Bent-Structure Liquid Crystalline Dimers Containing a Cholesteryl Group Exhibiting Blue Phases

Abstract

A new series of bent-structure liquid crystalline dimers containing a cholesteryl group were synthesized. The molecular structure and mesophase properties of the dimers were characterized by FTIR, 1H-NMR, DSC, XRD, POM, and UV–vis. The BPmem was proposed, which is considered to be a transition state appearing during the cooling process between BP I and N* and having memory for the original lattice network of BP I. The BPmem state was analyzed in detail, and it proved to be influenced by the molecular structure, the cooling rate, and the surface anchoring. For the planar-aligned sample, the macroscopic color of BPmem is the superposition of two selective reflection wavelengths, different from those of conventional N* and BPs, which has potential application value.