Simulation study of discotic molecules in the vicinity of the isotropic-liquid crystal transition

Bruno Martinez-Haya (1) , Alejandro Cuetos (2)

1 Departamento de Sistemas Fisicos, Quimicos y Naturales
2 Departamento de Fisica Aplicada

The equilibrium and microscopic properties of systems of discotic molecules have been investigated with Monte Carlo simulations. The study focuses on the behavior of the fluid in the isotropic phase in the vicinity of the first liquid crystal transition, which involves either a nematic or a columnar phase. The molecules are modelled by rigid oblate spherocylinders with various types of interaction potentials. Molecular thickness/diameter ratios within L/D=0.1-0.5 are considered. The Monte Carlo equations of state are compared with theoretical predictions for hard convex bodies, based on molecular shape and virial expansions. A good agreement is found for the hard spherocylinder system, although discrepancies arise for L/D<0.4 at sufficiently large packing fraction. Particular efforts are also devoted to characterizing the formation of domains of stacked molecules in the isotropic phase for the different repulsive and attractive interaction models.

Mots clés: Physical Sciences

Bruno Martinez-Haya, Alejandro Cuetos. Simulation study of discotic molecules in the vicinity of the isotropic-liquid crystal transition. Molecular Simulation, 2009, 35 (12-13), pp.1077-1083. ⟨10.1080/08927020902833111⟩. ⟨hal-00530448⟩