Translational diffusion of water in compacted clay systems
Laboratory for Waste Management, Paul Scherrer Institut, 5232 Villigen, Switzerland
2 Physical Chemistry, Saarland University, 66123 Saarbrücken, Germany
3 Laboratory for Neutron Scattering, Paul Scherrer Institut, 5232 Villigen, Switzerland
4 Institute of Geological Sciences, University of Bern, 3012 Bern, Switzerland
The translational diffusion of water in compacted clays at a high hydration level has been investigated by quasielastic neutron scattering at a time-of-flight spectrometer FOCUS (SINQ). Four compacted clays with systematic structural differences have been studied: Na-montmorillonite, Na-illite, kaolinite and pyrophyllite. The QENS experiments were performed using two different incident wavelengths in order to access a larger Q range and verify the data analysis. The translational diffusion coefficient for water in Na-montmorillonite and Na-illite are lower than those for bulk water, whereas the preliminary results for kaolinite and pyrophyllite show larger diffusion coefficient.
© EDP Sciences, Springer-Verlag, 2007