Large scale synthesis of nanoparticles
Stabilized zirconia is important for its outstanding thermal stability, chemical resistance, mechanical characteristics and ionic conductivity. The high temperature cubic ZrO2 phase can be stabilized down to room temperature by the addition of yttria (Y2O3), magnesia, calcium oxide or rare earth oxides.
Zirconia [1] and yttria stabilized zirconia (YSZ) [2] are produced in a pilot flame spray pyrolysis reactor with production rates up to 600 g/h. The metals are dissolved in a solvetn and feed trough a capillary with a piston pump and then dispersed by 50 l/min O2 The resulting spray is ignited by a supporting CH4/O2 diffusion flame (CH4 = 2 l/min, O2 = 4.5 l/min) surrounding the nozzle.
The product powder is collected continuously in a baghouse filter unit (Figure), cleaned periodically by air-pressure shocks. The effect of the liquid feed rate, production rate, oxidant flow rate and precursor solvent combination on product particle size, morphology, and composition is investigated experimentally.
Recent, relevant references:
- R. Mueller, R. Jossen, S. E. Pratsinis, M. Watson and M. K. Akhtar, „Zircona nanoparticles made in spray flames at high production rates“ J. Am.Ceram. Soc., 87 197 (2004)
- R. Jossen, R. Müller, S. E. Pratsinis, M. Watson and M. K. Akhtar „Morphology and composition of spray-flame-made yttria-stabilized zirconia nanoparticles”, Nanotechnology, 16 S609-S617 (2005)