A novel morphological model for carbon nanotube/polymer composites having high thermal conductivity and electrical insulation

Carbon nanotubes (CNTs), owing to their extremely high thermal conductivity (∼3000 W m−1 K−1), have recently attracted attention as notable nanofiller candidates to improve the thermal conductivity of polymers. However, CNTs cannot practically be used for highly electrically insulating polymers because even a few CNTs impart a high electrical conductivity to the polymers. Here, we design and fabricate CNT/polymer composites having a novel morphology, which achieves both enhanced thermal conductivity and high electrical insulation. This morphology comprises a matrix polymer and a CNT-localizing domain polymer encapsulated by a shell-forming component, which contributes to the selective localization of the CNTs into the dispersed domains. Such a controlled morphology is formed by the self-organization of the CNTs and the constituent polymers. A tailor-made morphology of CNT/polymer composite in accordance with our proposed model represents a promising route to a wide variety of applications of CNTs in materials requiring high electrical insulation.