However, using neutrons at IPNS, Argonne researchers were able to observe the rates, or kinetics, of the formation of carbon-dioxide hydrates from ice. By performing this measurement at several different temperatures, the Argonne scientists were able to determine the amount of energy needed to activate this process. Scientists used liquid nitrogen to freeze deuterated water, water made with an isotope of hydrogen containing one proton and one neutron in its nucleus, instead of regular hydrogen which contains only a proton. Plain hydrogen causes interference in the instrument they used. Under a barrage of neutrons, carbon dioxide gas was piped into the sample cell under high pressure.
Neutrons are uncharged particles found in nearly all matter.
When used to penetrate materials, neutrons reveal structural and dynamic properties that can provide scientists with a better understanding of the physics that control the material's behavior. This understanding can help scientists develop new materials with improved properties. Unlike X-rays and other forms of light, neutrons penetrate both the aluminum cell and the ice crystals, providing a series of snapshots as the ice restructured itself around the carbon dioxide molecules. The data hint at the mechanism by which the water molecules arrange themselves around the carbon dioxide molecules. Future projects include varying the ice grain size, pressures and type of gas molecules.