Nanoconfinement effects on the fragility of glass formation of a model freestanding polymer film.

Evidence suggests that the fragility (m) of glass formation both underpins and is sensitive to nanoconfinement effects on the glass transition. Here we present data indicating that nanoconfinement-induced changes in m of freestanding films emerge from a dominance of finite-size-driven fragility suppression over interfacial fragility enhancement.