Chemical Dosimetry of Ultrasonic Cavitation

Abstract

meters to evaluate the efficacy of various solvents in producing cavitational sonochemistry. Aqueous and alcoholic solvent systems-are easily standardized using the oxidation of I to 13 by spectrophotometry. The more common addition of CC14 in order to increase rates of 1) production dramatically reduces the reproducibility of this system, which in our hands can be well within 5%. The use of the stable free radical, diphenylpicrylhydrazyl, as a radical trap in non-aqueous sonochemistry is discussed. The relative rates of radical production decrease in the following order: methanol, decane, cyclohexane, acetonitrile, acetone, toluene, and benzene. A third dosimeter, the decomposition of iron pentacarbonyl, has proved useful as the measure of the intrinsic ability of various solvents to support sonochemical reactions.