Coarse-grained Computations for Interfacial Transport in Bijels

Bicontinuous Interfacially Jammed Emulsion Gels known as Bijels have industrial applications, including reactive separation [1]. Here, polymer transport through a Bijel structure is investigated with Dissipative Particle Dynamics (DPD) computations, available through the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) [2-4]. The two fluid phases are water and diethyl phthalate, stabilized with neutrally wetting nanoparticles. Interfacial parameters, such as interfacial tension and contact angle, are measured using DPD to verify the computations [4]. Firstly, we investigate the properties of multimer conformations in a pure solvent to determine the key model parameters and to ensure that these parameters generate the correct static and dynamic polymer scaling laws. Calculations of the polymer diffusivity in pure solution and the polymer chain relaxation time allow for the determination of the appropriate timestep window for accurate diffusivity computation. Secondly, we calculate the multimer diffusivity across the oil-water interface. In particular, we focus on interfacial transport as a function of the polymer-solvent interactions and the interfacial tension in the bijel system. The goal is to understand the behavior of multimer conformations in different solvent scenarios and in complex systems.

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