S. Blenk and W. Muschik
Mesoscopic concepts for constitutive equations of nematic liquid crystals in alignment tensor formulation
ZAMM 73(4-5), 1993, T331-T333

Starting out with mesoscopic orientational balance equations for a Cosserat Continuum macroscopic constitutive equations are derived by exploiting the dissipation inequality due to Coleman and Noll. The chosen state space includes the second order alignment tensor and its derivatives. The results are compared with with those obtained by Ericksen and Leslie, who introduced a unit director field indicating only the mean orientation of the media and Ericksen's '91-paper, which describes the general uniaxial case.