Dynamic Structural and Chemical Responses of Energetic Solids

2012 ◽  
Vol 1405 ◽  
Author(s):  
Haoyan Wei ◽  
Choong-Shik Yoo

ABSTRACTUnderstanding the dynamic responses of energetic materials is central to evaluating the energetic and chemical performance as well as development of novel energetic solids. These include thermal, mechanical and chemical processes in a relevant temporal (ns-to-μs) and spatial (atomistic-to-micro) scales. In this paper, we describe our recent developments of time-resolved characterization techniques capable of probing real-time structural and chemical evolutions across single event, metal combustions and intermetallic reactions. The methods utilize highspeed microphotography, spectro-pyrometry, and synchrotron x-ray powder diffraction and determine in-situ the particle sizes, temperatures and structures in μs time resolution. These timeresolved data provide insights into the fragmentation dynamics, thermal history, phase transitions, reaction mechanisms, and chemical kinetics governing these exothermic metal combustions and intermetallic reactions.

Author(s):  
Bruna F. Baggio ◽  
Yvonne Grunder

This article reviews progress in the study of materials using X-ray-based techniques from an electrochemistry perspective. We focus on in situ/in operando surface X-ray scattering, X-ray absorption spectroscopy, and the combination of both methods. The background of these techniques together with key concepts is introduced. Key examples of in situ and in operando investigation of liquid–solid and liquid–liquid interfaces are presented. X-ray scattering and spectroscopy have helped to develop an understanding of the underlying atomic and molecular processes associated with electrocatalysis, electrodeposition, and battery materials. We highlight recent developments, including resonant surface diffraction and time-resolved studies. Expected final online publication date for the Annual Review of Analytical Chemistry, Volume 14 is June 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2016 ◽  
Vol 52 (96) ◽  
pp. 13865-13868 ◽  
Author(s):  
Saul J. Moorhouse ◽  
Yue Wu ◽  
Hannah C. Buckley ◽  
Dermot O'Hare

We report the first use of high-energy monochromatic in situ X-ray powder diffraction to gain unprecedented insights into the chemical processes occurring during high temperature, lab-scale metal oxide syntheses.


2020 ◽  
Author(s):  
Luzia S. Germann ◽  
Sebastian T. Emmerling ◽  
Manuel Wilke ◽  
Robert E. Dinnebier ◽  
Mariarosa Moneghini ◽  
...  

Time-resolved mechanochemical cocrystallisation studies have so-far focused solely on neat and liquid-assisted grinding. Here, we report the monitoring of polymer-assisted grinding reactions using <i>in situ</i> X-ray powder diffraction, revealing that reaction rate is almost double compared to neat grinding and independent of the molecular weight and amount of used polymer additives.<br>


2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.


Carbon ◽  
2015 ◽  
Vol 87 ◽  
pp. 246-256 ◽  
Author(s):  
Périne Landois ◽  
Mathieu Pinault ◽  
Stéphan Rouzière ◽  
Dominique Porterat ◽  
Cristian Mocuta ◽  
...  

2017 ◽  
Vol 111 (8) ◽  
pp. 082907 ◽  
Author(s):  
Seiji Nakashima ◽  
Osami Sakata ◽  
Hiroshi Funakubo ◽  
Takao Shimizu ◽  
Daichi Ichinose ◽  
...  

2013 ◽  
Vol 374 ◽  
pp. 23-30 ◽  
Author(s):  
H. Nguyen-Thi ◽  
G. Reinhart ◽  
G. Salloum Abou Jaoude ◽  
R.H. Mathiesen ◽  
G. Zimmermann ◽  
...  

2008 ◽  
Vol 72 (1) ◽  
pp. 201-204 ◽  
Author(s):  
A. Sumoondur ◽  
S. Shaw ◽  
I. Ahmed ◽  
L. G. Benning

AbstractIn this study, direct evidence for the formation of magnetite via a green rust intermediate is reported. The Fe(II) induced transformation of ferrihydrite, was quantified in situ and under O2-free conditions using synchrotron-based time-resolved energy dispersive X-ray diffraction. At pH 9 and Fe(II)/Fe(III) ratios of 0.5 and 1, rapid growth (6 min) of sulphate green rust and its subsequent transformation to magnetite was observed. Electron microscopy confirmed these results, showing the initial rapid formation of hexagonal sulphate green rust particles, followed by the corrosion of the green rust as magnetite growth occurred, indicating that the reaction proceeds via a dissolution-reprecipitation mechanism. At pH 7 and Fe(II)/Fe(III) ratio of 0.5, sulphate green rust was the stable phase, with no transformation to magnetite.


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