Nanobubbles are defined as: “Nanoscopic gas cavities in aqueous solutions which diameter is smaller that 1 micron (d<1μm).”

  • Taking into consideration the classical thermodynamics, a paradox seems to appear in systems containing nanobubbles.
  • According to the Young-Laplace Law, the pressure in the interior of gas bubbles is inversely proportional to their diameter, with excess pressure:

Obviously, since the pressure inside gas bubbles is inversely proportional to their diameter, microscopic bubbles have large internal pressure.

  • Nanobubbles demonstrate an extended lifetime compared to larger size bubbles.
  • Over the last few years, nanobubbles have drawn great attention due to their exotic properties.
  • It would be expected that bubbles which their diameter is in the nanoscale (<1 μm), dissolve immediately, within a few microseconds. However, it is observed that nano-bubbles remain stable for extended periods of time and still exist even after several months!