| abstract |
The present invention relates to systems and methods for generating nanoscopically aligned carbon nanotubes in yarns, tapes and sheets. Some embodiments relate to methods and systems to allow in situ alignment of the tubes within the growth chamber. In particular, processes for in situ alignment include: (1) gas flow alignment using gas lenses introduced within the reaction tube, (2) electrostatic alignment using electrostatic lenses surrounding the reaction tube, (3) gas flow alignment by convergent flow within the reaction tube, (4) placing catalysts on a fixed substrate and flowing reaction gas parallel to the substrate. Other embodiments involve post processing of the CNT material in order to align the materials once it has been produced. In particular, processes for ex situ alignment include: (1) introducing a horizontal anchor within a standard sheet system and stretching that sheet with respect to a fixed drum and (2) adding chemicals to a sheet, tape or yarn to help break electrostatic bonds and enable stretch alignment. |