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

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

Authors 

Wani, Y. M., Institute of Physics, Johannes Gutenberg University Mainz
Kritika, K., Institute of Physics, Johannes Gutenberg University Mainz
Howard, M., University of Texas At Austin
Nikoubashman, A., Princeton University
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.