By a News Reporter-Staff News Editor at Science Letter -- Current study results on Nanoscopy have been published. According to news reporting out of Brisbane, Australia, by NewsRx editors, research stated, "Interfacial gas enrichment (IGE) covering the entire area of hydrophobic solid water interface has recently been detected by atomic force microscopy (AFM) and hypothesized to be responsible for the unexpected stability and anomalous contact angle of gaseous nanobubbles and the significant change from DLVO to non-DLVO forces. In this paper, we provide further proof of the existence of IGE in the form of a dense gas layer (DGL) by molecular dynamic simulation."
Our news journalists obtained a quote from the research from the University of Queensland, "Nitrogen gas adsorption at the water graphite interface is investigated using molecular dynamic simulation at 300 K and 1 atm normal pressure. The results show that a DGL with a density equivalent to a gas at pressure of 500 atm is formed and equilibrated with a normal pressure of 1 atm. By varying the number of gas molecules in the system, we observe several types of dense gas domains: aggregates, cylindrical caps, and DGLs. Spherical cap gas domains form during the simulation but are unstable and always revert to another type of gas domain. Furthermore, the calculated surface potential of the DGL-water interface, -17.5 mV, is significantly closer to 0 than the surface potential, -65 mV, of normal gas bubble-water interface. This result supports our previously stated hypothesis that the change in surface potential causes the switch from repulsion to attraction for an AFM tip when the graphite surface is covered by an IGE layer. The change in surface potential comes from the structure change of water molecules at the DGL-water interface as compared with the normal gas-water interface. In addition, the contact angle of the cylindrical cap high density nitrogen gas domains is 141 degrees."
According to the news editors, the research concluded: "This contact angle is far greater than 85 degrees observed for water on graphite at ambient conditions and much closer to the 150 degrees contact angle observed for nanobubbles in experiments."
For more information on this research see: Origin of Interfacial Nanoscopic Gaseous Domains and Formation of Dense Gas Layer at Hydrophobic Solid-Water Interface. Langmuir, 2013;29(49):15266-15274. Langmuir can be contacted at: Amer Chemical Soc, 1155 16TH St, NW, Washington, DC 20036, USA. (American Chemical Society - www.acs.org; Langmuir - www.pubs.acs.org/journal/langd5)
Our news journalists report that additional information may be obtained by contacting H. Peng, University of Queensland, Sch Chem Engn, Brisbane, Qld 4072, Australia. Additional authors for this research include G.R. Birkett and A.V. Nguyen (see also Nanoscopy).
Keywords for this news article include: Carbon, Brisbane, Graphite, Minerals, Nanoscopy, Nanotechnology, Emerging Technologies, Australia and New Zealand
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