H2O and Cation Structure and Dynamics in Expandable Clays: 2H and 39K NMR Investigations of Hectorite

The dynamic behavior of H2O and ionic species in two- and three-dimensional confinement plays a variety of important roles in processes such as ion transport and adsorption, water storage in hostile environments, dissolution/precipitation reactions in aqueous environments, and the swelling of smectite clays (low charge 2:1 type phyllosilicates with expandable interlayers). Historically, the structure and dynamics of ions and water in confined spaces and at solid-fluid interfaces have been difficult to characterize on the molecular scale, but the continued evolution of molecular modeling, neutron scattering, and nuclear magnetic resonance (NMR) spectroscopy has permitted ever more detailed theoretical and experimental investigations, particularly regarding the special case of H2O in the two-dimensional, nanometer-scale interlayer space of phyllosilicates