Lukas Vlcek, Chemical Engineering, Vanderbilt University, VU Station B 351604, 107 Olin Hall, Nashville, TN 37235, Eugene Mamontov, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6475, David R. Cole, Oak Ridge National Lab, PO Box 2008 MS6110, Oak Ridge, TN 37831, and Peter T. Cummings, Department of Chemical Engineering, Vanderbilt University, Nashville, TN 37235-1604.
Quasielastic neutron scattering (QENS) experiments were used to study water and the aqueous solutions of LiCl and CaCl2 in micro- and mesoporous silicates (MCM 41, SBA 15) over a wide range of thermodynamic conditions from below the water freezing point to above the critical temperature and pressure. The results were interpreted using molecular dynamics simulations and theoretical models, relating water and ion diffusivities to the structure of nanoconfined water in pores of varying sizes and at different salt concentrations. Both pore size and ion concentration were found to have strong influence on the dynamic transitions of water at low temperatures and phase transitions at high temperatures.