Associated press:
Viewpoint in Physics: http://physics.aps.org/articles/v4/70
Physics World: http://physicsworld.com/cws/article/news/47159
Nanotechweb: http://nanotechweb.org/cws/article/tech/47173
Highlighted in the Virtual Journal of Nanoscale Science & Technology, September 19, 2011.
"Surface nanobubbles are nanoscopic gaseous domains trapped at the solid/liquid interface. They are surprisingly stable to bulk dissolution, questioning the very basics of fundamental physics. We demonstrate that this stability comes because of their nanoscopic size. The bubbles are so small that the gas molecules interact rarely with each ("Knudsen" gas). The gas molecules thus keep their preferred direction of motion once they have desorbed from the solid substrate. Bulk gas motion drives bulk liquid motion, due to the continuity of shear-stress boundary condition, so, once the gas has escaped from the nanobubble, it gets trapped in the circulatory stream that it itself set into motion. We use atomic force microscopy to validate that nanobubbles are indeed in dynamic equilibria."
