| abstract |
The process for producing carbon nanotube particulates comprises the steps of providing a carrier material, such as magnesia, with a catalyst metal comprising a catalyst metal, such as iron and molybdenum or a metal derived from a VIB group or VIIIB group element; Contacting the catalyst with a gaseous carbon-containing feedstock, such as methane, for a sufficient time at a temperature sufficient to produce at least one wall and small diameter carbon nanotubes having an outer wall diameter of less than approximately 3 nm. Removing the carrier material from the carbon nanotubes yields particulates of the filtered carbon nanotubes that have a three-dimensional shape and size similar to the particulate carriers removed. The carbon nanotube particles may be composed of ropes of carbon nanotubes. Carbon nanotube particles are well dispersed in the polymer and exhibit high conductivity at low droppings. As the electron emitting electrode, the carbon nanotube particles show a very low "turn-on" emission field. |