Liquid-Crystalline Blue Phase II System Comprising a Bent-Core Molecule with a Wide Stable Temperature Range

A thermodynamically stable blue phase II (BPII) has been prepared, and its electrooptical (EO) performance has been evaluated in a host system of a conventional rodlike nematogen mixed with a bent-core molecule. For the mixed system presented, the widest temperature range of BPII stability, during cooling/heating, was >6 °C. This range is much wider than those of conventional nematogens blended with chiral dopants. EO observations show that the BPII produced exhibited stable EO performance based on the EO Kerr effect. The temperature dependence of the Kerr effect was found to be in approximate agreement with the Landau-de Gennes theory. Furthermore, this material demonstrated very fast, sub-millisecond-scale, response times, thus showing potential for use in high-speed EO devices.