Carbon nanotube-based hierarchical composites: a review

The introduction of carbon nanotubes (CNTs) into conventional fibre-reinforced polymer composites creates a hierarchical reinforcement structure and can significantly improve composite performance. This paper reviews the progress to date towards the creation of fibre reinforced (hierarchical) nanocomposites and assesses the potential for a new generation of advanced multifunctional materials. Two alternative strategies for forming CNT-based hierarchical composites are contrasted, the dispersion of CNTs into the composite matrix and their direct attachment onto the primary fibre surface. The implications of each approach for composite processing and performance are discussed, along with a summary of the measured improvements in the mechanical, electrical and thermal properties of the resulting hierarchical composites.