Impedance Spectroscopy and Dielectric Properties of Carbon Nanotube-Reinforced Epoxy Polymer Composites

Abstract

The aim of this work is to investigate the electric properties of carbon nanotubereinforced epoxy polymer composites, using impedance spectroscopy, in the frequency
range from 1 to 10 and over the temperature range from 25 to 105 . The
dielectric response was analyzed using the complex permittivity and the electrical modulus
formalisms, depending on temperature and filler concentration in the polymer matrix.
Furthermore, an equivalent circuit model is proposed to describe the impedance response of
carbon nanotubes/epoxy composites. The impedance studies disclosed the appearance of
grain and grain-boundary effects, as confirmed by the Nyquist plot.

Keywords: Carbon nanotubes, Composites, Impedance spectroscopy, Equivalent circuit
model, Grain effect, Grain-boundary effect.