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Rods in a lyotropic chromonic liquid crystal: emergence of chirality, symmetry-breaking alignment, and caged angular
Sophie Ettinger1, Clarissa F Dietrich2, Chandan K Mishra3
1Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, 19104, USA. asophie@sas.upenn.edu.
Soft Matter
|December 1, 2021
Summary
Rod-like particles in lyotropic chromonic liquid crystals (LCLCs) exhibit unique orientations and chiral director configurations. The particle
Area of Science:
- Soft Matter Physics
- Liquid Crystal Science
- Materials Science
Background:
- Lyotropic chromonic liquid crystals (LCLCs) exhibit low energy cost for twist distortion.
- This property enables novel mirror-symmetry breaking director configurations.
- Asymmetric rod-like particles introduce complex possibilities in aligned LCLCs.
Purpose of the Study:
- Investigate director configuration around rod-like particles in LCLCs.
- Determine equilibrium orientation and angular diffusion of these particles.
- Understand how particle aspect ratio and orientation influence LCLC behavior.
Main Methods:
- Video microscopy to observe particle behavior.
- Polarized optical video-microscopy for director configuration analysis.
- Landau-de Gennes numerical modeling for theoretical validation.
Main Results:
- Two-thirds of rods adopt an angled equilibrium orientation, decreasing with aspect ratio.
- One-third of rods align with the far-field director.
- Distinct chiral director configurations (LMP for angled, TLMP for aligned rods) were observed.
Conclusions:
- LCLC's low twist elastic constant promotes chiral configurations that alter particle orientation.
- Particle aspect ratio influences equilibrium orientation and angular confinement.
- Chiral director configurations are intrinsically linked to particle shape and alignment.
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