Water dynamics in controlled pore silica glasses

Water in porous silica glass is a suitable system for investigating the eff ect of confinement on translational diffusion. These systems are important because of their relevance in catalytic and separation processes. Here quas i-elastic neutron scattering experiments at room temperature on water-fille d controlled-pore glasses with radius of 15, 24 and 32 Angstrom, are presen ted and analyzed using the random-jump diffusion model. Both the average re sidence time and the mean jump distance increase with decreasing pore radiu s.