FLOW-ALIGNMENT IN BIAXIAL AND DISCOTIC NEMATICS

Continuum theory for nematic liquid crystals predicts two distinct typ es of flow alignment, one that observed in thermotropic rod-like nemat ics, and the second not so far observed but thought to be relevant to discotic nematics. This paper examines this latter possibility by cons idering recent flow alignment predictions for biaxial nematics, partic ularly for such materials where the molecular structure is close to di scotic, and obtains results that support this claim. In addition it sh ows that in the disc-like limit biaxial theory reduces to that for a u niaxial nematic with viscosities consistent with this conjecture.