Two-Dimensional Vesicle Hydrodynamics from Hydrophobic Attraction Potential

TL;DR

This paper introduces a new model for simulating the hydrodynamics of Janus particles forming vesicle structures, capturing their self-assembly, deformation, and rupture under flow conditions using an integral equation approach.

Contribution

The study presents a novel integral equation method for accurately modeling hydrophobic attraction and hydrodynamic interactions in Janus particle vesicles, enabling detailed flow behavior analysis.

Findings

Observed tank-treading deformation in Janus particle vesicles.

Measured inter-monolayer friction and membrane permeability.

Demonstrated membrane rupture at high shear rates.

Abstract

We develop a new model, to our knowledge, for the many-body hydrodynamics of amphiphilic Janus particles suspended in a viscous background flow. The Janus particles interact through a hydrophobic attraction potential that leads to self-assembly into bilayer structures. We adopt an efficient integral equation method for solving the screened Laplace equation for hydrophobic attraction and for solving the mobility problem for hydrodynamic interactions. The integral equation formulation accurately captures both interactions for near touched boundaries. Under a linear shear flow, we observe the tank-treading deformation in a two-dimensional vesicle made of Janus particles. The results yield measurements of inter-monolayer friction, membrane permeability, and at large shear rates, membrane rupture. The simulations studies include a vesicle in parabolic flow and vesicle-vesicle interactions in shear and extensional flows. The hydrodynamics of the Janus particles vesicle replicate the behaviour of an inextensible elastic vesicle membrane.