Molecular dynamics simulation of the conductivity mechanism of nanorod filled polymer nanocomposites.

We adopted molecular dynamics simulation to study the conductive property of nanorod-filled polymer nanocomposites by focusing on the effects of the interfacial interaction, aspect ratio of the fillers, external shear field, filler-filler interaction and temperature. The variation of the percolation threshold is anti N-type with increasing interfacial interaction. It decreases with an increase in the aspect ratio. At an intermediate filler-filler interaction, a minimum percolation threshold appears. The percolation threshold decreases to a plateau with temperature. At low interfacial interaction, the effect of an external shear field on the homogeneous probability is negligible; however, the directional probability increases with shear rate. Moreover, the difference in conductivity probabilities is reduced for different interfacial interactions under shear. Under shear, the decrease or increase of conductivity probability depends on the initial dispersion state. However, the steady-state conductivity is independent of the initial state for different interfacial interactions. In particular, the evolution of the conductivity network structure under shear is investigated. In short, this study may provide rational tuning methods to obtain nanorod-filled polymer nanocomposites with high conductivity.