Nanocomposites

7Computational Modeling of Carbon Nanofiller Networks in Polymer Composites

Angel MORA

CICY, Mérida, Mexico

7.1. Introduction

Conductive nanofillers are typically added into polymers to improve their electrical properties. Carbon-based nanofillers such as carbon nanotubes (CNTs), graphene nanoplatelets (GNPs) or carbon black (CB) are commonly used as conductive nanofillers (Zhou and Lubineau 2013, Li and Zhong 2011, Ezquerra et al. 1986). The resulting nanocomposite material can be used in a wide range of applications. For instance, the addition of GNPs into a polymer can reduce its dielectric properties, which reduces the accumulation of electrical charge (Ge and Cosgrove 2015). This prevents electronic equipment from suffering damage due to an electric discharge. Polymers filled with conductive nanofillers possess piezoresistive properties that may be exploited for strain sensing and structural health monitoring applications (Li et al. 2008b, Nanni et al. 2012, Wernik and Meguid 2010). Table 7.1 shows some examples of the wide range of applications and the type of conductive material obtained depending on the electrical conductivity of polymer nanocomposites.

The change in behavior of a polymer from insulator to electrical conductor by the addition of conductive nanofillers is explained by the percolation theory (Stauffer and Aharony 1994). Electrical percolation is illustrated in the schematic in Figure 7.1, where the composite’s conductivity is shown as a function of nanofiller ...