Process for producing carbon-nanotube grafted substrate

A process for producing a carbon nanotube-grafted substrate, the process comprising:

• a. providing a conductive substrate having a catalytic material deposited on a surface thereof, the catalytic material being configured to catalyse growth of carbon nanotubes;
• and
• b. synthesizing carbon nanotubes on the substrate by a chemical vapour deposition process comprising exposing the substrate to a reductive gas and a carbon feedstock gas at the elevated temperature, in the presence of an inerting gas and at a temperature in the range of 400° C. to 1200° C. in a reaction chamber while spooling the substrate through the reaction chamber,
• characterised in that the process comprises using the substrate as an electrode and providing a counter electrode, applying a potential difference to the substrate in relation to the counter electrode and maintaining the potential difference of the substrate in relation to the counter electrode during the chemical vapour deposition process;
• wherein the substrate comprises a carbon fibre material or precursor thereof;
• and
• wherein the carbon nanotubes are grafted continuously along a spoolable length of the substrate,
• wherein the carbon nanotubes are grafted directly to a carbon fibre surface of the carbon fibre material or precursor thereof, and
• wherein the applied potential difference does not generate a plasma.