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High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Two-dimensional chiral model for liquid crystals, bent hard needles: a Monte Carlo simulation
Jorge Peón1, Jimena Saucedo-Zugazagoitia, Fabian Pucheta-Mendez
1Instituto de Química, Universidad Nacional Autónoma de México, México 04510 Distrito Federal, México.
The Journal of Chemical Physics
|September 27, 2006
Summary
A novel two-dimensional zigzag needle model unexpectedly exhibits liquid crystal phases, including nematic and smectic. These phases arise from excluded volume effects, not typical molecular properties.
Area of Science:
- Physics
- Materials Science
- Chemistry
Background:
- Traditional liquid crystal models often feature molecular symmetry axes and three-dimensional chiral properties.
- Smectic phases typically require attractive forces or finite molecular volumes.
- Existing models do not fully explain the emergence of liquid crystalline behavior in simplified systems.
Purpose of the Study:
- To investigate the liquid crystalline behavior of a two-dimensional (2D) hard needle model with a zigzag shape.
- To identify the conditions and mechanisms driving mesophase formation in this simplified system.
- To contrast the observed behavior with established theories of liquid crystals.
Main Methods:
- Computational modeling of a 2D hard needle system with a zigzag geometry.
- Calculation of nematic and smectic order parameters.
- Analysis of distribution functions to characterize mesophases.
Main Results:
- The 2D zigzag needle model demonstrates liquid crystalline behavior, forming both nematic and smectic phases.
- These mesophases emerge despite the absence of typical molecular characteristics like symmetry axes or attractions.
- Excluded volume effects are identified as the primary driver for the observed liquid crystalline properties.
Conclusions:
- The study reveals that excluded volume interactions alone can induce liquid crystalline phases in simplified 2D models.
- The findings challenge conventional understanding by showing mesophase formation in athermal, infinitely repulsive, and infinitesimally thin systems.
- This model provides new insights into the fundamental principles governing liquid crystal formation.
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