(652b) Spraying Effect On Particle Size and Morphology in Recrystallization of RDX Using Supercritical Carbon Dioxide Anti-Solvent

Authors: 
Seo, B., Seoul National University
Lee, B. C., Hannam University
Lee, Y. W., Seoul National University
Kim, H. S., Agency for Defense Development


Supercritical fluid processes have gained great attention as a new and environmentally-benign method of preparing the micro-particles of energetic materials like explosives and propellants. In this work, RDX (cyclotrimethylenetrinitramine) was selected as a target explosive. The micro-particles formation of RDX using supercritical carbon dioxide (CO2) anti-solvent recrystallization process was performed and the effect of spraying method on the size and morphology of prepared particles was observed. N,N-Dimethylformamide was used as an organic solvent for dissolving the RDX. A spraying tube tip nozzle with an inside diameter of 0.0006 inches and a length of 10 ~ 20 mm was installed into the end of a feed line of RDX solution in order to make a pressure difference between the RDX solution phase and the CO2 phase during spraying the RDX solution into the CO2 phase. The pressure difference was controlled in the range of 0 to 100 bar by changing the length of the spraying nozzle. In our experiments, other operating conditions were kept constant at 40 oC, 100 bar, and 20 wt. % of RDX concentration in feed solution, 25 ml/min of CO2 feed flow rate, and 25 ml/min of RDX solution feed flow rate. A big pressure difference generated between CO2 phase and solvent phase during the spraying of RDX solution into CO2 phase could produce the RDX particles with better quality. Specifically, the RDX particles of uniform and spherical shape with the average size of less than 5 µm were obtained at the pressure difference of about 100 bar.
See more of this Session: Nanoenergetic Materials

See more of this Group/Topical: Particle Technology Forum