Influence of flexibility on the biaxial nematic phase of bent core liquid crystals: a Monte Carlo simulation study.

The influence of flexibility on the phase behavior of bent core biaxial nematic liquid crystals is investigated using Monte Carlo simulation. A generic model for rigid V-shaped molecules is extended to include a bending potential, which allows us to investigate the relationship between the flexibility of a bent core molecule and its ability to form a biaxial nematic phase. The simulation results indicate that, as the flexibility is increased, the biaxial nematic phase is typically forced to lower temperatures. In contrast, the stability of the uniaxial nematic phase with respect to the isotropic phase is not significantly affected. The Landau point is split into a line of first order phase transitions between two different uniaxial phases. In some cases, the uniaxial nematic to biaxial nematic transition becomes first order, and a shape change is observed at this transition.