Low‐temperature‐applicable polymer‐stabilized blue‐phase liquid crystal and its Kerr effect

Abstract

Abstract— A type of polymer‐stabilized blue‐phase liquid crystal, which can be used in a low‐temperature environment, is proposed. The blue‐phase range after polymerization was widened to more than 73°C, and the blue‐phase texture is very stable even at a temperature as low as −35°C. The electro‐optical performances dependence on polymer concentration was investigated. The results indicate that the saturation voltage increases and the hysteresis enhances as the polymer concentration increases. The rise and decay times could reach as low as 391 and 789 μsec, respectively. Such material also shows good electro‐optical behavior at a temperature of −35°C. In addition, the Kerr constant was tested under a uniformly distributed electric field to be 2.195 nm/V2 at room temperature and 2.077 nm/V2 at −35°C. The Kerr constant tested under white‐light illumination was 1.975 nm/V2, which shows a small dispersion.

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

“…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.…”

Dichroic-dye-doped polymer stabilized optically isotropic chiral liquid crystals

“…The chemical structure of PTPTP n has been reported in detail previously. 23,24 The weight ratio of 2-EHA and PTPTP n is 1 : 2.…”

“…The electric-eld dependent birefringence of the sample is tested through the conventional Senarmont method. 23,25 However, the IPS driving mode always leads to a non-uniform distribution of electric eld in the cell, which will bring about some testing errors of the Kerr constant. 19,23 Considering this aspect, planar ITO cells are selected to generate a uniform electric eld for the testing.…”

“…23,25 However, the IPS driving mode always leads to a non-uniform distribution of electric eld in the cell, which will bring about some testing errors of the Kerr constant. 19,23 Considering this aspect, planar ITO cells are selected to generate a uniform electric eld for the testing. It is noteworthy that the testing beam needs to be obliquely incident on the cell (the incident angle is dened as q), thus the change of Dn under the applied eld can be detected.…”

Bistable state in polymer stabilized blue phase liquid crystal

“…The N * LCs are prepared by our homemade nematic liquid crystal (clearing point: 60.1°C, Δε=34.2 @ 1 kHz rectangular wave signal applied and room temperature, mixed by 4'-pentylbiphenyl-4-carbonitrile, 4'-terphenyl-4-carbonitrile, 1-ethoxy-4-[(4'-pentylphenyl) ethynyl] benzene and 4'-pentylphenyl-4-ethoxybenzoate, with the weight ratio of 10:1:1:8) and the chiral dopant R811 (supported by Merck, Germany), with the weight ratio of 3:1; and the monomers are composed by PTPTP 6 and PTPTP 2 with 1:1 weight ratio. Chemical structures and preparations of LCs and PTPTP n have been presented with details in our previous paper [21]. For the polymerization of monomers, about 0.5 wt% UV initiator (Irgacure 184, supported by BASF) should be added.…”