Density and conformation with relaxed substrate, bulk, and interface electrophoretic deposition of polymer chains

TL;DR

This study uses Monte Carlo simulations to analyze polymer chain density and conformation during electrophoretic deposition, revealing how substrate, bulk, and interface densities depend on fields, temperature, and molecular weight.

Contribution

It introduces a detailed simulation approach to understand polymer density profiles and conformations across different regions during electrophoretic deposition, highlighting the effects of segmental dynamics and external parameters.

Findings

Substrate coverage grows as a power-law with time, exponent depends on field.

Bulk and substrate densities increase exponentially with field in low field regime.

Bulk volume fraction decreases with molecular weight and density remains Gaussian.

Abstract

Characteristics of relaxed density profile and conformation of polymer chains are studied by a Monte Carlo simulation on a discrete lattice in three dimensions using different segmental (kink-jump $K$, crank-shaft $C$, reptation $R$) dynamics. Three distinct density regimes, substrate, bulk, and interface, are identified. With the $KC$ segmental dynamics we find that the substrate coverage grows with a power-law, $d_s \propto t^{\gamma}$ with a field dependent nonuniversal exponent $\gamma = 0.23 + 0.7 E$. The bulk volume fraction $d_b$ and the substrate polymer density ($d_s$) increases exponentially with the field ($d_b \propto E^{0.4}$, $d_s \propto E^{0.2}$) in the low field regime. The interface polymer density $d_f$ increases with the molecular weight. With the $KCR$ segmental dynamics, bulk and substrate density decreases linearly with the temperature at high temperatures. The bulk volume fraction is found to decay with the molecular weight, $d_b \propto L_c^{-0.11}$. The radius of gyration remains Gaussian in all density regions.