TITLE:
Dynamic Molecular Behavior and Cluster Structure of Octanoic Acid in Its Liquid and CCl4 Solution
AUTHORS:
Hideyo Matsuzawa, Masaya Tsuda, Hideyuki Minami, Makio Iwahashi
KEYWORDS:
Octanoic Acid; Oleic Acid; Stearic Acid; X-Ray Diffraction; Near-Infrared Spectroscopy; Self-Diffusion Coefficient; 13C-NMR Spin-Lattice Relaxation Time; 1H-NMR Chemical Shift
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.4 No.9A,
August
21,
2013
ABSTRACT:
Fatty acids such as oleic and stearic acids having a long hydrocarbon chain are known to exist as dimers in their melt and even in a non-polar solvent. In their melt the dimers arrange longitudinally and alternately to form clusters which resemble a smectic liquid crystal. The clusters determine the liquid properties of the fatty acids such as density, viscosity and fluidity. Then, do the dimers of fatty acid having a moderate-length hydrocarbon chain construct such the clusters? In the present study the dynamic molecular behavior and assembly structure of octanoic acid in its melt and also in CCl4 solution have been investigated by the X-ray diffraction, near infrared spectroscopy, 1H-NMR chemical shift, self-diffusion coefficient and 13C-NMR spin-lattice relaxation time measurements. From these results it has been revealed that the clusters of octanoic acid exist in its melt and also in CCl4 and that the clusters in the melt disintegrate with an increase in temperature. The dissociation profile of dimers of octanoic acid into monomers in CCl4 also has been clarified.