5351.1:
Functional Nanoparticles by Flame Spray Pyrolysis
Abstract
The aim of the project is to develop a flexible flame process for large scale synthesis of nanostructured materials of pure and mixed metal oxides for electroceramics from a variety of precursors.
The motivation for this is the growing demand of nanoparticles with very defined properties such as purity, stoichiometry, and crystallinity at low prices. These requirements will be targeted using flame spray pyrolysis (FSP) which has proven to be capable of producing nanograined materials for high technology applications from a broad spectrum of liquid precursors. The FSP process has the advantages of high liquid and gas flow rates as well as the capability for rapid quenching of the aerosol formed in the gas phase after evaporation and burning of the liquid fuel and the reaction of the precursor mixture. Formation of the nanoscale ceramic particles occurs entirely within the thermal boundary region of burning droplets, making each carrier aerosol droplet effectively a micro-reactor. Synthesis of metal oxides such as Bi2O3 (electronics and varistors), CeO2 (gas sensors, fuel cells, varistors, etc.), Al2O3 (membrane supports, high strength ceramics) and mixed metal oxides such as e.g. CeO2-Al2O3 (automotive pollution control), or BaTiO3, SrTiO3 (ferrorelectric ceramics - applications in various fields because of their characteristics resulting from their spontaneous polarization) will be performed by dissolving their organometallic, nitric and other precursors in organic fuels. The outstanding advantage of FSP is the direct injection of the precursor in its liquid form which enables the synthesis of functional nanoparticles from non-volatile precursors. This makes FSP superior to conventional vapor flame and wet precipitation processes that have been used so far in industry. The project has the potential to contribute to the development and advancement of many other engineering disciplines particularly superconductors, electronics, but also ceramics.