Review on hypergolic ionic liquids

Hypergolic ionic liquids exhibit a potential application prospect in the field of green hypergolic propellents. The research progress in synthesis and performance of seven kinds of hypergolic ionic liquids, including dicyanamide, nitrocyanamide, borohydride, HP-cation, boronium, alminium, hydrazinium-based hypergolic ionic liquids were systematically reviewed. The initial combustion mechanism of dicyanamide-babed hypergolic ionic liquids was introduced. Combining the structure-activity relationship of hypergolic ionic liquids, pointing out that new hypergolic ionic liquids with the advantages of low vapor pressure, short ignition delay time, non-toxic, low characteristic signature, good thermal stability and green environmental protection are the focus of future research. In addition, the research of combustion mechanism for hypergolic ionic liquids could be done through detecting the highly active gaseous intermediate (HNCO etc) by using in situ IR spectroscopy in two stages of hypergolic process, and determining highly active gaseous species source. Based on the above technics, the accurate combustion mechanism of hypergolic ionic liquids can be finally deduced by means of quantum chemical calculation.