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International Journal of Energetic Materials and Chemical Propulsion

ISSN Print: 2150-766X
ISSN Online: 2150-7678

International Journal of Energetic Materials and Chemical Propulsion

DOI: 10.1615/IntJEnergeticMaterialsChemProp.v7.i1.30
pages 39-54

SYNTHESIS OF NANO-SIZED RDX USING AN ULTRA-HIGH-PRESSURE RESS SYSTEM

Andrew Cortopassi
The Pennsylvania State University
Peter J. Ferrara
Department of Mechanical and Nuclear Engineering, The Pennsylvania State University University Park, PA 16802
Timothy M. Wawiernia
The Pennsylvania State University, Department of Mechanical and Nuclear Engineering, University Park, PA 16802 USA
Jonathan T. Essel
Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802

ABSTRACT

It is advantageous to synthesize nano-sized energetic ingredients for the development of insensitive munitions. Some parameters of crystalline particles that affect the thermal and shock sensitivity are size and shape of crystalline particles, particle size distribution, and defects in individual crystals. Any internal cavities in the crystalline structure are subjected to initiation by external stimuli. Shock or mechanical impacts to a crystalline particle with defects can cause hot spot generation, which leads to initiation of ignition. One of the methods under present investigation to produce nano-sized particles is the rapid expansion of a supercritical solution (RESS) process. In this study, an ultra-high-pressure (up to 207 MPa) RESS system has been developed and tested. Even though collection of nano-sized particles represents a major challenge, an efficient particle recovery system with the formation of dry ice from the supercritical CO2 solution has been successfully developed. Collected RDX samples have been measured by dynamic light scattering (DLS) technique to determine particle size distributions. Examination of crystalline structure and particle size were performed by using scanning electron microscopy (SEM). Particles sizes from 93 to 509 nm were obtained, depending upon the nozzle size, upstream temperature, and pressure controlled under the expansion process.

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