Shielding effectiveness and bandgaps of interpenetrating phase composites based on the Schwarz Primitive surface

Abstract

Conductive composites possessing a polymeric matrix have been developed as an auspicious class of materials yielding superior properties to metal-based materials. The electromagnetic shielding effectiveness and bandgaps of a novel interpenetrating phase composite with a polymeric matrix are studied computationally. This composite is generated from a so-called Schwarz Primitive surface, a member of the triply periodic minimal surfaces family. The shielding effectiveness of the resulting Primitive-based composite is compared with those of composites reinforced with periodically and randomly distributed spherical conductive particles. For the composites with random spherical particles, the random sequential addition method is used to generate the realizations of fillers followed by the Monte Carlo relaxation step to obtain an equilibrated configuration. The Primitive-based composite shows higher shielding effectiveness due to the interconnectivity of both phases (conductive phase and polymeric matrix) leading to a higher effective electrical conductivity. Employing a finite element analysis leads to dispersion curves, which reveal the existence of electromagnetic bandgaps at low frequencies and low volume fractions of the conductive phase, in comparison to those of other structures reported in the literature. The Primitive-based composite shows the bandgaps for transverse-electric modes, where the widths of the bandgaps vary with the volume fraction of the conductive phase.