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Effects of Fe–AOT complex on the properties of iron oxide particles formed by an AOT isooctane/water emulsion system
Author(s) -
Oshitani J.,
Hatai I.,
Yoshida M.,
Gotoh K.
Publication year - 2008
Publication title -
asia‐pacific journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.348
H-Index - 35
eISSN - 1932-2143
pISSN - 1932-2135
DOI - 10.1002/apj.143
Subject(s) - emulsion , iron oxide , oxide , chemical engineering , chemistry , materials science , metallurgy , organic chemistry , engineering
Formation of iron oxide particles with aerosol‐OT (AOT)/isooctane/water emulsion was carried out employing a coprecipitation reaction for Fe 3 O 4 particles. Emulsions containing Fe 2+ /Fe 3+ were mixed with those containing OH − . Iron oxide particles were formed by changing the concentration ratio of AOT to iron ions and maintaining the volume fraction of water in the emulsion at 0.25. Particle formation was also carried out using nonemulsified aqueous solutions as a reference. The morphology, crystal structure, magnetic property and hydration degree of the particles formed under various conditions were compared. The α‐FeOOH or amorphous particles are formed instead of Fe 3 O 4 when the AOT concentration is comparable to, or higher than, the iron ion concentration. These particles contain an OH group and water, and are oxidized to become α‐Fe 2 O 3 by heating in N 2 . The Fe–AOT complex as the origin of OH‐rich particle formation was the focus of this investigation. The IR measurement was carried out for the Fe–AOT complex, separately prepared with the aqueous solution. It was found that the Fe–AOT complex was hydrated, indicating that hydration of the complex affects the properties of particles formed by the emulsion. A possible mechanism for formation of α‐FeOOH or amorphous particles with emulsion is proposed. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.