Mesoscale Structures at Complex Fluid-Fluid Interfaces: a Novel Lattice Boltzmann / Molecular Dynamics Coupling

TL;DR

This paper introduces a new coupled simulation method combining Lattice Boltzmann and molecular dynamics to efficiently study mesoscale structures at complex fluid-fluid interfaces, enabling advanced analysis of soft matter systems.

Contribution

A novel coupling approach of Lattice Boltzmann and molecular dynamics for simulating complex fluid interfaces with mesoscale structures.

Findings

Effective simulation of bicontinuous phases in polyelectrolyte solutions.

Analysis of ferrofluid emulsion behaviors.

Unveiling multiscale particle-fluid interactions through solvation energies.

Abstract

Complex fluid-fluid interfaces featuring mesoscale structures with adsorbed particles are key components of newly designed materials which are continuously enriching the field of soft matter. Simulation tools which are able to cope with the different scales characterizing these systems are fundamental requirements for efficient theoretical investigations. In this paper we present a novel simulation method, based on the approach of Ahlrichs and D\"unweg [Ahlrichs and D\"unweg, Int. J. Mod. Phys. C, 1998, 9, 1429], that couples the "Shan-Chen" multicomponent Lattice Boltzmann technique to off-lattice molecular dynamics to simulate efficiently complex fluid-fluid interfaces. We demonstrate how this approach can be used to study a wide class of challenging problems. Several examples are given, with an accent on bicontinuous phases formation in polyelectrolyte solutions and ferrofluid emulsions. We also show that the introduction of solvation free energies in the particle-fluid interaction unveils the hidden, multiscale nature of the particle-fluid coupling, allowing to treat symmetrically (and interchangeably) the on-lattice and off-lattice components of the system.