Polyelectrolyte-Colloid Complexes

9311433杜宾将探讨聚电解质-胶体络合物形成的两个方面：阐明临界结合现象，以及可溶络合物的表征。第一个主题将使用两种大小可变、表面电荷密度可测量和可变的小胶体颗粒：DMDAO胶束和羧化星爆树枝状大分子。第二个问题将通过应用准弹性光散射、浊度法、动态光散射和静态光散射来研究两个形成可溶络合物的体系：具有混合阴离子/非离子胶束的聚阳离子，以及与蛋白质形成的聚阳离子或聚阴离子。这些研究将提供有关络合物溶液结构的详细信息。对于聚电解质-胶束体系，他们还将使用荧光光谱和脉冲场梯度核磁共振，来阐明聚离子对结合胶束结构和动力学的影响。在聚电解质-蛋白质复合体的情况下，他们将利用计算机图形来尝试识别蛋白质上多离子结合部位的性质。聚电解质-蛋白质复合体的溶液表征将集中在凝聚形成的机理上。聚电解质与带相反电荷的胶体的相互作用是许多商业过程中的中心成分，与一些重要的细胞现象有关。凝聚具有开发蛋白质分离和酶固定化新技术的潜力。***

9311433 Dubin Two aspects of polyelectrolyte-colloid complex formation will be explored: elucidation of the critical binding phenomenon, and characterization of soluble complexes. The first theme will be pursued using two types of small colloidal particles of variable size, and of measurable and variable surface charge density: micelles of DMDAO, and carboxylated starburst dendrimers. The second matter will be investigated by the application of quasi- elastic light scattering, turbidimetry, dynamic light scattering, and static light scattering to two systems which form soluble complexes: polycations with mixed anionic/nonionic micelles, and polycations or polyanions with proteins. These studies will provide detailed information about the solution structure of the complexes. For the polyelectrolyte-micelle system, they will also use fluorescence spectroscopy and pulsed field gradient nmr, to elucidate the effect of the polyion on the structure and dynamics of the bound micelle. In the case of polyelectrolyte-protein complexes, they will make use of computer graphics in an attempt to identify the nature of the polyion-binding site on the protein. Solution characterization of polyelectrolyte-protein complexes will focus on the mechanism of coacervate formation. The interaction of polyelectrolytes with oppositely charged colloids is a central component in a number of commercial processes and is relevant to some important cellular phenomena. Coacervation carries the potential for the development of new techniques of protein separation and enzyme immobilization. ***