A multistep methodology for effective conductivity of carbon nanotubes reinforced nanocomposites

This study presents a multistep methodology to express the effective conductivity of polymer carbon nanotubes (CNTs) nanocomposites by filler aspect ratio, interphase zones, tunneling effects, and the dimensions of conductive networks. The effective resistance of supposed particles, including CNT/interphase and CNT/interphase/tunneling regions, as well as the volume fractions of all components in the conductive networks, is suggested. Predictions of the proposed method are compared with experimental results and the influences of all parameters on effective conductivity are investigated. The predictions show good agreement with the experimental measurements. In addition, all parameters reasonably control the effective conductivity, validating the multistep methodology. Effective conductivity cannot be improved with thick CNTs, while the thinnest CNTs and the thickest interphase produce the highest effective conductivity. Poor tunneling resistivity due to polymer layers, short tunneling distance, and large tunneling diameter all improve the effective conductivity. (C) 2019 Elsevier B.V. All rights reserved.