Simulation study of the electrical tunneling network conductivity of suspensions of hard spherocylinders

TL;DR

This study uses Monte Carlo simulations to analyze how the electrical conductivity of hard spherocylinder suspensions varies with volume fraction, revealing non-monotonic behavior under certain tunneling models and proposing a computationally efficient network metric.

Contribution

It introduces a simulation-based analysis of tunneling conductivity in rod suspensions, highlighting the impact of tunneling anisotropy and proposing a new network metric for qualitative estimates.

Findings

Non-monotonic conductivity at isotropic-nematic transition with isotropic tunneling

Anisotropic tunneling eliminates the non-monotonic behavior

Mesh number of Kirchhoff network offers a simple qualitative estimate

Abstract

Using Monte Carlo simulations, we investigate the electrical conductivity of networks of hard rods as a function of the volume fraction for two tunneling conductance models. For a simple, orientationally independent tunneling model, we observe non-monotonic behaviour of the bulk conductivity as a function of volume fraction at the isotropic-nematic transition. However, this effect is lost if one allows for anisotropic tunneling. We also compute the mesh number of the Kirchhoff network, which turns out to be a simple alternative to the computationally expensive conductivity of large systems in order to get a qualitative estimate.