Confocal Laser Scanning Microscopic Observation of Polymer-Stabilized Blue Phase I

Abstract

The structure of the polymer-stabilized blue phase I with a cubic structure of the order of optical wavelength was observed by the confocal laser scanning microscope. The spacing of a striped pattern observed in the (110) plane of the polymer-stabilized blue phase I was a couple of hundred nm, which agreed to the interval of the ordered double twisted cylinders estimated based on a well-known model of blue phase I with O 8 symmetry.

Polymer‐stabilized blue phases: promising mesophases for a new generation of liquid crystal displays

“…(f)). This very simple experiment confirms the results of earlier, very sophisticated microscopic studies, which indicated that the polymer network is located at the positions of the BP disclinations (Fig. (e)).…”

“…The latter systems may be useful for storage applications, but show no electro‐optic response. The largest BP temperature range for electrically addressable BPs is obtained for polymer‐stabilized LCs . The total monomer concentration is typically between 8% and 15% by weight.…”

Dendron‐Stabilized Liquid Crystalline Blue Phases with an Enlarged Controllable Range of the Photonic Band for Tunable Photonic Devices

“…As a host nematic liquid crystal (host LC), a mixture of fluorinated nematic liquid crystals (JC1041‐XX, JNC Co., Δ n = 0.142, Δ ϵ = 5.7 at 25 °C)/4‐cyano‐4′‐pentyl biphenyl (5CB, Aldrich, Δ n = 0.19, Δ ϵ = 11 at 25 °C) = 1:1 were used 8–16, 49, 50. A dendron molecule was newly synthesized to enlarge the BP temperature range.…”

“…Liquid crystalline blue phases (BPs) are one of the candidates for tunable photonic crystals, possessing an optical stopband in the visible wavelength range due to their lattice periods of several hundred nm, which can be continuously shifted by electric fields 4–7. Though originally BPs appeared over a very narrow temperature range (typically about 1 °C) between isotropic phase (Iso) and chiral nematic phase (N*), polymer‐stabilized blue phases (PSBPs) have been found to show a large temperature range of stable BPs of more than 60 °C; they also show excellent performance for application to liquid crystal displays, including fast electro‐optical responses of less than 1 ms (conventional nematic phase shows several ms in response time) and a large Kerr constant 8–24. Also, BPs show a great benefit compared to N*, which shows a 1D stopband as a photonic crystal,25, 26 because the lasing threshold energy needed to excite the BPs is much lower than that of N* 27–29.…”

Direct Observation of Polymer-Stabilized Blue Phase I Structure with Confocal Laser Scanning Microscope

“…If the positions of dots do not change entirely with depth, the detecting image should come from the reflection at the interface between the cover glass and sample. 2 However, it is noted that the positions of dots slightly moved, it means that the image comes from bulk structure of the sample.…”