Equivalent Electric Circuits for the Simulation of Carbon Nanotube-Epoxy Composites

Equivalent electric circuits allowing the simulation of the behaviour of nanocomposites based on thermosetting resin and nanocarbon filler are presented. The electric circuits are constructed by employing a multi-step simple procedure in which the values and number of the parameters are adjusted until a suitable criterion, based on the comparison between simulated and experimental frequency spectra is satisfied. A resistance-capacitance (RC) simple parallel branch in parallel with a variable number of RC series branches is shown to be capable to reproduce the frequency response of a pre-percolative carbon black and two carbon nanotube (CNT) nanocomposites with CNT concentration close to the percolation threshold. The obtained equivalent circuits may be employed for the interpretation of the physical mechanisms underlying the electromagnetic (EM) behaviour. Moreover, they can be used in circuit simulators for first-approximation design of EM devices based on such composites.