Powder monodispersed

Spray drying Slurry Powder Monodisperse product using sonic/ ultrasonic atomizers built-in filters in chamber new chamber designs and air handling systems multi-stage operations... 

Nucleation of particles in a very short time foUowed by growth without supersaturation yields monodispersed coUoidal oxide particles that resist agglomeration (9,10). A large range of coUoidal powders having controUed size and morphologies have been produced using these concepts (3,14). 

The synthesis of Pd/ACF (0.42wt.% Pd) catalyst with monodispersed nanoparticles carried out at cuo = 3 is illustrated, as well as its catalytic performance in a liquid-phase hydrogenation of 1-hexyne in comparison with a traditional powdered Lindlar catalyst. 

Particle dissolution models, which presume spherical monodisperse particle size, inadequately depict the complexity of typical pharmaceutical powders. 

ZnO particle morphologies are very complex and diversiform in comparison with Ti02. Thus, monodispersed ZnO particles with well-defined morphological characteristics, such as spherical, ellipsoidal, needle, prismatic, and rod-like shapes, have been obtained. Aggregates composed of these basic shape particles have also been achieved. The methods used for synthesis of these ZnO powders include alkali precipitation [214-216], thermal decomposition [217], hydrothermal synthesis [218], organo-zinc hydrolysis [219], spray pyrolysis [220], and other routes. 

Table 1.2.1 Chemical and Physical Properties of Monodisperse Oxide Powders...

To date, it has been difficult to produce monodisperse spherical powders from metal alkoxides with low valence, such as Al and Fe, because the hydrolysis and condensation of metal alkoxides in alcohol are too rapid to allow control of particle size, size distribution, and morphology. Many previous studies reported (28-30) that alkoxide-... 

Preparation of Monodisperse Oxide Powders by Hydrolysis of Metal Alkoxide Using Continuous Tube-Type Reactor... 

Generally, alkoxide-derived monodisperse oxide particles have been produced by batch processes on a beaker scale. However, on an industrial scale, the batch process is not suitable. Therefore, a continuous process is required for mass production. The stirred tank reactors (46) used in industrial process usually lead to the formation of spherical, oxide powders with a broad particle size distribution, because the residence time distribution in reactor is broad. It is necessary to design a novel apparatus for a continuous production system of monodispersed, spherical oxide particles. So far, the continuous production system of monodisperse particles by the forced hydrolysis... 

Table 1.2.3 Chemical Composition of Monodisperse Oxide Powders Determined by ICP Analysis...

Fig. 1.2.11 SEM photographs and particle size distribution of monodisperse Fe20, particles produced by CTTR and batch process. (From T. Ogihara et al., J Soc Powder Technol Jpn 31, 620 (1994). Courtesy of H. Masuda, The Society of Powder Technology, Kyoto, Japan.)...

Monodisperse spherical oxide particles were prepared by the hydrolysis of metal alkoxide in homogeneous alcohol in an emulsion state. The formation mechanism from homogeneous alcohol and emulsion state was discussed by chronomal analysis and in situ observation using laser photo scattering. Two types of continuous systems for the industrial production of monodispersed oxide powders were also offered. 

Fig. 1.6.9 X-ray powder diffraction pattern of monodispersed Fc,0. particles at room temperature. (From Ref. 5.)...

Monodisperse Metal Powders Preparation by the Polyol Process and Characterization... 

Fig. 9.23 SEM images of monodisperse silver powders obtained by reduction of AgNOj in ethylene glycol in the presence of PVP (a) quasi-spherical particles obtained by spontaneous nucleation (dm = 0.64 pun, cr = 0.13 p.m) (b) rodlike particles obtained by heterogeneous nucleation using H2PtCl6 as nucleating agent (particle dimensions 3 xm long and 0.3 xm thick). (From Ref. 13.)...

Ag-Pd Alloy Powders (7,27). Bimetallic colloids, namely, Ag-Pd and Au-Pt, can be obtained by the polyol process. The composition Ag7oPdx> is of particular interest to make the internal electrodes of multilayer ceramic capacitors (MLCC). Polymer-protected, monodisperse, nanoscale Ag70Pd30 particles have been obtained... 

Thus, monodisperse Co-Ni powders can be obtained by the polyol process in the whole composition range including pure Co or Ni powders. The particle size can be varied over a wide range, which can reach three orders of magnitude. 

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