Multilayer carbon nanotube films and method of making the same

A process for the preparation of a multilayer carbon nanotube film comprising:

• (a) synthesizing a layer of aligned carbon nanotubes on a suitable substrate by pyrolysis of a carbon-containing material in the presence of a suitable catalyst for nanotube formation to provide a nanotube coated substrate;
• and
• (b) synthesizing a further layer of aligned carbon nanotubes on said nanotube coated substrate by pyrolysis of a carbon-containing material in the presence of a suitable catalyst for nanotube formation,
• wherein the further layer is synthesized employing conditions which are different to those employed in step (a).

A process for the preparation of a hetero-structured multilayer carbon nanotube film comprising:

• (a) synthesizing a layer of aligned carbon nanotubes on a quartz glass substrate by pyrolysis of a carbon-containing material in the presence of a suitable catalyst for nanotube formation to provide a nanotube coated substrate;
• (b) coating a layer of a pyrolysis resistant material onto said nanotube coated substrate to provide a hetero-structured multilayered substrate;
• and
• (c) synthesizing a further layer of aligned carbon nanotubes on said hetero-structured multilayered substrate by pyrolysis of a carbon-containing material in the presence of a suitable catalyst for nanotube formation.

A process for the preparation of a hetero-structured multilayer carbon nanotube film comprising:

• (a) synthesizing a layer of aligned carbon nanotubes on a quartz glass substrate by pyrolysis of a carbon-containing material in the presence of a suitable catalyst for nanotube formation;
• (b) etching the quartz glass substrate at the nanotube/substrate interface to release said layer of aligned nanotubes from the substrate;
• and
• (c) intercalating the released substrate-free aligned carbon nanotube film into a multilayer structure.