Papers by Keyword: Spray-Drying Method

Abstract: Cobalt and nickel ferrites powders are synthesized by the co-precipitation technology, combined with the spray-drying method. The crystallite size, specific surface area (SSA), magnetic properties of synthesized products are investigated. All the synthesized ferrites are nanocrystalline single phase materials with crystallite size of 5-6 nm, the SSA of 80-85 m²/g and the calculated particle size of 13-15 nm. After spray-drying granules of the size up to 10 μm are obtained. After thermal treatment at 550 and 950 °C SSA decreases to 40-50 m²/g and 20-22 m²/g, respectively. The saturation magnetization at these temperatures increase from 17 to 40 emu/g for NiFe₂O₄ and from 51 to 77 emu/g for CoFe₂O₄. By the pressure-less sintering method the dense material forms at 1100 °C for CoFe₂O₄ and 1200-1300 °C for NiFe₂O₄.

Abstract: In dye-sensitized solar cells (DSC), large-size particles in photoanodes can act as　light-scattering center to enhance light harvesting efficiency. In this study, macroporous secondary　TiO2 particles were prepared by a spray drying method and were introduced to DSC. A few kinds of　layered structures were fabricated as photoanodes to evaluate effects of macroporous particles. It was　found that open circuit voltage increased due to the presence of macroporous particles. A photoanode　composed of stacked nanoparticles and macroporous particles showed better cell performance.

Abstract: The adsorption properties of metal ions containing hydroxyapatite (Ca10(PO4)6(OH)2, HAp) were elucidated for the development of protein drug carrier. As-prepared metal ion containing HAp nanocrystal showed plate-like morphology with 10-20nm in length and 5-10nm in width. The metal ion containing HAp microparticles had higher specific surface area than the HAp microparticle. The adsorption amount per unit area of HAp showed higher than those of metal ion containing HAp. The adsorption behavior followed the Langmuir curves for each protein, indicating the monolayer adsorption. The loaded amount of proteins could be one of the most important properties for the application of drug delivery carrier.

Abstract: The purpose of this work is to influence of CaO concentrations of 5.0 wt.% and 10.0 wt.%, slurry feeding rate of 200~400
/min, rotating rate of drum of 5,000 and 10,000 rpm, inlet and outlet temperature on the synthesis of Ca(OH)2 powder, and the synthesis of precipitated calcium carbonate by carbonation process using Ca(OH)2 prepared by spray drying method. As the feeding rate of slurry was increased, the particle size of Ca(OH)2 was decreased. Regardless of rotating rate of drum, when the concentration of CaO was 5.0 wt.% and 10.0 wt.%, the morphology of Ca(OH)2 showed spherical shape of 10~30 μm and 20~60 μm, respectively. The specific surface area of synthesized Ca(OH)2 was 27~30 m2/g. When the initial reaction temperature was 11 °C and 30 °C, the shape and particle size of precipitated calcium carbonate synthesized in the carbonation process showed the rectangular shape of 0.1~0.4 μm and the spindle shape of 0.5~1.0 μm, respectively.

Abstract: Control of protein release without the initial burst from zinc containing hydroxyapatite porous microparticles (Zn-HAp) was investigated with a novel formulation method. The formulation method was a coat of polyL(L-lactide; PLA) on the microparticle with nano-thickness, which obviously suppressed the initial burst of protein release compared with the microparticles without the formulation, the coat of PLA. The HAp/PLA microparticle with 1-20μm of the size distribution was available for the drug delivery carrier of proteins without the degradation.