Impact of Nanoparticle Curvature on Adsorbed Polymer Chain Structure and Local Glass Transition Properties*

Polymer properties are commonly enhanced via the addition of nanofiller, resulting in polymer nanocomposites with broad applications. Previous work suggests that a key feature governing the tuning of nanocomposite properties is the interfacial region between the nanoparticle and the polymer matrix, particularly where polymer chains experience frustrated packing during physical adsorption on the nanoparticle surface. Accordingly, nanoparticle morphology is expected to impact adsorbed chain packing and subsequent nanocomposite properties. Precise characterization and tuning of this interface has remained unrealized, however, as conventional characterization techniques are limited in spatial resolution of local polymer properties. In this study, fluorescence spectroscopy and transmission electron microscopy are combined to enable direct imaging and measurement of local structure and properties of polymer chains adsorbed on nanoparticles. Varying nanoparticle size allows us to elucidate how curvature impacts adsorbed chain structures and their corresponding local glass transition properties. This enhanced understanding paves the way for more intentional and effective approaches in designing nanocomposites.