Gallo, Paola; Rovere, Mauro; Spohr, Eckhard:

Supercooled Confined Water and the Mode Coupling Crossover Temperature

In: Physical review letters : PRL ; providing rapid publication of short reports of important fundamental research with coverage of major advances in all aspects of physics and of developments with significant consequences across subdisciplines, Jg. 85 (2000) ; Nr. 20, S. 4317-4320
ISSN: 0031-9007
Zeitschriftenaufsatz / Fach: Chemie
Fakultät für Chemie
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, TC, already at ambient temperature. The water closer to the center of the pore (free water) approaches upon supercooling TC as predicted by mode coupling theories. For free water the crossover temperature and crossover exponent γ are extracted from power-law fits to both the diffusion coefficient and the relaxation time of the late α region.