Stable amorphous blue phase of bent-core nematic liquid crystals doped with a chiral material

Abstract

We report an induction of the blue phase III (BPIII) at a relatively low and wide (over 20 °C) temperature range in nematogenic achiral bent-core liquid crystals doped with a high twisting power chiral material. The pitch decreases with increasing chiral dopant ratio, and easily reaches the ultraviolet wavelength, so that completely dark texture is obtained under crossed polarizers. Electrooptical switching was achieved in a time range of a few to a few tens of milliseconds. We propose for the stabilization of BPIII that broad-temperature range smectic nano-clusters inhibit the long-range order of the double twisted helical structures, and also inhibit possible separation of chiral dopants from the mixture.