In-operando high-speed microscopy and thermometry of reaction propagation and sintering in a nanocomposite.

ABSTRACT: An important proposed mechanism in nanothermites reactions - reactive sintering - plays a significant role on the combustion performance of nanothermites by rapidly melting and coalescing aggregated metal nanoparticles, which increases the initial size of the reacting composite powders before burning. Here, we demonstrate a high-speed microscopy/thermometry capability that enables ~ µs time and ~ µm spatial resolution as applied to highly exothermic reaction propagation to directly observe reactive sintering and the reaction front at high spatial and temporal resolution. Experiments on the Al+CuO nanocomposite system reveal a reaction front thickness of ~30 μm and temperatures in excess of 3000 K, resulting in a thermal gradient in excess of 10⁷ K m^-1. The local micro

SUBMITTER: Wang H 

PROVIDER: S-EPMC6620330 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature