Julia Yeomans OBE FRS

Abstract:

Simulations show that, when a phase-separated binary [Formula presented] fluid is driven to flow past chemically patterned substrates in a microchannel, the fluid exhibits unique morphological instabilities. For the pattern studied, these instabilities give rise to the simultaneous, periodic formation of monodisperse droplets of [Formula presented] in [Formula presented] and [Formula presented] in [Formula presented]. The system bifurcates between time-independent behavior and different types of regular, nondecaying oscillations in the structural characteristics. The surprisingly complex behavior is observed even in the absence of hydrodynamic interactions and arises from the interplay between the fluid flow and patterned substrate, which introduces nonlinearity into the dynamical system. © 2003 The American Physical Society.

Abstract:

A study was conducted on the growth of a domain of a nematic liquid crystal at the expense of a second domain with a different director orientation. As such, defects form at the walls between domains and their dynamics was vital in controlling the rate of growth. It was found that a spatial anisotropy in domain growth can result from backflow and discuss how the wall speed varies with the material parameters of the liquid crystal the geometry and the surface properties of the confining cell, and an external electric field.