The influence of the liquid crystalline core geometry on the mesogenicity of novel chiral 2-(4-substituted-phenoxy)propanonitriles

1994 ◽  
Vol 16 (6) ◽  
pp. 925-940 ◽  
Author(s):  
Christopher J. Booth ◽  
John W. Goodby ◽  
Judith P. Hardy ◽  
Olwen C. Lettington ◽  
Kenneth J. Toyne
Keyword(s):  
Liquid Crystalline ◽  
Crystalline Core

Molecular packing handedness dominated by the chirality of the lactic acid residue near the liquid crystalline core

2020 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaoqing Wu ◽  
Baining Ni ◽  
Limin Wu ◽  
Yongmin Guo ◽  
Yi Li ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Liquid Crystalline ◽  
Molecular Packing ◽  
Crystalline Core

Reactive Mesogenes: Synthesis and Application in Optoelectronic Devices

2001 ◽  
Vol 709 ◽  
Author(s):  
Peter Strohriegl ◽  
Doris Hanft ◽  
Markus Jandke ◽  
Thomas Pfeuffer
Keyword(s):  
Liquid Crystalline ◽  
Room Temperature ◽  
Polymer Networks ◽  
Optoelectronic Devices ◽  
Chiral Molecules ◽  
Glass Forming ◽  
Writing Beam ◽  
Crystalline Core ◽  
Crosslinked Networks ◽  
The Stability

ABSTRACTReactive mesogenes posess polymerizable groups attached to a rigid, liquid crystalline core. From such molecules, densely crosslinked networks in which the liquid crystalline order is permanentely fixed can be formed by photopolymerization.Our major synthetic goal was the formation of glass forming reactive mesogenes. Such compounds do not crystallize upon cooling but vitrify and form supercooled LC-phases ('LC-glasses'). They exhibit broad LC-phases and enable us to carry out photopolymerization in a broad range of temperatures.We have systematically investigated how the topology of the reactive mesogenes influences the stability of the resulting glasses. Comparing twin molecules with three- and four-armed stars we found that the supercooled LC-phase in the three-armed stars has a stability superior to both twin molecules and four-armed stars. In the three-armed star Triple-4 with a suitable substituent pattern the supercooled LC-phase is stable at room temperature for at least nine months. Doped with suitable chiral molecules the glass forming nematics form cholesteric phases which were used for cholesteric polymer networks and for polarization holograms with one s-and one p-polarized writing beam.Furthermore we have extended our synthetic efforts to reactive mesogenes with three or five conjugated fluorene units as LC-core. After orientation, the mesogenes were photocrosslinked and used as active layer in OLEDs that emit highly polarized blue light.

scholarly journals One-piece micropumps from liquid crystalline core-shell particles

2012 ◽  
Vol 3 (1) ◽  
Author(s):  
Eva-Kristina Fleischmann ◽  
Hsin-Ling Liang ◽  
Nadia Kapernaum ◽  
Frank Giesselmann ◽  
Jan Lagerwall ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Core Shell ◽  
Crystalline Core ◽  
Shell Particles

Single Mode Wave Guide with a Liquid Crystalline Core

1997 ◽  
Vol 06 (01) ◽  
pp. 81-93 ◽  
Author(s):  
J. A. Reyes ◽  
R. F. Rodriguez
Keyword(s):  
Spatial Distribution ◽  
Liquid Crystalline ◽  
Single Mode ◽  
Transverse Magnetic ◽  
Optical Field ◽  
Waveguide Effect ◽  
Crystalline Core ◽  
Waveguide Model ◽  
Optical Limit ◽  
Ray Trajectories

A model for a planar single mode waveguide with a thermotropic nematic core is discussed. In previous work we have shown that in the optical limit this guide is multimodal and that a waveguide effect exists and concentrates the ray trajectories in the central part of the cell. In this work we show that for the WKB limit the same waveguide model may become single modal. To derive the conditions under which this regime may be attained, we first calculate the propagating transverse magnetic (TM) modes, their cut off frequency and the maximum number of modes for a given frequency of the incident optical field. From these results we then derive the condition to have a unimodal waveguide and calculate the spatial distribution of the electromagnetic energy density within the cell. We show that the waveguide effect may still exist for the strong regime only, by exhibiting that this energy is concentrated between two caustics in the central part of the cell. Finally, we discuss the limitations and possible generalizations of our model and give some concluding remarks.

Chemiluminescence emission in cholesteric liquid crystalline core–shell microcapsules

2014 ◽  
Vol 2 (25) ◽  
pp. 4904-4908 ◽  
Author(s):  
Y. Iwai ◽  
H. Kaji ◽  
Y. Uchida ◽  
N. Nishiyama
Keyword(s):  
Liquid Crystalline ◽  
Double Emulsion ◽  
Core Region ◽  
Middle Phase ◽  
The Core ◽  
Emulsion Droplets ◽  
Crystalline Core ◽  
Oil Water ◽  
Double Emulsion Droplets ◽  
Cholesteric Liquid Crystalline

Chemiluminescence behaviour in the core region of water/oil/water double emulsion droplets with cholesteric liquid crystalline middle phase was demonstrated.

Field-controlled optical profile of a waveguide having a liquid-crystalline core

2002 ◽  
Vol 81 (13) ◽  
pp. 2337-2339 ◽  
Author(s):  
M. Marangoni ◽  
R. Osellame ◽  
R. Ramponi ◽  
M. Buscaglia ◽  
T. Bellini ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Crystalline Core

Freeze fracture imaging and computer simulation of liposome structure: Membrane geometry and defects

1983 ◽  
Vol 41 ◽  
pp. 646-647
Author(s):  
Joseph A. Zasadzinski
Keyword(s):  
Liquid Crystalline ◽  
Freeze Fracture ◽  
Continuum Theory ◽  
Closed Surfaces ◽  
Straight Line ◽  
Low Weight ◽  
Concentric Spheres ◽  
Membrane Geometry ◽  
Dupin Cyclides ◽  
Limiting Case

At low weight fractions, many surfactant and biological amphiphiles form dispersions of lamellar liquid crystalline liposomes in water. Amphiphile molecules tend to align themselves in parallel bilayers which are free to bend. Bilayers must form closed surfaces to separate hydrophobic and hydrophilic domains completely. Continuum theory of liquid crystals requires that the constant spacing of bilayer surfaces be maintained except at singularities of no more than line extent. Maxwell demonstrated that only two types of closed surfaces can satisfy this constraint: concentric spheres and Dupin cyclides. Dupin cyclides (Figure 1) are parallel closed surfaces which have a conjugate ellipse (r1) and hyperbola (r2) as singularities in the bilayer spacing. Any straight line drawn from a point on the ellipse to a point on the hyperbola is normal to every surface it intersects (broken lines in Figure 1). A simple example, and limiting case, is a family of concentric tori (Figure 1b).To distinguish between the allowable arrangements, freeze fracture TEM micrographs of representative biological (L-α phosphotidylcholine: L-α PC) and surfactant (sodium heptylnonyl benzenesulfonate: SHBS)liposomes are compared to mathematically derived sections of Dupin cyclides and concentric spheres.

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