Abstract:

In the present study we characterized the microstructures of the Lc and HII phases in a glycerol monooleate (GMO)/tricaprylin (TAG)/water mixt. as a function of temp. We studied the factors that govern the formation of a low-viscosity HII phase at relatively elevated temps. (\textgreater35°). This phase has very valuable phys. characteristics and properties. The techniques used were differential scanning calorimetry (DSC), wide- and small-angle x-ray scattering (WAXS and SAXS, resp.), NMR (self-diffusion and 2H NMR), and Fourier transform IR (FTIR) spectroscopies. The reverse hexagonal phase exhibited relatively rapid flow of water in the inner channels within the densely packed cylindrical aggregates of GMO with TAG mols. located in the interstices. The existence of two water diffusion peaks reflects the existence of both mobile water and hydration water at the GMO-water interface (hydrogen exchange between the GMO hydroxyls and water mols.). Above 35°, the sample became fluid yet hexagonal symmetry was maintained. The fluidity of the HII phase is explained by a significant redn. in the domain size and also perhaps cylinder length. This phenomenon was characterized by higher mobility of the GMO, lower mobility of the water, and a significant dehydration process. [on SciFinder(R)]