Carbon nanotube-infused fiber materials containing parallel-aligned carbon nanotubes, methods for production thereof, and composite materials derived therefrom

A method comprising:

• providing a carbon nanotube-infused fiber material comprising a fiber material and carbon nanotubes infused to the fiber material, the carbon nanotubes being aligned substantially perpendicular to the outer surface of the fiber material, and the carbon nanotubes being grown on the fiber material and infused to the outer surface;
• adding a crosslinking polymer to the carbon nanotube-infused fiber material to form crosslinked, substantially perpendicular-aligned, infused carbon nanotubes;
• wherein the crosslinking polymer forms pi-stacking interactions with the crosslinked, substantially perpendicular-aligned, infused carbon nanotubes;
• and
• reorienting at least a portion of the crosslinked, substantially perpendicular-aligned, infused carbon nanotubes into a substantially parallel orientation with respect to the longitudinal axis of the fiber material by drawing the carbon nanotube-infused fiber material from a liquid to form a layer of crosslinked, infused carbon nanotubes on the outer surface of the fiber material.

A continuous carbon nanotube growth process, the process comprising:

• providing a continuous fiber material;
• growing carbon nanotubes on the outer surface of the continuous fiber material in a continuous carbon nanotube growth process;
• wherein the carbon nanotubes are infused to the fiber material on the outer surface to form a carbon nanotube-infused fiber material, and the carbon nanotubes are aligned substantially perpendicular to the outer surface of the fiber material;
• crosslinking at least a portion of the infused carbon nanotubes to each other, to the fiber material, or both;
• wherein crosslinking comprises treating the infused carbon nanotubes with a crosslinking polymer that forms pi-stacking interactions with the infused carbon nanotubes to form crosslinked, infused carbon nanotubes;
• and
• after crosslinking, drawing the carbon nanotube-infused fiber material from a liquid to reorient at least some of the carbon nanotubes into a substantially parallel orientation with respect to the longitudinal axis of the fiber material and to form a layer of crosslinked, infused carbon nanotubes on the outer surface of the fiber material.