Rototranslational diffusion of biaxial probes in uniaxial liquid crystal phases

Rotational diffusion of uniaxial probes in biaxial liquid crystal phases

We discuss the reorientation of a cylindrically symmetric probe in a biaxial orthorombic medium, such as a biaxial nematic. We write down and solve for the first time the rotational diffusion equation for a rod-like or disc-like uniaxial probe reorienting in a medium of biaxial symmetry. We calculate first and second rank correlation functions both in the uniaxial and biaxial phase, giving the ...

Rotational diffusion of biaxial probes in biaxial liquid crystal phases, Mol. Phys., 85, 299-333 (1995)

Temperature-concentration behaviour of the order parameter in the nematic phases of a lyotropic liquid crystal

2014 The temperature variations of the order parameter invariants are measured in the uniaxial and biaxial nematic phases of different mixtures of potassium laurate, 1-decanoL D2O. They show that the uniaxial to biaxial nematic phase transitions are second-order and mean-field, including in the case of the reentrant concentration, which gives the sequence discotic-biaxial-discotic of nematic ph...

Molecular model of biaxial ordering in nematic liquid crystals composed of flat molecules with four mesogenic groups.

Relative stability of uniaxial and biaxial nematic phases is analyzed in a model nematic liquid crystal composed of flat molecules of C2h symmetry with four mesogenic groups rigidly linked to the same center. The generalized effective quadrupole mean-field potential is proposed and its constants are evaluated numerically for the pair intermolecular potential based on Gay-Berne interaction betwe...

Columnar phases and Ðeld induced biaxiality of a Gay–Berne discotic liquid crystal

We have studied a system of discotic particles with a central transverse dipole using Monte Carlo (MC) computer simulations at constant pressure. We have investigated several temperatures corresponding to nematic and columnar liquid crystal phases and determined the molecular and dipolar organizations. Low temperature columnar phases are characterized by local biaxial ordering of dipoles, even ...