Investigation of gelled ionic liquids as hypergolic fuels

The hypergolic reaction of 1-allyl-3-methylimidazolium dicyanamide (AMIM DCA), 1-ethyl-3-methylimidazolium dicyanamide (EMIM DCA) and 1-butyl-3-methyl-imidazolium dicyanamide (BMIM DCA) with nitric acid was investigated. AMIM DCA was characterized by thermal analysis (DSC, TGA) and density. Rheological measurements were performed on pure AMIM DCA and gelled AMIM DCA with silicon dioxide nanoparticles. The enthalpy of formation was calculated from the heat of combustion and the performance with nitric acid was calculated. The calculated results were compared to hypergolic agents such as monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH). The mass specific impulse of AMIM DCA is lower than MMH and UDMH. However, the volume specific impulse of AMIM DCA outranges the traditional hypergolic fuels. As an ionic liquid unlike conventional molecular liquids, it has practically no vapor pressure. Therefore significantly reduced environmental risk, better storage and handling properties are expected.