Topological Defect-Guided Regular Stacking of Focal Conic Domains in Hybrid-Aligned Smectic Liquid Crystal Shells
| Autor: | Jan P. F. Lagerwall, JungHyun Noh |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
General Chemical Engineering
Stacking Shell (structure) Antipodal point 02 engineering and technology smectic-A spherical topology 01 natural sciences Topological defect Inorganic Chemistry Liquid crystal Phase (matter) 0103 physical sciences Perpendicular General Materials Science 010306 general physics Crystallography Toroid Condensed matter physics liquid crystal shell 021001 nanoscience & nanotechnology Condensed Matter Physics QD901-999 focal conic domains nematic topological defects 0210 nano-technology |
| Zdroj: | Crystals, Vol 11, Iss 913, p 913 (2021) Crystals Volume 11 Issue 8 |
| ISSN: | 2073-4352 |
| DOI: | 10.3390/cryst11080913 |
| Popis: | We study liquid crystal (LC) shells in hybrid configuration (director tangential to the inside but normal to the outside) as they slowly undergo a transition from a nematic (N) to a smectic-A (SmA) phase. Every shell has two antipodal +1 topological defects, at the thinnest and thickest points, respectively. On cooling from N to SmA, the symmetry axis connecting the defects gradually reorients from along gravity to perpendicular to it, reversibly and continuously, if the LC and aqueous phase are density matched at the N-SmA transition. This suggests reduced density near the defects—reflecting a local reduction in order—under the strong confinement with antagonistic boundary conditions. In the SmA phase, a regular array of focal conic domains (FCDs) develops, templated in position and orientation by the +1 defect at the thinnest point. Around this defect, a single complete toroidal FCD always develops, surrounded by incomplete FCDs. In contrast to similar FCD arrangements on flat aqueous interfaces, this is a stable situation, since the two +1 defects are required by the spherical topology. Our results demonstrate how the topological defects of LC shells can be used to template complex self-organized structures. With a suitable adaption of the LC chemistry, shells might serve as a basis for producing solid particles with complex yet highly regular morphologies. |
| Databáze: | OpenAIRE |
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