Intermolecular Energy Transfer Dynamics at a Hot-Spot Interface in RDX Crystals
Joshi, K; Losada, M; Chaudhuri, S
| HERO ID | 3221977 |
|---|---|
| In Press | No |
| Year | 2016 |
| Title | Intermolecular Energy Transfer Dynamics at a Hot-Spot Interface in RDX Crystals |
| Authors | Joshi, K; Losada, M; Chaudhuri, S |
| Journal | Journal of Physical Chemistry A |
| Volume | 120 |
| Issue | 4 |
| Page Numbers | 477-489 |
| Abstract | The phonon mediated vibrational up-pumping mechanisms assume an intact lattice and climbing of a vibrational ladder using strongly correlated multiphonon dynamics under equilibrium or near-equilibrium conditions. Important dynamic processes far from-equilibrium in regions of large temperature gradient after the onset of decomposition reactions in energetic solids are relatively unknown. In this work, we present a classical molecular dynamics (MD) simulation-based study of such processes using a nonreactive and a reactive potential to study a fully reacted and unreacted zone in RDX (1,3,5-trinitro-1,3,5-triazocyclohexane) crystal under nonequilibrium conditions. The energy transfer rate is evaluated as a function of temperature difference between the reacted and unreacted regions, and for different widths and cross-sectional area of unreacted RDX layers. Vibrational up-pumping processes probed using velocity autocorrelation functions indicate that the mechanisms at high-temperature interfaces are quite different from the standard phonon-based models proposed in current literature. In particular, the up-pumping of high-frequency vibrations are seen in the presence of small molecule collisions at the hot-spot interface with strong contributions from bending modes. It also explains some major difference in the order of decomposition of C-N and N-N bonds as seen in recent literature on initiation chemistry. |
| Doi | 10.1021/acs.jpca.5b06359 |
| Pmid | 26741283 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Language Text | English |