The Glass Transition in Normal and Exceptional Glassformers

这个项目的重点是玻璃成型液体。它包括通过一阶液-液相变形成具有特殊性质的玻璃的研究，以测试是否存在一类具有非典型振动特征的异常低熵的玻璃材料(相当于混合了“完美玻璃”)。它还包括探索通过使用麦克斯韦随机连接的自由连接的板条方法来创造一种(可变的)多孔的、因此是轻质的玻璃的可能性，在枢轴点具有刚性的分子板条。这些新项目将与各种针对传统粘性液体玻璃成型器的新研究相结合。这里的一个新颖性来源是认识到，如果分子间相互作用具有不均匀的成分，液体的构型激发通常会在玻璃化转变温度过后持续进行，可以在不同的阶段发生。该项目的主要目的是寻求对玻璃化转变物理的更深层次的理解。一方面将探索“强”和“脆弱”液体和塑料晶体之间的分子水平区别，另一方面将探索“结构”玻璃形成器与固体物理中的各种自旋玻璃、偶极玻璃等之间的区别。该项目还将继续研究玻璃形成液体和生物分子之间的关系，或者使用玻璃形成液体来保存生物分子，研究单个分子(蛋白质)中折叠和较简单系统中的两层激发过程之间的关系，以及复杂系统中的成核现象和膜蛋白异常折叠成与“疯牛病”及其人类疾病相关的新形式之间的可能联系。%在纳米水平描述先进材料技术的许多领域中固体的无定形状态，这些领域包括聚合物、金属、制药和生物材料。了解非晶态以及它是如何制备和稳定的将为合成具有独特性能的新材料开辟新的途径。

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.