A simulation study of the kinetics of passage of CO2 and N2 through the liquid/vapor interface of water

Abstract

A spectroscopic study of the fullerene/metal interface in C 60 -Al multilayers AIP Conf. Proc. 442, 265 (1998) The rate of passage of molecules of carbon dioxide and nitrogen through the vapor-liquid interface of water at 300 K is studied by simulation. Previous work has established the form of the free energy profile which has a minimum when the solute molecule is on the surface and a barrier between this state and solution in the bulk liquid. In one set of simulations, trajectories were initiated in the gas phase. From these, the average lifetime of molecules in the surface is determined to be considerably longer than the inverse of the energy relaxation rate, so that the sticking coefficient is one and exiting molecules have no memory of their original velocities. However, most molecules do return to the gas phase rather than entering the bulk solution. The rate of passage of molecules over the free energy barrier is studied using the reactive flux method with trajectories initiated near the top of the barrier. The results for nitrogen, in particular, give a good plateau in the time-dependent transmission coefficient and hence a reliable rate constant. The results from these two sets of simulations are combined to give an effective interface width which is used to determine the permeability of thin water films. These results are compared to experimental permeabilities of thin Newton black soap films. The rate-determining step for solution in bulk water is not passage through the few Å ngstroms width of the interface we study, but rather the transport from the vicinity of the interface into the bulk over the larger distance scale of m.

Liquid–Solid Boundaries Dominate Activity of CO2 Reduction on Gas-Diffusion Electrodes

“…Using known energetics of CO2 molecules near the liquid surface, density functional theory (DFT) 51,52 and molecular dynamics (MD) simulations 69 can describe the CO2-water interaction.…”

A multi-scale perspective of gas transport through soap-film membranes

“…The choice of SPC/E was dictated by the fact that it has been already successfully implemented for reproducing the co-existence of liquid H 2 O and gaseous CO 2 . 23 In addition, the SPC potential accurately reproduces thermodynamic properties such as the second virial coefficient, enthalpy of vaporization and the surface tension of the air-water interface. 24 Periodic boundary conditions are applied in the x, y and z directions with a vacuum buffer of 215 Å between the two surfactant layers.…”

Molecular Dynamics Simulation Study on the Growth of Structure II Nitrogen Hydrate

“…In the N 2 2CLJQ force field, two Lennard-Jones sites with negative charges are placed at the atom position while a massless positive charge is placed at the center of the N–N bond where the N–N bond distance is 0.11 nm. These models for H 2 O and N 2 models have been successfully used to study the structure and mobility of dilute solutions of N 2 in water . Force field parameters for H 2 O and N 2 potential models mentioned above are given in Table .…”

“…These models for H 2 O and N 2 models have been successfully used to study the structure and mobility of dilute solutions of N 2 in water. 36 Force field parameters for H 2 O and N 2 potential models mentioned above are given in Table 1. The cross-interactions between different species are calculated by the standard Lorentz−Berthelot combining rules.…”