Fullerene release from the inside of carbon nanotubes: A possible route toward drug delivery

C60 fullerenes are encapsulated inside and removed from carbon nanotubes using solvents. We use high-resolution transmission electron microscopy, X-ray diffractometry and Raman spectroscopy to show that large diameter carbon nanotubes can be filled with fullerenes using methanol with a high efficiency and can be also removed from the inside of the tubes using dichlorobenzene. The latter solvent removes weakly bound C60s from inside the large diameter tubes, which is explained by the high solubility of the fullerenes in dichlorobenzene. The method opens the way for drug delivery using the combined fullerene-nanotube system.