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5327192 
Journal Article 
Interaction of the acid soap of triethanolamine stearate and stearic acid with water 
Zhu, S; Pudney, PD; Heppenstall-Butler, M; Butler, MF; Ferdinando, D; Kirkland, M 
2007 
Yes 
Journal of Physical Chemistry B
ISSN: 1520-6106
EISSN: 1520-5207 
111 
5 
1016-1024 
English 
17266256 
WOS:000243889800014 
Stearic acid and triethanolamine (TEA) in a molar ratio of 2:1 were mixed in aqueous solution at 80 degrees C and subsequently cooled to ambient temperature. The structural evolution of the resultant sample during storage was characterized by using light microscopy, Cryo-SEM, differential scanning calorimetery, pH, infrared spectroscopy, elemental analysis, and simultaneous small and wide-angle X-ray diffraction. It was found that a lamellar liquid crystalline phase was formed when stearic acid and TEA solution were mixed at 80 degrees C and multilamellar spheres of a few microns diameter were formed initially after cooling. A hydrolysis reaction (i.e., the reverse reaction of neutralization between stearic acid and TEA) occurred thereafter that caused the breakdown of the lamellar gel phase and the formation of platelet stearic acid crystals. Three polymorphs of stearic acid (defined following previous work as the A, C, and E forms) were formed as the result of hydrolysis reaction, which gave rise to a strong optically pearlescent appearance.