Dong-Won Lee Ji-Hun Yu Taesuk Jang Byoung-Kee Kim
材料科学技术（英）
In order to prevent the oxide formation on the surface of nano-size iron particles and thereby to improve the oxidation resistance in ordinary condition, iron nanoparticles synthesized by a chemical vapor condensation method were directly soaked in hexadecanethiol solution to coat them with a polymer layer. Oxygen content in the polymer-coated iron nanoparticles was significantly lower than that in usual air-passivated particles possessing iron-core/oxide-shell structure. Accordingly, oxidation resistance of the polymer-coated particles at an elevated temperature below 130°C in air was 10-40 times higher than that of the normally passivated particles.
关键词:
Powder technology
,
Nano materials
,
Iron
,
Chemical vapor condensation
Yongrui LI
,
Nanlin SHI
材料科学技术（英）
Ultrafine Fe3O4 powder was successfully synthesized via a novel ageing process from a precursor FeO(OH), which was the hydrolysate of FeCl3 in the urea solution. The structure of as-synthesized powder was characterized by X-ray diffraction (XRD), and the morphology of these nanoparticles was investigated using a transmission electron microscope (TEM). Pure phase Fe3O4 was obtained and the mean diameter of these nanoparticles was about 21nm. Furthermore, the study indicated that the precursor FeO(OH) played an important role in the formation of Fe3O4 nanoparticles. The mechanism was also discussed.
关键词:
Powder technology
,
null
,
null
,
null
Haiwen Wang
材料科学技术（英）
Indium tin oxide (ITO) nanoparticles with crystallite size of 12.6 nm and specific surface area of 45.7 m2·g-1 were synthesized by co-precipitation method. The indium solution was obtained by dissolving metal indium in HNO3. The tin solution was obtained by dissolving metal tin in HNO3 and followed by stabilizing with citric acid. The free of chlorine ions in the synthesis process brought several advantages: shortening the synthesis time, decreasing the particle agglomeration, decreasing the chlorine content in the ITO nanoparticles and improving the particle sinterability. This is the first time to report the synthesis of ITO nanoparticles free from chlorine contamination without using the expensive metal alkoxides as starting materials.
关键词:
Nanomaterials
,
Powder technology
,
Indium tin oxide
,
Coprecipitation method
