The electrolysis of molten ammonium dinitramide

Abstract

Electrolytic ignition systems are expected to be compatible with ammonium dinitramide (ADN)-based propellants, but it is necessary to understand the associated electrolysis mechanisms when developing such systems. The present study analyzed the electrolysis of molten ADN, employing a specially designed apparatus, while examining the various products using in situ microscopy, Raman spectroscopy, ion chromatography, gas detector tubes and Fourier transform infrared (FTIR) spectroscopy. During electrolysis, the formation of numerous bubbles was observed, and the color of molten ADN changed from yellow to pale yellow with the progress of electrolysis. Raman spectra and ion chromatogram confirmed the presence of nitrate ion in the resulting residue, while a gas detector tube indicated that gaseous nitrogen dioxide (NO₂) and ammonia were generated. FT-IR spectra demonstrated that N₂O and water present in the gaseous products. Using these results, a new mechanism for the processes occurring during the electrolysis of molten ADN was devised. The findings reported herein provide an improved understanding of the electrolysis mechanism of ADN-based propellants.