The influence of collapsed shape on the thermal transport of carbon nanotubes is studied by nonequilibrium molecular dynamics. Nanotubes of different lengths, diameters, chiralities, and degrees of twist are simulated in the regime in which the thermal transport extends from ballistic to diffusive. In contrast with graphene nanoribbons, which are known to exhibit substantial rough-edge and cross-plain phonon scatterings, the collapsed tubes preserve the quasiballistic phononic transport encountered in cylindrical nanotubes. Stacked-collapsed nanotube architectures, closely related with the strain-induced aligned tubes occurring in stretched nanotube sheets, are shown to inherit the ultrahigh thermal conductivities of individual tubes, and are therefore proposed to form highways for efficient heat transport in lightweight composite materials.
Bibliographical noteFunding Information:
This work was partially supported by an Early Stage Innovations grant from NASA's Space Technology Research Grants Program NNX16AE03G and by NSF CMMI Grant No. 1332228. J.A.-G. greatly acknowledges support from the Albert Swanson Fellowship. T.D. thanks the Hanse Wissenschaftskolleg Delmenhorst, Germany for hospitality. Resources supporting this work were provided by the NASA High-End Computing Program through the NASA Advanced Supercomputing Division at Ames Research Center.