Modeling the electrical resistivity of polymer composites with segregated structures

Abstract

Hybrid carbon nanotube composites with two different types of fillers have attracted considerable attention for various advantages. The incorporation of micro-scale secondary fillers creates an excluded volume that leads to the increase in the electrical conductivity. By contrast, nano-scale secondary fillers shows a conflicting behavior of the decreased electrical conductivity with micro-scale secondary fillers. Although several attempts have been made in theoretical modeling of secondary-filler composites, the knowledge about how the electrical conductivity depends on the dimension of secondary fillers was not fully understood. This work aims at comprehensive understanding of the size effect of secondary particulate fillers on the electrical conductivity, via the combination of Voronoi geometry induced from Swiss cheese models and the underlying percolation theory. This indicates a transition in the impact of the excluded volume, i.e., the adjustment of the electrical conductivity was measured in cooperation with loading of second fillers with different sizes.

Electrochemical Properties of Screen-Printed Carbon Nano-Onion Electrodes

“…The overall electrode resistance could be associated to the bulk resistance of fillers, constriction resistance (i.e., sites where there is direct contact between the conductive fillers) and tunnelling resistance. Tunnelling resistance comes from sites where conductive particles are not directly connected and electrons must overcome energy barriers to transfer between the particles [ 35 , 36 ]. The resistance strongly influences the electrochemical performance at the electrode interface and, for some formulations, makes the electrodes unsuitable for voltammetric applications.…”

Preparation and Characterization of Highly Elastic Foams with Enhanced Electromagnetic Wave Absorption Based On Ethylene-Propylene-Diene-Monomer Rubber Filled with Barium Titanate/Multiwall Carbon Nanotube Hybrid

“…In these studies, this type of behavior has been ascribed to the improved electrical conductivity as a result of enhanced connectivity between the one-dimensional MWCNTs in conjunction with the zero-dimensional particles. This improved connectivity has been modeled based on a Voronoi geometry, resulting from Swiss cheese model, combined with the percolation theory [ 39 ]. Based on this model the improved conductivity for the hybrid filler systems depends on the secondary filler size and was favored with micro-size particulate fillers, such as the BT particles used in the present work.…”

Bending Properties of Carbon Nanotube/Polymer Composites with Various Aspect Ratios and Filler Contents

“…The sensing mechanism of these sensors is the piezoresistive effect, i.e., when compression, tension, or bending is applied to these sensors by human motion, the location and morphology of the fillers in the sensors change, causing a change in electrical resistance. The magnitude of the piezoresistive effect and the electrical properties vary depending on the dimension, content, and morphology of the filler [ 12 , 13 , 14 ]. In addition, hysteresis may occur due to changes in the position and shape of the fillers in the composite, which are induced by various external deformations [ 15 , 16 , 17 ].…”