Process for preparing carbon nanotubes

A process for producing carbon nanotubes comprising the steps of:

• (a) passing an inert gas under-pressure through a tubular metal cathode while passing an electric current through the cathode to produce a plasma of fine catalyst particles;
• (b) depositing the catalyst particles thus produced onto a porous carbon substrate proximate the cathode whereby the substrate is heated;
• and
• (c) passing a feedstock gas containing a source of carbon through the heated substrate to cause a reaction between the catalyst and the carbon source resulting in the formation of carbon nanotubes.

An apparatus for producing carbon nanotubes comprising:

• (a) tube means defining a reaction chamber for receiving a hydrocarbon gas;
• (b) spaced apart electrode means in said tube means for retaining said carbon substrate in said container means;
• and
• (c) conductor means for supplying electrical power to said electrode means for heating said carbon substrate by the Joule effect, whereby, when the hydrocarbon gas is introduced into said reaction chamber and the carbon substrate is heated by introducing electrical power thereto, nanotubes are produced on said carbon substrate.

An apparatus for producing carbon nanotubes comprising:

• (a) a housing defining a reaction chamber for receiving a carbon substrate;
• (b) an inlet tube in said reaction chamber for introducing gas into said housing;
• (c) a catalytic metal cathode in said inlet tube;
• (d) an anode in said reaction chamber between and spaced apart from said cathode and a carbon substrate in said housing, whereby, when electric current is supplied to the anode and an inert gas is passed through said cathode under pressure, a primary plasma of fine metallic catalyst particles are produced and deposited on said carbon substrate, and, when a gas containing a source of carbon is passed through said inlet tube and impinges on said substrate, carbon nanotubes are formed.