Dynamics of a polymer adsorbed to an attractive homogeneous flat surface

The adsorption of a bond fluctuation self-avoiding walk polymer on an attractive homogeneous flat surface at temperature below the critical adsorption point is studied using dynamic Monte Carlo simulation. Results show that the apparent size Rg,xy(2) of the polymer parallel to the surface increases exponentially with time during the adsorption process. The relaxation time for Rg,xy(2) reaching its asymptotic value σeq decreases with the increase in the polymer-surface attraction strength Eps, whereas σeq increases with Eps, indicating that the polymer is adsorbed faster and becomes more extended at stronger adsorption. The polymer's asphericity Axy parallel to the surface is sensitive to intra-polymer interaction and its behavior is different from that of Rg,xy(2). Simulation results also show that the two-dimensional behaviors of Rg,xy(2) and Axy are different from that of the three-dimensional conformational size Rg(2) and asphericity A during the adsorption process. During the adsorption, the surface contacted monomer number M increases with time, but Rg(2) and A show novel behavior as they first increase with M at small M, then decrease with M at moderate M and finally increase with M again at large M. Whereas Rg,xy(2) and Axy first decrease with M and then increase with M during the adsorption.