AN INVESTIGATION OF SURFACE RE-FORMATION IN THE PRESENCE OF INERTIAL (TRANSIENT) CAVITATION (GR/N30989/01)

There is an international need to understand the influence of inertial (transient) cavitation on the erosion of surfaces. Electrochemical data, relevant to this area, has been concentrated on the bulk effects observed for relatively large electrode surface areas (e.g. mm diameters compared to µm diameters as employed here). However, in many of these examples the exact acoustic conditions are not reported at the electrode surface. This is due in part to the diverse nature of sonoelectrochemistry, relying on aspects of chemistry, electrochemistry and acoustics. In general the understanding of the acoustic environment of a sonochemical cell is complex and relies on the characterisation of the transducer/cell/cavitation interaction that can be generated within the system as a whole. This fundamental problem often results in poor reproducibility between experiments and laboratories even though the same chemical environment and system is being employed (assuming no differences in the chemistry occur). During this project, the authors set out to systematically and quantitatively identify the sources of these problems and formulated an experimental approach to rectify them considering both the chemistry and acoustics involved.1, 2 The project set out to investigate surface erosion caused by cavitation using an acoustoelectrochemical approach to this complex problem. In order to achieve these goals, a controlled and well characterised acoustic cell was employed with the ability to generate inertial and non-inertial cavitation