| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1991: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1990: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Research Abstract |
Temperature dependence of molecular conformation and liquid structure for cis-9-octadecenoic acid in the neat state has been studied by means of differential scanning calorimetry and by measurement of the density, viscosity, self-diffusion coefficient, infrared spectrum, fluorescence polarization of DPH dissolved in the acid, ESR order parameter for four kinds of spin probe incorporated in the acid, ^1H and ^<13>C NMR relaxation times T_1 and T_2, and X-ray diffraction.
On the basis of the experimental results, it is concluded that the acid has three kinds of liquid structure depending on temperature : (1)The first structure, in temperatures from the melting point to 303K, consists of clusters of a quasi-smectic liquid crystal ; the. clusters are randomly orientated and their sizes are smaller than the wavelength of visible light. (2)The second one, in the temperature range between 303 and ca. 323K, presumably consists of clusters having a less ordered structure. (3)The third one appears to be an isotropic liquid above ca. 323K.
Temperature dependence of near infrared spectrum for liquid oleic acid suggests that such the phase transitions resulted from the temperature qrizing are due to the dissociation of the cyclic dimer of the acid molecules linked together by a hydrogen bond of their carboxyl groups.
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