Length-dependent electrical and thermal properties of carbon nanotube-loaded epoxy nanocomposites

Sonication-induced scission was used to obtain carbon nanotubes (CNTs) with aspect ratios averaging 50 (short CNTs) and 500 (long CNTs). A series of carbon nanotube/epoxy nanocomposite samples with CNT content up to 1.0 wt.% were prepared using these tubes. Electrical and thermal characterisation was conducted to identify changes in such properties and the extent of these changes as a function of aspect ratio and CNT content. Results show significantly enhanced electrical conductivities and a modest increase in the thermal conductivities in both sets of samples. Further analysis of electrical conductivity of the long CNT and short CNT-based epoxy nanocomposites was carried out in order to understand their viability for EMI shielding and electrostatic dissipation applications. The processing behaviour of the long and short CNT-based composites and the corresponding electrical properties is also discussed which will help the researchers to select the right type of carbon nanotube aspect ratio achieve specific electrical properties as well as good processing behaviour.