Interactions, topology and photonic properties of liquid crystal colloids and dispersions

Liquid crystal-based colloids demonstrate new type of colloidal interaction between the particles, which is of elastic origin, has very long range and is extremely strong, with pair-binding elastic potential exceeding several thousands of kBT. This gives rise to novel and strong colloidal assembly mechanisms, which can be used to assemble 2D and 3D colloidal crystals. This mini-review discusses colloidal pair interaction mechanisms and topological aspects of colloidal interaction. Topological defects, which are responsible for elastic forces between colloidal particles show an amazing diversity of different structures, including colloidal entanglement, knotting and linking of particles. An introduction is given to dispersions of liquid crystal droplets in an immiscible fluid, which represent a new class of photonic micro-devices, including micro-lasers, micro-fibers and optical micro-cavities made of tuneable liquid crystals.