Core-shell structures in single flexible-semiflexible block copolymers: Finding the free energy minimum for the folding transition

TL;DR

This study explores the folding behavior of a diblock copolymer with semiflexible and flexible segments, revealing a stable core-shell structure that forms efficiently and independently of the folding pathway.

Contribution

It introduces a detailed analysis of core-shell folding structures in diblock copolymers, highlighting their formation dynamics and pathway independence.

Findings

Core-shell conformation is stable in the folded state.

Folding kinetics are more efficient than in semiflexible homopolymers.

Core-shell structure forms regardless of the transition pathway.

Abstract

We investigate the folding transition of a single diblock copolymer consisting of a semiflexible and a flexible block. We obtain a {\it Saturn-shaped} core-shell conformation in the folded state, in which the flexible block forms a core and the semiflexible block wraps around it. We demonstrate two distinctive features of the core-shell structures: (i) The kinetics of the folding transition in the copolymer are significantly more efficient than those of a semiflexible homopolymer. (ii) The core-shell structure does not depend on the transition pathway.