(630b) Investigation of Glassy Properties in Polymer Brushes in the Thin Film Geometry

Thin films in the brush morphology comprise polymer chains chemically anchored to a substrate by a single end. Due to this morphology, polymer brushes can exhibit properties that deviate from those observed in spin-coated films. Specifically, it has been suggested that the molecular packing in brushes can influence the glass transition temperature of confined polymer films. There has been less focus on studying the impact of morphology and confinement on the overall and local physical aging of thin films. In this work, we show a slight reduction in overall aging rates in spin-coated films under confinement compared to their macroscopic counterparts via ellipsometry. However, such a reduction is not observed in polymer brushes, suggesting that molecular packing can also impact physical aging behavior in thin films. In future studies, we will consider the influence of interfaces, such as the polymer-air and polymer-substrate interactions, on physical aging through local fluorimetry measurements. This series of experiments will allow us to understand how molecular packing can influence material properties in the thin film geometry and potentially lead to new approaches to designing polymer thin films.