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Microscopic modelling of nematic elastic constants beyond Straley theory
Davide Revignas1, Alberta Ferrarini1
1Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy. alberta.ferrarini@unipd.it.
Soft Matter
|December 22, 2021
Summary
New theories explain unusual elastic properties in non-rod-like nematics. This research develops a method to calculate Frank elastic constants, considering molecular shape and deformation, advancing liquid crystal elasticity understanding.
Area of Science:
- * Soft Matter Physics
- * Materials Science
- * Theoretical Chemistry
Background:
- * Nematic liquid crystals with non-prototypical molecular shapes exhibit unusual elastic properties.
- * Existing theories struggle to fully explain these phenomena due to the coupling between molecular structure and deformation.
Purpose of the Study:
- * To develop a theoretical and numerical methodology for calculating Frank elastic constants.
- * To account for the coupling between molecular shape and specific deformation modes in nematics.
- * To investigate the impact of molecular conformation on elastic properties.
Main Methods:
- * Utilized Onsager-Straley's second-virial theory.
- * Employed a non-local form of the orientational distribution function.
- * Developed a theoretical and numerical approach for calculating elastic constants.
Main Results:
- * Introduced a method that considers the coupling between molecular shape and deformation modes.
- * Identified additional order parameters induced by deformation.
- * Demonstrated an ideal contribution to the deformation free energy.
- * Illustrated differences between straight and bent rod systems.
Conclusions:
- * The developed methodology accurately calculates Frank elastic constants for diverse nematic structures.
- * Molecular conformation significantly impacts the elastic constants of liquid crystals.
- * Provides a framework for understanding elasticity in complex nematic systems.
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