Mioko Uematsu

Novel Ferroelectric Liquid Crystalline δ-Valerolactone Derivatives with Very Large Spontaneous Polarization

Abstract A series of new chiral compounds with a δ-valerolactone ring were synthesized and the physical properties of these compounds as well as the electrical properties of their ferroelectric liquid crystal (FLC) mixtures were investigated. The magnitude of spontaneous polarization (Ps) in the chiral smectic C phase (SmC*) was found to be as high as 384 nC/cm2 for (2R, 5R)-2-(4′-octyloxybiphenyl-4-carboxy)-5-butyl-δ-valerolactone at ΔT = Tc - T = 5°C, where Tc is the temperature of transition from the isotropic phase to the SmC* phase and T is the temperature at which the experiments were carried out. An FLC mixture containing 2% by weight of the optical isomer, (2S, 5R)-2-(4′-octyloxy-biphenyl-4-carboxy)-5-hexyl-δx-valerolactone exhibited a response time as fast as 96 μ seconds at 25°C, for an applied square-wave voltage of ± 10 volts. The relationship between the structural properties and the thermal properties, magnitude and polarity of Ps as well as the response times for their FLC mixtures are disc...

Novel Ferroelectric Liquid Crystals with Very Large Spontaneous Polarization

Several ferroelectric liquid crystals derived from a new optically active (2S, 5R)-2-hydroxy-5-hexyl-δ-valerolactone have been synthesized, and their mesomorphic and ferroelectric properties have been investigated. Very large spontaneous polarization (Ps) has been observed in these compounds, one of which shows an extremly large Ps value: as high as 320 nC/cm2.

Mesomorphic and ferroelectric properties of novel optically active compounds derived from (R)-3-hydroxynonanoic acid

Abstract Novel optically active compounds derived from (R)-3-hydroxynonanoic acid as shown in a general formula (I) have been synthesized and their mesomorphic and ferroelectric properties have been investigated. The kind of mesophases and the transition temperatures depend strongly on the linkage groups and the substituents in the core. The compounds with an unsubstituted core show non-titled smectic mesophases (smectic A or B). The chiral smectic C phase appears in the compounds having a central ester linkage and a chloro-substituent as the A 1 or B 1 position and in the compound having a central -OCH2- linkage and a chloro-substituent at the A 1 position. The maximum spontaneous polarization (500 μC/m2) was observed in 4-dodecyloxy-3-chlorobenzoyl-oxyphenyl (R)-3-hydroxynonanoate. The thermal stability of each mesophase and the ferroelectric properties have been discussed from the structural point of view.