Jane Lipson, Dartmouth College

Title: Approaching the Glass Transition From Different Directions (Video)

Abstract: In recent years a significant amount of experimental work has appeared on glassy systems, both polymeric and small molecule. However, this rich explosion in data has not been met with a concomitant leap in fundamental understanding. We have developed a number of approaches to elucidate some of the underlying mechanisms of behaviour in bulk and confined glassy systems.  Using both theory and simulation we have characterized the dynamic heterogeneity associated with approaching the glass transition, explored interfacial behaviour when layering materials of differing mobility, and analyzed the effect of one or more free surfaces on thin films. In our most recent work we have applied a simple thermodynamic model to reveal hints of the underlying glassy nature of a bulk polymer sample, even while above its transition temperature (Tg).  A signature feature of all these studies has been our extensive efforts in making connections with a substantive amount of experimental data. This talk will comprise an efficient summary of past progress from these different directions, and will then focus on our most recent results and current understanding.