Interfaces between highly incompatible polymers of different stiffness: Monte Carlo simulations and self-consistent field calculations

TL;DR

This study combines Monte Carlo simulations and self-consistent field calculations to analyze the interfacial properties of highly incompatible polymers with different stiffness, revealing deviations from Gaussian chain predictions at high incompatibilities.

Contribution

It introduces a combined simulation and theoretical approach to accurately characterize interfaces between incompatible semi-flexible polymers, highlighting limitations of Gaussian models.

Findings

Interfacial width decreases with increasing polymer stiffness.

Simulations and SCF calculations show near-quantitative agreement.

Deviations from Gaussian chain predictions occur at high incompatibility.

Abstract

We investigate interfacial properties between two highly incompatible polymers of different stiffness. The extensive Monte Carlo simulations of the binary polymer melt yield detailed interfacial profiles and the interfacial tension via an analysis of capillary fluctuations. We extract an effective Flory-Huggins parameter from the simulations, which is used in self-consistent field calculations. These take due account of the chain architecture via a partial enumeration of the single chain partition function, using chain conformations obtained by Monte Carlo simulations of the pure phases. The agreement between the simulations and self-consistent field calculations is almost quantitative, however we find deviations from the predictions of the Gaussian chain model for high incompatibilities or large stiffness. The interfacial width at very high incompatibilities is smaller than the prediction of the Gaussian chain model, and decreases upon increasing the statistical segment length of the semi-flexible component.