Abstract
The thermodynamic properties of porewater in sandstone were obtained as a function of water content and temperature by vapor pressure method. The activity, the relative partial molar Gibbs free energy (ΔG H2O). the relative partial molar enthalpy (ΔH H2O) and the relative partial molar entropy (ΔS H2O) of the porewater were determined at 298.15 K. The activity decreased with decreasing water content in the region where water content is about 1.5%, and drastically decreased in the region where water content is about 0.5%. No clear dependencies of ΔH H2O and ΔS H2O on water content were found. Synthesizing the correlations of the activity, ΔG H2O, ΔH H2O and ΔS H2O with water content and the enthalpy and entropy of fusion for ice, the porewater at the surface of the solid was found to have a low chemical potential compared with free water, and dissimilar with the structure of ice. Correlating the activity and ΔG H2O with water content, the specific surface area of sandstone and the porosity, the porewater is deduced to be weakly affected up to a distance of approximately 3 nm from the surface of the solid. However, as the porewater approaches a distance of approximately 1.1 nm from the solid surface, the effect from the solid surface abruptly becomes strong. This is deduced to be the effects of hydrogen bond at the solid surface and hydration to cations corresponding to the CEC.
| Original language | English |
|---|---|
| Pages (from-to) | 368-377 |
| Number of pages | 10 |
| Journal | Journal of Nuclear Science and Technology |
| Volume | 42 |
| Issue number | 4 |
| Publication status | Published - Apr 2005 |
| Externally published | Yes |
Fingerprint
Keywords
- Activity
- Enthalpy
- Entropy
- Geological disposal
- Gibbs free energy
- Porewater
- Radioactive waste
- Sandstone
- Thermodynamics
- Vapor pressure
ASJC Scopus subject areas
- Nuclear Energy and Engineering
Cite this
Measurements on the thermodynamic properties of porewater in sandstone by vapor pressure method. / Sato, Haruo.
In: Journal of Nuclear Science and Technology, Vol. 42, No. 4, 04.2005, p. 368-377.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Measurements on the thermodynamic properties of porewater in sandstone by vapor pressure method
AU - Sato, Haruo
PY - 2005/4
Y1 - 2005/4
N2 - The thermodynamic properties of porewater in sandstone were obtained as a function of water content and temperature by vapor pressure method. The activity, the relative partial molar Gibbs free energy (ΔG H2O). the relative partial molar enthalpy (ΔH H2O) and the relative partial molar entropy (ΔS H2O) of the porewater were determined at 298.15 K. The activity decreased with decreasing water content in the region where water content is about 1.5%, and drastically decreased in the region where water content is about 0.5%. No clear dependencies of ΔH H2O and ΔS H2O on water content were found. Synthesizing the correlations of the activity, ΔG H2O, ΔH H2O and ΔS H2O with water content and the enthalpy and entropy of fusion for ice, the porewater at the surface of the solid was found to have a low chemical potential compared with free water, and dissimilar with the structure of ice. Correlating the activity and ΔG H2O with water content, the specific surface area of sandstone and the porosity, the porewater is deduced to be weakly affected up to a distance of approximately 3 nm from the surface of the solid. However, as the porewater approaches a distance of approximately 1.1 nm from the solid surface, the effect from the solid surface abruptly becomes strong. This is deduced to be the effects of hydrogen bond at the solid surface and hydration to cations corresponding to the CEC.
AB - The thermodynamic properties of porewater in sandstone were obtained as a function of water content and temperature by vapor pressure method. The activity, the relative partial molar Gibbs free energy (ΔG H2O). the relative partial molar enthalpy (ΔH H2O) and the relative partial molar entropy (ΔS H2O) of the porewater were determined at 298.15 K. The activity decreased with decreasing water content in the region where water content is about 1.5%, and drastically decreased in the region where water content is about 0.5%. No clear dependencies of ΔH H2O and ΔS H2O on water content were found. Synthesizing the correlations of the activity, ΔG H2O, ΔH H2O and ΔS H2O with water content and the enthalpy and entropy of fusion for ice, the porewater at the surface of the solid was found to have a low chemical potential compared with free water, and dissimilar with the structure of ice. Correlating the activity and ΔG H2O with water content, the specific surface area of sandstone and the porosity, the porewater is deduced to be weakly affected up to a distance of approximately 3 nm from the surface of the solid. However, as the porewater approaches a distance of approximately 1.1 nm from the solid surface, the effect from the solid surface abruptly becomes strong. This is deduced to be the effects of hydrogen bond at the solid surface and hydration to cations corresponding to the CEC.
KW - Activity
KW - Enthalpy
KW - Entropy
KW - Geological disposal
KW - Gibbs free energy
KW - Porewater
KW - Radioactive waste
KW - Sandstone
KW - Thermodynamics
KW - Vapor pressure
UR - http://www.scopus.com/inward/record.url?scp=20944444419&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=20944444419&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:20944444419
VL - 42
SP - 368
EP - 377
JO - Journal of Nuclear Science and Technology
JF - Journal of Nuclear Science and Technology
SN - 0022-3131
IS - 4
ER -