Plasma Fluorination of Vertically Aligned Carbon Nanotubes

Functionalization of vertically aligned multiwalled carbon nanotube carpets was performed via exposure to CF₄ or Ar:F₂ RF plasmas. Rapid fluorination was observed via X-ray photoelectron spectroscopy (XPS) with surface fluorine concentration, bonding type, and patterning dependent on gas mixture and exposure time. Surface properties of the v-MWCNTs forests have been changed by the introduction of fluorine-containing groups, as demonstrated via surface wettability studies, while scanning electron microscopy shows that overall nanotube alignment and separation is conserved. Scanning X-ray photoelectron spectromicroscopy (SPEM) shows that the plasma treatment results in selective functionalization of the surface tips of the nanotubes. This opens the way to nanotube carpet structures with activated surfaces, which maintain the desirable conductive properties of the pristine nanotubes near to the substrate