Abstract:
Liquid water under ambient conditions always contains a small amount of gas. Gas in water is a general and fundamental phenomenon. Despite of numerous theoretical and experimental studies for decades, there remain many scientific puzzles about gas in water, such as nucleation of gas bubbles in water. Recent studies have indicated that air gases dissolved in water tend to enrich at the interfaces between hydrophobic solids and water and form several types of gas-containing structures. It remains challenging to explain the observations on these structures. Due to the very low solubility of gas molecules in water, it has been theoretically assumed that gas molecules are well dispersed as monomers and that the concentration of gas molecules at a given time and position is sufficient to describe the gas condition in water. Recent studies reveal that gas molecules may form microscopic structures in water when gas concentration is above the saturation level (super-saturated). I will review some of the issues related to gases in water and at solid-water interfaces and present new experimental evidence that hopefully will lead to new understanding.
Brief Bio:
Ing-Shouh Hwang completed his PhD degree in 1993 from Harvard University. He joined the Institute of Physics, Academia Sinica in 1994 and is currently a Research Fellow. He received Young Investigator Award of Academia Sinica in 1999, Outstanding Research Award of National Science Council of R.O.C. in 2000, and Outstanding Nanotechnology Research Award of Taiwan Nanotechnology Industry Development Association in 2006. His main research interests regard development and application of scanning probe microscopy, surface and interface science, solid-water interfaces, gas in water, and development of microscopy and spectroscopy based on coherent electron beams emitted from single-atom tips.