Exploring the role of hydrodynamic interactions in spherically-confined drying colloidal suspensions

Abstract

We study the distribution of colloidal particles confined in drying spherical droplets using both dynamic density functional theory (DDFT) and particle-based simulations. In particular, we focus on the advection-dominated regime typical of aqueous droplets drying at room temperature and systematically investigate the role of hydrodynamic interactions during this nonequilibrium process. In general, drying produces transient particle concentration gradients within the droplet in this regime, with a considerable accumulation of particles at the droplet's liquid-vapor interface. We find that these gradients become significantly larger with pairwise hydrodynamic interactions between colloidal particles instead of a free-draining hydrodynamic approximation; however, the solvent's boundary conditions at the droplet's interface (unbounded, slip, or no-slip) do not have a significant effect on the particle distribution. DDFT calculations leveraging radial symmetry of the drying droplet are in excellent agreement with particle-based simulations for free-draining hydrodynamics, but DDFT unexpectedly fails for pairwise hydrodynamic interactions after the particle concentration increases during drying, manifesting as an ejection of particles from the droplet. We hypothesize that this unphysical behavior originates from an inaccurate approximation of the two-body density correlations based on the bulk pair correlation function, which we support by measuring the confined equilibrium two-body density correlations using particle-based simulations. We identify some potential strategies for addressing this issue in DDFT.

16 pages, 7 figures

References in corpus (27)

• Dynamic Density Functional Theory of Fluids
• Dynamical density functional theory and its application to spinodal decomposition
• Multi-particle-collision dynamics: Flow around a circular and a square cylinder
• Classical dynamical density functional theory: from fundamentals to applications
• Multi-Particle Collision Dynamics -- a Particle-Based Mesoscale Simulation Approach to the Hydrodynamics of Complex Fluids
• Dynamical density functional theory for molecular and colloidal fluids: a microscopic approach to fluid mechanics
• Cross-interaction drives stratification in drying film of binary colloidal mixtures
• Rapid Sampling of Stochastic Displacements in Brownian Dynamics Simulations
• Power functional theory for Brownian dynamics
• Diffusiophoresis in non-adsorbing polymer solutions: the Asakura-Oosawa model and stratification in drying films
• Scalable Metropolis Monte Carlo for simulation of hard shapes
• Dynamical density functional theory with hydrodynamic interactions and colloids in unstable traps
• Power functional theory for many-body dynamics
• Dynamical density functional theory: binary phase-separating colloidal fluid in a cavity
• Efficient mesoscale hydrodynamics: multiparticle collision dynamics with massively parallel GPU acceleration
• Dynamic Density Functional Theory with hydrodynamic interactions and fluctuations
• Influence of hydrodynamic interactions on stratification in drying mixtures
• Perspective: How to overcome dynamical density functional theory
• Molecular dynamics simulations of the evaporation of particle-laden droplets
• Stratification of drying particle suspensions: Comparison of implicit and explicit solvent simulations
• Diffusion and sedimentation in colloidal suspensions using multiparticle collision dynamics with a discrete particle model
• Dynamical density functional theory for the drying and stratification of binary colloidal dispersions
• Perspective: New directions in dynamical density functional theory
• Stratification of polymer mixtures in drying droplets: hydrodynamics and diffusion
• Dynamics of localized particles from density functional theory
• Mesoscale simulations of diffusion and sedimentation in shape-anisotropic nanoparticle suspensions
• Dynamic density functional theory for drying colloidal suspensions: Comparison of hard-sphere free-energy functionals

Cited by in corpus (2)

• Inverse design of drying-induced assembly of multicomponent colloidal-particle films using surrogate models
• Mesoscale particle-based simulations of flow in expansion-contraction microchannels at low Reynolds number