A developed micromechanical model to predict electrical properties of polymer nanocomposites containing carbon nanotubes

In this paper, a developed micromechanical model to predict the effective electrical conductivity of polymer nanocomposites containing carbon nanotubes was presented. This model was based on mean field theory and considering the quantum tunneling phenomenon of electrons between nanofillers. Carbon nanotube was assumed to be cylindrical, which was covered by an interphase layer. Carbon nanotubes were randomly distributed and oriented inside the polymer matrix. The effect of various parameters such as the geometric dimensions of carbon nanotubes, their aspect ratio, the thickness of the interphase layer, the quantum tunneling of electrons, the conductivity of the polymer matrix, the conductivity of carbon nanotubes and the conductivity of the interphase layer on the effective conductivity of the nanocomposite were considered in the theoretical model. The presented model reproduced the electrical behavior of nanocomposites in the insulating region, the percolation region, and the metal region, as well as the sharp transition of conductivity or the beginning of percolation and the metal region in high volume fractions. The results showed that by increasing the size of carbon nanotubes in nanocomposite, the percolation threshold decreased. The conductivity values of the filler and the matrix, respectively, only affected the metal and insulation areas. Finally, the present model was used to reproduce the experimental reported data that the predicted results were in good agreement with the experimental data.