Thermal Characterization of Liquid Crystalline Materials

2010 ◽  
Vol 98 (7) ◽  
pp. 429-438 ◽  
Author(s):  
P. van Ende ◽  
G. Groeninckx ◽  
H. Reynaers ◽  
K. U. Leuven
2018 ◽  
Vol 1151 ◽  
pp. 135-141
Author(s):  
Asma Iqbal ◽  
Humaira Masood Siddiqi ◽  
Zareen Akhter ◽  
Muhammad Qaiser Fatmi

Author(s):  
Christopher Viney ◽  
Wendy S. Putnam

It is widely observed that nematic and cholesteric liquid crystalline materials develop a one-dimensional periodic microstructure during and/or after a uniaxial draw or simple shear (Fig. 1). This property is common to lyotropic and thermotropic examples of both small-molecule and polymeric liquid crystals. The periodic microstructure gives rise to a banded texture between crossed polars (Fig 2).A material under load will extend more readily if the microstructure contains crimps that can be straightened, compared to the extension that is achieved if covalent backbone bonds are highly aligned along the direction of load. The microstructure in Fig. 1 therefore is regarded as a stiffness-reducing defect. Two classes of stiff polymer that are produced from lyotropic solutions do not exhibit banded textures: the highest modulus variant of poly(p-phenyleneterephthalamide) (Kevlar), and various natural silk fibers. However, a banded texture is present in the less stiff variants of Kevlar, and also in silk fibers that have been drawn by hand from natural secretions, which demonstrates that the defect is not intrinsic to liquid crystalline molecular order, but is related to processing.


1991 ◽  
Vol 9 (6) ◽  
pp. 903-906 ◽  
Author(s):  
Fabio D. Cukiernik ◽  
Pascale Maldivi ◽  
Anne-Marie Giroud-godquin ◽  
Jean-Claude Marchon ◽  
Mohammed Ibn-elhaj ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (90) ◽  
pp. 87502-87512 ◽  
Author(s):  
Wenhuan Yao ◽  
Yanzi Gao ◽  
Fasheng Li ◽  
Lanying Zhang ◽  
Zhou Yang ◽  
...  

A series of thermochromism liquid crystalline materials with an unusual characterization of the centre selective light reflection wavelength (λm) vs. Xchol was prepared.


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