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

TL;DR

This study uses computer simulations to analyze how polymer chain deposition affects interface roughness, revealing nonuniversal scaling behavior and the influence of field and temperature on roughening dynamics.

Contribution

It introduces a detailed simulation analysis of polymer interface growth, highlighting nonuniversal scaling and the effects of field and temperature on roughness evolution.

Findings

Interface width exhibits a crossover in growth exponents.

Roughness depends on molecular weight and substrate length.

Roughening and deroughening are influenced by field and temperature.

Abstract

Growth and roughness of the interface of deposited polymer chains driven by a field onto an impenetrable adsorbing surface are studied by computer simulations in (2+1) dimensions. The evolution of the interface width W shows a crossover from short-time growth described by the exponent beta1 to a long-time growth with exponent beta2 (>beta1). The saturated width increases, i.e., the interface roughens, with the molecular weight Lc, but the roughness exponent alpha (from Ws~L^alpha) becomes negative in contrast to models for particle deposition; alpha depends on the chain length--a nonuniversal scaling with the substrate length L. Roughening and deroughening occur as the field E and the temperature T compete such that Ws=(A+BT)E^-1/2.