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Nematic liquid crystals on sinusoidal channels: the zigzag instability
Nuno M Silvestre1,2, Jose M Romero-Enrique3, Margarida M Telo da Gama1,2
1Departamento de Física da Faculdade de Ciências, Universidade de Lisboa, Campo Grande, P-1649-003 Lisboa, Portugal.
Journal of Physics. Condensed Matter : an Institute of Physics Journal
|November 11, 2016
Summary
Patterned substrates create complex liquid crystal textures. A zigzag disclination line forms in 5CB nematic liquid crystals within sinusoidal channels due to twist instability and surface anchoring effects.
Area of Science:
- Materials Science
- Soft Matter Physics
- Liquid Crystals
Background:
- Patterned substrates induce diverse liquid crystal (LC) textures.
- LC response depends on elastic anisotropy and length scales.
- Competing surface anchoring influences texture formation.
Purpose of the Study:
- Investigate nematic LC texture in sinusoidal channels.
- Analyze the formation of zigzag disclination lines.
- Understand the role of elastic constants and surface anchoring.
Main Methods:
- Utilized Landau-de Gennes free energy model.
- Simulated nematic behavior in patterned microchannels.
- Analyzed defect line behavior under varying elastic properties.
Main Results:
- Observed a zigzag disclination line in 5CB within micron-sized channels.
- Identified twist instability as the cause for zigzag pattern formation.
- Found zigzag periodicity depends non-linearly on channel geometry.
Conclusions:
- Elastic anisotropy and surface anchoring dictate LC texture.
- Zigzag disclination arises from twist instability and competing surface forces.
- Channel geometry significantly influences the observed zigzag pattern periodicity.
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