Tunneling Conductivity and Piezoresistivity of Composites Containing Randomly Dispersed Conductive Nano-Platelets

Abstract

In this study, a three-dimensional continuum percolation model was developed based on a Monte Carlo simulation approach to investigate the percolation behavior of an electrically insulating matrix reinforced with conductive nano-platelet fillers. The conductivity behavior of composites rendered conductive by randomly dispersed conductive platelets was modeled by developing a three-dimensional finite element resistor network. Parameters related to the percolation threshold and a power-low describing the conductivity behavior were determined. The piezoresistivity behavior of conductive composites was studied employing a reoriented resistor network emulating a conductive composite subjected to mechanical strain. The effects of the governing parameters, i.e., electron tunneling distance, conductive particle aspect ratio and size effects on conductivity behavior were examined.

Multi-Scale Finite Element Analysis of Graphene/Polymer Nanocomposites Electrical Performance

“…Since it has been assumed that the conductive phenomena taking place between two successive graphene plates would be taking into account in the unit cell analysis, it is necessary to modify the application of the tunnelling resistivity in the unit cell, so as to simulate the contribution of a single plate to the conduction. In many studies the cut-off distance, otherwise the maximum inter-particle distance above this the tunnelling effect is eliminated, was considered around 2 nm [17], [21], [26], leading to the polymer thickness range between 0 and 1.0 nm. In addition to this, it is crucial to note that the architecture of graphene plates forms conductive paths inside the insulating polymer, which could be represented as a typical 2D or even 3D resistor network.…”

Predictive Model of Graphene Based Polymer Nanocomposites: Electrical Performance

“…In a later work, Ambrosetti et al [23] studied the electrical conductivity of an insulating matrix reinforced with conductive ellipsoids by assuming that an expected curve of electrical conductivity variation would be applied and finally being reduced in a geometrical form taking into account the inter-particle distance and the tunnelling distance. Oskouyi et al [24] developed a 3D Monte Carlo model to study the percolation, conductivity, and piezoresistive behaviour of composites filled with randomly dispersed impenetrable conductive nano-disks. In this study, a Monte Carlo model was first developed to form a representative volume element (RVE) filled with randomly dispersed nano-platelet conductive inclusions.…”

“…Since the conduction phenomena take place between two successive conductive particles, it is necessary to modify the application of the tunnelling resistivity in the unit cell, so as to simulate the contribution of a single plate to the conduction. In many studies, the cut-off distance (maximum inter-particle distance above this the tunnelling effect is eliminated) was considered around 2 nm [22][23][24], leading to the polymer thickness range between 0 and 1.0 nm. Moreover, it is crucial to note that the architecture of graphene plates forms conductive paths inside the insulating polymer, which could be represented as a typical 2D or even 3D resistor network.…”

Conductive polymer foams with carbon nanofillers – Modeling percolation behavior

“…The minimum of the function is then evaluated, and two tubes are considered in contact (Figure 1a) when the distance is smaller than (d cut-off + tube diameter), where d cut-off is the cut-off distance for electron tunneling, set according to the current literature on electrical conductivity in polymer nanocomposites (between 1 and 10 nm) [13,14]. In this work CNTs of length 1.125 μm and diameter 9.75 nm (dimensions chosen based on representative experimental data [15]) were used to test the model in bulk solids using a cutoff distance of 7.5 nm, which is within the range reported by Ambrosetti et al [16] for CNTs with similar AR.…”