Organic chemical explosives are reactive materials that typically contain an overabundance of carbon and produce a mixture of carbon nanoallotropes (nanocarbon) when exposed to strong shocks such as detonation conditions. The concept that nanocarbon condensation is a critical process determining several aspects of explosives behavior, including initiation and performance, has become part of mainstream detonation research over the last decades. However, fundamental details remain to be explained.
We studied a prototypical carbon-rich reactive system—liquid carbon monoxide—using a combination of ultrafast shock measurements and large-scale molecular dynamics simulations. Our results demonstrated that nanocarbon condensation can occur on much faster (sub-nanosecond) time scales than assumed in detonating energetic materials. In conjunction with our efficient simulation technology, the study revealed the atomic-scale processes governing carbon nanoparticle formation and evolution under high pressure and temperature conditions, enabling more accurate physicochemical modeling of reactive materials under shock conditions, such as detonating insensitive, carbon-rich explosives. The ultrafast experimental technique developed for this project opened the door to better controlled carbon nanomaterials synthesis for research and industrial applications.
This study advances Lawrence Livermore National Laboratory's expertise towards R&D challenges in the fields of high explosive physics, chemistry, and materials science. Experimental techniques developed to conduct the research enhance Livermore's core capabilities in advanced materials, specifically carbon nanomaterials synthesis for research and industry applications. Results of this work support the Laboratory's mission as an innovative science and technology contributor to the Department of Defense.
Armstrong, M., et al. 2018. “Ultrafast Shock Experiments on Cryogenic Liquid Carbon Monoxide.” APS March Meeting, March 2018. LLNL-ABS-740937.
——— . 2018. “Shock-Induced Chemical Reactivity in CO on Picosecond Time Scales.” International Detonation Symposium, July 2018. LLNL-ABS-740040.
——— . 2019. “Ultrafast Shock Experiments on Cryogenic Liquid Carbon Monoxide.” APS March Meeting, March 2019. LLNL-PRES-769062.
——— . 2019. “Carbon Condensation Subsequent to Ultrafast Compression of Cryogenic Liquid CO.” Shock Compression of Condensed Matter Conference, June 2019. LLNL-ABS-768664.
Lindsey, R. 2019. “Machine Learning Reactive Force Fields for an Atomistically-Resolved View into Shockwave-Driven Carbon Condensation.” 21st Biennial Conference of the APS Topical Group on Shock Compression of Condensed Matter, Portland, OR, June 2019. LLNL-ABS-768127.
——— . 2019. "Toward an Atomistically-Resolved View into Shockwave-Driven Nanocarbon Synthesis: Uncovering Classicality in Chemistry-Coupled Phase Separation." Computational Chemistry and Materials Science Summer Institute, Livermore, CA, July 2019. LLNL-PRES-777957.
——— . 2019. ChIMES: Machine Learned Reactive Force Fields Enabling an Atomistically-Resolved View into Shock Compressed Materials." Advanced Simulation and Computing Machine Learning Workshop, Livermore, CA, September 2019. LLNL-PRES-789339.
Lindsey, R. et al. 2018. “Early Stage Chemistry in Shock Compressed Carbon Monoxide: Development and Application of the ChIMES Model.” American Physical Society March Meeting, Los Angeles, CA, March 2018. LLNL-ABS-740882.
——— . 2018. “Towards Description of Early Stage Chemistry in Shock Compressed Organics: Development and Application of the ChIMES Model.” Energetic Materials Gordon Conference, Newry, ME, June 2018. LLNL-ABS-746897.
——— . 2018. “ChIMES: Machine-Learned Force Fields for Quantum-Accurate Reactive Simulation.” International Union of Pure and Applied Physics Conference on Computational Physics, Davis, CA, July 2018. LLNL-PRES-754508.
——— . 2018. “ChIMES: Machine-Learned Force Fields for Quantum-Accurate Reactive Simulation.” Data Science Institute Meeting, Livermore, California, August 2018. LLNL-ABS-751889.
——— . 2018. “The Chebyshev Interaction Model for Efficient Simulations (ChIMES): Rapidly parameterizable force fields for quantum-accurate reactive simulation.” American Chemical Society National Meeting, Boston, MA, August 2018. LLNL-POST-754510.
——— . 2018. “Achieving Large Scale Quantum-Accurate Reactive Molecular Dynamics: The Chebyshev Interaction Model for Efficient Simulations (ChIMES).” American Institute of Chemical Engineers National Meeting, Pittsburgh, PA, October 2018. LLNL-ABS-749589.
——— . 2019. “Achieving Quantum-Accurate Condensed-Phase Reactive Simulations through Machine-Learned Force Fields.” American Physical Society March Meeting, Boston, MA, March 2019. LLNL-ABS-760433.
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