Study on Percolation State and Electrical Properties of Carbon Nanotube Network

Carbon nanotubes (CNTs) are often used as conductive fillers for nanocomposites thanks to their excellent electrical conductivity and high aspect ratio. Percolation probability and electrical conductivity are important parameters to measure the electrical properties of CNT network. In this work, a simulation model using Monte Carlo method in CNT network is proposed to study the effects of volume fraction and aspect ratio of CNTs on the percolation probability and electrical conductivity. The Monte Carlo method was introduced to simulate the random distribution of CNTs in the generation domain. It finds that the variation trends of percolation probability and electrical conductivity show a nonlinear rise with the increase of volume fraction of CNTs. Moreover, the network composed of CNTs with large aspect ratio can present percolation faster and reach saturation state earlier. Compared with a network formed by CNTs at aspect ratio of 80 in which percolation occurs at volume fraction of 2%, a network formed by CNTs at aspect ratio of 150 begins to percolate at volume fraction of 0.7%. The simulation results indicate that the simulation model based on Monte Carlo method can reflect the percolation state and electrical properties of CNT network and analyze the effects of volume fraction and aspect ratio on the percolation probability and electrical conductivity of CNT network quantitatively.