Competing crystallization pathways and cold crystallization kinetics in 10OS5 liquid crystal

TL;DR

This study investigates the crystallization behavior and kinetics of a liquid crystal, revealing how cooling rates influence phase formation and demonstrating potential for thermal energy storage.

Contribution

It provides detailed analysis of competing crystallization pathways and kinetics in 10OS5 liquid crystal using multiple models, highlighting tunable energy release for energy storage.

Findings

Slower cooling induces metastable Cr2 phase formation.

Heating leads to cold crystallization of Cr1 or mixed phases.

Energy release during cold crystallization is tunable by thermal history.

Abstract

The liquid crystalline 4-pentylphenyl-4'-decyloxythiobenzoate is investigated in various temperature programs for determination of crystallization kinetics and glassforming properties. The Avrami model, Augis-Bennett method and isoconversional method are used. Cooling at the 25-30 K/min rate results in formation of the glass of the tilted smectic Y phase with the herring-bone order within layers. Slower cooling leads to the partial or total (2 K/min) crystallization of the metastable Cr2 phase, which during subsequent heating or annealing in a proper temperature transforms to another Cr1 phase. Heating from the vitrified smectic Y leads to cold crystallization of the pure Cr1 phase or the Cr1/Cr2 mix. Both Cr1 and Cr2 are conformationally disordered crystal phases, which is indicated both by the melting entropy values and the dielectric spectra. The results demonstrate that the energy released during cold crystallization can be tuned by thermal history, highlighting 10OS5 as a candidate for thermal energy storage applications.