Light-Driven Electrohydrodynamic Instabilities in Liquid Crystals.

Yuanyuan Zhan, Albertus P. H. J. Schenning, Dirk J. Broer, Guofu Zhou, Danqing Liu

Light-Driven Electrohydrodynamic Instabilities in Liquid Crystals.

ABSTRACT
The induction of electrohydrodynamic instabilities in nematic liquid crystals through light illumination are reported. For this purpose, a photochromic spiropyran is added to the liquid crystal mixture. When an electrical field is applied in the absence of UV light, the homeotropic liquid crystal reorients perpendicular to the electrical field driven by its negative dielectric anisotropy. Upon exposure to UV light, the nonionic spiropyran isomerizes to the zwitterionic merocyanine form inducing electrohydrodynamic instabilities which turns the cell from transparent into highly scattering. The reverse isomerization to closed‐ring spiropyran form occurs thermally or under visible light, which stops the electrohydrodynamic instabilities and the cell becomes transparent again. It is demonstrated that the photoionic electrohydrodynamic instabilities can be used for light regulation. Local exposure, either to drive the electrohydrodynamics or to remove them enables the formation of colored images.


Language English
Journal Advanced Functional Materials
Year
2018
Pages 1707436
Volume 28
Issue
21
Status

published


KEYWORDS

electrohydrodynamic instabilities, light scattering, liquid crystals, photochemistry


DOI: 10.1002/adfm.201707436

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  • APA
Yuanyuan Zhan, Albertus P. H. J. Schenning, Dirk J. Broer, Guofu Zhou, Danqing Liu. Light-Driven Electrohydrodynamic Instabilities in Liquid Crystals. Advanced Functional Materials, 2018, 28(21), 1707436.


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