High thermal conductivities of carbon nanotube films and micro-fibres and their dependence on morphology

Gspann, Thurid S.; Juckes, Stefan M.; Niven, John F.; Johnson, Michel B.; Elliott, James A.; White, Mary Anne; Windle, Alan H.

Abstract:
Thermal conductivity of carbon nanotube (CNT) films and micro-fibres synthesised by floating catalyst chemical vapour deposition was measured by the parallel thermal conductance method. CNT films showed in-plane thermal conductivities of 110 W m$^{−1}$ K$^{−1}$. Online condensation into a micro-fibre morphology – a two-dimensional reduction in the transverse plane, including some axial stretching during solvent evaporation – resulted in room-temperature thermal conductivity values as high as 770 ± 10 W m$^{−1}$ K$^{−1}$, which is the highest thermal conductivity reported for CNT bulk materials to date. In specific terms, this matches the maximum thermal conductivity of heat-treated carbon fibre, but with a higher onset temperature for Umklapp scattering processes (300 K rather than 150 K). We selected four sample types to investigate effects of alignment, purity, and single- or multi-wall character on their thermal conductivity. For both the electrical and thermal conductivity of as-spun material, i.e. without any post-synthesis treatment, we show that the density and quality of CNT bundle alignment are still the predominant factors affecting these properties, outweighing the influence of single- or multi-walled character of the nanotubes. ... mehr

 Zugehörige Institution(en) am KIT Institut für Nanotechnologie (INT) Publikationstyp Zeitschriftenaufsatz Publikationsmonat/-jahr 04.2017 Sprache Englisch Identifikator ISSN: 0008-6223 KITopen-ID: 1000122466 Erschienen in Carbon Band 114 Seiten 160–168 Externe Relationen Abstract/Volltext Nachgewiesen in Web of ScienceScopus
KIT – Die Forschungsuniversität in der Helmholtz-Gemeinschaft
KITopen Landing Page