Thermal Roughening and Deroughening at Polymer Interfaces in Electrophoretic Deposition

TL;DR

This study investigates how the interface roughness in polymer electrophoretic deposition varies with temperature, revealing a transition from deroughening to roughening behavior influenced by chain length and dynamics.

Contribution

It introduces a Monte Carlo simulation approach to analyze thermal roughening and deroughening transitions at polymer interfaces in electrophoretic deposition.

Findings

Interface width decreases with temperature at low T, following a power law with exponent ~1/4.

Interface width increases with temperature at high T, following a power law with exponent ~0.4.

Transition temperature increases with longer chains and decreases with slower segmental dynamics.

Abstract

Thermal scaling and relaxation of the interface width in an electrophoretic deposition of polymer chains is examined by a three-dimensional Monte Carlo simulation on a discrete lattice. Variation of the equilibrium interface width $W_r$ with the temperature $T$ shows deroughening $W_r \propto T^{-\delta}$, with $\delta \sim 1/4$, at low temperatures and roughening $W_r \propto T^{\nu}$, with $\nu \sim 0.4$ at high temperatures. The roughening-deroughening transition temperature $T_t$ increases with longer chain lengths and is reduced by using the slower segmental dynamics.