Chiral Lyotropic Liquid Crystals: TGB Phases and Helicoidal Structures

Abstract

The molecules in lyotropic membranes are typically aligned with the surface\nnormal. When these molecules are chiral, there is a tendency for the molecular\ndirection to twist. These competing effects can reach a compromise by producing\nhelicoidal defects in the membranes. Unlike thermotropic smectics, the centers\nof these defects are hollow and thus their energy cost comes from the line\nenergy of an exposed lamellar surface. We describe both the\ntwist-grain-boundary phase of chiral lamellar phases as well as the isolated\nhelicoidal defects.\n