ChemInform Abstract: Synthesis of Highly Crystalline and Monodisperse Maghemite Nanocrystallites Without a Size-Selection Process.

School of Chemical Engineering and Institute of Chemical Processes, Seoul National University, Seoul 151-744, Korea.
Journal of the American Chemical Society (Impact Factor: 12.11). 04/2010; 123(51):12798-801. DOI: 10.1002/chin.200217234
Source: PubMed


The synthesis of highly crystalline and monodisperse gamma-Fe(2)O(3) nanocrystallites is reported. High-temperature (300 degrees C) aging of iron-oleic acid metal complex, which was prepared by the thermal decomposition of iron pentacarbonyl in the presence of oleic acid at 100 degrees C, was found to generate monodisperse iron nanoparticles. The resulting iron nanoparticles were transformed to monodisperse gamma-Fe(2)O(3) nanocrystallites by controlled oxidation by using trimethylamine oxide as a mild oxidant. Particle size can be varied from 4 to 16 nm by controlling the experimental parameters. Transmission electron microscopic images of the particles showed 2-dimensional and 3-dimensional assembly of particles, demonstrating the uniformity of these nanoparticles. Electron diffraction, X-ray diffraction, and high-resolution transmission electron microscopic (TEM) images of the nanoparticles showed the highly crystalline nature of the gamma-Fe(2)O(3) structures. Monodisperse gamma-Fe(2)O(3) nanocrystallites with a particle size of 13 nm also can be generated from the direct oxidation of iron pentacarbonyl in the presence of oleic acid with trimethylamine oxide as an oxidant.

Download full-text


Available from: Jongnam Park, Aug 24, 2015
79 Reads
  • Source
    • "The decomposition of iron pentacarbonyl in the presence of oleic acid is a well known method for Fe-NP formation[23]. Ferrocene has also been shown to decompose and form a carbon shell around the iron nanoparticles and has shown to exhibit novel structures[41]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: A method to simultaneously synthesize carbon-encapsulated magnetic iron nanoparticles (Fe-NPs) and attach these particles to multi-walled carbon nanotubes (MWCNT) is presented. Thermal decomposition of cyclopentadienyliron dicarbonyl dimer [(C5H5)2Fe2(CO)4], over a range of temperatures from 250° C to 1200° C, results in the formation of Fe-NPs attached to MWCNT. At the same time, a protective carbon shell is produced and surrounds the Fe-NPs, covalently attaching the particles to the MWCNT and leading to resistance to acid dissolution. The carbon coating varies in degree of graphitisation, with higher synthesis temperatures leading to a higher degree of graphitisation. The growth model of the nanoparticles and subsequent mechanism of MWCNT attachment is discussed. Adsorption potential of the hybrid material towards organic dyes (Rhodamine B) has been displayed, an indication of potential uses as material for water treatment. The material has also been electrospun in to aligned nanocomposite fibres to produce a soft magnetic composite (SMC) with future applications in sensors and fast switching solenoids.
    Carbon 04/2015; 84. DOI:10.1016/j.carbon.2014.11.042 · 6.20 Impact Factor
  • Source
    • "For large-scale synthesis it is important to find simple and cost-effective method for the production of nanoparticles with tunable particle size and also with high purity. Thermal decomposition of organic-TM precursors seems to be one of the most suitable candidates [4] [5] [6]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We successfully prepared MnO, Mn 2 O 3 and Mn 3 O 4 nanoparticles by thermal decomposition of manganese (II) glycerolate in air or inert atmosphere at various temperatures. The thermal behavior during decomposition was analyzed by simultaneous thermal analysis. The manganese precursor was analyzed by X-Ray diffraction, SEM, SEM-EDS and X-Ray photoelectron spectroscopy to evaluate exact composition. The particle size of the obtained nanoparticles was determined from XRD patterns using Scherrer equation and also by transmission electron microscopy. Thanks to the extremely low sizes, such nanoparticles can be used at large-scales for industrial use.
    Ceramics International 01/2015; 41(1):595-601. DOI:10.1016/j.ceramint.2014.08.108 · 2.61 Impact Factor
  • Source
    • ", M(CO) 5 [20], M n+ (acac − ) n [21], or Fe[N(SiMe 3 ) 2 ] 2 [22] in the presence of a surfactant. Colloidal synthesis routes provide much greater control over the size distribution of the products compared to e.g. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Here we demonstrate how monodisperse iron oxide nanocubes and nanospheres with average sizes between 5 and 27 nm can be synthesized by thermal decomposition. The relative importance of the purity of the reactants, the ratio of oleic acid and sodium oleate, the maximum temperature, and the rate of temperature increase, on robust and reproducible size and shape-selective iron oxide nanoparticle synthesis are identified and discussed. The synthesis conditions that generate highly monodisperse iron oxide nanocubes suitable for producing large ordered arrays, or mesocrystals are described in detail.
    Science and Technology of Advanced Materials 10/2014; 15(5):055010. DOI:10.1088/1468-6996/15/5/055010 · 3.51 Impact Factor
Show more