title: Sonication effects on non-radical reactions. A sonochemistry beyond the cavitation?
abstract: The kinetics of pH-independent hydrolysis of 4-methoxyphenyl dichloroacetate were investigated under ultrasonic irradiation with an application of 10% of the maximum power of the equipment and without sonication in acetonitrile-water binary mixtures with a content of acetonitrile ranging from 0.008 to 35 wt.%. Similar kinetic investigations were performed at intensities corresponding to 10%, 20%, 30%, 40%, and 50% of the input energy in solvent mixtures containing 10 wt.% and 25 wt.% acetonitrile. In parallel, the responses of KI and terephthalic acid dosimeters at applied irradiation levels were registered under the same experimental conditions. Significant kinetic sonication effects were found at sound intensities presumably not inducing cavitation in the solution. This result provides an experimental evidence of kinetic effects of ultrasound in the absence of cavitation. A disturbing impact of cavitation on the ultrasonic acceleration of the reaction was found. The implications of these findings were discussed.
authors.affiliation: Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia.
authors.forename: Ants
authors.initials: A
authors.lastname: Tuulmets
authors.affiliation: Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia.
authors.forename: Sander
authors.initials: S
authors.lastname: Piiskop
authors.affiliation: Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia.
authors.forename: Jaak
authors.initials: J
authors.lastname: Järv
authors.affiliation: Institute of Chemistry, University of Tartu, 14A Ravila St., 50411 Tartu, Estonia. Electronic address: siim.salmar@ut.ee.
authors.forename: Siim
authors.initials: S
authors.lastname: Salmar
keywords: Acoustic cavitation; Kinetic sonication effects; Organic aqueous solutions