Carbon nanotube percolation in a polymer matrix

Abstract

In this project, the phenomenon of ultra-low percolation threshold for electrical conduction in carbon nanotubes/polymer composites is investigated. Simple Monte-Carlo simulations are carried out which CNTs are modeled as either 1-D sticks or 1-D polylines or 2-D narrow rectangles. A simplistic extension to simulate 3-D composite is also achieved with CNTs modeled as polylines in 3-D. Typically, percolation probability is found to increase peculiarly with CNT volume fraction. The effect of the CNT length, degree of waviness, degree of anisotropy and aspect ratio are investigated. For a model system of 100 CNTs in 1μm*1μm simulation box, results show that a stabilized percolation threshold occurs with average CNT length of 0.256 μm. We also find that the percolation threshold could be lowered by decreasing the degree of anisotropy as well as decrease in the degree of waviness of nanotubes.