Electrically Conductive Polymer Nanocomposites with High Thermal Conductivity

The utility of one-dimensional nanostructures, such as linear and nonlinear carbon nanotubes (CNTs), as fillers in polymer matrices and their influence in modulating the electrical, electromagnetic, and thermal properties of the resulting composites. This chapter will first consider the rationale for the use of structures with a large aspect ratio, based on percolation theory. At the very outset, a large length-to-diameter ratio enables matrix spanning at lower volume fractions, with the implication of observing novel phenomena at relatively dilute filler content. Subsequent geometric effects on significantly affecting DC and AC electrical conductivity, with respect to nonlinearity in the structure will also be considered. A significant new result is the observation of a power–law relation for the thermal conductivity, indicative of percolation, which contradicts earlier assertions and indicates that synthesis methodologies may be adapted to facilitate such behavior. Modeling of the experimentally determined electrical and thermal conductivity anisotropy, in addition to the incorporation of interfacial resistance, provides a better understanding of the underlying mechanisms and variations.