An assessment of cleaning mechanisms driven by power ultrasound using electrochemistry and high-speed imaging techniques

Page 1AN ASSESSMENT OF CLEANING MECHANISMS DRIVEN BYPOWER ULTRASOUND USING ELECTROCHEMISTRY AND HIGH-SPEED IMAGING TECHNIQUESDOUGLAS OFFINA, CHRISTOPHER VIANA, PETER BIRKINA,TIMOTHY LEIGHTONBASchool of ChemistryBISVRUniversity of SouthamptonHighfield, Southampton, SO17 1BJ, UKprb2@soton.ac.ukThe cleaning of a surface is monitored in real time using a number of physical measurements.In particular an electrochemically inactive material is removed from an electrode while theelectrode is able to detect a redox system in the bulk liquid. The removal of the material fromthe surface is monitored as an increased Faradaic current at the electrode surface. Thissignal is used to assess the ability of the cleaning method employed, in this case theapplication of power ultrasound to the system, as a function of the position of the electrodewith respect to the sound source. It is shown that, depending on the conditions employed,surface cleaning is driven by different mechanisms. In order to validate these findings high-speed imaging of the system was undertaken and the results correlated with theelectrochemical data. In addition a number of novel electrodes were also employed to assessthe cleaning efficiency as a function of the electrode geometry employed. Implications forsurface cleaning in the presence of power ultrasound are suggeste