Using synchrotron X-ray diffraction the thermal behaviour was studied of the cubic phases in the 1-monooleoyl-rac-glycerol (MO)/n-octyl-b-D-glucopyranoside (OG)/ 2 H2O system with 58 or 45 wt % MO concentration and varying OG/ 2 H2O contents. These MO contents correspond to a Pn3mcubic single-phase or aPn3mcubic phase in excess water on the binary MO/water axis of the ternary phase diagram. The cubic liquid crystalline phases are stable with small fractions of OG, while higher OG concentrations trigger a cubic-to-lamellar phase transition. .
