High Birefringence Liquid Crystals

作者：Dabrowski Roman^*; Kula Przemyslaw; Herman Jakub

来源：Crystals, 2013, 3(3): 443-482.

DOI：10.3390/cryst3030443

• liquid crystal
• cyanide
• fluoride
• isothiocyanate
• biphenyl
• tolane
• terphenyl
• quaterphenyl
• high birefringence
• positive dielectric anisotropy

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 Delta n in the range of 0.2-0.5 are given.

• 出版日期2013-9