Non-isothermal model for the direct isotropic/smectic-A liquid crystalline transition

TL;DR

This paper extends a high-order model for isotropic to smectic-A liquid crystal transition by incorporating thermal effects, revealing diffusion-limited growth and complex phase kinetics through multi-scale simulations.

Contribution

It introduces a non-isothermal extension to the existing model, accounting for thermal diffusion and latent heat, and demonstrates its impact on phase transition dynamics.

Findings

Non-isothermal effects change growth from constant to diffusion-limited.

Meta-stable nematic pre-ordering influences smectic-A growth.

Observed non-monotonic phase-transformation kinetics.

Abstract

An extension to a high-order model for the direct isotropic/smectic-A liquid crystalline phase transition was derived to take into account thermal effects including anisotropic thermal diffusion and latent heat of phase-ordering. Multi-scale multi-transport simulations of the non-isothermal model were compared to isothermal simulation, showing that the presented model extension corrects the standard Landau-de Gennes prediction from constant growth to diffusion-limited growth, under shallow quench/undercooling conditions. Non-isothermal simulations, where meta-stable nematic pre-ordering precedes smectic-A growth, were also conducted and novel non-monotonic phase-transformation kinetics observed.