Criteria for producing yarns from vertically aligned carbon nanotubes

Critical yarning conditions from vertically aligned carbon nanotubes (VACNTs) using a chemical vapor deposition have been investigated. VACNTs with a diameter of around 15 nm have been synthesized with a length up to 3.7 mm. The yarning was realized exclusively in a limited range of the CNT lengths of about 170-1500 μm. Although CNTs became long for longer growth times, some of the CNTs were plucked out from the bottom substrate during growth so that the CNT density decreased at later stages of growth, prohibiting continuous yarning by the suppression of interconnection between CNTs at the bottom part of VACNTs.