High tensile strength carbon nanotube film and process for making the same

摘要

A conductive carbon nanotube film having high tensile strength and initial tensile modulus comprises primarily oxidized small-diameter carbon nanotubes wherein the diameter of the small-diameter carbon nanotubes are at most about 3 nm. A method for making the film comprises refluxing an aqueous mixture comprising carbon nanotubes and an oxidizing agent to form a refluxed nanotube dispersion; forming a carbon nanotube film from the refluxed carbon nanotube dispersion; optionally removing nitric acid or other oxidizing agent from the carbon nanotube film; drying the carbon nanotube film; and heat-treating the carbon nanotube film to form a heat-treated carbon nanotube film. The method can also comprise sonicating the nanotubes prior to or after refluxing. A heat-treated small-diameter carbon nanotube film can have a tensile strength of over 70 MPa and an initial tensile modulus of about 5 GPa.