Isotropic-nematic interfacial tension of hard and soft rods: application of advanced grand canonical biased sampling techniques

TL;DR

This paper uses advanced grand canonical biased sampling techniques to accurately estimate the isotropic-nematic interfacial tension in rod suspensions, aligning well with theoretical and experimental data.

Contribution

It introduces a biasing scheme in grand canonical Monte Carlo simulations to measure interfacial tension in systems of hard and soft rods.

Findings

Estimated interfacial tension for hard rods: ~1.4 kB T/L^2

Results agree with theoretical predictions

Findings are consistent with experimental observations

Abstract

Coexistence between the isotropic and the nematic phase in suspensions of rods is studied using grand canonical Monte Carlo simulations with a bias on the nematic order parameter. The biasing scheme makes it possible to estimate the interfacial tension gamma in systems of hard and soft rods. For hard rods with L/D=15, we obtain gamma ~ 1.4 kB T/L^2, with L the rod length, D the rod diameter, T the temperature, and kB the Boltzmann constant. This estimate is in good agreement with theoretical predictions, and the order of magnitude is consistent with experiments.