Micro Nano Bubbles
MNB What is it?
Characteristics of Micro-Bubbles
- Small bubble size <40 µ
- Slow rising velocity – For example, 10 µm MBs rise only 20 cm in 1 hr.
- High pressure inside MBs (self-compression effect) For example, the inner pressures of bubbles whose diameters are 1 µm and 100 nm are 3.87 and 29.7 atm, respectively,
- Large interfacial area Large gas dissolution By using MBs, the dissolution rate increases rapidly. Dissolution and contraction – a 20 µm MB contracts and under 10 µm, it contacts rapidly and disappears
- Negatively charged surface of MB -MBs are negatively charged with an average ζ potential between −30 and −40 mV independent of bubble diameter.
- Crushing and formation of free radicals -Under 50 µm MB, free radicals are produced in several minutes during compression at high concentrations of MBs
- Bioactivity effect
- Change of liquid properties by bubbling of MBs -Himuro found that by bubbling MBs in the city water at 25°C, liquid viscosity and surface tension decrease and electrical conductivity increases
MNB What is it?
MNB less than 40 micron in size shrinks
Shrink then dissolve (become Nano Bubbles)
Gas bubble comparison
Nano-bubble production by collapsing microbubble
Shrink Time of Micro-Nano-Bubbles
