@article{63830,
  abstract     = {{ This study investigates the effect of dispersion gas (DG) flow on the formation and properties of maghemite (γ-Fe2O3) nanoparticles using standardized SpraySyn burners (SS1 and SS2). Several diagnostics were employed to characterize the spray and nanoparticles. 
Increasing DG flow (6 - 12 slm) results in smaller droplet sizes (DS), cooler flame temperatures, shorter high-temperature droplet/particle residence times, and smaller agglomerates in the size range of 5 - 12 nm with narrower primary particle size distribution, corresponding to higher mass fractal dimensions, as supported by TEM and SMPS analysis, resulting in more compact agglomerates. BET and TEM confirmed decreasing primary particle sizes with increasing DG flow. Raman and XRD analyses predominantly identified maghemite, which shows a bimodal distribution of crystallite sizes, while SS1 samples have a greater proportion of larger crystallites.
The self-preserving size distributions of agglomerates with a geometric standard deviation of 1.5 are reached faster with increasing DG flow. The barrier effect of DG observed in SS1 leads to slower droplet combustion kinetics, higher temperatures, and delayed precursor release, which, along with downstream flow recirculation, result in significantly higher agglomeration rates outside the visible flame. SS2 demonstrates improved atomization, more stable flames, and finer, uniform nanoparticles with less carbonaceous residues (CR). Conversely, SS1 showed broader DS distributions and higher CR levels on the γ-Fe2O3 surface, especially at higher DG flow.
This work highlights the essential role of DG flow and nozzle geometry in controlling droplet evaporation, flame stability, and nanoparticle growth, offering insights for optimizing SFS and validating numerical models.
}},
  author       = {{Massopo, Orlando and Tischendorf, Ricardo and Gonchikzhapov, Munko and Kasper, Tina and Augustin, Peter and Özer, Burak and Reddemann, Manuel and Kneer, Reinhold and Sheikh, Mohammed-Ali and Mert, Aydan Akyildiz and Wiggers, Hartmut and Schmid, Hans-Joachim}},
  issn         = {{0032-5910}},
  journal      = {{Powder Technology}},
  keywords     = {{Spray flame synthesis, iron oxide nanoparticle, SpraySyn burner, Dispersion gas, Coaxial atomization, HiaT-SMPS}},
  publisher    = {{Elsevier BV}},
  title        = {{{Influence of dispersion gas flow on the spray characteristics and γ-Fe2O3 nanoparticles formation and properties in reference SpraySyn burners}}},
  doi          = {{10.1016/j.powtec.2025.121992}},
  volume       = {{470}},
  year         = {{2025}},
}

@inproceedings{14852,
  abstract     = {{In a variety of industrial applications, liquids are atomized to produce aerosols for further processing. Example applications are the coating of surfaces with paints, the application of ultra-thin adhesive layers and the atomization of fuels for the production of combustible dispersions. In this publication different atomizing principles (standing-wave, capillary-wave, vibrating-mesh) are examined and discussed. Using an optimized standing-wave system, tough liquids with viscosities of up to about 100 Pas could be successfully atomized.}},
  author       = {{Dunst, Paul and Bornmann, Peter and Hemsel, Tobias and Littmann, Walter  and Sextro, Walter}},
  booktitle    = {{Conference Proceedings - The 4th Conference on MicroFluidic Handling Systems (MFHS2019)}},
  editor       = {{Lötters, Joost and Urban, Gerald}},
  keywords     = {{atomization, ultrasound, standing-wave, capillarywave, vibrating-mesh}},
  location     = {{Enschede, The Netherlands}},
  pages        = {{140--143}},
  title        = {{{Atomization of Fluids with Ultrasound}}},
  year         = {{2019}},
}