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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 21: Poster II

CPP 21.20: Poster

Tuesday, March 19, 2024, 18:00–20:00, Poster E

Diffusion Dynamics in Glassy Polymer Films through MD Simulations — •Sharon Volpe, Hsiao-Ping Hsu, and Kurt Kremer — Max-Planck-Institut für Polymerforschung, Ackermannweg 10, Mainz 55128, Germany

Case II diffusion presents a unique challenge in materials science and polymer engineering. The slow rearrangement of the polymer chains in the glassy state leads to an anomalous sorption behavior: a sharp front is observed as an interface that moves at a constant velocity between the swollen plasticized region and the unswollen glassy region. Unraveling the microscopic mechanisms of Case II diffusion is fundamental for tailoring materials with precise diffusion properties, with applications ranging from drug delivery to food packaging. This study employs Molecular Dynamics (MD) simulations to investigate Case II diffusion in glassy polymer films. A dedicated explicit solvent model is developed to control and vary the solvent-polymer interactions. Our focus is on exploring diffusion for different solvent qualities, their impact on diffusion profiles and the chain characteristics in the swollen region. In certain conditions, the observed diffusion patterns align with the characteristic behavior of Case II diffusion. The simulations provide insights into the interplay between solvent and glassy polymer films and contribute to the knowledge of molecular diffusion in these materials.

Keywords: Case II diffusion; Polymer films; Molecular dynamics simulations; Coarse-grained modeling