Nanobubbles in water - how to identify them and why they are stable
In this work we demonstrate that several common nanobubble generation methods can generate contamination particles which can be mistaken for bubbles and that with sufficient cleanliness, neither particles, droplets or bubbles are generated. Theories on nanobubble stability that does not include impurities can thus be dismissed. (Paper 1). Lipid stabilization and the dynamic equilibrium model based on hydrophobic dirt particles appear to be the only valid models for nanobubble stability at present.
We furthermore demonstrate Holographic Nanoparticle Tracking Analysis (H-NTA) as a powerful new method to detect and differentiate between nanobubbles and nanoparticles in the same solution (Paper 2). As H-NTA determines the refractive index of tracked objects, bubbles will differ very significantly from solid particles or oil droplets. The refractive index of a bubble also indicates the amount of adsorbed material as well as possible clustering of multiple bubbles. The method also powerfully enables detection of different particle populationsclose in size and refractive index in a dispersion. The size range is 0.3-0.4 mm to 1.5 mm.
Digital holographic microscopy
Nanoparticle tracking analysis
Dynamic Light scattering
Chalmers, Fysik, Biologisk fysik
Stable Air Nanobubbles in Water: the Importance of Organic Contaminants
Langmuir,; Vol. 34(2018)p. 11003-11009
Artikel i vetenskaplig tidskrift
PJ lecture hall
Opponent: Johan Bergenholtz, Göteborgs Universitet