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Complex formation in a ternary system composed of lauroamphoglycinate, oleic acid, and water
Author(s) -
Nakama Y.,
Shiojima Y.,
Takeshita Y.,
Yamaguchi M.
Publication year - 1997
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-997-0222-x
Subject(s) - aqueous solution , dissolution , chemistry , emulsion , hexagonal crystal system , surface tension , coalescence (physics) , alkyl , oleic acid , stoichiometry , ternary operation , solubility , ternary numeral system , phase (matter) , crystallography , aqueous two phase system , liquid crystal , crystal habit , crystallization , materials science , organic chemistry , thermodynamics , biochemistry , physics , optoelectronics , astrobiology , computer science , programming language
The formation of a complex, composed of lauroamphoglycinate (LG), oleic acid (OA) and water, was investigated, and this system was applied to emulsification. The complex was formed in the water‐rich area (more than 90% in this system) at a molar ratio of OA to LG from 1 to 3, where two‐phase systems of water and the complex existed. The interaction between LG and OA, both in the aqueous solution and at the interface of liquid paraffin dissolving the OA and LG solution, was studied by pH measurements and interfacial tension measurements, respectively. The results implied that LG and OA were linked stoichiometrically, both in aqueous solution and at the interface, and formed complexes. X‐ray diffraction patterns and the strong hydrophobicity showed that the equimolar complex composed of LG, OA, and water was a liquid crystal with a reversed hexagonal structure. The reversed hexagonal liquid crystal was capable of solubilizing a certain amount of liquid paraffin in its alkyl group parts while maintaining its hexagonal structure. These results suggest the possibility to prepare a W/O‐type emulsion by using the liquid crystal formed by LG, OA, partial liquid paraffin, and water as the continuous phase. The authors could obtain a stable W/O emulsion without coalescence of the water droplets that contained a substantial amount of water (approximately 90%). Furthermore, various types of emulsions, O/W, W/O, W/O/W, could be prepared by changing the ratio of LG and OA.