A Computer Simulation and Investigation of Liquid-Solid Interfacial Phenomena for Ice and Clathrate Hydrates

Molecular dynamics has been employed to model the interface between liquid water and ice, liquid water and Structure I clathrate hydrates, and liquid water and Structure II clathrate hydrates. It has been found that the interfacial behavior between liquid water and ice and liquid water and hydrate crystal are qualitatively similar to each other and span a region of several molecular diameters on either side of the interface. Orientational and translational motion in the liquid is more vibrational in the interfacial region while temperature profiles are uniform across the interface. In addition, there was little tendency in any of the systems for the molecules in the liquid near the interface to arrange themselves in a more lattice-like structure. The exception to this was the hydration effect associated with exposed hydrocarbon molecules at the hydrate-water interface. The center of mass positions of molecules in the solid near the interface were somewhat perturbed.