Ediger M D
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Annu Rev Phys Chem. 2000;51:99-128. doi: 10.1146/annurev.physchem.51.1.99.
Although it has long been recognized that dynamics in supercooled liquids might be spatially heterogeneous, only in the past few years has clear evidence emerged to support this view. As a liquid is cooled far below its melting point, dynamics in some regions of the sample can be orders of magnitude faster than dynamics in other regions only a few nanometers away. In this review, the experimental work that characterizes this heterogeneity is described. In particular, the following questions are addressed: How large are the heterogeneities? How long do they last? How much do dynamics vary between the fastest and slowest regions? Why do these heterogeneities arise? The answers to these questions influence practical applications of glass-forming materials, including polymers, metallic glasses, and pharmaceuticals.
尽管人们早就认识到过冷液体中的动力学可能在空间上是不均匀的，但直到最近几年才出现明确的证据支持这一观点。当一种液体被冷却到远低于其熔点时，样品某些区域的动力学可能比仅几纳米之外的其他区域的动力学快几个数量级。在这篇综述中，描述了表征这种不均匀性的实验工作。特别地，探讨了以下问题：不均匀性有多大？它们持续多长时间？最快和最慢区域之间的动力学变化有多大？这些不均匀性为何会出现？这些问题的答案影响着玻璃形成材料的实际应用，包括聚合物、金属玻璃和药物。
