Physics Commons^™

Viscoelasticity, Dielectric Anisotropy, And Birefringence In The Nematic Phase Of Three Four-Ring Bent-Core Liquid Crystals With An L-Shaped Molecular Frame, Nejmettin Acvi, Volodymyr Borshch, Dipika Debnath Sarkar, Rahul Deb, Gude Venkatesh, Taras Turiv, Sergij V. Shiyanovskii, Nandiraju V. S. Rao, Oleg Lavrentovich

Oleg Lavrentovich

Molecular shape is an important factor in determining the material properties of thermotropic liquid crystals (LCs). We synthesized and investigated several LC compounds formed by asymmetrically bent molecules with a rigid four-ring core in the shape of the letter 'L'. We measured the temperature dependencies of dielectric permittivities, birefringence, splay K-1 and bend K-3 elastic constants, splay viscosity eta(splay) and flow viscosities eta(parallel to) and eta(perpendicular to). The bend-splay anisotropy delta K-31 - K-3 - K-1 is negative, similar to the case of nematic LCs formed by symmetrically bent molecules of V-shape. The dielectric anisotropy Delta epsilon and birefringence are …