The Glass Transition in Normal and Exceptional Glassformers

普通和特殊玻璃形成者的玻璃化转变

• 批准号: 0082535
• 负责人: C. Austen Angell
• 金额: $ 47.76万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-12-15 至 2004-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0082535&HistoricalAwards=false
• 关键词: Glass; Transition; Normal; Exceptional; Glassformers

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.

这个项目的重点是玻璃成型液体。它包括一项通过一阶液-液相变形成具有不寻常性质的玻璃的研究，以测试存在一类具有非典型振动特征的具有异常低熵（接近“完美玻璃”）的玻璃材料的可能性。它还包括探索通过使用麦克斯韦随机连接的自由连接板条方法来创建一类（可变）多孔，因此轻质玻璃的可能性，刚性分子板条在枢轴点化学连接。这些新项目将与解决传统粘性液体玻璃成形体的各种新研究相结合。这里的一个新奇之处来自于认识到，一旦超过玻璃化转变温度，液体的构型激发通常是连续进行的，如果分子间相互作用具有不均匀的成分，则可以在不同的阶段发生。该项目的主要推动力包括对玻璃化转变的物理学进行更深入的理解。在分子水平上区分“强”和“易碎”的液体和塑料晶体，一方面和区分“结构”玻璃，一方面和各种自旋玻璃，偶极子玻璃等固态物理，另一方面将进行探讨。该项目还将解决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护生物分子，研究单个分子（蛋白质）的折叠与更简单系统中的双层激发过程之间的关系。复杂系统中的成核现象和膜蛋白的异常折叠与疯牛病及其人类疾病亲属所涉及的新形式之间的可能联系将继续存在。在纳米水平上描述固体的无定形状态，在许多先进材料技术领域的核心，包括聚合物，金属，药物和生物材料。了解非晶态及其制备和稳定的方法将为合成具有独特性能的新材料开辟新的途径。