Seminar Speaker: Sindee Simon, NC State CBE

Abstract

The glass transition and structural recovery of glass-forming materials, including polymeric, small-molecule, inorganic networks, and co-amorphous glasses, have been studied in our laboratory using dilatometry and calorimetry, both in bulk and at the nanoscale. Of particular interest is how nanoconfinement influences structural recovery, whether the extrapolated liquid line is reached at equilibrium, and the ability of the phenomenological Kovacs-Aklonis-Hutchinson-Ramos (KAHR) and Tool-Narayanaswamy-Moynihan (TNM) models to describe the structural recovery process. Recent work has focused on using pressure-densified and pressure-expanded glasses to test the assumptions underlying these empirical models. We find, in contrast to model assumptions, that the relaxation time does not depend on the departure from equilibrium from the instantaneous liquid state and that the relaxation kinetics for temperature and pressure perturbations are not coupled. The implications of these findings will be discussed in the context of unanswered questions in the field.

Speaker Biography

Prof. Sindee L. Simon obtained her B.S. in Chemical Engineering at Yale University in 1983 and her Ph.D. in Chemical Engineering at Princeton University in 1992. She started her career at the University of Pittsburgh, then spent twenty years at Texas Tech moving up the ranks from Associate Professor to P.W. Horn Distinguish Professor to Department Chair. In 2022, she moved to North Carolina State University where she is Head of Chemical and Biomolecular Engineering. Dr. Simon’s research interests include the physics of the glass transition, cure and properties of thermosetting materials, and properties and reactivity at the nanoscale. She has published over 130 refereed journal publications, has over 6000 citations, and has an h-index of 44 according to Google Scholar. She has received numerous honors, including Fellowships in the American Physical Society, the Society of Plastics Engineers (SPE), the North American Thermal Analysis Society (NATAS), and the American Institute of Chemical Engineers. She is also the recipient of the 2019 SPE International Award, as well as the SPE Research/Technology Award and the NATAS Outstanding Achievement Award.