Cluster Formation in Metastable Solutions

该项目研究了甘氨酸、氯化钠、氯化钾和氯化铵的亚稳过饱和水溶液中临界前分子团簇的形成。这些分子簇影响溶液的性质，如粘度和扩散系数，并在成核和晶体生长中发挥重要作用。利用球形空泡电动悬浮器获得高过饱和度的液滴。通过准弹性光散射直接测量了这些液滴中团簇的尺寸分布。这些数据被用来解决成核理论中的一些重要的悬而未决的问题，涉及团簇的大小和演化。这项由一位化学工程师和一位物理学家完成的跨学科项目的结果，对于更好地理解和设计用于分离和提纯许多工业和医药产品的结晶过程具有重要意义。

The project examines the formation of precritical molecular clusters in metastable supersaturated aqueous solutions of glycine, NaCl, KCl, and NH4Cl. These molecular clusters affect solution properties such as viscosity and diffusivity and plays an important role in nucleation and crystal growth. A Spherical Void Electrodynamic Levitator is used to obtain highly supersaturated droplets. The size distribution of clusters in these droplets is measured directly by quasielastic light scattering. The data are used to resolve certain important outstanding problem in nucleation theory, involving cluster size and evolution. The results of this interdisciplinary project, by one chemical engineer and one physicist, are important for better understanding and designing crystallization process for separation and purification of many industrial and pharmaceutical products.