ENHANCEMENT OF CHEMICAL-REACTIVITY BY POWER ULTRASOUND - AN ALTERNATIVE INTERPRETATION OF THE HOT-SPOT

20 kHz ultrasound has been found to enhance the decomposition of the non-volatile initiator, potassium persulphate. The usual sonochemical correlation with solvent vapour pressure did not apply. The data was analysed by assuming that reaction took place at an elevated temperature in the interface between the cavitation bubble and the bulk solvent. The analysis indicated that the enhanced decomposition was proportional to both the acoustic pressure and the square root of the acoustic intensity. The analysis was also found to be applicable to the solvolysis of 2-chloro methylpropane, a volatile substrate.