(612d) Applying Pressure and Shear on Nitrogen-Rich Energetic Materials to Create Metamaterials

Farhad Forohar, Vasant Joshi, and Daniel Wilson

Research, Development Test and Engineering Department, Naval Surface Warfare Center Explosive Ordnance Disposal Technology Division, 4104 Evans Way Suite 102, Indian Head, MD 20640

Efforts to obtain metastable high pressure and high temperature states of nitrogen using Diamond Anvil Cell (DAC) techniques have indicated that some high density compounds may physically exist, but recovery of these materials at atmospheric pressure and temperature is still elusive. Stable poly-nitrogen compounds can be theoretically achieved by attaching them to non-nitrogen atoms. Application of combined pressure and shear to transform a nitrogen rich precursor material to a metastable condition is a new approach that should be easier than long duration-pure pressure application. This new method is being applied in an attempt to synthesize and recover novel materials from nitrogen rich precursors. Nitrogen rich precursors used in the present study include ammonium azide (N₄H₄), di-amino-tetra-azidocyclotriphosphazene (P₃N₁₇H₄), hexa-azidocyclotriphosphazene (P₃N₂₁) and 1,1â??-azobistetrazole (C₂H₂N₁₀). In order to get intramolecular interaction, co-crystallizations of mixtures were also made and were subjected to pressure-shear loading. Decomposition of materials at low pressure has been achieved for some precursors. Experimental fixture, method, results and analysis of recovered products will be presented.