A light-scattering study of deformation of liquid-crystalline spherulites of poly(γ-benzyl-L-glutamate) in an electric field

1981 ◽  
Vol 19 (10) ◽  
pp. 1531-1547 ◽  
Author(s):  
Masaru Matsuo ◽  
Fumihiko Ozaki ◽  
Yasuyuki Konno ◽  
Tetsuya Ogita
Keyword(s):  
Light Scattering ◽  
Electric Field ◽  
Liquid Crystalline ◽  
Scattering Study

Aggregation Structure and Electro—Optical Properties of (Liquid Crystalline Polymer)/(Low Molecular Weight Liquid Crystal) Composite System

1989 ◽  
Vol 171 ◽  
Author(s):  
Tisato Kajiyama ◽  
Hirotsugu Kikuchi ◽  
Akira Miyamoto ◽  
Satoru Moritomi ◽  
Jenn—Chiu Hwang
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Electric Field ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Smectic Phase ◽  
Side Chain ◽  
Low Molecular Weight ◽  
Smectic Layer

ABSTRACTA series of thin films composed of liquid crystalline polymer (LCP) and low molecular weight liquid crystal (LMWLC) was prepared by a solventcasting method or by a bar—coating method. LCPs were of mesogenic side chain type with strong or weak polar terminalgroups in the side chain portion. A mixture of smectic LCP (LCP with side chain of strong polar end) and nematic LMWLC formed a smectic phase in a LCP weight fraction range above 50 %. Also, a mixture of nematic LCP (LCP with side chain of weak polar end) and nematic LMWLC with strong polar group induced a new smectic phase in a LCP molar fraction range of 20–80 %. Reversible and bistable electro-optical effects based on light scattering were recognized for a smectic phase of a binary composite composed of LCP and LMWLC. A light scattering state caused by many fragmented smectic lamellae appeared in the case of application of an a.c. electric field below a threshold frequency (∼l Hz). Furthermore, application of a 100 Vp—p a.c. field of 1 kHz made the transmission light intensity increased to 94 % within a few seconds. The optical heterogeneity in asmectic layer composed of the side chain group of LCP was caused by the difference of twoforces based on both dielectric anisotropy of the side chain and electrohydrodynamic motion of the main chain. Since application of a low frequency electric field causes an ioniccurrent throughout the mixture film, it is reasonable to consider that an induced turbulent flow of main chains by an ionic current collapsed a fairly well organized large smectic layer into many small fragments, resulting in an increase in light scattering. The response speed of LCP upon application of an electric field increased remarkably by mixingLMWLC. In the case of a smectic mesophase, turbid and transparent states remained unchanged as it was, even though after removing an electric field.1Such abistable and reversiblelight switching driven by two different frequencies of electric field could be newly realized by both characteristics of turbulent effect of a wellorganized large smectic layer of LCP and rapid response of LMWLC. We believe that the LCP/LMWLC mixture system is promissing as a novel type of “light valve” exhibiting memory effect (bistable light switching).

Novel Memory Effect Found in Nematic Liquid Crystal/Clay Mineral Composites

1996 ◽  
Vol 425 ◽  
Author(s):  
M. Kawasumi ◽  
N. Hasegawa ◽  
A. Usuki ◽  
A. Okada ◽  
T. Kurauchi
Keyword(s):  
Liquid Crystal ◽  
Light Scattering ◽  
Electric Field ◽  
Memory Effect ◽  
Clay Mineral ◽  
Nematic Liquid Crystal ◽  
Liquid Crystalline ◽  
Optical Effect ◽  
Scattering States ◽  
Memory States

AbstractNovel liquid crystalline composites composed of a nematic two-frequency-addressing liquid crystal and organized clay mineral have been prepared. The particles of the clay mineral were dispersed homogeneously in the liquid crystal. The composite cells displayed a reversible and multistable electro-optical effect between transparent and turbid light scattering states by changing the frequency of the electric field. The light transmittances of both transparent and light scattering memory states did not change after 15 hrs without the electric field applied.

Light-scattering study of random disorder in liquid crystalline elastomers

1997 ◽  
Vol 198 (11) ◽  
pp. 3485-3498 ◽  
Author(s):  
S. M. Clarke ◽  
E. Nishikawa ◽  
H. Finkelmann ◽  
E. M. Terentjev
Keyword(s):  
Light Scattering ◽  
Liquid Crystalline ◽  
Scattering Study ◽  
Random Disorder

Phase transitions in C2O4HNH4, 1/2 H2O. A light scattering study at normal pressure

1987 ◽  
Vol 48 (5) ◽  
pp. 809-819 ◽  
Author(s):  
J.L. Godet ◽  
M. Krauzman ◽  
J.P. Mathieu ◽  
H. Poulet ◽  
N. Toupry
Keyword(s):  
Phase Transitions ◽  
Light Scattering ◽  
Normal Pressure ◽  
Scattering Study
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