Factors that may influence the micro-emulsion synthesis of nanosize magnetite particles

• Published in: Colloid and polymer science Vol. 285; no. 7; pp. 793 - 800
• Main Authors: GOTIC, M, JURKIN, T, MUSIC, S
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.04.2007; Springer Nature B.V
• Subjects: Atoms & subatomic particles; Chemistry; Colloidal state and disperse state; Deaeration; Dissolution; Emulsions. Microemulsions. Foams; Exact sciences and technology; General and physical chemistry; Magnetite; Microemulsions; Mossbauer effect; Nanocomposites; Nanomaterials; Nanostructure; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Transmission electron microscopy; Particle; Emulsion; Iron oxide; Magnetite; Synthesis; Nanoparticle; Preparation; Transition element compounds; Micro-emulsion; Goethite; Si-ferrihydrite; γ-irradiation
• ISSN: 0303-402X; 1435-1536
• DOI: 10.1007/s00396-006-1624-2

The influence of experimental conditions on the formation of nanosize magnetite by micro-emulsion method was investigated using Mossbauer and FT-IR spectroscopies, FE SEM/EDS and TEM. It was found that the concentration of starting chemicals (FeCl3/FeSO4), aeration/de-aeration, high alkalinity and Delta *g-irradiation influenced this precipitation process. Rod-like goethite particles ~200--300 nm long and up to 10 nm wide were obtained by destabilization of the micro-emulsions aged 5 to 45 days at RT. Si-containing ferrihydrite was also formed and it retarded the formation of goethite by the dissolution/re-precipitation mechanism. A small amount of Si from a glass flask was dissolved. A very strong influence of Delta *g-irradiation on the formation of nanosize magnetite by micro-emulsion method was observed. Delta *g-irradiation created strong reductive conditions in the micro-emulsions. At an ~460 kGy dose, nanosize magnetite particles sized ~5 to 20 nm and very small amounts of goethite particles were obtained. The EDS measurements on the particles suggested the formation of sub-stoichiometric magnetite (Fe3-x O4) and not of maghemite. This finding is in line with the strong reductive conditions induced with Delta *g-irradiation.