Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-17T21:42:41.776Z Has data issue: false hasContentIssue false
  • English
  • Français

Self- diffusion of H2O in stevensite gel: effects of temperature and clay fraction

Published online by Cambridge University Press:  09 July 2018

Y. Nakashima
Y. Nakashima*
Affiliation:
Exploration Geophysics Research Group, National Institute of Advanced Industrial Science and Technology, Central 7, Higashi 1-1-1, Tsukuba, Ibaraki 305-8567, Japan
*
*E-mail: yoshito@aist.go.jp
Get access Rights & Permissions [Opens in a new window]

Abstract

Self-diffusion coefficients of water molecules (1H2O) in Na-stevensite gel were measured by pulsed-gradient spin-echo (PGSE) proton nuclear magnetic resonance (NMR). The effects of clay fraction (0.00 37.7 wt.%) and temperature (20.0 60.3°C) were studied. The results show: (1) phenomenologically, the H2O self-diffusivity in the clay gel, D, is expressed by D/D0 = exp( 0.0198w) where D0 is the H2O self-diffusivity in bulk water of the temperature and wis the clay weight fraction (wt.%). (2) The activation energy of the diffusivity in the stevensite gel is nearly equal to that in bulk water. Thus, the normalized diffusivity, D/D0, obeys a temperature-independent master curve. (3) The exponential dependence of D/D0 on wfor w <25 wt.% (≈ 12 vol.%) can be explained by a random walk model, in which unbound H2O molecules diffuse in the geometrically tortuous pore structure of randomly scattered clay mineral grains. (4) The measured diffusivity can also be explained by a model of unbound H2O diffusing in a polymer network with a specific meshsize or characteristic interval of the crosslinkage.

Keywords

clay gel structureNMRporous mediarandom walkwater molecule
Type
Research Article
Information
Clay Minerals , Volume 37 , Issue 1 , March 2002 , pp. 83 - 91
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Callaghan, P.T. (1991) Principles of Nuclear Magnetic Resonance Microscopy. Oxford University Press, Oxford, UK.CrossRefGoogle Scholar
FejesTóth, L. (1972) Lagerungen in der Ebene, auf def Kugel und im Raum. Springer, Heidelberg, Germany.Google Scholar
Fripiat, J.J., Letellier, M. & Levitz, P. (1984) Interaction of water with clay surfaces. Philoso phical Transactions of the Royal Society of London, Series A, 311, 287–299.Google Scholar
Imai, N., Otsuka, R., Nakamura, T. & Tsunashima, A. (1970) Stevensite from the Akatani Mine, Niigata Prefecture, northeastern Japan. Clay Science, 4, 11–29.Google Scholar
Kleinberg, R.L. & Vinegar, H.J. (1996) NMR properties of reservoir fluids. The Log Analyst, 37, 20–32.Google Scholar
Krynicki, K., Green, C.D. & Sawyer, D.W. (1979) Pressure and temperature dependence of self-diffusion in water. Faraday Discussions of the Chemical Society, 66, 199–208.Google Scholar
Latour, L.L., Mitra, P.P., Kleinberg, R.L. & Sotak, C.H. (1993) Time-dependent diffusion coefficient of fluids in porous media as a probe of surface-tovolume ratio. Journal of Magnetic Resonance, A101, 342–346.Google Scholar
Low, P.F. (1979) Nature and properties of water in montmorillonite-water systems. Soil Science Society of America Journal, 43, 651–658.Google Scholar
Madsen, F.T. (1998) Clay mineralogical investigations related to nuclear waste disposal. Clay Minerals, 33, 109–129.Google Scholar
Mills, R. (1973) Self-diffusion in normal and heavy water in the range 1–45° . Journal of Physical Chemistry, 77, 685–688.Google Scholar
Nakashima, Y. (2000a) Effects of clay fraction and temperature on the H2O self-diffusivity in hectorite gel: A pulsed-field-gradient spin-echo nuclear magnetic resonance study. Clays and Clay Minerals, 48, 603–609.Google Scholar
Nakashima, Y. (2000b) Pulsed-gradient spin-echo NMR study of the H2O self-diffusivity in clay gels. Abstract of the 5th International Meeting on Recent Advance s in Magnet ic Resonance Applications to Porous Media, Bologna, Italy.Google Scholar
Nakashima, Y. (2001) Pulsed field gradient NMR study of the self-diffusion of H2O in montmorillonite gel: Effects of temperature and water fraction. American Mineralogist, 86, 132–138.Google Scholar
Nakashima, Y., Mitsumori, F., Nakashima, S. & Takahashi, M. (1999) Measurement of self-diffusion coefficients of water in smectite by stimulated echo 1H nuclear magnetic resonance imaging. Applied Clay Science, 14, 59–68.CrossRefGoogle Scholar
Netz, P.A. & Dorfmüller, T. (1997) Computer simulation studies of diffusion in gels: Model structures. Journal of Chemical Physics, 107, 9221–9233.Google Scholar
Randall, B.A.O. (1959) Stevensite from the Whin sill in the region of the North Tyne. Mineralogical Magazine, 32, 218–225.CrossRefGoogle Scholar
Seitz, M.G., Wogelius, R.A. & Flower, M.F. (1987) Nuclear waste elements slip through hydrothermally altered basalt. Chemical Geology, 64, 109–119.Google Scholar
Stejskal, E.O. & Tanner, J.E. (1965) Spin diffusion measurements: Spin echos in the presence of a timedependent field gradient. Journal of Chemical Physics, 42, 288–292.Google Scholar
Tokita, M., Miyoshi, T., Takegoshi, K. & Hikichi, K. (1996) Probe diffusion in gels. Physical Review E, 53, 1823–1827.Google Scholar
Trinh, S., Arce, P. & Locke, B.R. (2000) Effective diffusivities of point- like molecules in isotropic porous media by Monte Carlo simulat ion. Transport in Porous Media, 38, 241–259.CrossRefGoogle Scholar
Yu, J.W. & Neretnieks, I. (1997) Diffusion and sorption properties of radionuclides in compacted bentonite. SKB Technical Report (Swedish Nuclear Fuel and Waste Management Co.) 97-12, 1–98.Google Scholar
Yong, R.N. (1999) Overview of modeling of clay microstructure and interactions for prediction of waste isolation barrier performance. Engineering Geology, 54, 83–91.Google Scholar