Clathrate hydrates are semi-stable crystalline phases of water found deep in the Earth’s oceans and in the permafrost in polar regions of our planet. This crystalline structure of the ice forms cages, channels, and pores that entrap small, non-polar molecules such as carbon dioxide and methane.
Hydrates are an unusual material because they are an example of a phase of water stabilized by the presence of the hydrophobic guest molecules. Furthermore, clathrate hydrates naturally contain greenhouse gases. As clathrate hydrates melt due to global warming, more greenhouse gas molecules will be released into the atmosphere or dissolved into the ocean.
We are interested in understanding the interactions between the water cage and the entrapped molecules on the molecular length scale. Our research focuses on fundamental science questions about the energetics of these systems.
Central Research Questions:
- What is the extent to which clathrate hydrates behave like a host-guest systems?
- Quantitatively describe how the host (water) and the guest (greenhouse gases) interact with each other. Why does the rule of like-dissolves-like seem to not apply?
- How do the wave and particle natures of the guest molecule affect the properties of clathrate hydrates?
- How do the inter- and intramolecular motions appear in vibrational spectroscopy?
These research questions can be addressed by building mathematical models (theoretical chemistry) and simulating molecular motions (computational chemistry). Electronic structure software such as Gaussian is used to calculate the inter- and intra-molecular interactions and ultimately to build a potential energy surface. A computer algorithm called Diffusion Monte Carlo is used to explore the potential energy surface and determine the nuclear wavefunction. Molecular dynamics calculations are used to understand the classical dynamics of large crystal structures of the clathrate hydrates.
Jordyn has included a short video of the diffusion Monte Carlo algorithm on her webpage.