F1-A1: Vapor liquid equilibria of energetic materials (B. Weeks, TTU)

1. F1-A1: Vapor liquid equilibria of energetic materials(B. Weeks, TTU) Initial experiments on vapor equilibria yielded publishable data (J. Chem. Eng. Data) on model systems and was transitioned to solid /vapor equilibria. Objective: Initial project was to focus on the ternary phase diagram of peroxide mixtures. This project has been transitioning to solid explosives to determine how explosives collect on surfaces. Approach: Deposition of energetic materials is performed with a home-made deposition apparatus which can control the flux, vapor pressure and thickness. Various substrates are coated to determine the interaction between the explosive and a surface. Significance and relevance: To provide information on how explosives collect on surfaces for explosives detection- Will provide information on best surface to try and collect residue from to get most signal (eg. IMS) Results are relevant outside of explosives field Currently collaborating with INEL on a DHS summer research program on this topic. Deposition of PETN on various surfaces indicate how materials are collected from the vapor phase

2. Objective: The majority of energetic materials contain a high concentration of nitrate groups and can be detected by traditional methods. The goal of this work is to investigate the synthesis and characterization of energetic materials without nitrate groups (primarily non-ideal explosives). Approach: Investigated the synthesis of transition metal complexes to determine the effect of the metal on stability and energy output. Significance and relevance: By understanding synthetic routes will allow for targeted detection of precursors Metal containing energetics may provide replacement compounds for CP and BNCP (currently in deployed systems) Final compounds can be used to develop new detection methodology Patent applications, CAS registration (paid for by company), paper submitted to Science F1-B: Routes to synthesize non-nitrate containing energetic materials (L. Hope-Weeks, TTU) Crystal structure of nickel hydrazine perchlorate shows a polymer structure never before observed in this class of materials. The energy density is over double that of PETN theoretical energy is 2.3 kcal/g; PETN is 1 kcal/g. Inset shows the nitrate analog

3. F1-B: Formation of thin film energetic materials; Nanomaterials (aerogels and nanocrystals) for improved detection and mitigation(B. Weeks,L. Hope-Weeks TTU) Complex Patterns of PETN formed on a silicon surface can be used to better understand propogation Objective: To investigate nanoscale properties of energetic materials (ideal and non-ideal) to understand propagation and surface structure. Approach: Deposition of thin film energetic materials on the nanometer scale. Investigate the structure using AFM, FTIR, and ellipsometry Future studies will look at laser initiation for propagation experiments Significance and relevance: Provide data for thermochemical codes (e.g. CHEETAH). Understand the sensitivity of non-ideal HEs with a minimal amount of material (currently working with LLNL) Industrial interest in commercialization of aerogels Aerogels allow for controlled density of bulk energetics. In addition, initial ballistic studies show that these gels are stronger, and lighter than Kevlar – consider use in mitigation

4. F1-TTU: Metrics Metrics: 4 GS + 2 Faculty; Gengxin Zhang (now at Intel), Alex Bushuyev, Sanjoy Bhattacharia, Victoria Smith, Brandon Weeks, Louisa Hope-Weeks 2 postdocs; Charly Sisk (now at DOE Waste Isolation Pilot Plant); Geneva Peterson 5 publications (2 submitted) ‘Gold modified cadmium sulfide aerogels’ Journal of sol-gel science and technology, 57 68-75 (2011) - LJH ‘A device for testing the thermal impact sensitivity of high explosives’ Propellants, explosive, pyrotechnics, 35 440-445 (2010) - BW ‘Surface morphology of organic thin films at various vapour flux’ Applied Surface Science, 256 2363-2366 (2010) - BW ‘Engineering the microstructure of organic energetic materials’ ACS Applied Surfaces and Interfaces, 1 1086-1089 (2009) - BW ‘Effect of Zn doping on the sublimation rate of pentaerythritol tetranitrate using atomic force microscopy’ Scanning, 31 181-187 (2009) - BW ‘A new class of polymeric high explosives’ Sub. to Science 2011 – LJH, BW Novel energetic complexes of Copper (II) and acetonecarbohydrazide as potential flame colorants for pyrotechnic mixtures, Sub. To Inorg. Chem. 2011 - LJH Patents Functionalized apertures for the detection of chemical and biological materials - LJH Thermal drop-weight apparatus (disclosure 2010) – BW Leveraging Funding: Interactions with companies and government agency on HME performance starting in 2010 ($500K) – LJH, BW; SBIR proposal with Ceradyne for commercialization of aerogels (College Station, TX) - LJH ONR proposal ‘Resolving the complexity of hot spots caused by weak energy concentration and coupling in energetic materials’ submitted Dec. 2010 – BW, LJH Combating Terrorism Technical Support Office ‘Training video on ballistic impacts’ March 2011 University commitment to new equipment for thin film samples (XPS - $650K); August 2010.