Improving understanding of energetic materials: Compression behavior and co-crystal synthesis

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Improving understanding of energetic materials: Compression behavior and co-crystal synthesis Przemyslaw Dera University of Hawaii School of Ocean and Earth Science and Technology Hawaii Institute of

1 Improving understanding of energetic materials: Compression behavior and co-crystal synthesis Przemyslaw Dera University of Hawaii School of Ocean and Earth Science and Technology Hawaii Institute of Geophysics & Planetology Our research is supported by: NSF (Geophysics, GeoInformatics, EarthCube and SISI) CDAC/DOE-NNSA NASA (ASTID and SERA) ARL Summer Meeting Honolulu, HI, August 20, 2015 Partnership for extreme Xtallography: ThinkTech Hawaii interview about extreme conditions research at HIGP:

Structural transformations and energetic materials Structural, electronic and magnetic phase transitions have consequences on physical properties and behavior of technologically-relevant materials

These phenomena can significantly affect mechanical/elastic and transport properties, which are often critical for the material s performance in the field setting.

2 Structural transformations and energetic materials Structural, electronic and magnetic phase transitions have consequences on physical properties and behavior of technologically-relevant materials and play important role in the energy release from explosives. These phenomena can significantly affect mechanical/elastic and transport properties, which are often critical for the material s performance in the field setting. In particular, some phase transitions may lead to catastrophic mechanical failure of armor ceramics or may affect sensitivity of molecular explosives or solid propellants. Factors that can trigger phase transitions include: Pressure Temperature Stress anisotropy (shear component) Stress/strain rate Polymorphic pressure-induced transformation in Be(OH) 2, hydrogen-bonded analog of silica Shelton, Dera et. al. in press

Stress-rate controlled metastability Effects of temperature and hydrostatic pressure

$All of these effects can be measured using novel synchrotron in situ X-ray diffraction$ techniques developed by our group.

which known stable phase transitions take place (e.g.

3 Stress-rate controlled metastability Effects of temperature and hydrostatic pressure defining stable phase diagrams are fairly routine to measure, and for most fundamental systems have already been established. The effects of stress anisotropy and stress/strain rate are even more important/realistic for technological applications, but they are also much more elusive (e.g. path-dependent), harder to quantitatively control and often lead to metastable behavior. All of these effects can be measured using novel synchrotron in situ X-ray diffraction techniques developed by our group. Stress anisotropy and stress/strain rate are capable of: changing pressure/temperature at which known stable phase transitions take place (e.g. SiO 2 quartz) inducing new metastable phase transitions (e.g. CuGeO 3 ) suppressing known phase transitions (e.g. SiO 2 cristobalite) changing deformation mechanism (e.g. SiO 2 quartz) 0.1mm Explosive samples Ruby sphere Polymorphic pressure-induced transformation in SiO 2 cristobalite can be suppressed by rapid compression Dera et. al. Phys. Chem. Mineral. (2011)

inherit a combination of properties of the parent compounds.

4 Polymorphism related to hydrogen bond transformations plays important role in controlling explosive materials stability Stable and unstable molecules that have compatible molecular geometries and H-bond formation capabilities can often be combined in co-crystals that inherit a combination of properties of the parent compounds. Hydrothermal conditions (high p and T) often promote co-crystal formation This route offers possibility for synthesis of hybrid molecular materials with improved properties (e.g. high energy storage and high stability)

Stable molecular analogs of explosives provide convenient test cases to understand hydrogen bond

is not flat because of extensive intermolecular hydrogen bonding Stable, fire-retardant

$diffraction (below) provides unparalleled insight into the atomic details of compression$

5 Stable molecular analogs of explosives provide convenient test cases to understand hydrogen bond transformations s-triazine ring 6 out of 9 non-h atoms are nitrogen The molecule in the crystal is not flat because of extensive intermolecular hydrogen bonding Stable, fire-retardant properties (used for kitchen laminate applications) Molecular geometry compatible with TATB and TNB Forms co-crystals with some molecular explosives Synchrotron in situ single crystal X-ray diffraction (below) provides unparalleled insight into the atomic details of compression behavior Melamine

Two experiments carried out in Ne and He pressure media No

Displacive phase transition at 35 GPa to a triclinic phase

Series3 Series4 Power (Series1) Log. (Series1) 30.0 25.

7 graphite 15.0 10.0 0.6 benzene 5.0 0.5 melamine x10^3 31 32 33 34 35 36 0.

6 Two experiments carried out in Ne and He pressure media No symmetry change or volume discontinuity detected up to 35 GPa Displacive phase transition at 35 GPa to a triclinic phase Amorphisation observed above 45 GPa d e -distance to the nearest atom outside P=1 GPa Normalized contact distance d norm Series1 Series2 Series3 Series4 Power (Series1) Log. (Series1) [ _p _ ] In situ Raman spectroscopy V/V0 0.7 graphite benzene melamine x10^ p [GPa] P=30 GPa Synchrotron single-crystal X-ray diffraction and Hirshfeld surface analysis P=40 GPa P=45 GPa

Our facilities PX 2 Partnership for extreme Xtallography New Advanced Experimental Facility of HIGP at Argonne National Laboratory X-ray beam:

$six-circle diffractometer high rotation speed (up to 15deg/sec), high precision of rotation ( less than 10 micrometers sphere of confusion) High$ Unique laser heating system for single crystal experiments including 200 W NIR fiber laser Advanced research at conditions of extreme pressure,

Unique laser heating system for single crystal experiments including 200 W NIR fiber laser Advanced research at conditions of extreme pressure,

50% beam time available for high pressure experiments In house facilities for extreme conditions research at HIGP: Diamond anvil cells Dynamic

7 Our facilities PX 2 Partnership for extreme Xtallography New Advanced Experimental Facility of HIGP at Argonne National Laboratory X-ray beam: Goniometer: Detectors: Laser optics: Mission: Access: Bending magnet source, 30 kev fixed energy, 10x15 micrometers focal spot size Unique six-circle diffractometer high rotation speed (up to 15deg/sec), high precision of rotation ( less than 10 micrometers sphere of confusion) High load capacity (up to 25 lb) Mar165 CCD Ultrafast Perkin Elmer XRD1642 flat panel pixel array detector (30 exposures/sec) Online Raman spectroscopy Unique laser heating system for single crystal experiments including 200 W NIR fiber laser Advanced research at conditions of extreme pressure, temperature and strain rates, exploring structure, defects, strain, and transformations of minerals and materials of technological interest Up to 50% beam time available for high pressure experiments In house facilities for extreme conditions research at HIGP: Diamond anvil cells Dynamic compression membrane setup NIR laser heating CO 2 laser heating In situ ambient and high temperature Raman spectroscopy in DAC Large volume presses for sample synthesis

Dynamics of Crystallization and Melting under Pressure

prakapenka@cars.uchicago.edu Dynamics of Crystallization and Melting under Pressure Vitali Prakapenka GSECARS, University of Chicago, Chicago 1 The world s deepest borehole in Sakhalin is 12,345 m (40,502