Cluster Formation in Metastable Solutions

该项目研究了亚稳过饱和甘氨酸、NaCl、KCl和NH4Cl水溶液中临界分子团簇的形成。这些分子团簇影响溶液的粘度和扩散率等性质，并在成核和晶体生长中起重要作用。采用球形空腔电动力悬浮器获得高度过饱和液滴。通过准弹性光散射直接测量了液滴中团簇的大小分布。这些数据被用来解决成核理论中某些重要的突出问题，包括簇的大小和进化。这个跨学科项目的成果，由一位化学工程师和一位物理学家完成，对于更好地理解和设计用于分离和纯化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.