Molecular mobility in carbon dioxide hydrates

Abstract

Gas hydrates are at the center of current materials research due to their critical importance to the environment and energy supply, and further progress requires knowledge of their mechanical properties. In this work we use molecular dynamics to study the molecular mobility in carbon dioxide hydrates. Specifically, the influences of induced vacancy defects and changes in composition on diffusion coefficients were studied. Introducing few water vacancy defects and a 3% change in cage occupancy changed the diffusion coefficient by almost two orders of magnitude and a factor of four, respectively. The diffusion coefficient of the water molecules was also influenced but to a much lesser extent.