Water-based solids called clathrate hydrates are hydrogen bonded water cages that can trap small molecules in a crystal-like structure. The study of clathrate hydrates has useful technological applications. For example, clathrate hydrates are able to capture valuable hydrocarbons from the ocean floor, which can be used as an energy source. Also, because clathrate hydrates cause pipe clogging, clathrate hydrate research can help in the search for clathrate hydrate inhibitors. To gain a better understanding of clathrate hydrates, Ha Eun Samuel Cho '10 (Torrance, Calif.) is examining their properties with Assistant Professor of Chemistry Camille Jones this summer.
Specifically, Cho is looking at propylene oxide-water solutions, which are water soluble in the range when they turn into clathrate hydrates, because propylene oxides have relatively large sized guest molecules that display interesting dynamics inside a water cage. One property of propylene oxide-water solutions that Cho is measuring is their viscosity, or their resistance to flow. To measure and to analyze trends in the viscosity at different temperatures and at different concentrations of propylene oxide-water solutions, Cho uses a viscometer and a constant temperature bath. He has found that the propylene oxide-water solution exhibits a maximum viscosity when it contains 10% propylene oxide. Interestingly, 5.5% propylene oxide-water solutions are in the range of increasing viscosity and density, and the propylene oxide-water ratio is 5.5% propylene oxide when the clathrate hydrates form; therefore, Cho's viscosity measurements suggest that clathrate hydrates form as the attraction between molecules increases.
Another property of the propylene oxide-water solutions that Cho is calculating is their activation energy of viscous flow, or the minimum energy required for the molecules to flow past each other. When a solution has a large activation energy of viscous flow, it means that an attractive force is opposing the flow of molecules. He expects to find a high activation energy of viscous flow when the propylene oxide and water molecules are forming bonds and creating a clathrate hydrate. Cho says that he hopes to combine his data with the findings from other members of Jones's research group in order to increase their understanding of the interaction between propylene oxide and water before the clathrate hydrate forms.
This is Cho's first summer of research at Hamilton. A chemistry major and math minor, Cho is part of Hamilton's 3-2 engineering program. At the end of next year, he will be going to Columbia University to study chemical engineering. Currently, Cho is taking jiu jitsu classes three times a week at Syracuse.
-- by Stephanie Anglin '10
Specifically, Cho is looking at propylene oxide-water solutions, which are water soluble in the range when they turn into clathrate hydrates, because propylene oxides have relatively large sized guest molecules that display interesting dynamics inside a water cage. One property of propylene oxide-water solutions that Cho is measuring is their viscosity, or their resistance to flow. To measure and to analyze trends in the viscosity at different temperatures and at different concentrations of propylene oxide-water solutions, Cho uses a viscometer and a constant temperature bath. He has found that the propylene oxide-water solution exhibits a maximum viscosity when it contains 10% propylene oxide. Interestingly, 5.5% propylene oxide-water solutions are in the range of increasing viscosity and density, and the propylene oxide-water ratio is 5.5% propylene oxide when the clathrate hydrates form; therefore, Cho's viscosity measurements suggest that clathrate hydrates form as the attraction between molecules increases.
Another property of the propylene oxide-water solutions that Cho is calculating is their activation energy of viscous flow, or the minimum energy required for the molecules to flow past each other. When a solution has a large activation energy of viscous flow, it means that an attractive force is opposing the flow of molecules. He expects to find a high activation energy of viscous flow when the propylene oxide and water molecules are forming bonds and creating a clathrate hydrate. Cho says that he hopes to combine his data with the findings from other members of Jones's research group in order to increase their understanding of the interaction between propylene oxide and water before the clathrate hydrate forms.
This is Cho's first summer of research at Hamilton. A chemistry major and math minor, Cho is part of Hamilton's 3-2 engineering program. At the end of next year, he will be going to Columbia University to study chemical engineering. Currently, Cho is taking jiu jitsu classes three times a week at Syracuse.
-- by Stephanie Anglin '10
