Formation of magnetic fexoy/silica core-shell particles in a one-step flame aerosol process

Bing Guo, Hoon Yim, Airat Khasanov, John Stevens

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

In this study, iron silicon oxide particles were generated in a one-step flame assisted spray pyrolysis (FASP) process using H2/air or H2/O2 diffusion flames. A colloidal precursor solution was used, which contained dissolved iron nitrate and stably suspended silica nanoparticles. H2/air flames resulted in magnetic fexOy/silica core-shell particles. There was a correlation between particle size and particle structure; particles larger than 500 nm had the core-shell structure, but smaller particles had non-core-shell structures. H2/O2 flames only resulted in nanoparticles that had non-core-shell structures. The core-shell particles had a iron oxide core that was hermetically enclosed in a uniform silica shell with a typical thickness of approximately 100 nm; they were superparamagnetic with a room-temperature saturation magnetization greater than 24 emu/g. Temperature history of the particles may be used to explain the correlation between flame type and particle structure. The correlation between particle size and structure may be due to size-dependent thermodynamic stability of the structures, or kinetics of heat and mass transfer. The results from this study suggest that micrometer sized iron oxide silica core-shell magnetic particles could be generated from a one-step flame aerosol process, but FexOy/silica nanoparticles (<100 nm) with the core-shell structure cannot be generated in a one-step flame aerosol process.

Original languageEnglish
Pages (from-to)281-291
Number of pages11
JournalAerosol Science and Technology
Volume44
Issue number4
DOIs
Publication statusPublished - Apr 2010
Externally publishedYes

Fingerprint

Aerosols
Silicon Dioxide
Particles (particulate matter)
silica
Silica
shell
aerosol
Iron oxides
Nanoparticles
Particle size
Spray pyrolysis
Silicon oxides
Saturation magnetization
iron oxide
Air
Nitrates
particle size
Thermodynamic stability
Mass transfer
Iron

ASJC Scopus subject areas

  • Materials Science(all)
  • Environmental Chemistry
  • Pollution

Cite this

Formation of magnetic fexoy/silica core-shell particles in a one-step flame aerosol process. / Guo, Bing; Yim, Hoon; Khasanov, Airat; Stevens, John.

In: Aerosol Science and Technology, Vol. 44, No. 4, 04.2010, p. 281-291.

Research output: Contribution to journalArticle

Guo, Bing ; Yim, Hoon ; Khasanov, Airat ; Stevens, John. / Formation of magnetic fexoy/silica core-shell particles in a one-step flame aerosol process. In: Aerosol Science and Technology. 2010 ; Vol. 44, No. 4. pp. 281-291.
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