title: Homogeneous Nucleation of Methane Hydrate in Microsecond Molecular Dynamics Simulations.
abstract: We report atomistically detailed molecular dynamics simulations of homogeneous nucleation of methane hydrate in bulk aqueous phase in the absence of any interface. Subcritical clusters of water and methane molecules are formed in the initial segment of the simulations, which then aggregate to give the critical hydrate nucleus. This occurs over time scales of several hundred nanoseconds, indicating that the formation and aggregation of subcritical clusters can contribute significantly to the overall rate of hydrate nucleation. The clusters have elements of sI hydrate structure, such as 5(12) and 5(12)6(2) cages as well as other uncommon 5(12)6(3) and 5(12)6(4) cages, but do not possess long-range order. Clusters are dynamic in nature and undergo continuous structural rearrangements.
authors: †Department of Chemical and Biomolecular Engineering, Clemson University, Clemson, South Carolina 29634, United States.|‡Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States.
authors: Sapna
authors: S
authors: Sarupria
authors: ‡Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States.
authors: Pablo G
authors: PG
authors: Debenedetti
keywords: cages; clathrates; clusters; structure; water