POLYMER ADSORPTION.

Abstract

The adsorption of macromolecules at solid/solution interfaces differs in several respects from that of small molecules. Some of these differences are reflected in the adsorption isotherm. Region A corresponds to isolated adsorbed macromolecules, adsorbed in a tail/loop/train configuration. This minimum free energy situation depends on the balance between the net changes in potential energy ( DELTA U) and entropy ( DELTA S) associated with the adsorption process. DELTA U reflects changes in the number of segment/surface, solvent/surface and segment/solvent contacts; DELTA S reflects not only changes in the configurational entropy of the adsorbed polymer concerned, but also changes in the thermal entropy of the adsorbed polymer and desorbed (or released) solvent molecules.