Comprehensive exploration of geometric effects in sonoreactors: An extensive comparison of KI dosimetry, luminol maps and calorimetric power

This study investigates sonochemistry results of Weissler reaction using a 20kHz transducer immersed in three different glass vessels, under a total of 65 experimental geometrical configurations, already characterized in our previous papers through electrical, calorimetric and luminol measurements, and numerical simulation. In the first set of experiments, the transducer immersion depths is varied at constant liquid volume whereas in the second, the liquid level is altered at constant immersion. The study aims to identify the geometric conditions that maximize reaction rate, as measured by the concentration of triiodide ions obtained after a given reaction time, and the overall sonochemical efficiency , measuring the numbers of moles produced per joule dissipated in the liquid. By incorporating insights from the comparison between sono-chemiluminescence (SCL) of luminol and dosimetry, this study establishes connections between global sonochemical effects and luminol mapping. For the three vessels considered, both indicators and evolve non-monotonically in function of either immersion or liquid level, and exhibit extrema for some specific configurations. No definite correlation could be established between maximal sonochemical effects and the corresponding shape and size of the luminol bright zones. Furthermore, the production of does not correlate well with the volumetric energy density, suggesting that a fraction of the cavitation bubbles may heat the liquid without producing noticeable sonochemistry.