PNNL

Abstract

Tracing the flow of solid matter during an explosion requires a rugged tag that can be measured by a unique identifiable signature. Semiconductor nanoparticles, or quantum dots (QDs), provide a unique and tunable photoluminescent signature that is regulated by the material’s composition and electronic confinement. The particles were ruggedized by the growth of a silica layer around the QDs, which acts as a sacrificial layer during explosive events. Incorporating the QDs into a matrix allows identification of the debris by photoluminescence. Five different types of zinc sulfide QDs were synthesized and encapsulated in silica shells. The silica-shelled QDs were covalently bound to a commercial luminescent powder. The combination of five dots and five powders enables a matrix of 25 unique tags that fluoresce at different excitation wavelengths (?ex). These substrates can be applied for mass tracking and model confirmation. The use of commercial luminescent powder in the tag allows field identification and the QDs luminescence allows laboratory confirmation.