Preparation and properties of colloidal iron dispersions

• Published in: Journal of colloid and interface science Vol. 287; no. 2; pp. 485 - 495
• Main Authors: Butter, K., Kassapidou, K., Vroege, G.J., Philipse, A.P.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 15-07-2005; Elsevier
• Subjects: (cryo-)TEM; Chemistry; Colloidal state and disperse state; Colloids; Dipolar model system; Dynamic susceptibility measurements; Exact sciences and technology; Ferrofluids; General and physical chemistry; Magnetic particles; Magnetization measurements; Physical and chemical studies. Granulometry. Electrokinetic phenomena; SAXS; Size control; Synthesis and characterization; Magnetization measurements; Dynamic susceptibility measurements; Magnetic particles; (cryo-)TEM; Ferrofluids; Colloids; Synthesis and characterization; Dipolar model system; Size control; SAXS; Magnetization; Transition metal; Iron; Small angle X ray scattering; Colloidal dispersion; Colloid; Characterization; Particle; Transmission electron microscopy; Synthesis; Dynamics; Preparation; Models
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2005.02.014

We systematically study the properties of dispersions of iron-based colloids synthesized in a broad size range by thermal decomposition of ironcarbonyl using different stabilizing surfactants. The synthesis results in stable dispersions of monodomain magnetic colloids. Our particles appear to consist of an amorphous Fe
0.75C
0.25 alloy. Sizes of particles coated with modified polyisobutene or oleic acid can be easily controlled in the 2–10 nm range by varying the amounts of reactants. Extensive characterization with various techniques gives particle sizes that agree well with each other. In contrast to dispersions of small particles, which consist of single colloids, dynamic aggregates are present in dispersions of larger particles. On exposure to air, an oxide layer forms on the particle surface, consisting of a disordered Fe(III) oxide.