SEGMENTAL REARRANGEMENTS OF PMMA DURING ADSORPTION

The conformational rearrangement of adsorbing chains of polymethyl met hacrylate was monitored spectroscopically during the earliest phases o f adsorption. The number and fraction of chain segments associated wit hin 3 angstrom of the surface was found to go through a maximum corres ponding to saturation of available surface sites. At this stage, the h igh bound fraction (0.66) is indicative of a severe distortion of the chain from its isotropic conformation. The adsorption of further macro molecules liberates a large number of previously bound segments, which presumably enables the chains to adopt more favored, random conformat ions. (C) 1994 Academic Press, Inc.