Cholesterics blue phases

The B4 phase is complex a phase seemingly dominated by defects, similar to the cholesteric blue phase. While the detailed structure is not known, some facts are clear. From the viewpoint of this discussion, the key observation is the chirality of domains of the B4 phase in 4-. im LC cells. This... 

It was really only a matter of time until researchers in the field started doping blue phases with quasi-spherical nanoparticles. This area is very much in its infancy, but the few recent reports already show some promising results. Yoshida et al., for example, reported on an expansion of the temperature range of cholesteric blue phases from 0.5 to 5°C by doping blue phases with gold nanoparticles (average diameter of 3.7nm) as well as a decrease in the clearing point of approximately 13°C [427]. A similar effect was also observed by Kutnjak et al. for CdSe quantum dots simultaneously capped with oleyl amine and TOP (diameter of the core 3.5 nm) in CE8 (Merck) and CE6 (BDH). The authors found that particularly blue phase III was stabilized in these mixtures, blue phase II destabilized, and... 

Solid Cholesteric. . Blue phase I Blue phase U... 

Grebel, H., Homreich, R.M., Shtrikmann, S. Landau theory of cholesteric blue phase the role of higher harmonics. Phys. Rev. A 30, 3264—3278 (1984)... 

P. E. Cladis, A review of cholesteric blue phases in Theory and applications of liquid crystals ed. J. L. Ericksen and D. Kinderlehrer, p. 73 (Springer-Verlag, New York, 1987). 

J. P. Sethna, Frustration, curvature, and defect lines in metallic glasses and the cholesteric blue phase,... 

R. M. Hornreich and S. Shtrikman, Theory of light scattering in cholesteric blue phases, Phys. Rev. A, 28,... 

G. Heppke, B. Jerome, H. S. Kitzerow and P. Pieranski,Electrostriction of the cholesteric blue phases BPI and BPII in mixtures with positive dielectric anisotropy, J. Phys. France 50, 2991-2998 (1989). 

The cholesteric blue phase (ChBP) appears in a very narrow temperature range (usually within 1 °C) just below the isotropic phase in short helical pitch material. Recently it was found by Kikuchi et al. that the temperature range can be expanded by polymer stabilization [62], and application in high-speed displays is anticipated. In ChBP, the helices produced by the spontaneous twist of the director form a cubic lattice with a regular three-dimensional alignment. However, it cannot fill the space continuously, and defect lines called discbnations are embedded in the cubic lattice structure. 

Fig. 11.17 Schematic explanation of gold nanoparticle alignment in the defect of cholesteric blue phase liquid crystal...

Besides those phases mentioned above, many other phases of liquid crystals such as smectic G, H, I, F,...,Q,..., and cholesteric blue phase have been identi-fjed,2,7,8 name a few. Numerous new molecular engineered liquid crystalline... 

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