Modeling of an ionic liquid electrospray using molecular dynamics with constraints.
Arnaud Borner1, Zheng Li, Deborah A Levin
1Department of Aerospace Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA. apb170@psu.edu
The Journal of Chemical Physics
|April 3, 2012
Summary
Molecular dynamics simulations revealed the behavior of EMIM-BF(4) ionic liquid under electrospray thruster conditions. A threshold electric field of 1.2 V/nm was identified for particle emission, crucial for thruster design.
Area of Science:
- Physical Chemistry
- Materials Science
Background:
- Ionic liquids (ILs) are promising propellants for electrospray thrusters.
- Understanding ion behavior in ILs under electric fields is critical for thruster performance.
Purpose of the Study:
- Investigate the behavior of EMIM-BF(4) ionic liquid under conditions relevant to electrospray thrusters.
- Determine the threshold electric field for ion emission from the ionic liquid.
Main Methods:
- Molecular dynamics simulations of a large system (approx. 2160 ion pairs) of EMIM-BF(4) in a platinum capillary.
- Constrained dynamics model with a coarse-grained potential was employed.
- Analysis of solvated and non-solvated emitted ions under an applied electric field.
Main Results:
- Calculated diffusion coefficients and electrical conductivity agreed well with literature values.
- Validated the use of the coarse-grained model for simulating IL behavior.
- Identified a threshold electric field of 1.2 V/nm for particle emission.
Conclusions:
- The study successfully models EMIM-BF(4) behavior under electrospray conditions.
- The determined threshold electric field provides key data for electrospray thruster design.
- Coarse-grained molecular dynamics is a valid approach for simulating ionic liquid behavior in such applications.
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