(189bc) Combining Molecular Simulation, Liquid State Theory, and Gibbs Ensemble Techniques to Study the Structure, Thermodynamics, and Phase Behavior of Polymer-Solvent Mixtures

Solvent processing techniques (e.g. solvent vapor annealing, flash nanoprecipitation, reverse emulsion assembly, various thin-film casting and coating processes) play a vital role in the fabrication of functional polymer materials. In each of these examples, the presence of solvent alters polymer thermodynamics by screening polymer-polymer interactions and tunes polymer dynamics by increasing chain mobility, phenomena which can be exploited to trigger some structural or morphological change in a polymer material. However, in order to design effective solution processing methods, there is a need for a fundamental understanding of how varying solvent content (dilute, semidilute, concentrated) and solvent quality (poor, theta, good) affect the structure and thermodynamics of polymer solutions. In this poster, we describe our recent developments of computational techniques to study the solvent processing of polymer systems. First, we present a hybrid Monte Carlo/molecular dynamics (MC/MD) Gibbs ensemble approach to study vapor-liquid equilibria in polymer-solvent systems. We apply this technique to the solvent vapor annealing of polymer blends to uncover the impacts of changing solvent content on blend structure and thermodynamics. Second, we detail a combined simulation and theory approach using coarse-grained MD simulation and Polymer Reference Interaction Site Model (PRISM) theory to study polymer chain conformations and polymer-solvent thermodynamics over a range of solvent qualities. Thus, using our computational techniques, we can provide a useful mapping of the structure and thermodynamics of polymers in varying solution conditions to inform the design of solvent processing methods.