A method for cutting single-wall carbon nanotubes involves partially fluorinating single-wall carbon nanotubes and pyrolyzing the partially fluorinated nanotubes in an inert atmosphere or vacuum up to about 1000 C. The nanotubes are optionally purified before cutting. The partial fluorination involves fluorinating the nanotubes to a carbon-fluorine stoichiometry of CF_x, where x is up to about 0.3. The invention also relates to the derivatization of fluorinated and cut single-wall carbon nanotubes. The single-wall carbon nanotubes can be cut to any length depending on the fluorination and pyrolysis conditions. Short nanotubes are useful in various applications, such as field emitters for flat panel displays and as "seeds" for further nanotube growth.