---
_id: '63830'
abstract:
- lang: eng
text: " 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. \r\nIncreasing 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.\r\nThe 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.\r\nThis 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.\r\n"
article_number: '121992'
article_type: original
author:
- first_name: Orlando
full_name: Massopo, Orlando
last_name: Massopo
- first_name: Ricardo
full_name: Tischendorf, Ricardo
last_name: Tischendorf
- first_name: Munko
full_name: Gonchikzhapov, Munko
last_name: Gonchikzhapov
- first_name: Tina
full_name: Kasper, Tina
last_name: Kasper
- first_name: Peter
full_name: Augustin, Peter
last_name: Augustin
- first_name: Burak
full_name: Özer, Burak
last_name: Özer
- first_name: Manuel
full_name: Reddemann, Manuel
last_name: Reddemann
- first_name: Reinhold
full_name: Kneer, Reinhold
last_name: Kneer
- first_name: Mohammed-Ali
full_name: Sheikh, Mohammed-Ali
last_name: Sheikh
- first_name: Aydan Akyildiz
full_name: Mert, Aydan Akyildiz
last_name: Mert
- first_name: Hartmut
full_name: Wiggers, Hartmut
last_name: Wiggers
- first_name: Hans-Joachim
full_name: Schmid, Hans-Joachim
last_name: Schmid
citation:
ama: Massopo O, Tischendorf R, Gonchikzhapov M, et al. Influence of dispersion gas
flow on the spray characteristics and γ-Fe2O3 nanoparticles formation and properties
in reference SpraySyn burners. Powder Technology. 2025;470. doi:10.1016/j.powtec.2025.121992
apa: Massopo, O., Tischendorf, R., Gonchikzhapov, M., Kasper, T., Augustin, P.,
Özer, B., Reddemann, M., Kneer, R., Sheikh, M.-A., Mert, A. A., Wiggers, H., &
Schmid, H.-J. (2025). Influence of dispersion gas flow on the spray characteristics
and γ-Fe2O3 nanoparticles formation and properties in reference SpraySyn burners.
Powder Technology, 470, Article 121992. https://doi.org/10.1016/j.powtec.2025.121992
bibtex: '@article{Massopo_Tischendorf_Gonchikzhapov_Kasper_Augustin_Özer_Reddemann_Kneer_Sheikh_Mert_et
al._2025, title={Influence of dispersion gas flow on the spray characteristics
and γ-Fe2O3 nanoparticles formation and properties in reference SpraySyn burners},
volume={470}, DOI={10.1016/j.powtec.2025.121992},
number={121992}, journal={Powder Technology}, publisher={Elsevier BV}, 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 et al.}, year={2025} }'
chicago: Massopo, Orlando, Ricardo Tischendorf, Munko Gonchikzhapov, Tina Kasper,
Peter Augustin, Burak Özer, Manuel Reddemann, et al. “Influence of Dispersion
Gas Flow on the Spray Characteristics and γ-Fe2O3 Nanoparticles Formation and
Properties in Reference SpraySyn Burners.” Powder Technology 470 (2025).
https://doi.org/10.1016/j.powtec.2025.121992.
ieee: 'O. Massopo et al., “Influence of dispersion gas flow on the spray
characteristics and γ-Fe2O3 nanoparticles formation and properties in reference
SpraySyn burners,” Powder Technology, vol. 470, Art. no. 121992, 2025,
doi: 10.1016/j.powtec.2025.121992.'
mla: Massopo, Orlando, et al. “Influence of Dispersion Gas Flow on the Spray Characteristics
and γ-Fe2O3 Nanoparticles Formation and Properties in Reference SpraySyn Burners.”
Powder Technology, vol. 470, 121992, Elsevier BV, 2025, doi:10.1016/j.powtec.2025.121992.
short: O. Massopo, R. Tischendorf, M. Gonchikzhapov, T. Kasper, P. Augustin, B.
Özer, M. Reddemann, R. Kneer, M.-A. Sheikh, A.A. Mert, H. Wiggers, H.-J. Schmid,
Powder Technology 470 (2025).
date_created: 2026-02-02T11:41:04Z
date_updated: 2026-02-25T07:45:44Z
doi: 10.1016/j.powtec.2025.121992
intvolume: ' 470'
keyword:
- Spray flame synthesis
- iron oxide nanoparticle
- SpraySyn burner
- Dispersion gas
- Coaxial atomization
- HiaT-SMPS
language:
- iso: eng
main_file_link:
- open_access: '1'
oa: '1'
publication: Powder Technology
publication_identifier:
issn:
- 0032-5910
publication_status: published
publisher: Elsevier BV
status: public
title: Influence of dispersion gas flow on the spray characteristics and γ-Fe2O3 nanoparticles
formation and properties in reference SpraySyn burners
type: journal_article
user_id: '98419'
volume: 470
year: '2025'
...
---
_id: '51136'
abstract:
- lang: eng
text: "Iron oxide nanoparticles are very interesting for many applications in different
industrial sectors. A promising\r\nprocess to manufacture these nanoparticles
is flame spray pyrolysis (FSP). A lack of understanding of the\r\nindividual sub-processes
in FSP makes it challenging to tailor nanoparticle properties. This work provides\r\ninsights
into the formation of iron oxide nanoparticles in a turbulent spray flame using
Large Eddy Simulations\r\n(LES), which are based on a comprehensive model, including
customized submodels. Highlights are the\r\nadaption of a turbulent combustion
model and a bivariate hybrid method of moments for modeling nanoparticle\r\ndynamics.
The work focuses on the SpraySyn burner, which is a standardized laboratory burner
and was\r\noperated with a precursor-solvent mixture of ethanol and iron(III)
nitrate nonahydrate. For studying the\r\nrelevance of precursor chemistry, LES
using an evaporation-limited precursor chemistry model is compared\r\nwith a model
that includes detailed iron chemistry. A further novelty is the inclusion of adsorption
in the\r\nsimulation, which defines a third model for comparison. Sufficient validation
is achieved for the undoped LES\r\nusing experimental data from the literature.
A strong impact of the detailed iron chemistry and adsorption\r\nis found on the
precursor consumption and the aggregate and primary particle formation. Comparing
the\r\nparticle diameters with experimental measurements from the literature and
data generated for this work is\r\nfound unsuitable to asses the precursor chemistry
model and revealed an urgent need for future experimental\r\nand numerical research.
This work serves as a step forward in realizing a reliable model."
citation:
ama: Fröde F, Grenga T, Pitsch H, et al., eds. Large Eddy Simulation of Iron
Oxide Formation in a Laboratory Spray Flame. Elsevier; 2023. doi:https://doi.org/10.1016/j.jaecs.2023.100191
apa: Large eddy simulation of iron oxide formation in a laboratory spray flame.
(2023). In F. Fröde, T. Grenga, H. Pitsch, S. Dupont, R. Kneer, R. Tischendorf,
O. Massopo, & H.-J. Schmid (Eds.), Applications in Energy and Combustion
Science. Elsevier. https://doi.org/10.1016/j.jaecs.2023.100191
bibtex: '@book{Fröde_Grenga_Pitsch_Dupont_Kneer_Tischendorf_Massopo_Schmid_2023,
title={Large eddy simulation of iron oxide formation in a laboratory spray flame},
DOI={https://doi.org/10.1016/j.jaecs.2023.100191},
journal={Applications in Energy and Combustion Science}, publisher={Elsevier},
year={2023} }'
chicago: Fröde, Fabian , Temistocle Grenga, Heinz Pitsch, Sophie Dupont, Reinhold
Kneer, Ricardo Tischendorf, Orlando Massopo, and Hans-Joachim Schmid, eds. Large
Eddy Simulation of Iron Oxide Formation in a Laboratory Spray Flame. Applications
in Energy and Combustion Science. Elsevier, 2023. https://doi.org/10.1016/j.jaecs.2023.100191.
ieee: F. Fröde et al., Eds., Large eddy simulation of iron oxide formation
in a laboratory spray flame. Elsevier, 2023.
mla: Fröde, Fabian, et al., editors. “Large Eddy Simulation of Iron Oxide Formation
in a Laboratory Spray Flame.” Applications in Energy and Combustion Science,
Elsevier, 2023, doi:https://doi.org/10.1016/j.jaecs.2023.100191.
short: F. Fröde, T. Grenga, H. Pitsch, S. Dupont, R. Kneer, R. Tischendorf, O. Massopo,
H.-J. Schmid, eds., Large Eddy Simulation of Iron Oxide Formation in a Laboratory
Spray Flame, Elsevier, 2023.
date_created: 2024-02-05T12:17:35Z
date_updated: 2024-02-05T12:38:43Z
department:
- _id: '150'
doi: https://doi.org/10.1016/j.jaecs.2023.100191
editor:
- first_name: 'Fabian '
full_name: 'Fröde, Fabian '
last_name: Fröde
- first_name: 'Temistocle '
full_name: 'Grenga, Temistocle '
last_name: Grenga
- first_name: 'Heinz '
full_name: 'Pitsch, Heinz '
last_name: Pitsch
- first_name: Sophie
full_name: Dupont, Sophie
last_name: Dupont
- first_name: Reinhold
full_name: Kneer, Reinhold
last_name: Kneer
- first_name: Ricardo
full_name: Tischendorf, Ricardo
id: '67002'
last_name: Tischendorf
- first_name: Orlando
full_name: Massopo, Orlando
id: '98419'
last_name: Massopo
- first_name: Hans-Joachim
full_name: Schmid, Hans-Joachim
id: '464'
last_name: Schmid
orcid: 000-0001-8590-1921
has_accepted_license: '1'
keyword:
- Flame spray pyrolysis
- Iron oxide formation
- Large eddy simulation
- Method of moments
- SpraySyn
language:
- iso: eng
main_file_link:
- url: https://www.sciencedirect.com/science/article/pii/S2666352X23000808
publication: Applications in Energy and Combustion Science
publication_status: published
publisher: Elsevier
status: public
title: Large eddy simulation of iron oxide formation in a laboratory spray flame
type: journal_editor
user_id: '98419'
year: '2023'
...
---
_id: '13185'
abstract:
- lang: eng
text: Abstract Polylactide is a biodegradable versatile material based on annually
renewable resources and thus CO2-neutral in its lifecycle. Until now, tin(II)octanoate
[Sn(Oct2)] was used as catalyst for the industrial ring-opening polymerization
of lactide in spite of its cytotoxicity. On the way towards a sustainable catalyst,
three iron(II) hybrid guanidine complexes were investigated concerning their molecular
structure and applied to the ring-opening polymerization of lactide. The complexes
could polymerize unpurified technical-grade rac-lactide as well as recrystallized
l-lactide to long-chain polylactide in bulk with monomer/initiator ratios of more
than 5000:1 in a controlled manner following the coordination–insertion mechanism.
For the first time, a biocompatible complex has surpassed Sn(Oct)2 in its polymerization
activity under industrially relevant conditions.
author:
- first_name: Ruth D.
full_name: Rittinghaus, Ruth D.
last_name: Rittinghaus
- first_name: Pascal M.
full_name: Schäfer, Pascal M.
last_name: Schäfer
- first_name: Pascal
full_name: Albrecht, Pascal
last_name: Albrecht
- first_name: Christian
full_name: Conrads, Christian
last_name: Conrads
- first_name: Alexander
full_name: Hoffmann, Alexander
last_name: Hoffmann
- first_name: Agnieszka N.
full_name: Ksiazkiewicz, Agnieszka N.
last_name: Ksiazkiewicz
- first_name: Olga
full_name: Bienemann, Olga
last_name: Bienemann
- first_name: Andrij
full_name: Pich, Andrij
last_name: Pich
- first_name: Sonja
full_name: Herres-Pawlis, Sonja
last_name: Herres-Pawlis
citation:
ama: 'Rittinghaus RD, Schäfer PM, Albrecht P, et al. New Kids in Lactide Polymerization:
Highly Active and Robust Iron Guanidine Complexes as Superior Catalysts. ChemSusChem.
2019;12(10):2161-2165. doi:10.1002/cssc.201900481'
apa: 'Rittinghaus, R. D., Schäfer, P. M., Albrecht, P., Conrads, C., Hoffmann, A.,
Ksiazkiewicz, A. N., … Herres-Pawlis, S. (2019). New Kids in Lactide Polymerization:
Highly Active and Robust Iron Guanidine Complexes as Superior Catalysts. ChemSusChem,
12(10), 2161–2165. https://doi.org/10.1002/cssc.201900481'
bibtex: '@article{Rittinghaus_Schäfer_Albrecht_Conrads_Hoffmann_Ksiazkiewicz_Bienemann_Pich_Herres-Pawlis_2019,
title={New Kids in Lactide Polymerization: Highly Active and Robust Iron Guanidine
Complexes as Superior Catalysts}, volume={12}, DOI={10.1002/cssc.201900481},
number={10}, journal={ChemSusChem}, author={Rittinghaus, Ruth D. and Schäfer,
Pascal M. and Albrecht, Pascal and Conrads, Christian and Hoffmann, Alexander
and Ksiazkiewicz, Agnieszka N. and Bienemann, Olga and Pich, Andrij and Herres-Pawlis,
Sonja}, year={2019}, pages={2161–2165} }'
chicago: 'Rittinghaus, Ruth D., Pascal M. Schäfer, Pascal Albrecht, Christian Conrads,
Alexander Hoffmann, Agnieszka N. Ksiazkiewicz, Olga Bienemann, Andrij Pich, and
Sonja Herres-Pawlis. “New Kids in Lactide Polymerization: Highly Active and Robust
Iron Guanidine Complexes as Superior Catalysts.” ChemSusChem 12, no. 10
(2019): 2161–65. https://doi.org/10.1002/cssc.201900481.'
ieee: 'R. D. Rittinghaus et al., “New Kids in Lactide Polymerization: Highly
Active and Robust Iron Guanidine Complexes as Superior Catalysts,” ChemSusChem,
vol. 12, no. 10, pp. 2161–2165, 2019.'
mla: 'Rittinghaus, Ruth D., et al. “New Kids in Lactide Polymerization: Highly Active
and Robust Iron Guanidine Complexes as Superior Catalysts.” ChemSusChem,
vol. 12, no. 10, 2019, pp. 2161–65, doi:10.1002/cssc.201900481.'
short: R.D. Rittinghaus, P.M. Schäfer, P. Albrecht, C. Conrads, A. Hoffmann, A.N.
Ksiazkiewicz, O. Bienemann, A. Pich, S. Herres-Pawlis, ChemSusChem 12 (2019) 2161–2165.
date_created: 2019-09-11T10:58:09Z
date_updated: 2022-01-06T06:51:30Z
doi: 10.1002/cssc.201900481
intvolume: ' 12'
issue: '10'
keyword:
- bioplastics
- guanidines
- iron
- lactide
- ring-opening polymerization
language:
- iso: eng
page: 2161-2165
project:
- _id: '52'
name: Computing Resources Provided by the Paderborn Center for Parallel Computing
publication: ChemSusChem
status: public
title: 'New Kids in Lactide Polymerization: Highly Active and Robust Iron Guanidine
Complexes as Superior Catalysts'
type: journal_article
user_id: '40778'
volume: 12
year: '2019'
...