Liquid Crystalline Blue Phases - Liquid Crystalline Functional Assemblies and Their Supramolecular Structures - page 104

the route of molecule arrangement. In this way, all the angles of molecules can
be regulated. In other words, all molecules in the simple twist can be arranged
continuously in three-dimensional space. On the other hand, if the molecules
are twisted along two axes even when the angle of a molecule is determined
at one point, its angle at another location differs depending on the route of
arrangement, as shown in Fig. 2b [11]. In short, the double twist within the
entire space inevitably results in a defect of discontinuous arrangements of
the molecular angles. The topological effect forcing the chiral liquid crystal
to become continuous by preventing this defect effectively and autonomously
restricts the twisting arrangement to a single axis alone in a chiral nematic
Fig. 3 Comparison of simple-twist and double-twist arrangements
Fig. 4 Model of molecule arrangements within a double-twisted cylinder