CHIRAL DISCOTIC COLUMNAR PHASES IN LIQUID-CRYSTALS

We introduce a model to describe columnar phases of chiral discotic li quid crystals in which the normals to disc-like molecules are constrai ned to he parallel to columnar axes. The model includes separate chira l interactions favoring, respectively, relative twist of chiral molecu les along the axes of the columns and twist of the two-dimensional col umnar lattice. It also includes a coupling between the lattice and the orientation of the discotic molecules. We discuss the instability of the aligned hexagonal lattice phase to the formation of a soliton latt ice in which molecules twist within their columns without affecting th e lattice and to the formation of a moire phase consisting of a period ic array of twist grain boundaries perpendicular to the columns.