title: Microemulsion Synthesis of Iron Core/Iron Oxide Shell Magnetic Nanoparticles and Their Physicochemical Properties.
abstract: Iron magnetic nanoparticles were synthesized under an inert atmosphere via the reaction between FeCl3and NaBH4in droplets of water in a microemulsion consisting of octane with cetyl trimethylammonium bromide and butanol as surfactants. A thin Fe3O4layer was produced on the iron nanoparticles using slow, controlled oxidation at room temperature. A silica shell was deposited on the Fe3O4using 3-aminopropyltrimethoxysilane following the method of Zhang et al. [Mater. Sci. Eng. C 30 (2010) 92-97]. The structure and chemistry of the resulting nanoparticles were studied using variety of methods and their magnetic properties were determined. The diameter of the iron core was typically 8-16 nm, while the thickness of the Fe3O4shell was 2-3 nm. The presence of the silica layer was confirmed using Fourier transform infra-red spectroscopy and the number of NH2-groups on each nanoparticle was determined based on colorimetric tests using ortho-phthalaldehyde.
authors.affiliation: Thayer School of Engineering at Dartmouth College, Hanover, New Hampshire, USA.
authors.forename: Katsiaryna
authors.initials: K
authors.lastname: Kekalo
authors.affiliation: Thayer School of Engineering at Dartmouth College, Hanover, New Hampshire, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Koo
authors.affiliation: Thayer School of Engineering at Dartmouth College, Hanover, New Hampshire, USA.
authors.forename: Evan
authors.initials: E
authors.lastname: Zeitchick
authors.affiliation: Thayer School of Engineering at Dartmouth College, Hanover, New Hampshire, USA.
authors.forename: Ian
authors.initials: I
authors.lastname: Baker
keywords: Fe/Fe oxide; magnetic nanoparticles; magnetic properties; microemulsion synthesis; size distribution