Dynamical Crossover in Hot Dense Water: The Hydrogen Bond Role
Authors: Ranieri U., Giura P., Gorelli F., Santoro M., Klotz S., Gillet P., Paolasini L., Koza MM., Bove LE.
Autors Affiliation: Ecole Polytech Fed Lausanne, ICMP, EPSL, Stn 3, CH-1015 Lausanne, Switzerland; Inst Laue Langevin, 71,Ave Martyrs,BP 156, F-38042 Grenoble 9, France; Univ Paris 06, CNRS, UMR 7590, Inst Mineral Phys Mat & Cosmochim, 4 Pl Jussieu, F-75252 Paris, France; CNR, INO, Via N Carrara 1, I-50019 Sesto Fiorentino, Italy; LENS, European Lab Non Linear Opt, Via N Carrara 1, I-50019 Sesto Fiorentino, Italy; ESRF, 71,Ave Martyrs,CS 40220, F-38043 Grenoble 9, France
Abstract: We investigate the terahertz dynamics of liquid H2O as a function of pressure along the 450 K isotherm, by coupled quasielastic neutron scattering and inelastic X-ray scattering experiments. The pressure dependence of the single molecule dynamics is anomalous in terms of both microscopic translation and rotation. In particular, the Stokes-Einstein-Debye equations are shown to be violated in hot water compressed to the GPa regime. The dynamics of the hydrogen bond network is only weakly affected by the pressure variation. The time scale of the structural relaxation driving the collective dynamics increases by a mere factor of 2 along the investigated isotherm, and the structural relaxation strength turns out to be almost pressure independent. Our results point at the persistence of the hydrogen bond network in hot dense water up to ice VII crystallization, thus questioning the long-standing perception that hydrogen bonds are broken in liquid water under the effect of compression.9051
Journal/Review: JOURNAL OF PHYSICAL CHEMISTRY B
Volume: 120 (34) Pages from: 9051 to: 9059
KeyWords: NEUTRON-SCATTERING SPECTRA; STOKES-EINSTEIN RELATION; LIQUID WATER; PRESSURE-DEPENDENCE; MOLECULAR-DYNAMICS; TRANSITION; RELAXATION; VISCOSITY; BEHAVIOR; MOTIONSDOI: 10.1021/acs.jpcb.6b04142Citations: 10data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2021-10-17References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here