Massive generation of metastable bulk nanobubbles in water by external electric fields
Published Date: 4/8/2020
Source: phys.org
Nanobubbles can exist on solid surfaces or in bulk liquids as nanoscopic gaseous domains. The phenomenon has attracted substantial attention due to the long-time (meta)stability and potential for practical applications. In a new report, Mohammad Reza Ghaani and a team of researchers in chemistry and bioprocess engineering in Ireland and Canada used a novel approach to explore the surface of electrostatic nanobubble (NB) formation. They observed the stability of the constructs by applying external electric fields in gas-liquid systems to observe massive gas uptake into the liquid in nanobubble form. During a period of time lasting months, the gas solubility enhanced from 2.5 fold for oxygen to 30-fold for methane, based on Henry's Law values for gas solubility—i.e., the more hydrophobic the gas, the greater the intake. Using molecular dynamics solutions, Ghaani et al. revealed the origin of NB's movement to result from dielectrophoresis, while the substantial stability of NB arose from surface-polarization interactions. The work is now published on Science Advances.