Effect of carbon nanotube geometry upon tunneling assisted electrical network in nanocomposites

This paper examines the effect of carbon nanotube (CNT) geometry upon the electrical properties of the corresponding functionalized nanocomposites. Specifically, Monte Carlo (MC) simulations are conducted to evaluate the effect of CNT length non-uniformity and waviness upon tunneling. Three aspects of the work are considered. The first is concerned with the application of periodic boundary condition that ensures periodic connectivity of the percolating paths via the use of an improved connective percolating network recognition scheme. The second is concerned with the determination of the electrical conductivity of the percolated system rather than the critical percolation threshold for varied CNT geometries using Weibull distribution to statistically account for the geometry variations. The third is concerned with the validation of our MC simulations. Our results reveal that (i) the CNT geometry, as determined by CNT length variability and waviness, plays a more dominant role in percolation threshold rather than tunneling barrier height and (ii) higher CNT loading beyond a critical percolation significantly influences the role of tunneling barrier height upon the electrical conductivity. (C) 2013 AIP Publishing LLC.