1998 Fiscal Year Final Research Report Summary
The Molecular Dynamics Study of the Molecular Structure of Highly Concentrated Aqueous Solution and the Control of Crystallization
| Project/Area Number |
09650225
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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 |
Thermal engineering
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| Research Institution | the University of Tokyo |
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Principal Investigator |
HIHARA Eiji The Univ.of Tokyo, Dept.of Eng., Associate Professor, 大学院・工学系研究科, 助教授 (00156613)
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| Co-Investigator(Kenkyū-buntansha) |
DAIGUJI Hirofumi The Univ.of Tokyo Dept.of Eng., Research Associate, Assistant, 大学院・工学系研究科, 助手 (10302754)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Molecular Dynamics / Aqueous electrolyte Solution / Vapor-liquid interface / Solubility / Pressure depression / Crystallization / Absorption / EXAFS |
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| Research Abstract |
The objectives of this study are to clarify the molecular structure of the highly concentrated aqueous electrolyte solution and to explain the macroscopically measured properties, such as solubility or pressure drop, on a molecular level using molecular dynamics simulation. As for liquid computer simulation, in the case of simple liquid, say liquid noble gases, where interactions between particles are well known, the results derived from the simulation deserve high degree of reliability. On the other hand, in the case of complicated liquid, which have not yet been treated analytically. They can predict the properties of liquid which cannot or not directly be measured and at the same time various tests of reliability are required. The contents and results are as follows.
1. Comparison between J4D calculation and EXAFS analysis about molecular structure
In the mixture of aqueous electrolyte solutions, such as LiBr & KBr, the structure around Br was investigated. The calculation results using simplified pair potentials well agree with experimental ones. Even with a simplified potential, molecular dynamics simulation gives quantitative structural features.
2. Prediction of the macroscopically measured properties
When the concentration of a solution is over the solubility, the computational domain in which both vapor and liquid exist is effective. Because the pressure of the system is the same to the saturation vapor pressure, the control of pressure is not needed. The properties of a solution surface, such as density profile or surface tension, were calculated and the pressure drop was estimated.
3. The MD simulation of absorption process and crystallization process The state of the solution surface during water vapor absorption and the effects of the non-equilibrium state on absorption rate were investigated. The simulation of a crystallization process is the next theme.
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Research Products
(9 results)
