Journal of Nanoparticle Research

, Volume 13, Issue 7, pp 2715–2725 | Cite as

Uniform nanoparticles by flame-assisted spray pyrolysis (FASP) of low cost precursors

  • Thomas Rudin
  • Karsten Wegner
  • Sotiris E. PratsinisEmail author
Research paper


A new flame-assisted spray pyrolysis (FASP) reactor design is presented, which allows the use of inexpensive precursors and solvents (e.g., ethanol) for synthesis of nanoparticles (10–20 nm) with uniform characteristics. In this reactor design, a gas-assisted atomizer generates the precursor solution spray that is mixed and combusted with externally fed inexpensive fuel gases (acetylene or methane) at a defined height above the atomizing nozzle. The gaseous fuel feed can be varied to control the combustion enthalpy content of the flame and onset of particle formation. This way, the enthalpy density of the flame is decoupled from the precursor solution composition. Low enthalpy content precursor solutions are prone to synthesis of non-uniform particles (e.g., bimodal particle size distribution) by standard flame spray pyrolysis (FSP) processes. For example, metal nitrates in ethanol typically produce nanosized particles by gas-to-particle conversion along with larger particles by droplet-to-particle conversion. The present FASP design facilitates the use of such low enthalpy precursor solutions for synthesis of homogeneous nanopowders by increasing the combustion enthalpy density of the flame with low-cost, gaseous fuels. The effect of flame enthalpy density on product properties in the FASP configuration is explored by the example of Bi2O3 nanoparticles produced from bismuth nitrate in ethanol. Product powders were characterized by nitrogen adsorption, X-ray diffraction, X-ray disk centrifuge, and transmission electron microscopy. Homogeneous Bi2O3 nanopowders were produced both by increasing the gaseous fuel content and, most notably, by cutting the air entrainment prior to ignition of the spray.


Bi2O3 Flame assisted spray pyrolysis Flame spray pyrolysis Gas phase synthesis Low-cost production Flame enthalpy density Product homogeneity Bimodal size distribution 



The support of Dr. F. Krumeich for TEM is gratefully acknowledged, as well as financial support by ETH Research Grant TH-23 06-3 and European Research Council.


  1. Bickmore CR, Waldner KF, Treadwell DR, Laine RM (1996) Ultrafine spinel powders by flame spray pyrolysis of a magnesium aluminum double alkoxide. J Am Ceram Soc 79(5):1419–1423CrossRefGoogle Scholar
  2. Blower SK, Greaves C (1988) The structure of beta-Bi2O3 from powder neutron-diffraction data. Acta Crystallogr C 44:587–589CrossRefGoogle Scholar
  3. Cheary RW, Coelho A (1992) A fundamental parameters approach to X-ray line-profile fitting. J Appl Crystallogr 25:109–121CrossRefGoogle Scholar
  4. Gardner TJ, Messing GL (1984) Magnesium salt decomposition and morphological development during evaporative decomposition of solutions. Thermochim Acta 78(1–3):17–27CrossRefGoogle Scholar
  5. Heine MC, Madler L, Jossen R, Pratsinis SE (2006) Direct measurement of entrainment during nanoparticle synthesis in spray flames. Combust Flame 144(4):809–820CrossRefGoogle Scholar
  6. Jossen R, Mueller R, Pratsinis SE, Watson M, Akhtar MK (2005a) Morphology and composition of spray-flame-made yttria-stabilized zirconia nanoparticles. Nanotechnology 16(7):S609–S617CrossRefGoogle Scholar
  7. Jossen R, Pratsinis SE, Stark WJ, Madler L (2005b) Criteria for flame-spray synthesis of hollow, shell-like, or inhomogeneous oxides. J Am Ceram Soc 88(6):1388–1393CrossRefGoogle Scholar
  8. Kilian A, Morse TF (2001) A novel aerosol combustion process for the high rate formation of nanoscale oxide particles. Aerosol Sci Technol 34(2):227–235CrossRefGoogle Scholar
  9. Kriegel R, Topfer J, Preuss N, Grimm S, Boer J (1994) Flame pyrolysis—a preparation route for ultrafine powders of metastable beta-SrMnO3 and NiMn2O4. J Mater Sci Lett 13(15):1111–1113CrossRefGoogle Scholar
  10. Lewis DJ (1991) Technique for producing mullite and other mixed-oxide systems. J Am Ceram Soc 74(10):2410–2413CrossRefGoogle Scholar
  11. Lide DR (2007) Properties of the elements and inorganic compounds. In: Lide DR (ed) CRC handbook of chemistry and physics: a ready-reference book of chemical and physical data, 88 edn. CRC, Boca RatonGoogle Scholar
  12. Loher S, Stark WJ, Maciejewski M, Baiker A, Pratsinis SE, Reichardt D, Maspero F, Krumeich F, Gunther D (2005) Fluoro-apatite and calcium phosphate nanoparticles by flame synthesis. Chem Mater 17(1):36–42. doi: 10.1021/cm048776c CrossRefGoogle Scholar
  13. Madler L (2004) Liquid-fed aerosol reactors for one-step synthesis of nano-structured particles. Kona 22:107–120Google Scholar
  14. Madler L, Pratsinis SE (2002) Bismuth oxide nanoparticles by flame spray pyrolysis. J Am Ceram Soc 85(7):1713–1718CrossRefGoogle Scholar
  15. Madler L, Kammler HK, Mueller R, Pratsinis SE (2002a) Controlled synthesis of nanostructured particles by flame spray pyrolysis. J Aerosol Sci 33(2):369–389CrossRefGoogle Scholar
  16. Madler L, Stark WJ, Pratsinis SE (2002b) Flame-made ceria nanoparticles. J Mater Res 17(6):1356–1362CrossRefGoogle Scholar
  17. Marshall BS, Telford I, Wood R (1971) Field method for determination of zinc oxide fume in air. Analyst 96(1145):569–578CrossRefGoogle Scholar
  18. Matsoukas T, Friedlander SK (1991) Dynamics of aerosol agglomerate formation. J Colloid Interf Sci 146(2):495–506CrossRefGoogle Scholar
  19. McCusker LB, Von Dreele RB, Cox DE, Louer D, Scardi P (1999) Rietveld refinement guidelines. J Appl Crystallogr 32:36–50CrossRefGoogle Scholar
  20. Merkle BD, Kniseley RN, Schmidt FA, Anderson IE (1990) Superconducting YBa2Cu3Ox particulate produced by total consumption burner processing. Mater Sci Eng A-Struct 124(1):31–38CrossRefGoogle Scholar
  21. Messing GL, Zhang SC, Jayanthi GV (1993) Ceramic powder synthesis by spray-pyrolysis. J Am Ceram Soc 76(11):2707–2726CrossRefGoogle Scholar
  22. Mueller R, Madler L, Pratsinis SE (2003) Nanoparticle synthesis at high production rates by flame spray pyrolysis. Chem Eng Sci 58(10):1969–1976CrossRefGoogle Scholar
  23. Pratsinis SE (1998) Flame aerosol synthesis of ceramic powders. Prog Energy Combust Sci 24(3):197–219CrossRefGoogle Scholar
  24. Purwanto A, Wang WN, Ogi T, Lenggoro IW, Tanabe E, Okuyama K (2008) High luminance YAG: Ce nanoparticles fabricated from urea added aqueous precursor by flame process. J Alloy Compd 463(1–2):350–357. doi: 10.1016/j.jallcom.2007.09.023 CrossRefGoogle Scholar
  25. Rohner F, Ernst FO, Arnold M, Hibe M, Biebinger R, Ehrensperger F, Pratsinis SE, Langhans W, Hurrell RF, Zimmermann MB (2007) Synthesis, characterization, and bioavailability in rats of ferric phosphate nanoparticles. J Nutr 137(3):614–619Google Scholar
  26. Sahm T, Madler L, Gurlo A, Barsan N, Pratsinis SE, Weimar U (2004) Flame spray synthesis of tin dioxide nanoparticles for gas sensing. Sens Actuators B-Chem 98(2–3):148–153. doi: 10.1016/j.snb.2003.10.003 CrossRefGoogle Scholar
  27. Schulz H, Schimmoeller B, Pratsinis SE, Salz U, Bock T (2008) Radiopaque dental adhesives: dispersion of flame-made Ta2O5/SiO2 nanoparticles in methacrylic matrices. J Dent 36(8):579–587CrossRefGoogle Scholar
  28. Seo DJ, Park SB, Kang YC, Choy KL (2003) Formation of ZnO, MgO and NiO nanoparticles from aqueous droplets in flame reactor. J Nanopart Res 5(3–4):199–210CrossRefGoogle Scholar
  29. Seo DJ, Ryu KO, Park SB, Kim KY, Song RH (2006) Synthesis and properties of Ce1−xGdxO2−x/2 solid solution prepared by flame spray pyrolysis. Mater Res Bull 41(2):359–366. doi: 10.1016/j.materresbull.2005.08.012 CrossRefGoogle Scholar
  30. Stark WJ, Madler L, Maciejewski M, Pratsinis SE, Baiker A (2003) Flame synthesis of nanocrystalline ceria-zirconia: effect of carrier liquid. Chem Commun (5):588–589Google Scholar
  31. Strobel R, Pratsinis SE (2007) Flame aerosol synthesis of smart nanostructured materials. J Mater Chem 17:4743–4756CrossRefGoogle Scholar
  32. Strobel R, Baiker A, Pratsinis SE (2006) Aerosol flame synthesis of catalysts. Adv Powder Technol 17(5):457–480CrossRefGoogle Scholar
  33. Tani T, Watanabe N, Takatori K, Pratsinis SE (2003) Morphology of oxide particles made by the emulsion combustion method. J Am Ceram Soc 86(6):898–904CrossRefGoogle Scholar
  34. Tani T, Takatori K, Pratsinis SE (2004) Dynamics of hollow and solid alumina particle formation in spray flames. J Am Ceram Soc 87(3):523–525CrossRefGoogle Scholar
  35. Tikkanen J, Gross KA, Berndt CC, Pitkanen V, Keskinen J, Raghu S, Rajala M, Karthikeyan J (1997) Characteristics of the liquid flame spray process. Surf Coat Technol 90(3):210–216CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Thomas Rudin
    • 1
  • Karsten Wegner
    • 1
  • Sotiris E. Pratsinis
    • 1
    Email author
  1. 1.Department of Mechanical and Process Engineering, Particle Technology Laboratory Institute of Process Engineering, ETH ZurichZurichSwitzerland

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