Dye-containing liquid crystalline

Dichromatic dyes when introduced in LC elastomers can be used to investigate the LC orientation behavior. The stress-induced orientational elastomers could be developed to form a color polarizer. It can be designed by chemically attaching dye molecules in side chains of LC elastomer [54]. Also, dichromatic dye-containing liquid crystalline elastomers can be synthesized by reacting a terpolymer, as a precursor, with hexamethylene diisocyanate. The elastomers, even with 10 mol% of cross-linkage, remain nematic in their liquid crystalline nature [55]. 

Ringsdorf, H. and Schmidt, H.-W. (1984) Electro-optical effects of azo dye containing liquid crystalline copolymers , Makromol. Chem., 185,1327-1334. 

PHASE BEHAVIOUR OF DYE-CONTAINING LIQUID CRYSTALLINE COPOLYMERS AND THEIR MIXTURES WITH LOW MOLECULAR WEIGHT LIQUID CRYSTALS ... 

Fig. 1. Schematic stracture of dye-containing liquid crystalline side-chain...

The tetralins (181-183) collated in Table 3.23 are red liquid crystals with a transition moment orthogonal to the molecular long axis, see Figure 3.13. Since they are liquid crystalline themselves they are very soluble in nematic host mixtures. Such mixtures exhibit high negative dichroic ratios and can be used in White and Taylor GH-LCDs with positive contrast. Furthermore, mixtures containing an additional anthraquinone dye of positive dichroic ratio can be used to switch from one colour to another under the action of an electric field. 

Rosenhauer R, Fischer T, Stumpe J, Vinuales A, Gimenez R, Pinol M, Serrano JL, Broer D. 2005. Light induced orientation of liquid crystalline terpolymers containing azoben zene and dye moieties. Macromolecules 38 2213 2222. 

The introduction of dye molecules into the liquid crystalline host does not change the majority of the properties of the host, provided that not too much dye is introduced (not more than 1-2%). The N I transition temperature of the liquid crystal, the viscous and elastic properties, the electrical conductivity (provided the dye is not ionic and does not contain ionic impurities), the dielectric permittivities, (provided the dye molecule does not have a large dipole moment), and even the refractive indices all remain the same. The only significant change in the properties of the crystal is the appearance of absorption bands in the visible region of the spectrum and a slight increase in viscosity [151]. 

Dielectric and Electro-Optical Properties of a Ferroelectric Side-Chain Liquid Crystalline Polysiloxane Containing Azobenzene Dyes as Guest Molecules... 

In this chapter we describe the synthesis and the phase behaviour of liquid crystalline anthraquinone copolymers with different mesogenic units and azo dye-containing copolymers of the general structure ... 

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