Relationship between Mesogenic Side Chain Fraction in Liquid Crystalline Copolymer and Bistable Electro-Optical Switching for (Liquid Crystalline Copolymer/Liquid Crystals) Composite Systems

1998 ◽  
Vol 31 (23) ◽  
pp. 8100-8109 ◽  
Author(s):  
Hirokazu Yamane ◽  
Hirotsugu Kikuchi ◽  
Tisato Kajiyama
Keyword(s):  
Liquid Crystals ◽  
Optical Switching ◽  
Liquid Crystalline ◽  
Side Chain ◽  
Composite Systems ◽  
Chain Fraction

Spontaneous homeotropic alignment of nematic liquid crystals induced by a double-armed side chain liquid crystalline polymethacrylate

2017 ◽  
Vol 656 (1) ◽  
pp. 96-104 ◽  
Author(s):  
Osamu Haba ◽  
Wataru Matsuno ◽  
Nao Nakamura ◽  
Hiroshi Awano ◽  
Tatsuhiro Takahashi ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Nematic Liquid Crystals ◽  
Side Chain ◽  
Homeotropic Alignment

Liquid Crystal Elastomers with Piezoelectric Properties

MRS Bulletin ◽  
1991 ◽  
Vol 16 (1) ◽  
pp. 29-31 ◽  
Author(s):  
Wolfgang Meier ◽  
Heino Finkelmann
Keyword(s):  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Three Dimensional ◽  
Polymer Chains ◽  
Side Chain ◽  
Shape Stability ◽  
Technical Application ◽  
Mechanical Field ◽  
Dimensional Network ◽  
Liquid Crystal Elastomers

During the last few years, liquid crystalline elastomers (LCEs) have been systematically produced by cross-linking liquid crystalline side-chain polymers. In these networks, a liquid crystalline molecule is fixed at each monomeric unit. LCEs exhibit a novel combination of properties. Due to liquid crystalline groups, they show anisotropic liquid crystalline properties similar to conventional liquid crystals (LCs); but due to the three-dimensional network-structure of the polymer chains, they show typical elastomer properties, such as rubber elasticity or shape stability. One exceptional property of this combination is demonstrated when a mechanical deformation to the LCE causes macroscopically uniform orientation of the long molecular axis of the LC units (the so-called “director”).This response of the LC-phase structure to an applied mechanical field is similar to the effect of electric or magnetic fields on low molecular weight liquid crystals (LMLC), as illustrated in Figure 1. Figure la shows an undeformed LCE. Because of the non-uniform orientation of the director, the sample scatters light strongly so the elastomer is translucent like frosted glass. On the other hand, applying a mechanical field the director becomes uniformly aligned and the sample is transparent (Figure 1b). Such a macroscopically ordered rubber exhibits optical properties very similar to single crystals. These propertie s of LCEs offer new prospects for technical application, e.g., in nonlinear and integrated optics.

Flory's parameters in solutions of liquid-crystalline side-chain polymers in low-molecular weight liquid crystals

1990 ◽  
Vol 23 (23) ◽  
pp. 5020-5024 ◽  
Author(s):  
Gilles Sigaud ◽  
M. F. Achard ◽  
F. Hardouin ◽  
C. Coulon ◽  
H. Richard ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Side Chain ◽  
Low Molecular Weight

scholarly journals Light Propagation in Confined Nematic Liquid Crystals and Device Applications

2021 ◽  
Vol 11 (18) ◽  
pp. 8713
Author(s):  
Antonio d’Alessandro ◽  
Rita Asquini
Keyword(s):  
Liquid Crystals ◽  
Optical Switching ◽  
Liquid Crystalline ◽  
Light Propagation ◽  
Soda Lime ◽  
Significant Feature ◽  
Molecular Reorientation ◽  
Crystalline Materials ◽  
Integrated Optic Devices ◽  
Liquid Crystalline Materials

Liquid crystals are interesting linear and nonlinear optical materials used to make a wide variety of devices beyond flat panel displays. Liquid crystalline materials can be used either as core or as cladding of switchable/reconfigurable waveguides with either an electrical or an optical control or both. In this paper, materials and main device structures of liquid crystals confined in different waveguide geometries are presented using different substrate materials, such as silicon, soda lime or borosilicate glass and polydimethylsiloxane. Modelling of the behaviour of liquid crystal nanometric molecular reorientation and related refractive index distribution under both low-frequency electric and intense optical fields is reported considering optical anisotropy of liquid crystals. A few examples of integrated optic devices based on waveguides using liquid crystalline materials as core for optical switching and filtering are reviewed. Reported results indicate that low-power control signals represent a significant feature of photonic devices based on light propagation in liquid crystals, with performance, which are competitive with analogous integrated optic devices based on other materials for optical communications and optical sensing systems.

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