Statistical Mechanics of Supercooled Liquids and the Glass Transition

科罗拉多州立大学的Grzegorz Szamel得到了理论和计算化学计划的支持，以探索玻璃化转变的基本统计力学描述。首先，将采用一种新的计算机模拟技术来检验Parisi及其合作者提出的玻璃化转变的一般理论，该理论假设玻璃化转变与过冷液体的熵的一个分量，即所谓的构型熵的消失有关。其次，通过阐明模式耦合理论和Parisi方法之间的联系，从理论上加深了对玻璃化转变的理解。此外，还将发展一种新的扩展模式耦合理论，该理论适用于具有随机(布朗)动力学的系统，如胶体悬浮液。许多有用的聚合物材料在室温下是柔性的。将这些塑料冷却到玻璃化转变温度以下会导致它们变得像玻璃一样脆弱，无定形材料的结构类似于液体，但具有一些截然不同的性质。物理化学中最有趣的悬而未决的问题是关于玻璃化转变和玻璃态的性质的理论。这一研究项目的结果预计将导致对玻璃行为的新见解，这可能在先进材料加工中具有广泛的技术影响。

Grzegorz Szamel of Colorado State University is supported by the Theoretical and Computational Chemistry Program to explore the fundamental statistical mechanical descriptions of the glass transition. First, a novel computer simulation technique will be implemented to test the general theory of the glass transition proposed by Parisi and collaborators, which assumes that the glass transition is associated with the vanishing of one component of the supercooled liquid's entropy, the so-called configurational entropy. Second, theoretical understanding of the glass transition will be advanced by elucidating the connection between mode-coupling theory and the Parisi approach. In addition, a new extended mode-coupling theory will be developed that is applicable to systems with stochastic (Brownian) dynamics such as colloidal suspensions. Many useful polymer materials are flexible at room temperature. Cooling these plastics below their glass transition temperature causes them to become brittle like glassy, amorphous materials with structures similar to that of a liquid but with some profoundly different properties. Among the most interesting unsolved problems in physical chemistry are a theory for the glass transition and the nature of the glassy state. The outcomes of this research project are expected to lead to new insights into glass behavior, which could have broad technological implications in advanced materials processing.