(317g) Coarsening and Arrest Dynamics in a Ternary Polymer Solution Undergoing Phase Separation

The late stages of the dynamics of a liquid-liquid phase separation are characterized by a phenomenon known as “coarsening”, where the domain sizes increase until phase separation is achieved at bulk scales. Coarsening plays a critical role in the formation of microstructure and patterns in various soft material systems. A key aspect of the coarsening dynamics for many systems is how it can be kinetically arrested to “freeze in” a desired microstructure. To study the phenomenon more carefully, we have extensively characterized the coarsening and arrest dynamics of a model ternary system consisting of a polymer, good solvent, and poor solvent using a phase field model. To model kinetic arrest, we endow the polymer component with a phenomenological glass transition where the diffusivity approaches zero and the viscosity diverges at a specified polymer concentration. We characterize the coarsening dynamics of this system with and without the influence of hydrodynamics and in the presence and absence of kinetic arrest. We find that the composition of the mixture is a critical factor for predicting the coarsening dynamics. Interestingly, we also observe the phenomenon of “phase inversion” in certain regions of the parameter space, an effect which was previously attributed to viscoelasticity.