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High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Polydispersity stabilizes biaxial nematic liquid crystals
1Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands.
Physical Review Letters
|November 24, 2011
Summary
Size polydispersity in boardlike particles creates a new phase diagram topology. This leads to favored oblate uniaxial nematic order and a large stable biaxiality regime between nematic and smectic phases.
Area of Science:
- Soft Matter Physics
- Materials Science
Background:
- A stable biaxial nematic phase in boardlike particles has been observed.
- Understanding factors influencing phase behavior is crucial for materials design.
Purpose of the Study:
- Investigate the impact of size polydispersity on phase behavior.
- Explore the resulting phase diagram topology and order parameters.
Main Methods:
- Onsager theory
- Restricted orientation (Zwanzig) model
- Theoretical modeling of particle suspensions
Main Results:
- Polydispersity induces a novel phase diagram topology.
- Two Landau tetracritical points were identified.
- Oblate uniaxial nematic order is favored over prolate order.
- A significant stable biaxiality regime emerges between uniaxial nematic and smectic phases.
Conclusions:
- Size polydispersity fundamentally alters the phase behavior of boardlike particle suspensions.
- This work reveals new possibilities for controlling liquid crystal phases.
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