Monolaurin-water phase diagram

This paper discusses some of the results of nuclear magnetic resonance (NMR), infrared, dielectric, and viscosity measurements on the liquid phases of mono- and dihydric alcohols alone and with water. Finally, the monolaurin-water phase diagram is briefly described. 

There are two types of lipid-water phase diagrams. The first type, discussed above, is obtained from polar lipids, which are insoluble in water (i.e. the solubility is quite small, monolaurin for example has a solubility of about 10 m). Fig. 8.12 illustrates the principles of phase equilibria in this type of lipid-water system. The second type of binary system is obtained when the lipid is soluble as micelles in water. Examples of such lipids are fatty acid salts and lysolecithin. An aqueous soap system is illustrated in Fig. 8.13. When the lipid concentration in the micellar solution is increased, the spherical micelles are transformed into rod-shaped micelles. At still higher lipid concentrations the lipid cylinders are hexagonally arranged and the liquid-crystalline phase Hi is formed. The lamellar liquid-crystalline phase is usually formed in the region between Hi and the anhydrous lipid. Excellent reviews of the association behaviour of amphiphiles of this type have been published (Wennerstrom and Lindman, 1979 Lindman and Wennerstrom, 1980). 

Figure 11.17 Phase diagram of the 0.1 u aq. NaCl/CnEO /monolaurin/n-decane system as a function of temperature. The CnEOftmonolaurintn-decane ratio is kept constant at 3.5 1.5 95. The weight percentage of 0.1 M aq. NaCl in the system is plotted horizontally. I, II and III indicate one-, two- and three-phase regions. W, excess water phase O, excess oil phase W oil-in-water microemulsion 0 , water-in-oil microemulsion Ls, reverse bicontinuous phase D, surfactant phase LLC, multiphase region including lamellar liquid crystal (Reproduced by permission of Academic Press from ref 41)...

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