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. ***
