Charge-, salt- and flexoelectricity-driven anchoring effects in nematics

Effects of flexoelectricity and weak anchoring on a Freedericksz transition cell.

We consider a mathematical model that consists of a nematic liquid crystal layer sandwiched between two parallel bounding plates, across which an external field is applied. We investigate how the number and type of solutions for the director orientation within the layer change as the field strength, anchoring conditions, and material properties of the nematic liquid crystal layer vary. In parti...

Fluctuation-induced interactions in nematics with disordered anchoring energy.

We examine fluctuation-induced (pseudo-Casimir) interactions in nematic liquid-crystalline films confined between two surfaces, where one of the surfaces imposes a strong homeotropic anchoring (ensuring a uniform mean director profile), while the other one is assumed to be a chemically disordered substrate exhibiting an annealed distribution of anchoring energies. We employ a saddle-point appro...

Convection driven by centrifugal buoyancy in nematics

The onset of thermal convection in a nematic contained in a vertical rotating cylindrical annulus heated from the outside is studied as a function of the planar alignment of the liquid crystal director n. When n is horizontal, the results confirm data on gravitational buoyancy. An original first order like convection mode is obtained when n is parallel to the cylinder axis. Thermal convection i...

Simple models for charge and salt effects in protein crystallisation

A simple extension of existing models for protein crystallisation is described, in which salt ions and charge neutrality are explicitly incorporated. This provides a straightforward explanation for the shape of protein crystallisation boundaries, the associated scaling properties seen for lysozyme, and can also explain much of the salt dependence of the second virial coefficient. The analysis h...

On-off Intermittency in Stochastically Driven Electrohydrodynamic Convection in Nematics