This research is aimed at developing an understanding of the physical properties of dispersed systems such as emulsions, micelles, colloidal suspensions, and polymer solutions. One thrust of this research is a quantitative study of block copolymer adsorption. Systems under study include polar-nonpolar block copolymers currently in use as pigment stabilizers. Another aspect of this project is a statistical mechanical model of the structure in electrorheological (ER) fluids. These fluids exhibit dramatic changes of their rheological properties upon the application of an electric field.