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Two electro-optical phenomena of liquid-crystal blue phase with cubic lattice structure-(1) a fast and reversible shift in reflection band and (2) a phase transition from blue phase to chiral nematic phase-are observed in this study. By increasing the magnitude of a vertical electric field, the reflected wavelength of the blue phase can be shifted to a longer wavelength in a range of 80 nm within a few ms. This reflection band shift is induced by the reorientation of liquid-crystal molecules constructing double twist cylinders, which induces lattice distortion of the blue phase. [ABSTRACT FROM AUTHOR]

Correlations between the stability of blue phases and the physical parameters of liquid-crystal hosts are reported in this study. Experimental results show that liquid-crystal blue phases are more thermostabilized when the dielectric anisotropy is reduced or the elastic constants increased. These correlations can be explained by Defect theory and Landau theory for blue phases. Moreover, the results give us the clues to develop more suitable blue-phase materials for fundamental researches or fast photonic devices. [ABSTRACT FROM AUTHOR]

The response times of rotational molecular orientation of neat and carbon-nanotube-doped nematic liquid crystals were acquired through the measurement of transient current induced by a direct-current step voltage and from optical transmission data. A model based on the dielectric displacement current was developed to describe the electric field dependence of the response and to yield a rotational viscosity that would decrease with increasing concentration of carbon nanotubes. Optical dynamic response also showed a reduced rotational viscosity, with the lightly doped cells exhibiting a faster relaxation process than that of the neat cell. [ABSTRACT FROM AUTHOR]

Transient currents induced by the polarity reversal of an applied dc electric field have been measured in planar-aligned nematic liquid-crystal cells. Experimental results indicate that a minute addition of carbon nanotubes as a dopant leads to a reduction of the ion concentration and thus suppresses the undesired field-screening effect. Observed simultaneously is a higher charge mobility in the doped cells in the presence of a strong field. Such increase of mobility, in comparison with that of undoped counterparts, is attributed to the parallel alignment of both the long axis of carbon nanotubes and the nematic director along the electric field. [ABSTRACT FROM AUTHOR]