Impact of Covalently Attached Model Probes on Polymer Physical Properties - a Quantitative Assessment

Understanding polymer thin films and their properties is an important part of polymer physics however, many bulk characterization techniques cannot be easily applied to thin films. Therefore, using molecular probes is a common approach. Particularly, dyes are often employed to investigate polymer dynamics and structures, such as single-particle tracking, super-resolution optical imaging, and polymer glass transition temperature (Tg). A common assumption in these systems is that the inclusion of dilute amounts of fluorophore will not, or only minimally, alter the studied material properties. However, this assumption has not been fully validated and the development of advanced imaging techniques requires the use of higher concentration and/or larger dyes, making it necessary to systematically investigate their impact on polymer systems. This work focuses on quantitatively understanding the impact of molecular probes on chain conformation and Tg (bulk and thin film) using amino pyrene and Sudan IV covalently attached to high and low molecular weight polymer model systems, assessed over a wide range of concentrations. This research will inform the efficient use of molecular probes for understanding polymer physics.