The roles of interphase and filler dimensions in the properties of tunneling spaces between CNT in polymer nanocomposites

In this article, the properties of tunneling mediums between adjacent nanotubes in polymer carbon nanotubes nanocomposites are investigated assuming the main tunneling mechanism of electrical conductivity. The tunneling distance is expressed as a function of filler and interphase dimensions by the roles of these parameters in percolation threshold and effective filler fraction. In addition, the tunneling resistance and conductivity are defined based on the tunneling distance. The properties of tunneling spaces are determined in some samples and their variations at different ranges of parameters are analyzed. It is found that the addition of filler concentration decreases both tunneling distance and resistance. Also, low percolation threshold and high filler concentration are necessary to reduce the tunneling distance and resistance. Moreover, thin nanotubes, low waviness, thick interphase and long nanotubes cause desirable properties for tunneling mediums. According to this analysis, short tunneling distance and low tunneling resistance create high conductivity in polymer nanocomposites. POLYM. COMPOS., 40:801–810, 2019.