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Liquid crystals ferroelectricity

As witli tlie nematic phase, a chiral version of tlie smectic C phase has been observed and is denoted SniC. In tliis phase, tlie director rotates around tlie cone generated by tlie tilt angle [9,32]. This phase is helielectric, i.e. tlie spontaneous polarization induced by dipolar ordering (transverse to tlie molecular long axis) rotates around a helix. However, if tlie helix is unwound by external forces such as surface interactions, or electric fields or by compensating tlie pitch in a mixture, so tliat it becomes infinite, tlie phase becomes ferroelectric. This is tlie basis of ferroelectric liquid crystal displays (section C2.2.4.4). If tliere is an alternation in polarization direction between layers tlie phase can be ferrielectric or antiferroelectric. A smectic A phase foniied by chiral molecules is sometimes denoted SiiiA, altliough, due to the untilted symmetry of tlie phase, it is not itself chiral. This notation is strictly incorrect because tlie asterisk should be used to indicate the chirality of tlie phase and not tliat of tlie constituent molecules. [Pg.2549]

Lagerwall S T 1998 Ferroelectric liquid crystals Handbook of Liquid Crystals Vol 2B. Low Molecular Weight Liquid Crystals II ed D Demus, J Goodby, G W Gray, H-W Speiss and V Vill (New York Wiley-VCH)... [Pg.2571]

Ferroelectric Liquid Crystals Principles, Properties and Applications (PMade ph a Gordon and Breach)... [Pg.2571]

Clark N A, Handschy M A and Lagerwall S T 1983 Ferroelectric liquid crystal electro-optics using the surface stabilized structure Molec. Cryst. Liq. Cryst. 94 213-34... [Pg.2571]

K. A. Epstein and co-workers, "Fluorinated Ferroelectric Liquid Crystals Overview and Synthesis," Eleventh Winter Fluorine Conference, St. Petersburg, Fla., 1993. [Pg.316]

In the operation of ferroelectric liquid crystal devices, the applied electric field couples directly to the spontaneous polarisation Ps and response times depend on the magnitude E Ps. Depending on the electronic structure (magnitude and direction of the dipole moment as well as position and polarity of the chiral species) and ordering of the molecules P can vary over several orders of magnitude (3 to 1.2 x 10 ), giving response times in the range 1-100 ps. [Pg.14]

Omenat, A., Serrano, J.L., Sierra, T., Amabilino, D.B., Minguet, M., Ramos, E. and Veciana, J. (1999) Chiral linear isocyanide palladium(II) and gold(I) complexes as ferroelectric liquid crystals. Journal of Materials Chemistry, 9, 2301-2305. [Pg.392]

Photopolymerization and Electrooptic Properties of Polymer Network/Ferroelectric Liquid-Crystal... [Pg.16]

To produce novel LC phase behavior and properties, a variety of polymer/LC composites have been developed. These include systems which employ liquid crystal polymers (5), phase separation of LC droplets in polymer dispersed liquid crystals (PDLCs) (4), incorporating both nematic (5,6) and ferroelectric liquid crystals (6-10). Polymer/LC gels have also been studied which are formed by the polymerization of small amounts of monomer solutes in a liquid crystalline solvent (11). The polymer/LC gel systems are of particular interest, rendering bistable chiral nematic devices (12) and polymer stabilized ferroelectric liquid crystals (PSFLCs) (1,13), which combine fast electro-optic response (14) with the increased mechanical stabilization imparted by the polymer (75). [Pg.17]

The amorphous diacrylate monomers chosen for study were two commercially available monomers, p-phenylene diacrylate (PPDA) and 1,6-hexanediol diacrylate (HDDA) (Polysciences, Inc., Warrington, PA). The liquid crystalline diacrylate studied was 1,4-di-(4-(6-acryloyloxyhexyloxy)benzoyloxy)-2-methylbenzene (C6M) (13). Chemical structures of these monomers as well as pertinent physical and LC properties are given in Figure 1. All monomers were used without further purification. The ferroelectric liquid crystal mixture consisted of a 1 1 mixture of W7 and W82 (1) (Displaytech, Boulder, CO). This mixture exhibits isotropic (I), smectic A... [Pg.18]

It was quickly recognized that chirality would play an important role in discotic liquid crystals, not only for the possibility of creating cholesteric and ferroelectric liquid crystals but also as a tool for studying the self-assembly of these molecules as a whole, both in solution and in the solid state. However, initial studies revealed that expression of chirality in discotic liquid crystals was not as straightforward as for liquid crystals derived from calamitic molecules. More recently, with the increase in interest in self-assembly and molecular recognition, considerably more attention has been directed to the study of chiral discotics and their assemblies in solution. The objective of this chapter is... [Pg.376]

Along with the prediction and discovery of a macroscopic dipole in the SmC phase and the invention of ferroelectric liquid crystals in the SSFLC system, the discovery of antiferroelectric liquid crystals stands as a key milestone in chiral smectic LC science. Antiferroelectric switching (see below) was first reported for unichiral 4-[(l-methylheptyloxy)carbonyl]phenyl-4/-octyloxy-4-biphenyl carboxylate [MHPOBC, (3)],16 with structure and phase sequence... [Pg.470]


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Alignment and Bistability of Ferroelectric Liquid Crystals

Anti-ferroelectric liquid crystal

Applications of ferroelectric liquid crystals

Bistable switching, ferroelectric liquid crystals

Design of ferroelectric liquid crystals

Discotic liquid crystals ferroelectricity

Electro-optic response ferroelectric liquid crystal

Electrooptical Effects in Ferroelectric Liquid Crystals

Ferroelectric and Antiferroelectric Liquid Crystals

Ferroelectric crystals

Ferroelectric crystals liquid-like behavior

Ferroelectric liquid crystal cell

Ferroelectric liquid crystal displays

Ferroelectric liquid crystal-polymer

Ferroelectric liquid crystal-polymer composites

Ferroelectric liquid crystals

Ferroelectric liquid crystals applications

Ferroelectric liquid crystals chiral smectic

Ferroelectric liquid crystals excellence

Ferroelectric liquid crystals ferroelectricity

Ferroelectric liquid crystals ferroelectricity

Ferroelectric liquid crystals for

Ferroelectric liquid crystals improper ferroelectrics

Ferroelectric liquid crystals influence

Ferroelectric liquid crystals layer tilt angle

Ferroelectric liquid crystals materials

Ferroelectric liquid crystals molecular orientational state

Ferroelectric liquid crystals optical properties

Ferroelectric liquid crystals polymer linearity

Ferroelectric liquid crystals rotational viscosities

Ferroelectric liquid crystals smectic layer structures

Ferroelectric liquid crystals, definition

Ferroelectric polymer-dispersed liquid crystal

Ferroelectric smectic C liquid crystals

Ferroelectricity crystals

Ferroelectrics liquid crystals

Ferroelectrics liquid crystals

Free Energy of Ferroelectric Liquid Crystals

Microphase Stabilized Ferroelectric Liquid Crystal Displays

Phases ferroelectric liquid crystal

Reflection symmetry, ferroelectric liquid crystals

SSFLCs ferroelectric liquid crystals

Smectic liquid crystals, ferroelectricity

Smectic-C and Ferroelectric Liquid Crystals

Soft mode ferroelectric liquid crystal

Spontaneous Polarization Behavior of FLCPs (Ferroelectric Liquid Crystal Polymers)

Stephen M. Kelly 2 Ferroelectric Liquid Crystals

Surface Stabilized Ferroelectric Liquid Crystal Displays

Surface stabilised ferroelectric liquid crystal

Surface stabilized ferroelectric liquid crystal

Surface-stabilized ferroelectric liquid crystal SSFLC)

Surface-stabilized ferroelectric liquid crystal applications

Surface-stabilized ferroelectric liquid crystal devices

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