Supercooled confined water and the Mode Coupling crossover temperature

Abstract

We present a Molecular Dynamics study of the single particle dynamics of supercooled water confined in a silica pore. Two dynamical regimes are found: close to the hydrophilic substrate molecules are below the Mode Coupling crossover temperature, $T_C$, already at ambient temperature. The water closer to the center of the pore (free water) approaches upon supercooling $T_C$ as predicted by Mode Coupling Theories. For free water the crossover temperature and crossover exponent ${\hat{I}}^3$ are extracted from power-law fits to both the diffusion coefficient and the relaxation time of the late $\hat{I}\pm$ region.

To be published, Phys. Rev. Lett., 4 pages, 3 figures, revTeX, minor changes in the figures, references added, changes in the text