Flexoelectro-Optic Properties of a Series of Novel Chiral Nematic Liquid Crystals

We present a series of chiral nematic liquid crystal bimesogenic compounds based on estradiol as the chiral unit and the highly polarizable cyanobiphenyl as the terminal group. The mesophases have temperature ranges up to 40°C wide, entering the isotropic phase at about 100°C. We have observed the flexoelectro-optic effect and have found that the average flexoelectric coefficients of our materials are high (≥ +5×10−12 Cm−1). The electro-optic response times, for 0 to 90% of transmitted intensity, are of the order 1 ms.