Splay Stiffening and Twist Softening in a Ferroelectric Nematic Liquid Crystal

TL;DR

This study explores how ferroelectric nematic liquid crystals exhibit increased splay stiffness and decreased twist elasticity due to polar ordering, highlighting the impact of electrostatic interactions on their mechanical properties.

Contribution

It provides the first direct comparison of splay and twist elastic constants in ferroelectric nematic phases, revealing how polar order influences elastic behavior.

Findings

Polar ordering increases splay rigidity.

Polar ordering reduces twist elasticity.

Electrostatic interactions significantly affect mechanical properties.

Abstract

The recent discovery of ferroelectric nematics-genuine 3D ferroelectric fluids-has underscored the importance of electrostatic interactions in shaping the physical behaviour of soft matter systems. In this paper, we investigate the mechanical properties of ferroelectric nematics by directly comparing the splay and twist elastic constants in a liquid crystal system that exhibits both nonpolar and ferroelectric nematic phases. Our results reveal that polar ordering results in increased splay rigidity and a concomitant reduction in twist elasticity.