Kinetics of hydrazinium nitrate decomposition in nitric acid solutions under the effect of power ultrasound.
The effect of ultrasound (f = 20 kHz) on the decomposition of hydrazinium nitrate was investigated in a nitric acid medium. The kinetics of N2H5+ decomposition and initial HN3 formation increase in a linear manner with the HNO3 concentration (from 1 to 6 M) and with the ultrasonic intensity (from 0.5 to 3.1 W cm-2). Both rates were equal to that of HNO2 formation in the absence of N2H5+, indicating that the N2H5+ decomposition mechanism is the same as observed without ultrasound between HNO2 and N2H5+. The variation of the steady-state HN3 concentration with the HNO3 concentration and the ultrasonic intensity suggests the existence of a nonexplosive HN3 thermal decomposition mechanism in the cavitation bubble under the effect of ultrasound. It was also observed at ultrasonic intensities exceeding 3.5 W cm-2 that the decomposition of HN3 led to the accumulation of NH4+ in solution.
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Commissariat à l'Energie Atomique (CEA/Valrhô), DRRV/SEMP, BP 17171, 30207 Bagnols-sur-Cèze, France.
Moisy
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Blanc
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Madic
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