Green propellant development has been the focus of research efforts aimed at creating a more sustainable and affordable future for space. Green propellant alternatives that are ready for implementation have yet to be realized for bipropellant systems. Requirements for green bipropellants alternatives include energetic properties with an ignition delay (ID) below 10 milliseconds. They must also have comparable or improved performance over hydrazine and its derivatives while also having improved stability, reduced volatility, and reduced toxicity to minimize the extra costs typically associated with using the heritage fuels. Ionic liquids are a class of chemicals which provide promising green propellant candidates depending on the cation/anion pairing. In order to find the most viable alternative, the ignition kinetics of energetic ionic liquids (EILs) need to be better understood. Fourier transform infrared spectroscopy (FTIR) work by Chambreau et al. has highlighted some species present during the ignition process of various EILs with white fuming nitric acid (WFNA), including the presence of nitrous oxide (N_2O). In this study, the ID of two EILs (1-butyl-3-methylimidazolium dicyanamide (BMIM~+DCA~-) and 1-butyl-1-methylpyrrolidinium dicyanamide (BMPY~+DCA~-)) with WFNA was measured in a 100% N_2 atmosphere and then in a 25% N_2O and 75% N_2 atmosphere. The addition of the N_2O was found to decrease the average ID for both EILs. Knowing this may allow bipropellant systems using EILs to be more tunable for a given application by controlling the presence of N_2O.
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