Study on Compressed Fluids in the Critical Region
Grant-in-Aid for Scientific Research (C).
|Research Institution||Osaka University|
OHGAKI Kazunari Osaka Univ., Faculty of Eng. Sci., 基礎工学部, 助手 (80107078)
|Project Fiscal Year
1989 – 1990
Completed(Fiscal Year 1990)
|Budget Amount *help
¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1990 : ¥600,000 (Direct Cost : ¥600,000)
|Keywords||Thermo-dynamical ropoerties / Critical state / Phase behavior / Super-critical fluid / Fine particle / Solution structurd / Solubility / Cluster / 熱力学物性 / 臨界 / 高圧相挙動 / 超臨界流体 / 微粒子 / 溶液構造 / 溶解度 / 分子集団 / 密度ゆらぎ / 臨界流体 / スケ-リング則 / 超臨界流体抽出 / 超微粒子 / 臨界異常 / 高圧相平衡|
This project consists of the following subprojects.
Pressure-Density-Temperature Relations in the Critical Region
The pressure-density-temperature relation were determined for CHF_3, N_2O, and C_3H_6 by means of a direct method. The critical properties were determined from a logarithmic plot based on the power law for each system. The restricted linear model, one of the simplest scaled equation of state, was applied to describe thermodynamic relations in the critical region.
Substituent Effect on Solubilities of Solid in Super-critical Fluids
One of the interesting findings is that a di-substitution does not always show the depression in solubilities of each mono-substituted derivatives. The substituent effect on solubilities was discussed by use of electronic properties of substituents. The empirical principles of solubility changes have been drawn out from experimental results. Finally, the empirical rules in choosing appropriate super-critical solvents have been itemized in terms of fiv
Solute clusters in aqueous solutions
The density gradients observed in supersaturated solutions can be expressed satisfactorily by use of a theoretical model based on the Brownian diffusion equation for solute clusters under gravity. Electron microscopy also strongly suggests the existence of solute clusters in supersaturated solutions. The cluster size was estimated to be about 16 nm in diameter.
Whisker formation from jet of supercritical fluid solution
The growth mechanism of a whisker of stigmasterol particles deposited by rapid expansion from supercritical CO_2 solutions has been investigated by scanning electron microscope. Amorphous fine particles were found to be under relatively low pre-expansion pressures while whisker-like crystals were observed under relatively high pre-expansion pressures. It was found that the secondary products grew on a screen in the expansion jet after deposition of primary particles of about 15 nm diameter. The morphology of secondary products was found to strongly depend on the surface condition of the primary particle. Less
Research Output (21results)