Preparation of Fe3O4 nanoparticles modified with n-dodecylphosphonic acid via a one-pot nonaqueous process using an oxidation reaction of tetrachloroferrate (III) anions by pyridine-N-oxide

Atsuo Kamura, Masahiko Ozaki, Naokazu Idota, Yoshiyuki Sugahara

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Magnetite (Fe3O4) nanoparticles (NPs) modified with n-dodecylphosphonic acid (DDPA) were prepared by one-pot nonaqueous synthesis using a salt comprising tetrachloroferrate (III) anions and methyltrioctylammonium cations as an Fe source, n-octylamine as a reductant, pyridine-N-oxide as an oxygen donor and DDPA as a phosphorus coupling reagent. The X-ray diffraction patterns, X-ray photoelectron spectroscopy and high-resolution transmission electron microscope (HRTEM) observation showed the formation of Fe3O4 NPs when the amount of DDPA was small (DDPA/Fe < 1/16). Thermogravimetry and infrared spectroscopy demonstrated surface modification of Fe3O4 NPs with DDPA. TEM observation showed the size range of Fe3O4 NPs to be 2–10 nm. Dynamic light scattering analysis showed narrow particle size distribution of Fe3O4 NPs in toluene, moreover, with median diameters of 9.1 (DDPA1/32) and 16 nm (DDPA1/64). Magnetic characterization of Fe3O4 NPs modified with DDPA showed lower saturation magnetization as compared with unmodified Fe3O4 NPs, and indicated superparamagnetic Fe3O4 NPs formation.

Original languageEnglish
Article number110475
JournalMaterials Research Bulletin
Volume118
DOIs
Publication statusPublished - 2019 Oct

Keywords

  • A. Magnetic materials
  • A. Nanostructures
  • B. Chemical synthesis
  • B. Magnetic properties

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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