Characterization of polymorphic states in energetic samples of 1,3,5-trinitro-1,3,5-triazine (RDX) fabricated using drop-on-demand inkjet technology.
The United States Army and the first responder community are evaluating optical detection systems for the trace detection of hazardous energetic materials. Fielded detection systems must be evaluated with the appropriate material concentrations to accurately identify the residue in  theater. Trace levels of energetic materials have been observed in mutable polymorphic phases and, therefore, the systems being evaluated must be able to detect and accurately identify variant sample phases observed in spectral data. In this work, we report on the novel application of drop-on-demand  technology for the fabrication of standardized trace 1,3,5-trinitro-1,3,5-triazine (RDX) samples. The drop-on-demand sample fabrication technique is compared both visually and spectrally to the more commonly used drop-and-dry technique. As the drop-on-demand technique allows for the fabrication  of trace level hazard materials, concerted efforts focused on characterization of the polymorphic phase changes observed with low concentrations of RDX commonly used in drop-on-demand processing. This information is important when evaluating optical detection technologies using samples prepared  with a drop-on-demand inkjet system, as the technology may be "trained" to detect the common bulk α phase of the explosive based on its spectral features but fall short in positively detecting a trace quantity of RDX (β-phase). We report the polymorphic shifts observed  between α- and β-phases of this energetic material and discuss the conditions leading to the favoring of one phase over the other.
Science Applications International Corporation, Gunpowder Branch, Aberdeen Proving Ground, Maryland 21010-5424, USA.
Erik D
ED
Emmons
Mikella E
ME
Farrell
Ellen L
EL
Holthoff
Ashish
A
Tripathi
Norman
N
Green
Raphael P
RP
Moon
Jason A
JA
Guicheteau
Steven D
SD
Christesen
Paul M
PM
Pellegrino
Augustus W
AW
Fountain
D003460:Crystallization; D053834:Explosive Agents / Q000737:chemistry*; D008958:Models, Molecular; D011327:Printing; D012015:Reference Standards; D013059:Spectrum Analysis, Raman / Q000379:methods* / Q000592:standards; D014227:Triazines / Q000737:chemistry*
D053834:Explosive Agents; D014227:Triazines; C009160:cyclonite