Toward the microstructure-properties relationship in MWCNT/epoxy composites: Percolation behavior and dielectric spectroscopy

In this paper, the electrical and dielectric properties of epoxy composites containing multi walled carbon nanotubes (MWCNTs) are investigated by means of direct and alternate current measurements and correlated with the internal composite microstructure. A systematically study on the role of different nanotube network structures produced by varying the processing parameters: sonication time and curing temperature is performed. The percolation behavior of the produced composites is studied and the correlation between carbon nanotube networks induced by processing and the final properties is analyzed. An equivalent electrical circuit is proposed as a model to describe the dielectric property behavior due to different multi-scale composite microstructure and the interaction between tubes-tubes and tubes-matrix. (C) 2014 Elsevier Ltd. All rights reserved.