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High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Twist grain boundaries in cubic surfactant phases
Maxim Belushkin1, Gerhard Gompper
1Institut für Festkörperforschung, Forschungszentrum Jülich, D-52425 Jülich, Germany. m.belushkin@fz-juelich.de
The Journal of Chemical Physics
|April 10, 2009
Summary
Twist grain boundaries in surfactant phases are minimal surfaces. The P phase is unstable, while lamellar, gyroid, and diamond phases exhibit low interfacial free energy with twist angle dependence.
Area of Science:
- Soft Matter Physics
- Materials Science
- Physical Chemistry
Background:
- Surfactant phases exhibit complex structures, including bicontinuous cubic phases.
- Grain boundaries in these phases influence material properties.
- Understanding interfacial energy is crucial for phase stability.
Purpose of the Study:
- Investigate twist grain boundaries in bicontinuous cubic surfactant phases.
- Determine the interfacial free energy as a function of twist angle.
- Analyze the stability of different surfactant phases.
Main Methods:
- Ginzburg-Landau model for ternary amphiphilic systems.
- Discrete real-space lattice calculations with periodic boundary conditions.
- Isosurface analysis of scalar order parameter and curvature distributions.
Main Results:
- Grain boundaries in surfactant phases are identified as minimal surfaces.
- Lamellar (Lα), gyroid (G), and diamond (D) phases show low, similar interfacial free energy.
- Interfacial free energy exhibits nonmonotonic dependence on twist angle for Lα, G, and D phases.
- The Schwarz P phase is unstable and prone to grain boundary nucleation.
Conclusions:
- The study elucidates the structure and energetics of twist grain boundaries in surfactant phases.
- Minimal surface geometry is key to grain boundary formation.
- Phase stability is strongly influenced by twist angle and interfacial energy, with the P phase being particularly sensitive.
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