Quantum Molecular Dynamics Simulation of Hypergolic Reactions Between an Energetic Ionic Liquid and Nitric Acid

摘要

Recently, Energetic Ionic Liquids (EILs) have emerged as potential alternative hypergolic propellants to replace toxic monomethyl hydrazine (MMH). Ionic liquids have no appreciable vapor pressures, are safe to handle and can be tailored to have desired properties. One challenge is to design EILs with short ignition delays. In this paper, we report density functional tight binding molecular dynamics simulations (DFTB-MD) to study initial stages of hypergolic reaction between an EIL and nitric acid. Calculations were performed at various temperatures, and reaction mechanisms were identified. The reaction products, such as H2O, HNCO and CO2, predicted by DFTB-MD simulations are in agreement with the recent experiments by AFRL. These simulations predict that the reaction mechanism is very complex and it changes with temperature.