Luminescent silica microagglomerates, synthesis, and environmental testing

Trevor Cell,Michael Foxe,Lance Hubbard,Nicolas Uhnak,Nathaniel Smith,Clara Reed,Caleb Allen,April Carman,Erin Kinney,Ryan Sumner

doi:10.1557/s43579-022-00150-3

Abstract

Tracking mass through harsh environments requires surrogate particles that withstand the event and endure until sampling. Silica-covered quantum dots have been shown to withstand a range of environmental pHs from months to years; in this work they are shown to endure in anticipated local environments. Two methods of particle synthesis were employed to produce luminescent silica with particle diameters 0.1–4 μm. These tracer particles scale for mass production, tolerate harsh environments, and endure in debris. They could be deployed in places such as chemical explosions, industrial processes, geologic test beds, oil and gas fields, nuclear reactors, and geothermal plants to track mass under harsh conditions.Graphical abstract

Highlights

Particulate tracking through chemical explosions and other harsh environments requires surrogate particles that withstand the dynamics of the event and endure in the local environment until sampling is possible.[1–3]
Layering silica shells was found to increase the sizes of the particles for submicron diameters, as measured using Dynamic light scattering (DLS)
Tracer particulates for harsh environments required controllable sizes that maintain their luminescent signature in the local environment

Summary

Introduction

Particulate tracking through chemical explosions and other harsh environments requires surrogate particles that withstand the dynamics of the event and endure in the local environment until sampling is possible.[1–3] The authors have reported previously on the survivability of ruggedized particulate tracers during explosions.[4]. Moving from an organicbased tracer to a particulate such as inorganic quantum dots can increase the survivability of a tracer but still lead to large degradations as the environment directly attacks the particulates.[4]. To increase a tracer’s environmental endurance, a chemically inert, signal-transmissive layer can be added to protect the tracer from the hostile environment (i.e., serve as a shield). This layer of the tracer protects the inner signal-producing portion while allowing the signal to be received during sampling and debris analysis. As previously reported results have explored the ruggedization of silica-covered ZnS:Mn quantum-dot tracers, this work expands the scope to explore the environmental endurance of the ruggedized tracers

Results

Discussion

Conclusion