Hydrochemical interactions of phoretic particles: a regularized multipole framework

Abstract

Chemically-active colloids modify the concentration of chemical solutes surrounding them in order to self-propel. In doing so, they generate long-ranged hydrodynamic flows and chemical gradients that modify the trajectories of other particles. As a result, the dynamics of reactive suspensions is fundamentally governed by hydro-chemical interactions. A full solution of the detailed hydro-chemical problem with many particles is challenging and computationally expensive. Most current methods rely on the Green's functions of the Laplace and Stokes operators to approximate the particle signatures in the far-field, which is only valid in the very dilute limit in simple geometries. To overcome these limitations, we propose a regularized mutipole framework, directly inspired by the Force Coupling Method (FCM), to model phoretic suspensions. Our approach, called Diffusio-phoretic FCM (DFCM), relies on grid-based volume averages of the concentration field to compute the particle surface concentration moments. These moments define the chemical multipoles of the diffusion (Laplace) problem and provide the swimming forcing of the Stokes equations. Unlike far-field models based on singularity superposition, DFCM accounts for mutually-induced dipoles. The accuracy of the method is evaluated against exact and accurate numerical solutions for a few canonical cases. We also quantify its improvements over far-field approximations for a wide range of inter-particle distances. The resulting framework can readily be implemented into efficient CFD solvers, allowing for large scale simulations of semi-dilute diffusio-phoretic suspensions.

arXiv comment24 pages, 8 figures, to appear in the Journal of Fluid Mechanics

References in corpus (41)

• Active Particles in Complex and Crowded Environments
• The hydrodynamics of swimming microorganisms
• Self-motile colloidal particles: from directed propulsion to random walk
• Motility-Induced Phase Separation
• Physics of Microswimmers - Single Particle Motion and Collective Behavior
• Dynamic clustering in active colloidal suspensions with chemical signaling
• Designing phoretic micro- and nano-swimmers
• Bacterial hydrodynamics
• Circular motion of asymmetric self-propelling particles
• Active Brownian Motion Tunable by Light
• Hydrodynamics determines collective motion and phase behavior of active colloids
• Self-propulsion of pure water droplets by spontaneous Marangoni stress driven motion
• Clusters, asters and collective oscillations in chemotactic colloids
• Self-assembly of catalytically active colloidal molecules: Tailoring activity through surface chemistry
• Self-propulsion of a catalytically active particle near a planar wall: from reflection to sliding and hovering
• Spontaneous autophoretic motion of isotropic particles
• Phoretic self-propulsion at finite Péclet numbers
• Clustering and pattern formation in chemorepulsive active colloids
• Flow-induced phase separation of active particles is controlled by boundary conditions
• Light-controlled Assembly of Active Colloidal Molecules
• Spontaneous aggregation and global polar ordering in squirmer suspensions
• Self-assembly of Active Colloidal Molecules with Dynamic Function
• Autophoretic locomotion from geometric asymmetry
• Which Interactions Dominate in Active Colloids?
• Multiple phoretic mechanisms in the self-propulsion of a Pt-insulator Janus swimmer
• Exact phoretic interaction of two chemically-active particles
• Stresslets induced by active swimmers
• Many-body dynamics of chemically propelled nanomotors
• Pair Interaction of Catalytically Active Colloids: From Assembly to Escape
• Phoretic and hydrodynamic interactions of weakly-confined autophoretic particles
• Simulating squirmers with multiparticle collision dynamics
• How walls affect the dynamics of self-phoretic microswimmers
• A regularised singularity approach to phoretic problems
• Competing chemical and hydrodynamic interactions in autophoretic colloidal suspensions
• Exact axisymmetric interaction of phoretically active Janus particles
• Artificial chemotaxis of phoretic swimmers: Instantaneous and long-time behaviour
• Modeling chemo-hydrodynamic interactions of phoretic particles: a unified framework
• A Minimally-Resolved Immersed Boundary Model for Reaction-Diffusion Problems
• Hydro-chemical interactions in dilute phoretic suspensions: from individual particle properties to collective organization
• PyStokes: phoresis and Stokesian hydrodynamics in Python
• Kernel Aggregated Fast Multipole Method: Efficient summation of Laplace and Stokes kernel functions

Cited by in corpus (8)

• Interactions in Active Colloids
• Confined self-propulsion of an isotropic active colloid
• Theoretical modeling of catalytic self-propulsion
• Stokes traction on an active particle
• Self-organisation of auto-phoretic suspensions in confined shear flows
• Self-organization of active colloids mediated by chemical interactions
• Micro-swimmer collective dynamics in Brinkman flows
• A numerical framework for phoretic particles