# Masoomeh Hashemi: Nonspherical Colloidal Particles in Nematic Liquid Crystals: Role of geometrical parameters

**Nonspherical Colloidal Particles in Nematic Liquid Crystals: Role of geometrical parameters**

__Masoomeh Hashemi__, Department of physics, Sharif University of Technology, Tehran, Iran

Since the recognition of a novel class of long range
intercolloidal interactions mediated by the elasticity of
the nematic liquid crystal host, extensive research has
been devoted to the role of particle geometry in uniform
nematic media. Defect structures specifically depend on
the geometry of the particles. Therefore, by carefully
choosing the geometrical shapes of the particles one can
be able to design defect structures with pre-determined
architecture in a liquid crystal colloidal system. Finite
element methods are powerful tools in dealing with
colloidal surfaces in liquid crystals. By employing a
finite element method for numerical minimization of the
Landau-de Gennes free energy we study the equilibrium
orientation and defect structures of a circular
cylindrical particle with flat ends under homeotropic
anchoring condition in a uniform nematic medium. Different
aspect ratios of this colloidal geometry from thin
discotic to long rod-like shapes and several colloidal
length scales ranging from mesoscale to nanoscale are
investigated. We show that the equilibrium state of this
colloidal geometry is sensitive to the two geometrical
parameters: aspect ratio and length scale of the particle.