Interfaces in Diblocks: A Study of Miktoarm Star Copolymers

TL;DR

This paper investigates the influence of AB interfaces on phase behavior in miktoarm star copolymers using theoretical models and numerical simulations, providing insights into interface shapes and stability of various phases.

Contribution

It extends the kinked-path approach to analyze interfacial shapes and explores phase transitions and stability in miktoarm star copolymers with new theoretical and numerical methods.

Findings

Identified the role of interfacial shape in phase transitions.

Predicted stability of A15 lattice of micelles.

Validated models with self-consistent field theory simulations.

Abstract

We study AB$_n$ miktoarm star block copolymers in the strong segregation limit, focussing on the role that the AB interface plays in determining the phase behavior. We develop an extension of the kinked-path approach which allows us to explore the energetic dependence on interfacial shape. We consider a one-parameter family of interfaces to study the columnar to lamellar transition in asymmetric stars. We compare with recent experimental results. We discuss the stability of the A15 lattice of sphere-like micelles in the context of interfacial energy minimization. We corroborate our theory by implementing a numerically exact self-consistent field theory to probe the phase diagram and the shape of the AB interface.