Ordering dynamics of blue phases entails kinetic stabilization of amorphous networks

TL;DR

This study uses large-scale simulations to reveal that blue phases of liquid crystals tend to form metastable amorphous defect networks rapidly, delaying the formation of their thermodynamically stable cubic structure.

Contribution

First large-scale simulation of blue phase domain growth showing disorderly amorphous network formation driven by defect dynamics.

Findings

Rapid formation of metastable amorphous defect networks

Destruction of initial nuclei during growth

Potential need for second nucleation for stable phase emergence

Abstract

The cubic blue phases of liquid crystals are fascinating and technologically promising examples of hierarchically structured soft materials, comprising ordered networks of defect lines (disclinations) within a liquid crystalline matrix. We present the first large-scale simulations of their domain growth, starting from a blue phase nucleus within a supercooled isotropic or cholesteric background. The nucleated phase is thermodynamically stable; one expects its slow orderly growth, creating a bulk cubic. Instead, we find that the strong propensity to form disclinations drives the rapid disorderly growth of a metastable amorphous defect network. During this process the original nucleus is destroyed; re-emergence of the stable phase may therefore require a second nucleation step. Our findings suggest that blue phases exhibit hierarchical behavior in their ordering dynamics, to match that in their structure.