Photonic Materials Based on Mixtures of Cholesteric Liquid Crystals with Polymers

2003 ◽  
Vol 107 (29) ◽  
pp. 6961-6964 ◽  
Author(s):  
P. V. Shibaev ◽  
V. I. Kopp ◽  
A. Z. Genack
Keyword(s):  
Liquid Crystals ◽  
Cholesteric Liquid Crystals ◽  
Photonic Materials

Photoinduced Isotropic State of Cholesteric Liquid Crystals: Novel Dynamic Photonic Materials

2007 ◽  
Vol 19 (20) ◽  
pp. 3244-3247 ◽  
Author(s):  
U. A. Hrozhyk ◽  
S. V. Serak ◽  
N. V. Tabiryan ◽  
T. J. Bunning
Keyword(s):  
Liquid Crystals ◽  
Cholesteric Liquid Crystals ◽  
Photonic Materials ◽  
Isotropic State

scholarly journals Diffusionless transformation of soft cubic superstructure from amorphous to simple cubic and body-centered cubic phases

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jie Liu ◽  
Wenzhe Liu ◽  
Bo Guan ◽  
Bo Wang ◽  
Lei Shi ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
X Ray Diffraction ◽  
Photonic Materials ◽  
Simple Cubic ◽  
Cubic Phases ◽  
Transmission Electron ◽  
Phase Liquid ◽  
Blue Phase ◽  
Blue Phases ◽  
Temperature Window

AbstractIn a narrow temperature window in going from the isotropic to highly chiral orders, cholesteric liquid crystals exhibit so-called blue phases, consisting of different morphologies of long, space-filling double twisted cylinders. Those of cubic spatial symmetry have attracted considerable attention in recent years as templates for soft photonic materials. The latter often requires the creation of monodomains of predefined orientation and size, but their engineering is complicated by a lack of comprehensive understanding of how blue phases nucleate and transform into each other at a submicrometer length scale. In this work, we accomplish this by intercepting nucleation processes at intermediate stages with fast cross-linking of a stabilizing polymer matrix. We reveal using transmission electron microscopy, synchrotron small-angle X-ray diffraction, and angle-resolved microspectroscopy that the grid of double-twisted cylinders undergoes highly coordinated, diffusionless transformations. In light of our findings, the implementation of several applications is discussed, such as temperature-switchable QR codes, micro-area lasing, and fabrication of blue phase liquid crystals with large domain sizes.

scholarly journals Synthesis and Characterization of Novel Bio-Chiral Dopants Obtained from Bio-Betulin Produced by a Fermentation Process

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 785
Author(s):  
Veridiana G. Guimarães ◽  
Anastasiia Svanidze ◽  
Tianyi Guo ◽  
Pawan Nepal ◽  
Robert J. Twieg ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Natural Product ◽  
Fermentation Process ◽  
Synthesis And Characterization ◽  
Cholesteric Liquid Crystals ◽  
And Performance ◽  
Chiral Dopants

Cholesteric liquid crystals are frequently produced by the addition of chiral dopants to achiral nematic hosts. We report here the synthesis and performance of chiral dopants obtained from bio-betulin produced by a fermentation process. An important aspect of this work is to point out that the fermentation process used to obtain the starting materials is much easier and cheaper when carried out in large volumes than isolating it from the natural product. The performance of the dopants obtained from bio-betulin is indistinguishable from those obtained from commercially available synthetic betulin.

scholarly journals Augmented Lagrangian preconditioners for the Oseen–Frank model of nematic and cholesteric liquid crystals

2021 ◽  
Author(s):  
Jingmin Xia ◽  
Patrick E. Farrell ◽  
Florian Wechsung
Keyword(s):  
Liquid Crystals ◽  
Augmented Lagrangian ◽  
Augmented Lagrangian Method ◽  
Mass Matrix ◽  
Unit Length ◽  
Mesh Size ◽  
Schur Complement ◽  
Cholesteric Liquid Crystals ◽  
Multigrid Algorithm ◽  
The Cost

AbstractWe propose a robust and efficient augmented Lagrangian-type preconditioner for solving linearizations of the Oseen–Frank model arising in nematic and cholesteric liquid crystals. By applying the augmented Lagrangian method, the Schur complement of the director block can be better approximated by the weighted mass matrix of the Lagrange multiplier, at the cost of making the augmented director block harder to solve. In order to solve the augmented director block, we develop a robust multigrid algorithm which includes an additive Schwarz relaxation that captures a pointwise version of the kernel of the semi-definite term. Furthermore, we prove that the augmented Lagrangian term improves the discrete enforcement of the unit-length constraint. Numerical experiments verify the efficiency of the algorithm and its robustness with respect to problem-related parameters (Frank constants and cholesteric pitch) and the mesh size.

scholarly journals Pitch tuning induced by optical torque in heliconical cholesteric liquid crystals

2019 ◽  
Vol 1 (3) ◽  
Author(s):  
G. Nava ◽  
F. Ciciulla ◽  
O. S. Iadlovska ◽  
O. D. Lavrentovich ◽  
F. Simoni ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Cholesteric Liquid Crystals ◽  
Optical Torque

scholarly journals Light-driven rotation of gratings formed by electroconvection patterns in cholesteric liquid crystals

2021 ◽  
pp. 116366
Author(s):  
Ying Xiang ◽  
Hongzhen Jing ◽  
Hao Chen ◽  
Jun zhang ◽  
Xiaoyu Ding ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Cholesteric Liquid Crystals

scholarly journals Optical Response Associated with the Orientation and Structure of Liquid Crystals with Respect to Phosphatidylcholine Concentration

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 678
Author(s):  
Yuqi Han ◽  
Yan Jiang ◽  
Wei Guo ◽  
Bing Li ◽  
Lu Zhang ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Reflectance Spectrum ◽  
Optical Response ◽  
The Self ◽  
Cholesteric Liquid Crystals ◽  
Anchoring Effect ◽  
Self Assembling ◽  
Sensitization Effect ◽  
Structure Of Liquid

Based on the anchoring effect due to the self-assembling behavior of the phospholipid molecules at the interface between the liquid crystal and water phases on the orientation of liquid crystals, the optical response associated with the orientation and structure of liquid crystals with respect to the concentration of 1,2-didodecanoyl-sn-glycero-3-phosphocholine solution has been investigated. The optical response owing to changes in the orientation and structure of the mixed cholesteric liquid crystals with respect to the change in the concentration of phosphatidylcholine has been obtained. Moreover, the feasibility of using as-prepared mixed cholesteric liquid crystals to measure the phosphatidylcholine concentration has been verified. A methodology to measure the reflectance spectrum by using mixed cholesteric liquid crystals to sensitize the phosphatidylcholine concentration has been further realized. The sensitization effect of the mixed cholesteric liquid crystals on the measurement of phosphatidylcholine concentration was also verified.

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