A reaction kinetics model of water sonolysis in the presence of a spin-trap

The time development of the concentration of a spin-trapped OH radical was studied by electron spin resonance at various sound intensities and various 5,5-dimethyl-1-pyrroline N-oxide (DMPO) concentrations in water sonolysis. The lifetime of the spin-trapped OH radical was also studied, and factors governing sonolysis are discussed. We found that the production of spin-tra pped OH radical increases with increasing ultrasound intensity. The lifetim e of a spin-trapped OH radical decreases linearly with increase in sonicati on time. This result suggests that an unknown scavenger is produced by ultr asound. Based on the above results, we suggested a model of the reaction ki netics and estimated the production rate of OH radical from this model. (C) 1999 Elsevier Science B.V. All rights reserved.