V-Shaped SmC* switching FLC compounds

Chiral aryl esters of 4-alkyl-3-chlorobiphenyl-4'-carboxylic and 4(6-aIky1cyc1ohex-2-enonoy1-3)benzoic acids have been synthesized. The phase transition temperatures and V-shaped SmC* switching ofthe prepared compounds are discussed

Shock-free ferroelectric liquid crystal displays with high optical contrast

Shock-free ferroelectric liquid crystal displays with high optical contrast and low operating voltage are the concern of this contribution. Ferroelectric liquid crystal compositions with a wide temperature range of the chiral smectic C phase are designed. The influence of the chiral fragments of the molecules, especially their length, on the mechanical stability of the SmC phase has been investigated. The relation between the surface anchoring energy of the aligning polymer and the viscoelastic properties of the SmC phase has been described. Our qualitative model reflects the resistance of the SmC layer structure against mechanical and thermal action

XRD Study of New FLC's: Correlation Between the Chemical Structure of Molecules, the Sign of the Optical Rotation and the Tilt Angle

New 4-ring FLC’s with different positions of lateral substituents and bridge fragments in the central core were synthesized. These compounds have a wide temperature range of the smectic C* phase and similar length of the molecules. Different ways of the preparation of the FLC mixtures with a high tilt angle and the results of electrooptical and XRD measurements of the FLC mixtures based upon the chiral compounds are presented

Unique chiral compounds as part of mixtures with optimized properties for different types of FLCDs

The effect of the molecular structure of liquid crystals on their mesomorphic and physico-chemical properties is studied. The unique compounds described in this work contain three or four phenyl rings. Modifications of the molecules via bridge fragments or via lateral substituents allowed the preparation and optimization of specific mixtures for different purposes. The formation of defect-free layers in ferroelectric liquid crystals (FLCs) stable against various mechanical or temperature deformations is studied. The impact of viscous-elastic and chiral properties on the formation of smectic C* layers were established. A new electro-optic effect based on chiral-nematic mixtures for creating high-speed devices with switching time less than 1 ms was developed. All the boundary conditions necessary for the realization of this effect were experimentally investigated

Defect-Free FLCD's with High Optical Quality Based Upon New FLC's

We have designed new FLC compounds and new FLC materials based upon them, and we have found general criteria of the preparation of FLCD’s with uniform and stable orientation of FLC materials [1]. The influence of the molecular structure on the quality of orientation, on thermal and mechanical stability and on the contrast ratio was investigated by using 4 types of aligning materials in the thin and thick testing cells. The correlation between the number, type and amount of achiral and 3-, 4-ring chiral compounds in the mixture and contrast ratio of our FLCD’s was found. Finally we optimized the FLC-mixtures, alignment conditions and we prepared the defect-free samples with optical contrast about 700:1