through transmission electron microscopy, we found that the C 60 incorporation efficiency reached its maximum at diameters of 1–2 nm, while the efficiency of C 60 release from SWCNTs in toluene was maximized at 3–5 nm. The difficulty of C 60 release from SWCNTs with diameters of 5–6 nm might reflect either the effective packing of C 60 inside SWCNTs or a flattened SWCNT structure. We occasionally observed C 60 molecules arranged in a line along the sidewall inside SWCNTs with large diameters/width (>7 nm), indicating that large diameter SWCNTs were sometimes flattened.