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Photonic Spring‐Like Shell Templated from Cholesteric Liquid Crystal Prepared by Microfluidics
Author(s) -
Kim JongGyu,
Park SooYoung
Publication year - 2017
Publication title -
advanced optical materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.89
H-Index - 91
ISSN - 2195-1071
DOI - 10.1002/adom.201700243
Subject(s) - materials science , microfluidics , dopant , cholesteric liquid crystal , chemical engineering , solvent , shrinkage , rhodamine 6g , liquid crystal , annealing (glass) , composite material , curing (chemistry) , rhodamine , nanotechnology , optoelectronics , doping , organic chemistry , optics , molecule , engineering , chemistry , physics , fluorescence
Solid‐state photonic shells are prepared with a reactive cholesteric liquid crystal (CLC) mixture that consists of a reactive mesogen mixture and the nonreactive chiral dopant. The shells are prepared using a microfluidic glass‐capillary chip, followed by UV‐curing and extraction of the chiral dopant. CLC shells with relatively uniform thickness are produced by density matching and annealing. The produced solid‐state CLC (CLC solid ) shells show a good reversible swelling/shrinkage behavior that is dependent on the solvent quality and temperature. The swelling or shrinkage simultaneously induces a color change in the reflection point at the center and in the cross‐communication dots. Encapsulation and release from the CLC solid ‐shell cores are successfully tested with Rhodamine 6G by controlling the solvent quality and temperature. Nanosized Fe 3 O 4 particles encapsulated in the core give the CLC solid shells mobility, and are assembled at the desired location using a magnet. The color changes caused by external stimuli can be applied to new types of small hollow sensors that will respond to changes in temperature, and solvent quality. The shells can be used, for example, as a chemical container that can be triggered by temperature to release for a delayed reaction, or in a security patch controlled by tuneable multicolored patterns.