Cp. Borgmeyer et S. Hess, UNIFIED DESCRIPTION OF THE FLOW-ALIGNMENT AND VISCOSITY IN THE ISOTROPIC AND NEMATIC PHASES OF LIQUID-CRYSTALS, Journal of non-equilibrium thermodynamics, 20(4), 1995, pp. 359-384
Using the second rank alignment tensor as an additional macroscopic va
riable, it is demonstrated how a unified description of the flow aligm
ent and viscous properties in the isotropic and nematic (or nematic di
scotic) phases of liquid crystals can be formulated within the framewo
rk of irreversible thermodynamics such that the full anisotropy of the
viscosity is obtained in the nematic phase.