Journal of Nanoparticle Research

, Volume 8, Issue 3, pp 379–393

Silica-based composite and mixed-oxide nanoparticles from atmospheric pressure flame synthesis

Authors

  • Kranthi K. Akurati
    • Laboratory for High Performance CeramicsSwiss Federal Laboratories for Materials Testing and Research (EMPA)
  • Rainer Dittmann
    • Laboratory for High Performance CeramicsSwiss Federal Laboratories for Materials Testing and Research (EMPA)
    • Laboratory for High Performance CeramicsSwiss Federal Laboratories for Materials Testing and Research (EMPA)
  • Ulrich Klotz
    • Laboratory for High Performance CeramicsSwiss Federal Laboratories for Materials Testing and Research (EMPA)
  • Paul Hug
    • Laboratory for High Performance CeramicsSwiss Federal Laboratories for Materials Testing and Research (EMPA)
  • Thomas Graule
    • Laboratory for High Performance CeramicsSwiss Federal Laboratories for Materials Testing and Research (EMPA)
  • Markus Winterer
    • Nanoparticle Process Technology, Institute of Combustion and Gas DynamicsUniversity of Duisburg-Essen
Article

DOI: 10.1007/s11051-005-9024-y

Cite this article as:
Akurati, K.K., Dittmann, R., Vital, A. et al. J Nanopart Res (2006) 8: 379. doi:10.1007/s11051-005-9024-y

Abstract

Binary TiO2/SiO2 and SnO2/SiO2 nanoparticles have been synthesized by feeding evaporated precursor mixtures into an atmospheric pressure diffusion flame. Particles with controlled Si:Ti and Si:Sn ratios were produced at various flow rates of oxygen and the resulting powders were characterized by BET (Brunauer–Emmett–Teller) surface area analysis, XRD, TEM and Raman spectroscopy. In the Si–O–Ti system, mixed oxide composite particles exhibiting anatase segregation formed when the Si:Ti ratio exceeded 9.8:1, while at lower concentrations only mixed oxide single phase particles were found. Arrangement of the species and phases within the particles correspond to an intermediate equilibrium state at elevated temperature. This can be explained by rapid quenching of the particles in the flame and is in accordance with liquid phase solubility data of Ti in SiO2. In contrast, only composite particles formed in the Sn–O–Si system, with SnO2 nanoparticles predominantly found adhering to the surface of SiO2 substrate nanoparticles. Differences in the arrangement of phases and constituents within the particles were observed at constant precursor mixture concentration and the size of the resultant segregated phase was influenced by varying the flow rate of the oxidant. The above effect is due to the variation of the residence time and quenching rate experienced by the binary oxide nanoparticles when varying the oxygen flow rate and shows the flexibility of diffusion flame aerosol reactors.

Keywords

flame aerosol processatmospheric pressuremixed oxidecompositeSiO2SnO2TiO2
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© Springer Science+Business Media, Inc. 2005