NanoTeflons:  Structure and EELS Characterization of Fluorinated Carbon Nanotubes and Nanofibers

For the first time, we report high-resolution electron energy loss spectroscopy (HREELS) studies on fluorinated carbon nanotubes and nanofibers of various diameters. In addition, we have carried out high-resolution transmission electron microscope studies on the material, as well as HREELS elemental line scans, and elemental mappings. From the experimental EEL near edge structure of the F−K edge, we observed that F establishes two different types of bonds with C: covalent and ionic. From the elemental mapping, we noted that F is always uniformly distributed within the fluorinated carbon tubes of diameters >20 nm. EELS calculations using density functional theory confirmed the existence of covalent and ionic F bonded to the carbon within the tubes at ∼685 and 690 eV, respectively. These values are in good agreement with those obtained experimentally.