Chiral Lyotropic Liquid Crystals: TGB Phases and Helicoidal Structures

TL;DR

This paper explores the formation and structure of chiral lyotropic liquid crystals, focusing on TGB phases and helicoidal defects, highlighting their unique energetic and structural properties compared to thermotropic smectics.

Contribution

It introduces a detailed description of twist-grain-boundary phases and helicoidal defects in chiral lyotropic liquid crystals, emphasizing their distinct structural and energetic characteristics.

Findings

Helicoidal defects are hollow centers with unique energy costs.

Chiral effects induce twisting in lyotropic membranes.

TGB phases exhibit specific structural arrangements.

Abstract

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