Chiral Phases of a Confined Cholesteric Liquid Crystal: Anchoring-Dependent Helical and Smectic Self-Assembly in Nanochannels
| Autor: | Mark Busch, Sylwia Całus, Patrick Huber, Wiktor Piecek, Andriy V. Kityk |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Phase transition
Birefringence Materials science Cholesteric liquid crystal Physics::Optics 02 engineering and technology 021001 nanoscience & nanotechnology Polarization (waves) 01 natural sciences Thermotropic crystal Surfaces Coatings and Films Electronic Optical and Magnetic Materials Condensed Matter::Soft Condensed Matter Crystallography General Energy Chemical physics Liquid crystal 0103 physical sciences Self-assembly Physical and Theoretical Chemistry 010306 general physics 0210 nano-technology Chirality (chemistry) |
| Zdroj: | The Journal of Physical Chemistry C. 120:11727-11738 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/acs.jpcc.6b03553 |
| Popis: | Chiral liquid crystals (ChLCs) allow a fundamental insight into the interplay of molecular chirality and the formation of macroscopic, self-assembled helices. They also exhibit unique optical properties, in particular huge polarization rotation, which is employed in a wide range of photonic technologies. Here, we present a study of linear and circular optical birefringence in combination with X-ray diffraction experiments on an archetypical ChLC, i.e., the cholesteric ester CE6, confined in cylinders of mesoporous alumina and silica with distinct polymer surface graftings resulting in normal or tangential wall anchoring. The unconfined ChLC exhibits a discontinuous, first-order isotropic-to-chiral nematic (cholesteric) phase transition with the formation of double-twist helices and a discontinuous cholesteric-to-smectic A transition. The thermotropic behavior of the confined ChLC, explored in a channel radii range of 7–21 nm, deviates substantially from bulk behavior. There is no isotropic state. In contr... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|