THE ROLE OF CRITICAL-POINTS IN THE FORMATION OF COEXISTING LIQUIDS IN THE META-XYLENE WATER I-C9H19C6H4(OC2H4)9.2OH - TEMPERATURE TRIGONAL PRISMATIC DIAGRAM

The complete trigonal prism diagram - including lower and upper critical temperatures for formation of three coexisting isotropic liquids - has been constructed for an oil/water/nonionic surfactant-temperature system (5 less than T less than 95 degree C). The diagram demonstrates the complete oleic-middle-phase ('microemulsion') binodal surface, the aqueous-middle-phase binodal surface, and their relation to the appearance, evolution, and disappearance of the middle-phase tie-triangle as the temperature is raised from below the lower critical temperature to above the upper critical temperature.