Sulfates‐Based Nanothermites: An Expanding Horizon for Metastable Interstitial Composites1. Issue 15 (20th February 2015)

• Record Type: Journal Article
• Authors: Comet, Marc; Vidick, Geoffrey; Schnell, Fabien; Suma, Yves; Baps, Bernard; Spitzer, Denis
• Is Part Of: Angewandte Chemie international edition. Volume 54:Issue 15(2015)
• Page Start: 4458
• Page End: 4462
• Publication Date: 2015-02-20
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201410634
• Languages: English
• ISSNs: 1433-7851

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Metal sulfates (Ba, Bi, Ca, Cu, Mg, Mn, Na, Zn, Zr) were used as oxidizers in reactive compositions with Al nanopowder. These new kinds of nanothermites have outstandingly high reaction heats (4–6 kJ g⁻¹) compared to conventional Al/metal oxides (1.5–4.8 kJ g⁻¹) and also have good combustion velocities (200–840 m s⁻¹ vs 100–2500 m s⁻¹). These compositions are extremely insensitive to friction making their preparation and handling easy and safe. The sulfate hydration water increases the reaction heats and has a significant effect on the sensitivity to impact and to electrostatic discharge. The reaction of Al with water is easier to initiate than the one with sulfate which leads to two possible decomposition modes for samples exposed to an open flame. The pyrotechnical properties observed with sulfates have also been found for other sulfur oxygenates (SO₃²⁻, S₂O₃²⁻, S₂O₈²⁻) which opens up new horizons in the domain of metastable interstitial composites.</p> </abstract>