Interface relaxation in electrophoretic deposition of polymer chains: Effects of segmental dynamics, molecular weight, and field

Using different segmental dynamics and relaxation, characteristics of the interface growth is examined in an electrophoretic deposition of polymer chains on a three (2+1)-dimensional discrete lattice with a Monte Carlo simulation. Incorporation of faster modes such as crankshaft and reptation movements along with the relatively slow kink-jump dynamics seems crucial in relaxing the interface width. As the continuously released polymer chains are driven (via segmental movements) and deposited, the interface width W grows with the number of time steps t, W∝t^β, (β∼0.4–0.8), which is followed by its saturation to a steady-state value W_s. Stopping the release of additional chains after saturation while continuing the segmental movements relaxes the saturated width to an equilibrium value (W_s→W_r). Scaling of the relaxed interface width W_r with the driving field E,  W_r∝E^-1/2 remains similar to that of the steady-state W_s width. In contrast to monotonic increase of the steady-state width W_s, the relaxed interface width W_r is found to decay (possibly as a stretched exponential) with the molecular weight.