High Birefringence Liquid Crystals

Crystals

Roman Dၛrowski¹  Przemysᐪw Kula² 

[1] Institute of Chemistry, Military University of Technology, Warsaw 00-908, Poland;

关键词: liquid crystal;    cyanide;    fluoride;    isothiocyanate;    biphenyl;    tolane;    terphenyl;    quaterphenyl;    high birefringence;    positive dielectric anisotropy;   

DOI  :  10.3390/cryst3030443

来源: mdpi

【 摘 要 】

Liquid crystals, compounds and mixtures with positive dielectric anisotropies are reviewed. The mesogenic properties and physical chemical properties (viscosity, birefringence, refractive indices, dielectric anisotropy and elastic constants) of compounds being cyano, fluoro, isothiocyanato derivatives of biphenyl, terphenyl, quaterphenyl, tolane, phenyl tolane, phenyl ethynyl tolane, and biphenyl tolane are compared. The question of how to obtain liquid crystal with a broad range of nematic phases is discussed in detail. Influence of lateral substituent of different kinds of mesogenic and physicochemical properties is presented (demonstrated). Examples of mixtures with birefringence ∆n in the range of 0.2–0.5 are given.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.