Abstract
Lyotropic liquid crystals given by binary systems have been known for a long time to investigators in the soap and detergent field, mainly by the work of McBain and his school.1, 2 The first analysis by X-ray diffraction of soap mesophases was done by Stauff3 and by Kiessig and Philippoff.4 Liquid crystals obtained with phospholipids in the presence of water were examined by X-ray analysis already in 1941 by Schmitt et al.5 More recently Luzzati et al.6 defined the structure of the different mesophases with more precision.