(525a) Mesoscale Simulation Approach for Dynamics and Assembly of Deformable Objects

In dilute suspensions, surfactant micelles and emulsion droplets often take spherical shapes. But at high enough concentrations, contact among the micelles or droplets leads to nonspherical shapes. In this limit, the dynamics and assembly of the suspension depend more on the interfaces between objects than the bulk objects themselves. This has similarities with foams and biological tissues in which the interfaces between deformable objects (gas bubbles or cells) play a critical role. We have adapted a mesoscale approach (called vertex models) in order to apply it to the dynamics and assembly of small deformable objects where thermal fluctuations are important. In particular, we have quantified the phase diagram of assembly and kinetics of assembly when a system is quenched into an ordered region of the phase diagram. A unique feature of 3D materials is that multiple ordered states are possible. We have quantified the meta-stability of these ordered states and found a “diffusionless transformation” between ordered states. These transformations are well-known in metallic systems, but have only more recently been found in experiments with soft materials. Exchange of material and volume between objects also plays an important role in determining the ideal packing structures.