Naslov
Bubbling Potential as a Measure of the Charge of Gas Bubbles in Aqueous Environment

Autori
Preočanin, Tajana ; Šupljika, Filip ; Lovrak, Matija ; Barun, Josip ; Kallay, Nikola

Izvornik
Colloids and surfaces. A, Physicochemical and engineering aspects (0927-7757) 443 (2014); 129-134

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
gas/water interface; bubbles; bubbling potential; electrokinetics; electrokinetic ζ-potential

Sažetak
Gas bubbles in aqueous environment cause changes in electrical potential of the electrodes containinga ceramic porous plug. It was found that collision and interception of bubbles and porous plug surfaceare responsible for the observed phenomenon. In the course of collision bubble approaches porous plugsurface to a certain distance within diffuse layer of air/water interface. At that distance the electrostaticpotential of gas bubble affects the electrode potential. Reversible redox electrodes cannot serve as abubbling indicator electrode due to relaxation of the electrode reactions. Bubbling potential is definedas the difference of indicator electrode potential in presence and absence of bubbles. It provides infor-mation on the isoelectric point of the gas bubbles, and may be recalculated to -potentials using theGouy–Chapman theory. For that purpose, the distance between electrokinetic slip plane and plane ofbubble contact with porous plug surface should be known. This distance was estimated to be between 6and 10 nm. As electrokinetic potential, the bubbling potential is also significantly reduced by increasingelectrolyte concentration, which is markedly more pronounced for counterions of higher charge. Theeffect of pH and several various electrolytes on argon bubbles was examined and discussed. Measure-ment of bubbling potential is fast and reproducible and may be used as a useful tool for examination ofgas/water interfaces.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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