Kolloquimsvortrag: Dr. Karsten Wegner, ETH Zurich / 20.04.2015
20.04.2015 von 17:15 bis 18:45
Institut für Materialwissenschaft, Kaiser Str. 2, Geb.C , Raum "Aquarium
Titel: Flame Manufacture of ZnO and other Metal Oxide Nanoparticles
Abstract:
Flame spray pyrolysis has evolved into an extremely versatile process
for production of single and multicomponent oxide nanoparticles of
almost all periodic table elements. Material development has been
carried out mostly with laboratory reactors at g/h scale, now requiring
transfer into an industrial production environment. Successful process
scale-up to kg/h output has been achieved for instance for zirconia or
iron phosphate whereas the transfer remained challenging for zinc oxide
nanoparticles.
This prompted us to investigate flame synthesis of ZnO
in more detail. Formation and growth of spherical and rod-like
structures was tracked by sampling nanoparticles thermophoretically
in-situ the reactor and analyzing their morphology by electron
microscopy. Along with temperature measurements and process simulations,
conditions for production of sphere-like particles and nanorods could
be developed. Characterization of the surface chemistry revealed
shape-dependent differences that could affect the performance of the
powders in catalytic hydrogen production, one envisioned application.