Drastically Reduced Thermal Conductivity of Self-Bundled Single-Walled Carbon Nanotube

An individual single-walled carbon nanotube was taking U-turns and joining itself during growth, forming two distinguishable suspended sections across the slits on transmission electron microscope grid: the isolated nanotube and the self-bundled nanotube (three-nanotube bundle of the same chirality). This special formation provides the perfect specimen to study the bundling effect on various properties of carbon nanotubes. The most striking effect we elaborate on here is the drastically reduced thermal conductivity of this individual single -walled carbon nanotube after its self-bundling. The estimated thermal conductivity of the isolated nanotube is in the order of (3 -4) x 103 Wm- 1K-1, but under the heating of the same laser power, the center temperature rise of the suspended nanotube was increasing from around 150 K to about 600 K, resulting in more than 75% reduction of thermal conductivity of the self-bundled nanotube.