Cross-linked carbon nanotube networks

A method of producing an aerogel or a xerogel having a covalently cross-linked carbon nanotube network, comprising:

• a) dispersing carbon nanotubes in a solvent compatible with said carbon nanotubes;
• b) cross-linking said carbon nanotubes with a linking molecule comprising at least two functional sites capable of reacting with the surface of said carbon nanotubes, to form a covalently cross-linked carbon nanotube network
• wherein said cross-linking is carried out directly to the nanotube sidewall with a linking molecule selected from the group consisting of bis(diazonium) salts, and multifunctional molecules suitable for 1,3-dipolar cycloadditions or Bingel condensations;
• or by the reduction of the carbon nanotubes followed by the reaction of the nanotubes with an electrophilic cross-linking molecule;
• and
• c) removing said solvent to form an aerogel or a xerogel having the covalently cross-linked carbon nanotube network with a solvent content of less than 10% by weight.