combustion synthesis of functional metal oxide nanoparticles (COSYMONA)

abstract

Nanosized tin dioxide (SnO2) particles are in the focus of current research efforts because of their outstanding properties related to gas sensing. Among numerous synthesis pathways, flame spray pyrolysis (FSP) offers essential advantages. For optimum sensing properties, control of primary particle and crystal sizes as well as in situ noble metal doping are required; in addition synthesized nanopowders can be collected after one single high-temperature process step. The understanding of particle formation processes in combustion systems, particularly in flame spray pyrolysis, requires a combination of efforts in combustion diagnostics and modelling. As a general difficulty, the description of nanoparticle formation, growth and agglomeration is complicated by gravitation-related effects like buoyancy, which crucially affects flow conditions in flames. Microgravity might influence the morphology of the synthesized particles and thus enhance the sensing properties of the desired product. In this context appropriate diagnostics are indispensable to gain further insights in particle formation processes, which is an essential prerequisite for precise particle tailoring.

In order to enable a comprehensive characterization of particle and aggregate morphology thermophoretic sampling (TS) was employed to gain primary particle and aggregate sizes by electron microscopy analysis (TEM). Because local temperature distribution is an important process parameter affecting particle synthesis and aggregate growth, two-colour pyrometry (2CP) was used to measure temperature fields.

experiment year: 2011
number of drops: 10