Authors: C.W. Lee, S.G. Kim, Jai Sung Lee
Abstract: The influence of reaction temperature on phase evolution of iron oxide hollow
nanoparticles during chemical vapor condensation (CVC) process using iron acetylacetonate was
investigated. X-ray diffraction (XRD) analyses revealed that three iron oxide phases (α-Fe2O3,
γ-Fe2O3, and Fe3O4) and a mixture of β-Fe2O3 and small amount of γ-Fe2O3 were synthesized at
700oC and 900oC, respectively. TEM observation disclosed that the iron oxide particles are almost
composed of hollow structured nanoparticles of 10~20 nm in size and 3~5 nm in shell thickness. This
result implies that reaction temperature determining various reaction parameters plays an important
role for the phase- and structural evolutions of iron oxide hollow nanoparticles. Especially, the
present investigation attempted to explain temperature dependence of the phase evolution of β-Fe2O3
hollow nanoparticles in association with the decomposition of iron acetylacetonate.
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Authors: Jong Keun Ha, Kwon Koo Cho, Ki Won Kim, Tae Hyun Nam, Hyo Jun Ahn, Gyu Bong Cho
Abstract: Various physical, chemical and mechanical methods, such as inert gas condensation,
chemical vapor condensation, sol-gel, pulsed wire evaporation, evaporation technique, and
mechanical alloying have been used to synthesize nanoparticles. Among them, chemical vapor
condensation(CVC) represents the benefit for its applicability to almost materials because a wide
range of precursors are available for large-scale production with a non-agglomerated state. In this
work, iron nanoparticles and nanowires have synthesized by chemical vapor condensation(CVC)
process, using iron pentacarbonyl(Fe(CO)5) as precursor. The effects of processing parameters on the
morphology, microstructure and size of iron nanoparticles and nanowires were studied. Iron
nanoparticles and nanowires having various diameters were obtained by controlling the inflow of
metallic organic precursor. Both nanoparticles and nanowires were crystallized. Characterization of
obtained nanoparticles and nanowires were investigated by using a field emission scanning electron
microscopy, transmission microscopy and X-ray diffraction.
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Authors: Qing Wei Ding, Tian Wei Qian, Hong Fang Liu, Xue Wang
Abstract: Zero-valent iron (ZVI) nanoparticles are prepared by wet chemical method, unlike conventional methods, we applied a water-soluble dextrin、CMC and starch in the preparation. The starch serves as a stabilizer and dispersant that prevents the resultant nanoparticles from agglomeration, and characterized by XRD、SEM and USP. Compare the dispersion of particles and particle size in progress of reducing. According to the characterization results, the nanoparticles can be dispersed more efficiently, maintained the activity of it owned and kept the stability longer with the dispersing agent. Based on the results obtained, the starch as a dispersion agent on the preparation of Zero-valent iron (ZVI) nanoparticles is an ideal approach.
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Authors: Zhi Hua Pang, Xiao Shan Jia, Kai Liu, Zhen Xing Wang, Qi Jing Luo, Jun Luo
Abstract: Taking the organic modified montmorillonite as a carrier and dispersant, the supported nanoscale zero-valent iron materials with different iron contents were synthesized through the ferrous sulfate (FeSO4) and the sodium borohydride (NaBH4) in it. The structure and morphology of the materials were characterized by X-ray diffraction(XRD) and scanning electron microscopy(SEM). Finally, the performances of the supported nanoscale zero-valent iron were studied by high-performance liquid chromatography to determine the adsorption and degradation of 4-chlorophenol. The results indicate that the supported nanoscale zero-valent iron was well dispersed,different iron dosages imposed a visible effect on the morphology and particle diameter of iron;the degradation of 4-chlorophenol resulted from adsorption and degradation processes. Materials with different iron contents exhibited significantly different performance levels in terms of 4-chlorophenol adsorption and degradation.
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Authors: Wan Ju Zhang, Fang Wang
Abstract: Iron oxide (Fe3O4) nanoparticles as one of the most important nanomaterials are suitable for many applications. Monodisperse magnetic Fe3O4 nanoparticles were synthesized by the thermal decomposition of the iron oleate precursor in octadecene (ODE). The iron oleate complex was prepared by reaction between sodium oleic and FeCl3·6H2O at low temperature. The Fe3O4 nanoparticles were transferred from organic solvent into water by amphiphilic copolymer. The aqueous dispersion of Fe3O4 nanoparticles was stable in water and physiological buffers. This method with low cost can be used to prepare large scale of aqueous dispersion of Fe3O4 nanoparticles.
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