Surface persistence of trace level deposits of highly energetic materials
Cargando...
Archivos
Fecha
2019
Autores
Pacheco-Londoño, Leonardo C.
Ruiz-Caballero, José L.
Ramírez-Cedeño, Michael L.
Infante-Castillo, Ricardo
Gálan-Freyle, Nataly J.
Hernández-Rivera, Samuel P.
Título de la revista
ISSN de la revista
Título del volumen
Editor
MDPI
Resumen
In the fields of Security and Defense, explosive traces must be analyzed at the sites
of the terrorist events. The persistence on surfaces of these traces depends on the sublimation
processes and the interactions with the surfaces. This study presents evidence that the sublimation
process of these traces on stainless steel (SS) surfaces is very different than in bulk quantities.
The enthalpies of sublimation of traces of four highly energetic materials: triacetone triperoxide
(TATP), 2,4-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT), and 1,3,5- trinitrohexahydro-s-triazine
(RDX) deposited on SS substrates were determined by optical fiber coupled-grazing angle probe
Fourier Transform Infrared (FTIR) Spectroscopy. These were compared with enthalpies of sublimation
determined by thermal gravimetric analysis for bulk amounts and differences between them were
found. The sublimation enthalpy of RDX was very different for traces than for bulk quantities,
attributed to two main factors. First, the beta-RDX phase was present at trace levels, unlike the case of
bulk amounts which consisted only of the alpha-RDX phase. Second, an interaction between the RDX
and SS was found. This interaction energy was determined using grazing angle FTIR microscopy.
In the case of DNT and TNT, bulk and traces enthalpies were statistically similar, but it is evidenced
that at the level of traces a metastable phase was observed. Finally, for TATP the enthalpies were
statistically identical, but a non-linear behavior and a change of heat capacity values different from
zero was found for both trace and bulk phases.
Descripción
Palabras clave
Sublimation, Explosive, FTIR, Thermogravimetric analysis, Grazing angle
