Fluorination of Arc-Produced Carbon Material Containing Multiwall Nanotubes

The fluorination of arc-produced carbon material, which contained multiwall carbon nanotubes, was performed at room temperature by using a gaseous mixture of BrF 3 and Br 2 . The elemental composition of the sample was determined by X-ray photoelectron spectroscopy to be CF 0.3 Br 0.02, while graphite is fluorinated up to a C 2 F stoichiometry under the same reaction conditions. The fluorinated carbon material and graphite fluoride were comparatively analyzed by means of X-ray diffraction, infrared spectroscopy, and thermogravimetry. Transmission electron microscopy indicated that only the outer shells of carbon nanotubes and polyhedral particles were fluorinated whereas the inner shells remained intact. We suggest that some of the arc-produced multiwall carbon nanotubes are composed of concentric cylindrical shells surrounded by nestled scrolls.