Monte Carlo Model for Piezoresistivity of Hybrid Nanocomposites

Abstract

Hybrid nanocomposites with multiple fillers like carbon nanotubes (CNT) and graphene nanoplatelets (GNP) are known to exhibit improved electrical and electromechanical performance when compared to monofiller composites. We developed a two-dimensional Monte Carlo percolation network model for hybrid nanocomposite with CNT and GNP fillers and utilized it to study the electrical conductivity and piezoresistivity as a function of nanocomposite microstructural variations. The filler intersections are modeled considering electron tunneling as the mechanism for electrical percolation. Network modification after elastic deformation is utilized to model the nanocomposite piezoresistive behavior. Systematic improvement in electrical conductivity and piezoresistivity was observed in the hybrid nanocomposites, compared to monofiller CNT nanocomposites. Parametric studies have been performed to show the effect of GNP content, size, aspect ratio, and alignment on the percolation threshold, the conductivity, and piezoresistivity of hybrid CNT–GNP polymer composites.