We use classical molecular dynamics simulations to study the interfacial resistance for heat flow between a carbon nanotube and octane liquid. We find a large value of the interfacial resistance associated with weak coupling between the rigid tube structure and the soft organic liquid. Our simulation demonstrates the key role played by the soft vibration modes in the mechanism of the heat flow. These results imply that the thermal conductivity of carbon-nanotube polymer composites and organic suspensions will be limited by the interface thermal resistance and are consistent with recent experiments.

We use molecular dynamics simulations to analyze the role of chemical bonding between the matrix and the fiber on thermal transport in carbon nanotube organic matrix composites. We find that chemical bonding significantly reduces tube-matrix thermal boundary resistance, but at the same time decreases intrinsic tube conductivity. Estimates based on the effective medium theory predict increase, by about a factor of two, of the composite conductivity due to functionalization of single-walled nanotubes with aspect ratios within $100–1000$ range. Interestingly, at high degree of chemical functionalization, intrinsic tube conductivity becomes independent of the bond density.

Polymer nanocomposite foams, polymer foams with nanoparticles, are an intriguing class of materials with unique structure and properties. The shape, size and surface chemistry of nanoparticles can be tailored to control the foam structure, and therefore, foam properties. Nanoparticles also add functionality to polymer foams. In this paper, we briefly review the recent developments in polymer nanocomposites and nanocomposite foams. This is followed by an extensive discussion regarding the role of nanoparticles in foam morphology and properties. Finally, the current and future trends of polymer nanocomposite foams are summarized. Both challenges and opportunities in this field are discussed.