Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

This proposal aims to tackle some of the most difficult outstanding problems in soft condensed matter physics. Many soft solids are glassy (amorphous solids). Glasses could be argued to be the most common solids, as with sufficiently rapid cooling, even materials that usually adopt a crystalline structure can be made to form a glass. Despite their importance, both as technilogically important materials, and as one of the most common forms of condensed matter, we lack a deep theoretical understanding of the formation of glasses. One of the challenges that face the experimental study of glasses is the very long relaxation times associated with glassy materials, as this results in materials that are inherently out of equilibrium, and continue to age (change over time) for indefinite time periods. The recent discovery of stable glasses - those which mimic glasses that have aged for thousands over even millions of years- are ideal candidates as we look for near equilibrium glassy systems to study. We will continue on our quest to develop an understanding of glasses and glass formation by making and studying the first stable glasses made from polymers. We will couple this with our theoretical efforts that aim to provide a more simple framework to understand much of the physics of glassy materials. In addition to our study of glassy solids, we will also explore aspects of crystallinity in polymers as well. Many polymers are partially crystalline, and we will study highly monodisperse small polymers in order to deepen our understanding of crystal formation in polymers. Polymers are known to exhibit various forms of self assembly, and one form of this is segregation of one species to the surface. The case of chain ends is particularly interesting as the driving force for segregation is purely entropic. The weak driving force from chain end segregation makes it very challenging to study. We will provide a definitive answer to the existence and extent of surface segregation in blends of polymer with different values of molecular weight, and thus provide experimental verification of chain end segregation. All of the experimental projects will utilize our new technique of direct physical vapour deposition of polymers. This technique allows for the isolation of small polymer molecules ( comprised of <~ 10 monomer units) with unprecedented monodsipersity and in bulk quantities. Our new technique also has the ability to redefine how solid polymers can be deposited onto a substrate, and opens up new avenues in soft nanotechnology. Overall, the proposal has great promise for impact in both our fundamental understanding of soft condensed matter and the technological applications of these materials.