DYNAMICS OF RELAXATION AT STRONGLY INTERACTING POLYMER-SOLID INTERFACES - EFFECTS OF CHAIN ARCHITECTURE

The relaxation dynamics of a polymer chain strongly adsorbed to a solid surface are simulated via a kinetic Ising model that includes chain connectivity constraints (steric hindrance, rotational strain, and configurational entropy). The two polymer architectures examined consist of one or two chemisorbing functional groups per segment. In both architectures, the chemisorbed polymer chain is trapped in nonequilibrium conformational states at low temperatures, but relaxes to equilibrium at higher temperatures with stretched exponential (KWW) relaxation kinetics. The average relaxation time for the two pendant group architecture has a strongly non-Arrhenius temperature dependence that obeys the Vogel-Fulcher law. In contrast, average relaxation times for the one pendant group architecture cannot be described b the Vogel-Fulcher law.