Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 2000-2004  (4)
Source
Material
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Structure and dynamics of ice Ih films upon HCl adsorption between 190 and 270 K. II. Molecular dynamics simulations (2002)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 116 (2002), S. 5150-5157 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Classical molecular dynamics simulations are carried out between 190 and 250 K on an ultrathin ice film doped by HCl deposition with a coverage varying from 0.3 to 1.0 monolayer. These conditions are similar to those defined in the experiments described in the companion paper. Within the assumption that the hydracid molecule remains in its molecular form, the order parameters and the diffusion coefficients for the H2O molecules are determined in the HCl doped ice film, and compared to the experimental data. The residence times of HCl at the ice surface are also calculated. Below 200 K, the HCl molecules are found to remain localized at the ice surface, while above 200 K, the HCl diffusion inside the film is easy and leads to a strong disorder of the ice structure. Although the formation of hydrates cannot be interpreted by the present calculations, the lowering of the ice melting temperature by 15 K measured in neutron experiments for an HCl doped ice film is qualitatively explained by simulation results. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1454991
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The passage of small molecules through a water film supported by MgO(100): Transfer times from molecular dynamics simulations (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 113 (2000), S. 1184-1193 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The passage of small pollutant molecules (HCl, CO2) through a thin water film supported on a MgO substrate at 300 K has been studied by constrained classical molecular dynamics simulations. The calculated free energy profile of the pollutants exhibits two minima, one at the gas/liquid film interface, and the other inside the film near the ionic substrate. Lifetimes of the pollutants in these two sites have been characterized by unconstrained simulations. The residence times in these sites are in the range of a few tens of picoseconds. The transfer times from one site to the other, and the times spent by the pollutants in the liquid and at the liquid/gas interface (∼ one hundred ps) are always twice longer for CO2 than for HCl. This difference is interpreted in terms of correlated dynamics of HCl and H2O due to hydrogen bond interactions with water. The duration of the hydrogen bond Cl–H⋅⋅⋅O increases significantly (∼2 ps) at the film surface with respect to its value inside the film (〈1 ps). © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.481897
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Adsorption of acetone molecules on proton ordered ice. A molecular dynamics study (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 9898-9908 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The adsorption of acetone molecules on a proton ordered ice Ih(0001) surface was studied using classical molecular dynamics simulations between 50 and 150 K. At low coverage, we show that acetone molecules form an ordered monolayer on this ice surface, which is stable for T≤100 K. At higher temperature, it exhibits orientational disordering, though local translational order remains. Preliminary simulations at higher coverage indicates the formation of additional ordered layers above the first monolayer, which are also stable below 100 K. These results support previous conclusions on the acetone/ice interactions based on the interpretation of experimental data. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.481627
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Dynamics of ice layers deposited on MgO(001): Quasielastic neutron scattering experiments and molecular dynamics simulations (2001)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 114 (2001), S. 6371-6381 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The dynamical behavior of a thin film of ice Ih deposited on MgO(001) surface has been investigated both experimentally and theoretically. Incoherent neutron quasielastic scattering experiments, using uniform MgO powders, show that a quasiliquid water layer of monolayer thickness exists at T=265 K. The translational mobility of this layer, with a diffusion coefficient Dt=1.5×10−5 cm2 s−1, is close to that of liquid water. At T=270 K, the thickness of the quasiliquid layer increases to about two layers, showing no appreciable change in the Dt value but an increase of the rotational mobility from 6×109 s−1 to 1.2×1010 s−1. Classical molecular dynamics simulations are performed to determine the translational and orientational order parameters and diffusion coefficients of the supported ice film as a function of temperature within 190 and 270 K, and to compare the results with those obtained for bulk ice. It is shown that the whole supported ice film is much more disordered than bulk ice, with melting temperature around 235 K for the TIP4P potential used, while the melting temperatures of the outermost layer are nearly the same (around 220 K) for the supported film and bulk ice. Comparison of the values of the translational and orientational diffusion coefficients obtained in simulation and experiments displays a good agreement. Although the calculated value of the surface melting temperature is underestimated by 15% with respect to the experimental result, the present study indicates clearly the influence of the support on the melting process. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1355238
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...