1995 Fiscal Year Final Research Report Summary
INFRARED STUDY OF FLUID MIXTURES AT HIGH-TEMPERATURE AND HIGH-PRESSURE
Project/Area Number |
06640639
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
Physical chemistry
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Research Institution | HOKKAIDO UNIVERSITY |
Principal Investigator |
IKAWA Shun-ichi Hokkaido University, Graduate School of Science, Professor, 大学院理学研究科, 教授 (90001841)
|
Project Period (FY) |
1994 – 1995
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Keywords | WATER / BENZENE / HEXANE / HIGH-TEMPERATURE-HIGH-PRESSURE / INFRARED / HYDROGEN BOND |
Research Abstract |
The purpose of this study is to investigate molecular-level mixing of water with hydrocarbons such as benzene and hexane by infrared spectroscopy. [Experimental setup] the high-temperature and high-pressure infrared cell was made by the following specifications. Material of the cell body : Nimonic Alloy 80A ; working pressure/temperature : 1000 bar/400゚C ; Effective opening : 6 mm ; total length : 100 mm ; heater : electric heating jackets ; windows material : colorless sapphire ; temperature measurement of specimens : thermocouple. A syringe pump for liquid chromatography was used for introducing organic liquid into the cell and pressurising it. [Experimental results and summary] OH and OD stretching infrared absorptions of H_2O and HDO dissolved in benzene, hexane, and cyclohexane were measured at temperatures in the 373-573 K range and at pressures in the 1-400 bar range. In the every hydrocarbons mentioned above, absorption intensity of water increased with increasing temperature, which indicates how the water solubility increased. In benzene, the absorption at low temperature was mostly assigned to monomeric water molecules, but with the increase in water solubility a broad band assigned to dimeric water grew remarkably. This fact indicates that the effect of the mass action is superior to the entropy effect which prefer the monomer to the dimer, owing to the rapid increase in water concentration with increasing temperature. the relative ratio of the dimers to the monomers in hexane and cyclohexane was larger than that in benzene at the same temperature and pressure. This fact seems to be related to the fact that the water solubility in hexane and cyclohexane is smaller than in benzene.
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