| Abstract
| - Acoustic cavitation considerably enhances the mass transport toward a surface. When suitably fastelectrochemical equipment is used, periodic peak currents can be observed. Previous observations attributedthese peaks to diffusion inside a thin liquid layer present between the electrode and the bubble (Maisonhaute,E.; White, P.C; Compton, R. G. J. Phys. Chem. B2001, 105, 12087−12091). This paper provides asemiquantitative model for explaining the bubble behavior, leading to an estimation of the diffusion layerthickness as well as the time during which the bubble “discovers” the electrode. Layer thicknesses rangingfrom 25 nm for very high acoustic pressures up to ca. 60 nm for smaller ones are found. Collapse velocitiesare estimated to be more than hundreds meters per second. Moreover, between two collapses, a slow bubblemovement apart from the surface is evidenced. The force balance responsible for the collapse is reexaminedand the viscosity constraint found to be an important parameter in explaining the global behavior.
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