Homogeneity particle mixing

Transition-metal oxides and their mixtures are widely employed in numerous industrial applications, especially as cathode materials for batteries and fuel cells [1,2], Practice poses certain well-known requirements to oxide materials, first of all, to uniformity of the size distribution of particles, to homogeneity of mixed oxides, etc. To meet these demands, two broad categories of methods are now in use, vs (i) mechanical methods and (ii) chemical methods. 

Spatial homogeneity of a system (needed for making use of the formal chemical kinetics) is secured, first of all, by complete particle mixing. On... 

The Hanusse theorem [23] discussed in Section 2.1.1 was later generalized for the case of diffusion by Tyson and Light [32], Therefore, the mono- and bimolecular reactions with one or two intermediate products are expected to strive asymptotically, as t —> oo, for the stationary spatially-homogeneous solution Ci(r, oo) = nt(oo) corresponding to equations (2.1.2) for a system with the complete particle mixing. 

Studies of KH clearly indicate complexity that is only partially resolved (49). DiflFerential staining reveals small, dense, homogeneous particles within amorphous KH masses, usually associated with tono-fibrils (32, 48, 49). Amino acid analyses of supposed KH materials show at least three distinctive patterns (see Table I). The amorphous material of Tezuka and Freedberg (72) has much less proline and cystine than KH studied by Matoltsy (51). Other workers have associated histidine with KH in granular cells (48, 49, 76). Tezuka s histidine values (72) fall between those of Matoltsy (51) and Hoober (76) and conceivably represent an analysis of mixed components. UgeFs bovine material is a nucleoprotein that may be either a ribosomal product or still another KH component (71, 77). 

Variations in assay results can be avoided by the preparation of homogeneous, well-mixed, or non-settling fine particle suspensions (size 1-10 pm). Particle size reduction results in slow, more uniform settling rates. The bioavailability of drugs is improved by reducing the size of suspension particles. Furthermore, drug particles smaller than 20 pm produce less pain and tissue irritation when injected parenterally. However, fine particles may have a deleterious effect on chemical stability because of their high dissolution rate. 

The combination of experimental evidence and computational modeling show conclusively that stable, homogeneously blended (bulk-immiscible) mixed-polymer composites can be formed in a single microparticle of variable size. To our knowledge, this represents a new method for suppressing phase-separation in polymer-blend systems without compatibilizers that allows formation of polymer composite micro- and nanoparticles with tunable properties such as dielectric constant. Conditions of rapid solvent evaporation (e.g. small (<10 pm) droplets or high vapor pressure solvents) and low polymer mobility must be satisfied in order to form homogeneous particles. While this work was obviously focused on polymeric systems, it should be pointed out that the... 

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