Twist elasticity and anchoring in a lamellar nematic phase.

Director Structures in a Chiral Nematic Slab: Threshold Field and Pitch Variations

Abstract The liquid crystal director distribution is determined for a confined chiral nematic slab. The molecular director distribution of the field-controlled chiral nematic slab is directly calculated. The director profiles for the tilt and the twist angles, under different applied fields, are calculated in the slab with weak boundary conditions. Then, the dependence of the threshold field on...

Local distortion energy and coarse-grained elasticity of the twist-bend nematic phase.

The recently discovered twist-bend nematic phase of achiral bent-shaped molecules, NTB, has a doubly degenerate ground-state with a periodically modulated heliconical structure and unusual distortion elasticity, the theoretical description of which is still debated. We show that the NTB phase has the same macroscopic symmetry as another periodic mesophase, the chiral smectic-A, SmA*. Based on t...

A twist-bend nematic to an intercalated, anticlinic, biaxial phase transition in liquid crystal bimesogens.

In this article we describe for bimesogens the first observed transition from a "heliconical" twist-bend nematic liquid crystal to a novel biaxial, anticlinic, intercalated lamellar phase. The phase behaviour and structures of both polymorphs is similar to that of polymers, confirming that bimesogens can act as model systems for main chain liquid crystal polymers, and in principle are separate ...

Relevance of saddle-splay elasticity in complex nematic geometries.

We demonstrate the relevance of saddle-splay elasticity in nematic liquid crystalline fluids in the context of complex surface anchoring conditions and the complex geometrical confinement. Specifically, nematic cells with patterns of surface anchoring and colloidal knots are shown as examples where saddle-splay free energy contribution can have a notable role which originates from nonhomogeneou...

Hierarchical elasticity of bimesogenic liquid crystals with twist-bend nematic phase