Electrical Percolation Behavior in Silver Nanowire–Polystyrene Composites: Simulation and Experiment

Abstract

Abstract The design and preparation of isotropic silver nanowire‐polystyrene composites is described, in which the nanowires have finite L/D (< 35) and narrow L/D distribution. These model composites allow the L/D dependence of the electrical percolation threshold, ϕ c , to be isolated for finite‐ L/D particles. Experimental ϕ c values decrease with increasing L/D , as predicted qualitatively by analytical percolation models. However, quantitative agreement between experimental data and both soft‐core and core–shell analytical models is not achieved, because both models are strictly accurate only in the infinite‐ L/D limit. To address this analytical limitation, a soft‐core simulation method to calculate ϕ c and network conductivity for cylinders with finite L/D are developed. Our simulated ϕ c results agree strongly with our experimental data, suggesting i) that the infinite‐aspect‐ratio assumption cannot safely be made for experimental networks of particles with L/D < 35 and ii) in predicting ϕ c , the soft‐core model makes a less significant assumption than the infinite‐ L/D models do. The demonstrated capability of the simulations to predict ϕ c in the finite‐ L/D regime will allow researchers to optimize the electrical properties of polymer nanocomposites of finite‐ L/D particles.