Equivalent electric circuits for the comparison of nanocarbon-based epoxy resin systems

Equivalent electric circuits allowing the simulation of the behaviour of nanocomposites based on thermosetting resin and nanocarbon filler over a broad range of frequency 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. An 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 in circuit simulators for first-approximation design of EM devices based on such composites for. Moreover, they allow an interpretation of the physical mechanisms underlying the EM behaviour of the composites.