(481a) Dynamic Density Functional Theory for Drying Colloidal Suspensions: Hydrodynamic Interactions in Spherical Confinement.

Hydrodynamic interactions play an important role in dictating nonequilibrium self-assembly processes for soft materials. Here, we investigate the role hydrodynamic interactions play in the evolution of structures in drying colloidal suspensions confined within spherical droplets. We develop a continuum model for predicting the distribution of hard-sphere particles in the droplet based on dynamic density functional theory (DDFT). To compute the particle flux during drying, we employ a highly accurate free-energy functional based on fundamental measure theory (FMT) in conjunction with pairwise far-field hydrodynamic interactions described by the Rotne–Prager–Yamakawa (RPY) mobility tensor. We model the behavior of both one- and two-component suspensions, with the latter able to form core–shell structures stratified by particle size. To validate the DDFT model, we compare the DDFT predictions with particle-based Brownian dynamics (BD) and multiparticle collision dynamics (MPCD) simulations in selected cases. To systematically characterize the effects of hydrodynamic interactions between particles, we perform additional DDFT calculations and particle-based simulations with free draining hydrodynamics. Our work illustrates the importance of hydrodynamic interactions in nonequilibrium self-assembly processes such as drying and demonstrates a systematic route for constructing such models.