Preparation and Characteristics of Arginine Oleate Liquid Crystal Holding a Large Amount of Water

Abstract

Solution properties of arginine oleate (ArgOA) were investigated by means of small angle X-ray scattering device, tensiometer, transmittance measuring device, transmission electron microscope, NMR, etc. Whereas arginine stearate which is different in hydrophobic moiety or sodium oleate which is different in counterion from ArgOA formed lamellar liquid crystals in a limited region, ArgOA formed over a wide ranges of temperature and concentration. The surface tension versus concentration curve of ArgOA had two bending points (C1 and C2). When the state of its aqueous solution was observed, transmittance of the aqueous solution decreased in the concentration range of C1 and more and, in the region until C2 where the concentration further increased, particles of several tens nm and several hundreds nm were observed. At concentrations above C2, the viscosity of the aqueous solution began to increase due to the formation of bigger molecular aggregates. The formation of micelles, vesicle-like highly associated aggregates, and lamellar liquid crystals with large amount of water were observed as a result of an increase in concentration of ArgOA. © 2005, Japan Oil Chemists' Society. All rights reserved.