Thermophysical properties of energetic ionic liquidsitric acid mixtures: Insights from molecular dynamics simulations

摘要

Molecular dynamics (MD) simulations of mixtures of the room temperature ionic liquids (ILs) 1-butyl-4-methyl imidazolium BMIM/dicyanoamide DCA and BMIMNO_3~- with HNO_3 have been performed utilizing the polarizable, quantum chemistry based APPLEP? potential. Experimentally it has been observed that BMIMDCA exhibits hypergolic behavior when mixed with HNO_3 while BMIMNO_3~- does not. The structural, thermodynamic, and transport properties of the IL/HNO_3 mixtures have been determined from equilibrium MD simulations over the entire composition range (pure IL to pure HNO_3) based on bulk simulations. Additional (non-equilibrium) simulations of the composition profile for IL/HNO_3 interfaces as a function of time have been utilized to estimate the composition dependent mutual diffusion coefficients for the mixtures. The latter have been employed in continuum-level simulations in order to examine the nature (composition and width) of the IL/HNO_3 interfaces on the millisecond time scale.