Gas bubbles electrolytically generated at microcavity electrodes used for the measurement of the dynamic surface tension in liquids

A new method is proposed for the measurement of dynamic surface tension in aqueous solutions. The advantage of this method with respect to the classical method based on sparging is that the use of gas pumps is avoided, resulting in a miniaturized system. This method is based on the in situ generation of gas bubbles by means of electrolysis at microcavity electrodes (MCEs). As a consequence of electrode surface shaping, a single nucleation site for gas bubbles is created. The MCE is used simultaneously as a bubble actuator (generator) and as a bubble size and/or frequency sensor. Measurement results prove the suitability of the electrolytic method for the monitoring of the dynamic surface tension in aqueous solutions.