(4j) Colloidal Assembly and Reconfiguration Dynamics

Beltran-Villegas, D. J. - Presenter, University of Michigan

Understanding concentrated colloidal dynamics in the presence of different pairwise interactions and external fields provides a basis to predict the temporal evolution of colloidal microstructures in diverse phenomena including suspension rheology and colloidal assembly. However, a microscopic theory of concentrated colloidal dynamics does not yet exist that rigorously includes both statistical mechanical (configuration dependent free energy changes) and fluid mechanical (configuration dependent multi-body hydrodynamic interactions) contributions. This work shows the implementation of a novel approach to model colloidal assembly by means of analyzing the Smoluchowski Equation to describe temporal evolution of microstructures with a small number of sytem descriptors or order parameters. Colloidal assembly is simulated via Brownian dynamic and Stokesian dynamic methods to generate high-dimensional assembly trajectories. These trajectories are analyzed and converted to order parameter evolution data and used to generate a low-dimensional decription assembly dynamics. Results of this approach to a model colloidal crystallizing system show low-dimensional dynamic models that capture relevant thermodynamic and kinetic information. This methodology is used, then, to analyze the structure re-configurability of anisotropic colloidal building blocks. Knowledge of these dynamic models enable the fundamental understanding of assembly systems, as well as the optimization, design and control of assembly systems to produce low-defect colloidal crystals.