Strachan, Alejandro and Kober, Edward M. and van Duin, Adri C. T. and Oxgaard, Jonas and Goddard, William A., III (2005) Thermal decomposition of RDX from reactive molecular dynamics. Journal of Chemical Physics, 122 (5). Art. No. 054502. ISSN 0021-9606 http://resolver.caltech.edu/CaltechAUTHORS:STRAjcp05
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We use the recently developed reactive force field ReaxFF with molecular dynamics to study thermal induced chemistry in RDX [cyclic-[CH2N(NO2)]3] at various temperatures and densities. We find that the time evolution of the potential energy can be described reasonably well with a single exponential function from which we obtain an overall characteristic time of decomposition that increases with decreasing density and shows an Arrhenius temperature dependence. These characteristic timescales are in reasonable quantitative agreement with experimental measurements in a similar energetic material, HMX [cyclic-[CH2N(NO2)]4]. Our simulations show that the equilibrium population of CO and CO2 (as well as their time evolution) depend strongly of density: at low density almost all carbon atoms form CO molecules; as the density increases larger aggregates of carbon appear leading to a C deficient gas phase and the appearance of CO2 molecules. The equilibrium populations of N2 and H2O are more insensitive with respect to density and form in the early stages of the decomposition process with similar timescales.
|Additional Information:||Copyright © 2005 American Institute of Physics. Received: 3 August 2004; accepted: 21 October 2004; published online: 13 January 2005. Work at Los Alamos National Laboratory was supported by the ASC Materials and Physics Modeling Program, LANL. Work at Caltech was supported by ONR (program manager Judah Goldwasser).|
|Subject Keywords:||pyrolysis; thermochemistry; molecular force constants; organic compounds; molecular dynamics method; chemical reactions|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Lindsay Cleary|
|Deposited On:||30 Oct 2006|
|Last Modified:||26 Dec 2012 09:14|
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