Entropic competition in polymeric systems under geometrical confinement

TL;DR

This study uses molecular dynamics to explore how geometrical confinement influences the organization and segregation of inhomogeneous stiff polymer chains, revealing entropy-driven mechanisms and mobility differences under various confinement regimes.

Contribution

It introduces a detailed simulation analysis of entropic competition and segregation in confined inhomogeneous polymer systems, highlighting the role of entropy in chain organization.

Findings

Segregation occurs as confining volume decreases.

Peripheral chains exhibit higher angular mobility under strong confinement.

Both weak and strong confinement regimes show competition effects.

Abstract

Using molecular dynamics simulation, we investigate the effect of confinement on a system that comprises several stiff segmented polymer chains where each chain has similar segments, but length and stiffness of the segments vary among the chains which makes the system inhomogeneous. The translational and orientational entropy loss due to the confinement plays a crucial role in organizing the chains which can be considered as an entropy-driven segregation mechanism to differentiate the components of the system. Due to the inhomogeneity, both weak and strong confinement regimes show the competition in the system and we see segregation of chains as the confining volume is decreased. In the case of strong spherical confinement, a chain at the periphery shows higher angular mobility than other chains, despite being more radially constrained.