|Budget Amount *help
¥3,200,000 (Direct Cost : ¥3,200,000)
Fiscal Year 1998 : ¥1,100,000 (Direct Cost : ¥1,100,000)
Fiscal Year 1997 : ¥2,100,000 (Direct Cost : ¥2,100,000)
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.