POLYELECTROLYTE ADSORPTION AT SOLID LIQUID INTERFACES - A SIMPLE-MODEL FOR THE STRUCTURAL RELAXATION AND EXCLUDED AREA EFFECTS

We investigated experimentally and by computer simulation the combined effects of structural relaxation of macromolecules and excluded area on sorbent surfaces on the amount of polymer adsorbed at a solid-liquid interface. Experiments concerned the adsorption of poly(vinyl-4-pyridine) on polystyrene latex. The procedure allowed creation of starved polymer surfaces waiting for macromolecules to adsorb. Consideration of the structural reorganization of individual macromolecules contituting the incomplete layer permitted interpretation of the variation of the amount of polymer adsorbed with the rate of polymer supply. The algorithm of random sequential adsorption was used to simulate the adsorption process without structural relaxation. In the presence of conformational relaxation, an adsorbed disk was allowed to increase its radius, thus schematizing polymer interfacial flattening. Relative coverages furnished by experiments and simulation permitted determination of the temporal variation of the area occupied by one adsorbed polyelectrolyte. © 1991 Academic Press, Inc. All rights reserved.