The diffusion of interlamellar water in the 23.3 A Na-montmorillonite: pyridine/H20 intercalate by quasielastic neutron scattering

Abstract The diffusion of water in the title intercalate has been measured by quasielastic neutron scattering. The diffusion coefficient (6.1 • 10-T cm 2 s-t at 23.5 ~ is one order less than that found previously for a sodium-exchanged montmo-rillonite which, however, contained 4 times as much water in the interlamellar space. The activation energy for the motion has been deduced to be 18 kJ mo1-1. Also it has been demonstrated that upon the time scale of the neutron scattering events (faster than 10- ~ s) the hydroxyl groups of the clay lattice are not in motion