Phase behavior of liquid-crystalline emulsion systems.
The phase behavior of a mixture containing a surfactant, fatty alcohols and water has been analyzed. Depending on the amount of surfactant, i.e. N-(3-dimethylaminopropyl) octadecanamide, the emulsion-like system forms different microstructures. With increasing surfactant content the formulation evolves from a system with lyotropic lamellar phases to a system with crystal layer phases. (13)C-CPMAS NMR studies carried out at varying surfactant levels showed significant differences in the behavior of the system. Using (2)H and (13)C-CPMAS NMR, X-ray scattering, DSC and polarization microscopy a phase diagram of this system could be derived. Additionally, ultrasonic velocity measurements showed that the ripening process of the emulsions can take up to 2 weeks and longer.
Kudla
Petra
P
Beiersdorf AG, 20245 Hamburg, Germany.
Sokolowski
Tobias
T
Blümich
Bernhard
B
Wittern
Klaus-Peter
KP