9602884 C. Austen Angell "Transitions in Bulk and Mesoscopic Liquids" This award will provide partial support for three months of a six month visit to the University of Sydney, Australia, by Professor C. Austen Angell of the Department of Physics, Arizona State University. Professor Angell will conduct collaborative research with Professors P. Harrowell and G. Warr on current aspects of the dynamics and thermodynamics of the glass transition, or polyamorphism glassy and liquid systems, and of the relation of such polyamorphism to major structural transitions in mesoscopic systems such as protein and RNA folding transitions. Angell's interest in glass transition phenomenology will be combined with Harrowell's theoretical expertise in kinetic Ising models, and the consequent microscopic origins of liquid fragility, and Warr's experience in microemulsion structure and stability, to improve current understanding of glasses and polyamorphism in glasses and biopolymers. The investigators will 1) use control of system size at constant chemical potential to see system size effects, in particular in systems with dimensions comparable to those attributed to microheterogeneities which now seem to appear near the glass temperature; 2) perform theoretical studies based on a facilitated spin microheterogeneous model to determine the conditions necessary to produce the smeared-out, glass- liquid transformation characteristic of hydrated protein systems; 3) undertake multi-step calorimetric studies of protein refolding kinetics to assess the relevance of nucleation and growth kinetics to the first order complex systems transition; and 4) utilize microemulsion techniques to examine effects of confinement on folding kinetics and to explore single molecule observation strategies.
