Irradiation effect of gas-hydrate cluster ions on solid surfaces

Abstract

In our newly developed gas-hydrate cluster ion source, a vapor of water bubbling with carbon dioxide (CO2) gas was ejected through a nozzle into a vacuum region, and mixed beams of water clusters and carbon dioxide-hydrate clusters were produced by adiabatic expansion. According to time-of-flight measurements, the largest water clusters consisted of approximately 2800 molecules at a vapor pressure of 0.3 MPa. Also, the largest mixed clusters contained approximately 2000 molecules. Copper and silicon substrates were irradiated by the water cluster ions as well as carbon dioxide-hydrate cluster ions. X-ray photoelectron spectroscopy measurements showed that carbon was included in the Cu and Si substrates irradiated by the carbon dioxide-hydrate cluster ions, and a chemical shift owing to the formation of carboxyl radicals occurred on the Cu surface. Furthermore, the Cu surface was sputtered, and the sputtering depth was larger than the distance penetrated by the water cluster ion irradiation. Therefore, the formation of carboxyl radicals played an important role in the sputtering of the Cu surface, which occurred effectively in carbon dioxide-hydrate cluster ion irradiation.

Nanocluster Ions and Beam Techniques for Material Modification

“…The inclusion of gas molecules into water cluster cages with a specific number of cluster sizes could be performed by introducing gas into liquid water for the cluster formation. In the previous study, water vapor mixed with methane or carbon dioxide gas was ejected through a nozzle into a vacuum region, and the gas-hydrate clusters were produced by adiabatic expansion [38,39].…”

Crystal Structure and Accelerated Ion-Irradiation Effect of Water Clusters

“…Gas hydrates, also known as clathrate hydrates, are crystalline compounds consisting of both water and gas molecules like methane [19,20]. Gas hydrates exhibit many features that are useful for a number of applications such as flow assurance, safety, energy recovery, gas storage or transportation, and climate change mitigation [21,22]. A vapor of waters bubbling with methane gas was ejected through a nozzle into a vacuum region, and mixed beams of water clusters and methane-hydrate clusters were produced by adiabatic expansion.…”

Mesenchymal Stem Cell Adhesion on Metal and Polymeric Surfaces Modified by Oxygen Cluster Ion Irradiation

“…Cluster ion beams have several advantages for material surface modification [10][11][12][13]. For example, high-density irradiation enhances the surface temperature of the impact region, which enhances the chemical reactions occurring on the surface.…”