Dynamics of absorbed water in saponite clay: Neutron scattering study

This report concerns measurement of water dynamics associated within the interlamellar region of native saponite and its tridecameric 'Al-13' intercalated polycation, as investigated using the quasielastic neutron scattering technique. The diffusion constant corresponding to the translational motion is found to be much lower as compared to that of bulk water that indicates the water adsorbed in between layers of saponite clays is dynamically hindered. The dynamics is described by a model in which the molecules undergo random jump diffusion. Diffusivity is found to be larger in case of the Al-13 intercalated saponite than native saponite because of the larger interlayer spacings in the former. (c) 2006 Elsevier B.V. All rights reserved.