The effect of nanoparticle conglomeration on the overall conductivity of nanocomposites

Abstract

This study provides a multi-step analytical model to investigate the synergistic effects of carbon black nanoparticles and micro-scale carbon fibers on the electrical conductivity of the polymer matrix multi-scale nanocomposites. In the first step, the homogenized electrical conductivity of the nanoparticle-polymer nanocomposites containing the nanoparticle agglomeration is calculated using the percolation like electrical network model. The second step presents the details of Mori-Tanaka micromechanical model to predict the effective electrical conductivity of the multi-scale nanocomposites composed of the micro-fibers embedded in the nanoparticle-enriched polymer as the matrix phase. The influences of different parameters such as the nanoparticle agglomerate diameter to tunneling distance ratio, fiber aspect ratio, intrinsic electrical conductivity, volume fraction, and polymer potential barrier height on the electrical resistivity of the multi-scale nanocomposites are investigated. Based on the comparative studies, the model predictions are in good agreement with the available experimental results. It is found that the electrical resistivity decreases with the addition of multi-scale fillers. The results also suggest that the tunneling distance between the agglomerates plays a dominant role in the electrical conductivity of the multi-scale nanocomposites.