III-1　Dynamics of Confined Water Phase Transition of Supercooled Water

Abstract

The dynamic behavior of low-temperature water confined in MCM-41(pore diameter 2.1nm) is investigated over a temperature range 180 - 298K by quasielastic neutron scattering and neutron spin-echo methods. The relaxation time of capillary condensed water with temperature follows the Vogel-Tamman-Fulcher equation above 222K, but shows the Arrhenius type behavior below 222K, i.e. there is a dynamical crossover at 222K. The relaxation time of monolayer adsorbed water shows only the Arrhenius type behavior. This dynamical crossover corresponds to a structural transition between high density water and low density water in confinement.