Roughening, deroughening, and nonuniversal scaling of the interface width in electrophoretic deposition of polymer chains

Growth and roughness of the interface of deposited polymer chains driven by a field onto an impenetrable adsorbing surface are studied by computer sim ulations in (2 + 1) dimensions. The evolution of the interface width W show s a crossover from short-time growth described by the exponent beta(1) to a long-time growth with exponent beta(2) (>beta(1)) Tne saturated width incr eases, i.e., the interface roughens, with the molecular weight L-c, but the roughness exponent alpha (from W-s similar to L-alpha) becomes negative in contrast to models for particle deposition; cr depends on the chain length -a nonuniversal scaling with the substrate length L. Roughening and derough ening occur as the field E and the temperature T compete such that W-s appr oximate to (A+BT)E-1/2.