Capillary and winding transitions in a confined cholesteric liquid crystal.

Capillary smectization and layering in a confined liquid crystal.

Using density-functional theory, we have analyzed the phase behavior of a model liquid crystal confined between two parallel, planar surfaces (i.e., the so-called slit pore). As a result of confinement, a rich phase behavior arises. The complete liquid-crystal phase diagram of the confined fluid is mapped out as a function of wall separation and chemical potential. Strong commensuration effects...

Cholesteric Liquid Crystal Flakes—a New Form

LLE Review, Volume 74 139 The last 20 years have seen a growth of mixed-media systems in which cholesteric liquid crystals (CLC’s) are one component. These include polymer-dispersed CLC’s1 in which the CLC’s are confined to microdroplets within a continuous isotropic polymer and CLC’s in gels2 in which there is a small amount of polymer to stabilize the CLC structure. In either case, the contin...

Observation of Newtonian Capillary Shear Flow in an Oriented Cholesteric Liquid Crystal

Optical vortices generated by dislocations in a cholesteric liquid crystal.

We report the observation of optical vortices in a laser beam propagating through the stripe pattern of a cholesteric liquid crystal. The liquid crystal is confined in a cell with homogeneous boundary conditions and forms a diffraction phase grating. Optical vortices are produced by edge dislocations of the cholesteric grating. The vortices show up as spots of zero light intensity in the diffra...

Phase diagrams of mixtures of a polymer and a cholesteric liquid crystal under an external field.

We present a mean field theory to describe phase behaviors in mixtures of a polymer and a cholesteric liquid crystal under an external magnetic or electric field. Taking into account a chiral coupling between a polymer and a liquid crystal under the external field, we examine twist-untwist phase transitions and phase separations in the mixtures. It is found that a cholesteric-nematic phase tran...