TY - JOUR

T1 - Molecular Simulation of Nanoclusters of Gas Hydrates in a Water Shell. The Mechanical State of the System

AU - Brodskaya, E.N.

AU - Sizov, V.V.

PY - 2013

Y1 - 2013

N2 - The molecular dynamics method is employed to study hydrates of methane (sI), and krypton hydrate (sII), as well as an ice nanocluster in a supercooled water shell. The main attention is focused on the local structure and the mechanical state of two-phase nanosized systems, which is described using the local pressure tensor. Analysis of the temperature dependence of the local pressure allows one to compare two possible mechanisms responsible for the anomalous stability of gas hydrates at ambient pressure. According to the first mechanism, the water shell plays the role of a barrier that prevents the gas from escaping from the hydrate core. The second mechanism implies that the water shell generates additional pressure, which transfers the hydrate to a thermodynamically stable state. Results of molecular dynamics simulation indicate that both mechanisms are simultaneously involved in the stabilization of the hydrate nanocluster.

AB - The molecular dynamics method is employed to study hydrates of methane (sI), and krypton hydrate (sII), as well as an ice nanocluster in a supercooled water shell. The main attention is focused on the local structure and the mechanical state of two-phase nanosized systems, which is described using the local pressure tensor. Analysis of the temperature dependence of the local pressure allows one to compare two possible mechanisms responsible for the anomalous stability of gas hydrates at ambient pressure. According to the first mechanism, the water shell plays the role of a barrier that prevents the gas from escaping from the hydrate core. The second mechanism implies that the water shell generates additional pressure, which transfers the hydrate to a thermodynamically stable state. Results of molecular dynamics simulation indicate that both mechanisms are simultaneously involved in the stabilization of the hydrate nanocluster.

KW - Local pressure tensors

KW - Molecular dynamics methods

KW - Molecular dynamics simulations

KW - Molecular simulations

KW - Possible mechanisms

KW - Supercooled water

KW - Temperature dependence

KW - Thermodynamically stable

U2 - 10.1134/S1061933X13030046

DO - 10.1134/S1061933X13030046

M3 - Article

VL - 75

SP - 366

EP - 372

JO - Colloid Journal

JF - Colloid Journal

SN - 1061-933X

IS - 4

ER -