Zero field N.M.R. of uniaxial and biaxial smectic liquid crystals

Molecular simulation study of polar order in orthogonal bent-core smectic liquid crystals.

We explore the phase behavior and structure of orthogonal smectic liquid crystals consisting of bent-core molecules (BCMs) by means of Monte Carlo molecular simulations. A simple athermal molecular model is introduced that describes the basic features of the BCMs. Phase transitions between uniaxial and biaxial (antiferroelectric) orthogonal smectics are obtained. The results indicate the presen...

Surface alignment, anchoring transitions, optical properties, and topological defects in the nematic phase of thermotropic bent-core liquid crystal A131.

We study optical, structural, and surface anchoring properties of thermotropic nematic bent-core material A131. The focus is on the features associated with orientational order as the material has been reported to exhibit not only the usual uniaxial nematic but also the biaxial nematic phase. We demonstrate that A131 experiences a surface anchoring transition from a perpendicular to tilted alig...

Zero-field N.M.R. study of the biaxial smectic E phase

Rototranslational diffusion of biaxial probes in uniaxial liquid crystal phases

We discuss the problem of rototranslational diffusion of a rigid biaxial molecule dissolved in a uniaxial smectic liquid crystal phase. We examine distorted rod and disk like molecules and show how biaxiality and rototranslational coupling can produce significant effects on some of the correlation functions and spectral densities most useful in analyzing experimental observables.

Polydispersity stabilizes biaxial nematic liquid crystals.

Inspired by the observations of a remarkably stable biaxial nematic phase [van den Pol et al., Phys. Rev. Lett. 103, 258301 (2009)], we investigate the effect of size polydispersity on the phase behavior of a suspension of boardlike particles. By means of Onsager theory within the restricted orientation (Zwanzig) model we show that polydispersity induces a novel topology in the phase diagram, w...