Synthesis of Nearly Monodisperse Iron Oxide and Oxyhydroxide ..

N2 - The fabrication of small structured spherical particles that are essentially small photonic crystals is described. The particles are 1-50 μm in diameter and are porous with nearly close-packed monodisperse pores whose size is comparable to the wavelength of light. The solid matrix of the particles is titania, which provides a large refractive index contrast between the particle matrix and pores. The particles are made by encapsulating polymer colloidal particles in emulsion droplets of hexanes in which a titanium alkoxide precursor is dissolved. Subsequent osmotic removal of the hexanes from the droplets and condensation of the alkoxide precursor leads to spherical aggregates of polymer spheres with titania filling the spaces between the polymer spheres. The polymer particles are then burned out leaving behind the desired porous titania particles. The size and structure of the pores and high refractive index of the titania matrix are expected to produce particles that are very efficient scatterers of light, making them useful as pigments.

Large-Scale Synthesis of Nearly Monodisperse …

Synthesis of nearly monodisperse nanoparticles in …

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Nearly monodisperse cobalt ferrite (CoFe2O4)nanoparticles without any size-selection process have been preparedthrough an alluring method in an oleylamine/ethanol/water system.

Wet synthesis of nearly monodisperse CdSe nanoparticles at room ..

Designed Synthesis of Solid and Hollow Cu2-xTe Nanocrystals with Tunable Near-Infrared Localized Surface Plasmon Resonance.
2013, 117, 21955 (SCI IF: 4.536)

Microwave Synthesis of Nearly Monodisperse …

The process for synthesizing nearly monodisperse CoFe2O4 with superparamagnetic behavior at room temperature was carried out as follows: In a typical synthesis, 1.6 g (6 mmol) of FeCl3·6H2O and 0.7 g of (3 mmol) CoCl2·6H2O were dissolved in the solvent composed of 80 ml of water and 40 ml of ethanol. After that, 7.3 g (24 mmol) of sodium oleate and 7 ml of oleic amine were added into the above solution with strongly stirring at room temperature for 2 h. Then, the reaction precursor was transferred into a Teflon-lined stainless autoclave with a capacity of 150 ml. In order to crystallize the particles, the reaction temperature of the autoclave was increased and maintained at 180°C for 12 h. Then, the system was cooled down to room temperature naturally. The products were separated from the final reaction solution by the addition of hexane. The red supernatant liquor containing CoFe2O4 nanoparticles was separated by a separating funnel. The as-prepared cobalt ferrite could be deposited by adding ethanol and obtained by centrifugating at a high speed (10,000 rpm) without any size-selecting process. The as-prepared samples could be well redispersed in a hexane solvent and stored for several months without delamination.

Microwave Synthesis of Nearly Monodisperse CdSe …

AB - The fabrication of small structured spherical particles that are essentially small photonic crystals is described. The particles are 1-50 μm in diameter and are porous with nearly close-packed monodisperse pores whose size is comparable to the wavelength of light. The solid matrix of the particles is titania, which provides a large refractive index contrast between the particle matrix and pores. The particles are made by encapsulating polymer colloidal particles in emulsion droplets of hexanes in which a titanium alkoxide precursor is dissolved. Subsequent osmotic removal of the hexanes from the droplets and condensation of the alkoxide precursor leads to spherical aggregates of polymer spheres with titania filling the spaces between the polymer spheres. The polymer particles are then burned out leaving behind the desired porous titania particles. The size and structure of the pores and high refractive index of the titania matrix are expected to produce particles that are very efficient scatterers of light, making them useful as pigments.

Nearly all natural polymers are monodisperse

Properties of the as-synthesized samples were charactered through several techniques. The phase contents and crystal structures of the samples were analyzed by X-ray diffraction (XRD) with Cu Kα radiation on a Philips X’pert diffractometer. Elemental analysis for metal iron was measured by an IRIS ER/S inductively coupled plasma emission spectrometer (ICP-ES). High-resolution TEM (HRTEM) analysis was carried out on a JEM-2010 transmission electron microscope with an accelerating voltage of 200 kV. One droplet of hexane dispersion of CoFe2O4 nanoparticles was dropped on a carbon-coated copper grid and then dried naturally before recording the micrographs. FTIR spectra of the samples capped with oleic amine were performed on a 170SX spectrometer in the range of 500–4,000 cm−1. Magnetic properties of the products were characterized at room temperature with a Lake Shore 7,304 vibrating sample magnetometer (VSM). Temperature and field dependences of the samples were recorded on a Quantum Design MPMS-XL superconducting quantum interference device (SQUID). ZFC/FC measurements were carried out in the temperature range of 10–330 K with an applied field of 100 Oe.