  We apply a set of different techniques to analyze the physical properties and
phase transitions of monoglycerides (MG) in oil. In contrast to many studies of
MG in water or aqueous systems, we find a significant difference in the phase
structure at different concentrations and temperatures. By adding small
quantities of water to our base MG/oil systems we test the effect of hydration
of surfactant head-groups, and its effect on the phase behavior. The phase
diagrams are determined by calorimetry and their universal features are
recorded under different conditions. Two ordered phases are reported: the
inverse lamellar gel phase and the sub-alpha crystalline gel phase. This
sequence is very different from the structures in MG/water; its most striking
feature is the establishing of a 2D densely packed hexagonal order of glycerol
heads in the middle of inverse lamellar bilayers. Rheology was examined through
temperature scans to demonstrate the gelation phenomenon, which starts from the
onset of the lamellar phase during the cooling/ordering process.
