Electrophoresis of Janus Particles: a Molecular Dynamics simulation study

TL;DR

This study uses molecular dynamics and lattice-Boltzmann simulations to analyze how charged Janus particles behave under electric fields, revealing their mobility, alignment, and the influence of electrostatic layer thickness.

Contribution

It provides new insights into the electrophoretic behavior of Janus particles, especially regarding the effects of charge, diffuse layer thickness, and particle orientation.

Findings

Janus particles have lower mobility than uniformly charged colloids at higher charges and thinner diffuse layers.

Janus particles align with electric fields, with their orientation related to their dipole moment.

Electrophoretic mobility is strongly correlated with the electrostatic diffuse layer thickness.

Abstract

In this work, we use Molecular Dynamics and Lattice-Boltzmann simulations to study the properties of charged Janus particles in an electric field. We show that for relatively small net charge and thick electrostatic diffuse layer mobilities of Janus particles and uniformly charged colloids of the same net charge are identical. However, for higher charges and thinner diffuse layers Janus particles always show lower electrophoretic mobility. We also demonstrate that Janus particles align with the electric field and the angular deviation from the field's direction are related to their dipole moment. We show that the latter is affected by the thickness of the electrostatic diffuse layer and strongly correlates with the electrophoretic mobility.