U.S.-Japan Cooperative Ressearch: Fluorescence and Scattering Studies of Polyelectrolytes-Colloid Systems

9315326 Dubin该奖项支持印第安纳大学-普渡大学化学系Paul Dubin教授与大阪大学大分子科学系Mikiharu Kamachi教授和大阪大学大分子科学系Yotaro Morishima教授之间为期两年的合作研究项目。联合研究的重点是聚电解质与胶束和蛋白质两种类型的反向带电胶体之间的复杂形成。在前一种情况下，人们对聚电解质结合的临界条件特别感兴趣，因为该系统为聚电解质吸附提供了独特的理论测试。大阪小组率先使用染料标记的聚电解质来探测聚离子附近的静电电位，这些将用于建立和理解在临界结合条件下胶体表面电荷密度，聚离子电荷密度和离子强度之间的基本关系。研究的第二个主题是聚电解质-蛋白质络合，这是一个在生物分离和酶固定化方面具有相当潜在意义的领域。一个关键问题是复合物中蛋白质的构象。在大阪提炼的荧光猝灭方法将被用来回答这个问题。对于该系统和聚电解质-胶束系统，将使用印第安纳波利斯的动态和电泳光散射以及大阪的强制瑞雷散射和纳秒荧光光谱来探索输运过程。＊＊＊

9315326 Dubin This award supports a two-year cooperative research project between Professor Paul Dubin, Department of Chemistry, Indiana University- Purdue University at Indianapolis, and Professor Mikiharu Kamachi, Department of Macromolecular Science, Osaka University, and Professor Yotaro Morishima, Department of Macromolecular Science, Osaka University. The joint research focuses on the complex formation between polyelectrolytes and oppositely charged colloids of two types: micelles and proteins. In the former case, there is particular interest in the critical conditions for polyelectrolyte binding, inasmuch as this system provides a unique test of theories for polyelectrolyte adsorption. The Osaka group has pioneered the use of dye- labeled polyelectrolytes to probe the electrostatic potential in the vicinity of the polyion, and these will be used to establish and understand the fundamental relationship among colloid surface charge density, polyion charge density and ionic strength at critical binding conditions. The second topic of investigation is polyelectrolyte-protein complexation, an area of considerable potential significance in bio- separations and enzyme immobilization. A key question is the conformation of the protein in the complex. Fluorescence quenching methods refined in Osaka will be used to answer this question. For both this system and the polyelectrolyte-micelle system, transport processes will be explored using dynamic and electrophoretic light scattering in Indianapolis and forced Rayleight scattering and nanosecond fluorescence spectroscopy in Osaka. ***