Fringing field-induced monodomain of a polymer-stabilized blue phase liquid crystal

Abstract

The influence of fringe electric field applied during photopolymerization on the electro-optic properties of polymer-stabilized blue phase liquid crystals (PS-BPLCs) was investigated. It has been found that the thermal stability would not degrade if the electric field was less than a critical value. The contrast ratio of PS-BPLC can be improved significantly because the uniformity of blue phase liquid crystal domain was enhanced by the electric fields, which were applied during photopolymerization. Meanwhile, with the electric filed, the potential energy of the BPLC molecules may lower the anchoring energy of the polymer network resulting in the improvement of electro-optic response properties. With optimized electric field during polymerization, the contrast ratio and the Kerr constant of PS-BPLC can be improved by 4.1 times and 15%, respectively, and the hysteresis can be decreased by 10%, while the response time and residual birefringence have no degradation.

Symmetric Continuously Tunable Photonic Band Gaps in Blue-Phase Liquid Crystals Switched by an Alternating Current Field

“…Thus, the platelet textures in this cell were more uniform, and the reflecting color looks more clear and vivid. This state of affairs is also experimentally consistent with other directions . On the one hand, the only effect of the alignment layer on the surface in several hundreds of nanometers made the reflection slightly lower than that driven by a vertical AC electric field.…”

“…This state of affairs is also experimentally consistent with other directions. 37 On the one hand, the only effect of the alignment layer on the surface in several hundreds of nanometers made the reflection slightly lower than that driven by a vertical AC electric field. For another, the strong anchoring energy suppresses the lattice elongation along the electric field, resulting in the low reflection and a higher electric field of 2.5 V/μm.…”

Monodomain Blue Phase Liquid Crystal Layers for Phase Modulation

“…Homogeneous BPI layers have been previously reported in the literature, however they were multidomain layers123, not aligned13 and/or not stabilized at room temperature2224.…”

Microstructure-Stabilized Blue Phase Liquid Crystals

“…In general, it is necessary to apply an electric field or provide an anisotropically strong anchoring force on the LC molecules from the sample substrates during the formation of the BP crystals to obtain more uniformly oriented BP crystals. − Herein, although no electric field or strong anchoring force from the aligned substrates is exerted on the LC molecules, the results suggest that the hexagonal microcell can lead to highly ordered crystal growth and high uniformity of lattice plane orientation. In other words, the BPs in each microwell of the microstructure have a higher probability to grow into a single-crystal-like domain, unlike the polycrystalline BP outside the microstructure.…”