9414289 Schlenoff Kinetics and isotherms of the adsorption of polyelectrolytes to solid/liquid and liquid/liquid interfaces will be investigated. Metal surfaces derivatized with surface-attached redox groups will be employed to control the surface charge precisely in an effort to relate polymer conformation and coverage to surface charge density. These "smart" redox-active surfaces will be used to ascertain whether adsorption falls under thermodynamic or kinetic control. Radiolabelled hydrophilic/hydrophobic copolymers, such as styrene sulfonate/butyl styrene, will be synthesized and their adsorption at the interface between two immiscible liquids will be studied. For adsorbed polyelectrolytes, the dependence of average coil radius on salt concentration will be measured and compared with the well-known dependence of solution polyelectrolyte dimensions on screening length. Diblock copolymers yielding brush-type morphologies will be adsorbed at the solid/liquid and liquid/liquid interfaces and their surface coverages at these two interfaces will be compared and related to the mobility of the hydrophobic surface-anchoring block. Absorption of a polyelectrolyte into an oppositely- charged gel will be measured to determine the extent and kinetics of penetration of a charged macromolecule into a charged matrix under conditions of zero applied electric field. %%% Adsorption of polyelectrolytes is the critical step in the treatment of water for environmental purposes (drinking water, municipal and industrial effluents, etc.). This research will provide important experiments that can be correlated with various adsorption theories.
