Theory and Modelling of Liquid Crystals
A liquid crystal is an intermediate phase of matter that exists between an isotropic liquid phase (such as water) and a solid crystalline phase. These fascinating liquids can have many of the features of solid materials, such as the ability to maintain internal stress and anisotropies of optical and electromagnetic properties, and flow like a normal liquid. Under a microscope their beautiful optical properties are clear (see above) and it is the birefringence of the material that makes it useful in many technological applications – including the ubiquitous liquid crystal display that is present in the vast majority of electronic displays such as in mobile phones, laptops, monitors, televisions.
In those materials that exhibit a liquid crystal phase, some of which consist of calamitic (rod-like) molecules as illustrated above, a solid phase melts to form a nematic liquid crystal phase, where the molecules, on average, align with each other to create an anisotropic axis.
At Glasgow, members of the Continuum Mechanics group use both continuum theories and statistical mechanics to describe the behaviour of these materials, to explain physical effects seen in experiments and to model and predict many of the applications of liquid crystals.
Current projects include investigations into: the effects of electric fields; static and dynamic configurations of interfaces between liquid crystals and solids or gases; defects in liquid crystal alignment; active nematics; chirality and flexoelectricity; colloidal phases consisting of solid particles in a liquid crystal phase, and many others.
[photo credit: S. Cowling, University of York]