Formation and kinetics of transient metastable states in mixtures under coupled phase ordering and chemical demixing

TL;DR

This paper develops a theory and simulation approach to understand how transient metastable states form and evolve during coupled phase separation and ordering in polymer-liquid crystal mixtures, revealing the role of mobility ratios.

Contribution

It introduces a novel theoretical framework and simulation method to study the kinetics of metastable states in coupled phase ordering and demixing processes.

Findings

Transient metastable phases surround the ordered phase during formation.

Lifetime of metastable states depends on diffusional and orientational mobility ratios.

Kinetic phase ordering in polymer-mesogen mixtures resembles crystallization in polymer solutions.

Abstract

We present theory and simulation of simultaneous chemical demixing and phase ordering in a polymer-liquid crystal mixture in conditions where isotropic- isotropic phase separation is metastable with respect to isotropic-nematic phase transition. It is found that mesophase formation proceeds by a transient metastable phase that surround the ordered phase, and whose lifetime is a function of the ratio of diffusional to orientational mobilities. It is shown that kinetic phase ordering in polymer-mesogen mixtures is analogous to kinetic crystallization in polymer solutions.