The Glass Transition in Normal and Exceptional Glassformers

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This project focuses on glassforming liquids. It includes a study of formation of glasses of unusual properties via first order liquid-liquid phase transitions to test the possibility that there exists a class of vitreous materials of unusually low entropy (appromixating "perfect glasses"), with atypical vibrational characteristics. It also includes exploring the possibilty of creating a class of (variably) porous, hence lightweight, glasses by using the Maxwell randomly-connected freely-joited slats approach, with rigid molecular slats chemically linked at pivot points. These new project will be blended with a variety of novel studies addressing conventional body of visocous liquid glassformers. One source of novelty here comes from the recognition that the configurational excitation of liquids, which usually progresses continuously once the glass transition temperature has been passed, can occur in distinct stages if the intermolecular interactions have inhomogeneous components. The major thrust of the project involves a search for deeper understanding of the physics of the glass transition. The molecular level distinction between "strong" and "fragile" liquids and plastic crystals, on the one hand and the distinction between "structural" glassformers on the one hand, and the various spin glasses, dipole glasses, etc of solid state physics, on the other will be explored. The project will also address the relation between glassforming liquids and biomolecules and, alternatively the use of glassforming liquids to preserve biomolecules studies of the relation between folding in individual molecules(proteins) and two-tier excitation processes in simpler systems, and possible links between the nucleation phenomenon in complex systems and the aberrant folding of membrane proteins to new forms involved in "mad cow" disease and its human disease relatives will continued.%%%Describing at the nanometer level the amorphous state of solids in central to many areas of advanced materials technologies that include polymers, metals, pharmaceuticals and biomaterials. An understanding of the amorphous state and how it is prepared and stabilized will lead to new routes for synthesizing novel materials with unique properties.