1993 Fiscal Year Final Research Report Summary
STUDY ON CRITICAL SOLUTION PHENOMENA AND CAHN TRANSITION
| Project/Area Number |
04453010
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
物理化学一般
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
ARATONO Makoto FACULTY OF SCIENCE, ASSOCIATE PROFESSOR, 理学部, 助教授 (20175970)
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| Project Period (FY) |
1992 – 1993
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| Keywords | critical solution phenomea / interfacial adsorption / phase transition / wetting-nonwetting transition |
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| Research Abstract |
1 The phase behavior of ternary two-phase system composed of water, nonane, and ethylene glycol monobutyl ether(C4E1) was investigated thermodynamically. The compositions of the water and nonane phases were measured precisely as a function of total concentration of C4E1 and temperature under atmospheric pressure by gas liquid chromatography. A new kind of criterion of ideality for the two-phase equilibrium was proposed and examined by using the composition data obtained. The composition region of ideal dilute solution behavior was determined for the two phases as a function of temperature. It was suggested that the formation of aggregate of C4E1 in the water phase is enhanced at lower temperatures and that in the nonane phase does at higher temperatures, respectively. Furthermore the entropy and enthapy of transfer of ether molecules from the water to the nonane phase were evaluated not by calorimetry but by applying the thermodynamics to the composition data. The transfer was found to
… More
accompany the positive entropy and be endothermic.
2 The interfacial tension of the ternary two-phase system of water -nonane- ethylene glycol monobutyl ether(C4E1) was measured as a function of the total mole fraction of C4E1 at siz temperatures under atmospheric pressure. To analyze the experimental results thermodynamically, it was shown that the value should be plotted not against the total mole fraction of C4E1 but against the equilibrium one in the nonane and water phases. It was found that the entropy of adsorption of C4E1 from the nonane phase decreases and that from the water phase increases from the entropy of the pure nonane/water interface formation with increasing the surface density of C4E1. The adsorption was discussed on the basis of the thermodynamic quantities of adsorption and transfer of C4E1 molecules.
3 The dihedral angle of the lens of long chain alcohol at air/water interface was measured by using video microscopy. The phase transition of the interfacial film of alcohol, wetting-nonwetting transition, and the intruding of water phase into air/alcohol interface was observed. Furthermore the dihedral angles were examined by the values of interfacial tension. Less
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