2000 Fiscal Year Final Research Report Summary
Dynamical Molecular Conformation and Structure of Cluster for Saturated and Unsaturated Fatty Acids in the Liquid State
| Project/Area Number |
10640566
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
機能・物性・材料
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| Research Institution | KITASATO UNIVERSITY |
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Principal Investigator |
IWAHASHI Makio Kitasato Univ.School of Sci., Professor, 理学部, 教授 (70087120)
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| Project Period (FY) |
1998 – 2000
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| Keywords | cis-6-octadecenoic acid / cis-9-octadecenoic acid / cis-11-octadecenoic acid / trans-9-octadecenoic acid / fatty acids / self-diffusion coefficient / density / X-ray diffraction for liquid |
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| Research Abstract |
The translational movement, the dynamical molecular conformation, and the aggregate structure in the liquid state for three kinds of cis-type unsaturated fatty acids (cis-6-, cis-9-, and cis-11-octadecenoic acids), trans-type unsaturated acid (trans-9-octadecenoic acid), and n-saturated acid (octadecanoic acid) have been studied through the measurements of density, self-diffusion coefficient, ^<13>C NMR spin-lattice relaxation time, and X-ray diffraction. The magnitude of the self-diffusion coefficient, D, fell in sequence of cis-type unsaturated acids > trans-type acids > saturated acid below 350 K.Above 350 K the value of D for the trans-type acid rose to those for the cis-type acids. On the other hand, the density ρ for the acids also fell in the order of cis-type acids > trans-type acid > saturated acid ; the order of the density is just opposite to that expected from the results of the self-diffusion coefficient and other physical properties such as melting point and heat of fusion. This discrepancy between D and ρ values for the acids is well explained by the models of the clusters in their liquids.
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