title: Sharp burnout failure observed in high current-carrying double-walled carbon nanotube fibers.
abstract: We report on the current-carrying capability and the high-current-induced thermal burnout failure modes of 5-20 μm diameter double-walled carbon nanotube (DWNT) fibers made by an improved dry-spinning method. It is found that the electrical conductivity and maximum current-carrying capability for these DWNT fibers can reach up to 5.9 × 10(5) S m(-1) and over 1 × 10(5) A cm(-2) in air. In comparison, we observed that standard carbon fiber tended to be oxidized and burnt out into cheese-like morphology when the maximum current was reached, while DWNT fiber showed a much slower breakdown behavior due to the gradual burnout in individual nanotubes. The electron microscopy observations further confirmed that the failure process of DWNT fibers occurs at localized positions, and while the individual nanotubes burn they also get aligned due to local high temperature and electrostatic field. In addition a finite element model was constructed to gain better understanding of the failure behavior of DWNT fibers.
authors.affiliation: Department of Mechanical Engineering and Materials Science, Rice University, Houston, TX 77005, USA. ls17@shinshu-u.ac.jp
authors.forename: Li
authors.initials: L
authors.lastname: Song
authors.forename: Geza
authors.initials: G
authors.lastname: Toth
authors.forename: Jinquan
authors.initials: J
authors.lastname: Wei
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.forename: Lijie
authors.initials: L
authors.lastname: Ci
authors.forename: Robert
authors.initials: R
authors.lastname: Vajtai
authors.forename: Morinobu
authors.initials: M
authors.lastname: Endo
authors.forename: Pulickel M
authors.initials: PM
authors.lastname: Ajayan