Fast spectroscopy of energy release in nanometric explosives

Wang, Shufeng; Yang, Yanqiang; Sun, Zhaoyong; Dlott, Dana D.

doi:10.1016/s0009-2614(02)01846-8

Cited by 40 publications

(64 citation statements)

References 24 publications

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“…This reduces the mass transport limitations and increases the reaction rate of the mixtures. They are extensively studied as they may have potential applications as propellants, explosives and primers [1,2]. Nanoenergetic Materials may have higher energy densities than conventional explosives [3][4][5][6] and may generate shock wave with velocities of up to 2500 m/s [7,8].…”

Section: Introductionmentioning

confidence: 99%

Novel nanoenergetic system based on iodine pentoxide

Martirosyan

Wang

Luss

2009

Chemical Physics Letters

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Section: Introductionmentioning

confidence: 99%

Novel nanoenergetic system based on iodine pentoxide

Martirosyan

Wang

Luss

2009

Chemical Physics Letters

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“…However, unlike the featureless spectrum from the aggregate initiated by the slow-rising pulse, the spectrum from the aggregate initiated by the flat-top laser profile has a peak at 590 nm. This peak is assigned to Na emission that originates from the glass substrate [14,15].…”

Section: Effect Of Laser-pulse Duration and Temporalmentioning

confidence: 99%

“…However, studies that measure reaction progress in bulk phase cannot predict the effects of size because of the large number of simultaneously sampled particles with a broad distribution of parameters [7,8]. To address these difficulties, spectroscopic studies of laser-initiated monodisperse nanoparticle reactions have been carried out [7,[9][10][11][12][13][14][15][16]. In these studies, laser ignition of energetic materials was performed with weakly focused laser beams leading to simultaneous excitation of multiple isolated nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

Micro-Optical Initiation of Nanoenergetic Materials Using a Temporally Tailored Variable-Pulse-Width Laser

Slipchenko

Moody²,

Miller

et al. 2012

Journal of Nanotechnology in Engineering and Medicine

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Nanoenergetic materials can provide a significant enhancement in the rate of energy release as compared with microscale materials. The energy-release rate is strongly dependent not only on the primary particle size but also on the level of agglomeration, which is of particular interest for the inclusion of nanoenergetics in practical systems where agglomeration is desired or difficult to avoid. Unlike studies of nanoparticles or nanometer-size aggregates, which can be conducted with ultrafast or nanosecond lasers assuming uniform heating, microscale aggregates of nanoparticles are more sensitive to the thermophysical time scale of the heating process. To allow control over the rate of energy deposition during laser initiation studies, a custom, temporally tailored, continuously variable-pulse-width (VPW) laser was employed for radiative heating of nanoenergetic materials. The laser consisted of a continuous-wave master oscillator, which could be sliced into desired pulses, and a chain of amplifiers to reach high peak power. The slicer allowed control over the time profile of the pulses via the combination of an arbitrary waveform generator and acousto-optic modulator (AOM). The effects of utilizing flat-top or ramped laser pulses with durations from 100 ns to 150 ls and energies up to 20 mJ at 1064 nm were investigated, along with a broad range of heating rates for single particles or nanoparticle aggregates up to 100-lm diameter. In combination with an optical microscope, laser heating of aggregates consisting of 70-nm diameter Al nanoparticles in a Teflon matrix showed significant dependence on the heating profile due to the sensitivity of nanoenergetic materials to heating rate. The ability to control the temporal pulse-intensity profile leads to greater control over the effects of ablative heating and the resulting shockwave propagation. Hence, flexible laser-pulse profiles allow the investigation of energetic properties for a wide size range of metal/metal-oxide nanoparticles, aggregates, and composites. Nanoenergetic materials can provide a significant enhancement in the rate of energy release as compared with microscale materials. The energy-release rate is strongly dependent not only on the primary particle size but also on the level of agglomeration, which is of particular interest for the inclusion of nanoenergetics in practical systems where agglomeration is desired or difficult to avoid. Unlike studies of nanoparticles or nanometer-size aggregates, which can be conducted with ultrafast or nanosecond lasers assuming uniform heating, microscale aggregates of nanoparticles are more sensitive to the thermophysical time scale of the heating process. To allow control over the rate of energy deposition during laser initiation studies, a custom, temporally tailored, continuously variable-pulse-width (VPW) laser was employed for radiative heating of nanoenergetic materials. The laser consisted of a continuous-wave master oscillator, which could be sliced into desired pulses, and a chain of amplifiers ...

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“…1 is the laser-launch facility that was developed and constructed during the add-on final year of the project. [148]. A NEEM is sandwiched between confining windows and a short-duration (typically 100 ps) laser pulse suddenly heats the fuel elements [145,146].…”

Section: Figure 98mentioning

confidence: 99%

Nano Engineered Energetic Materials (NEEM)

Dlott¹,

Eden²,

Girolami³

et al. 2011

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The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. The ARO Nano Engineered Energetic Materials (NEEM) MURI program has been exploring new methodologies for developing energetic material formulations with control of all constituents over a wide range of length scales from 1 nm to 1 mm and larger and employing the latest techniques in molecular self-assembly and supramolecular chemistry for synthesizing and assembling NEEMs. The synthetic efforts have been guided by theoretical calculations and dynamic performance testing methodologies that also operate on all length scales. This final report ABSTRACTThe ARO Nano Engineered Energetic Materials (NEEM) MURI program has been exploring new methodologies for developing energetic material formulations with control of all constituents over a wide range of length scales from 1 nm to 1 mm and larger and employing the latest techniques in molecular self-assembly and supramolecular chemistry for synthesizing and assembling NEEMs. The synthetic efforts have been guided by theoretical calculations and dynamic performance testing methodologies that also operate on all length scales. This final report provides a summary of the accomplishments. In particular, new methods to generate metal nanoclusters were developed that are stabilized against environmental degradation while preserving their high energy content. Rapid expansion supercritical solution processes were developed and applied to synthesize nanosized particulate oxidizers and energetic oxidizer shell/fuel core composites. Surface science and experimental chemistry methods were applied to study the structures and energy releasing reaction pathways of NEEMs. Unique diagnostic capabilities were developed and applied to study the fundamental mechanisms that underlie NEEM dynamic performance. Combustion mechanisms of various NEEMs, including nanothermites and nanoparticulate fuel/liquid oxidizer systems, were experimentally analyzed. The reactive and thermal characteristics of NEEMs were studied using large (billion atoms) multiscale simulations that couple quantum-mechanical calculations to molecular dynamics calculations. In particular, the stability, structure and energetics of metallic nanoparticles with a special focus on the relationships between particle size, shape and excess surface free energy were studied. A unified theory of ignition and combustion of aluminum particles for a wide range of sizes, from nano to meso scales was established. . 12, 777-787 (2010 (b) Papers published in non-peer-reviewed journals or in conference proceedings (N/A for none)18.00 Number of Papers published in peer-reviewed journals:Number of Papers published in non peer-reviewed journals:1. USC group, "Multibillion-atom simulations of nano-mechano-chemistry on petaflops computers," First

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Fast spectroscopy of energy release in nanometric explosives

Cited by 40 publications

References 24 publications

Novel nanoenergetic system based on iodine pentoxide

Novel nanoenergetic system based on iodine pentoxide

Micro-Optical Initiation of Nanoenergetic Materials Using a Temporally Tailored Variable-Pulse-Width Laser

Nano Engineered Energetic Materials (NEEM)

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