Monte Carlo simulation of nanotube suspensions and composites

Monte Carlo simulations have been performed, aimed at finding a critical fractional volume associated with the onset of percolation for randomly oriented nanotubes dispersed in a low thermo- or electro-conductive medium. Nanotubes were treated as capped interpenetrating conductive cylinders ("sticks") with a high (up to 2000) aspect ratio a. It has been found that for these aspect ratios critical fractional volume is inversely proportional to a resulting in a surprisingly low filler volume loadings of the order of 0.01% required to achieve percolation in such systems in a good agreement with recent experimental data on thermal and electrical conductivity of carbon nanotube suspensions and composites.