Particle size morphology

Alex CCT, Goh NN, Chia LS (1995) Effects of particle size morphology on ultrasound induced cavitational mechanism in heterogeneous systems. J Chem Soc Chem Commun 2 201-201... 

Closely spaced magnetic nanocrystals that are found in nature are often more perfect in their sizes, shapes and arrangements than their synthetic counterparts. As a result, they can be chosen as model systems to study the effect of particle size, morphology, crystallography and spacing on magnetic microstructure. 

Si02 NP-5-tNP-9 and cyclohexane Influence of pH and concentration of sodium orthosUicate on the silica particle size, morphology and specific surface area [153]... 

Anatase, brookite and rutile are three polymorphs of titanium dioxide. Anatase is a kind of thermodynamically metastable form while rutile is a kind of stable one. Anatase can transform irreversibly to rutile at elevated temperatures ranged from 400 to 1200 °C according to particle size, morphology and additives. The solid-state phase transformation behavior has been widely investigated while the phase evolution between anatase and rutile under hydrothermal condition has been little paid attention to so far [5]. In this work, the structural evolution from anatase to rutile under milder hydrothermal conditions is proposed as well [7, 10]. 

EBL was used to fabricate uniform platinum nanoparticle arrays on Si02 (mean platinum particle diameter 30-1000 nm 52,53,106,107,398)), and evaporation techniques were used to prepare smaller particles and a continuous platinum film. The EBL microfabrication technique allows the production of model catalysts consisting of supported metal nanoparticles of uniform size, shape, and interparticle distance. Apart from allowing investigations of the effects of particle size, morphology, and surface structure (roughness) on catalytic activity and selectivity, these model catalysts are particularly well suited to examination of diffusion effects by systematic variations of the particle separation (interparticle distance) or particle size. The preparation process (see Fig. 1 in Reference 106)) is described only briefly here, and detailed descriptions can be found in References 53,106,399). 

The main characteristics of the green mixture used to control the CS process include mean reactant particle sizes, size distribution of the reactant particles reactant stoichiometry, j, initial density, po size of the sample, D initial temperature, Tq dilution, b, that is, fraction of the inert diluent in the initial mixture and reactant or inert gas pressure, p. In general, the combustion front propagation velocity, U, and the temperature-time profile of the synthesis process, T(t), depend on all of these parameters. The most commonly used characteristic of the temperature history is the maximum combustion temperature, T -In the case of negligible heat losses and complete conversion of reactants, this temperature equals the thermodynamically determined adiabatic temperature (see also Section V,A). However, heat losses can be significant and the reaction may be incomplete. In these cases, the maximum combustion temperature also depends on the experimental parameters noted earlier. 

Accurate representation of these processes must treat particle size, morphology, and composition. This requirement contrasts with the present situation in which large-scale aerosol models for the most part treat the particle composition as uniform, with properties corresponding to spherical particles having a uniform composition and single effective radius. Studies of individual particles show particles are more complex and that these assumptions are too approximate (e.g., Buseck and Posfai, 1999 Buseck et al., 2002). In practice, much of the information required to represent aerosol evolution is not known. However, levels of accuracy must be balanced against feasibility and complexity of model appropriate to the problem at hand. 

For industrial applications, the particle size, morphology, and texture of the mesoporous material are important, which include several critical points such as mechanical stability and macroscopic shapes with well defined properties. Morphology control is one of the most interesting issues in the research field of mesoporous materials. It plays a very important role in understanding the basic synthesis mechanism. 

Manufacture of nanoparticle formulations with controlled particle sizes, morphology, and surface properties would be more effective and less expensive than other technologies. 

Studies have shown that the type of solvent used has effect on the particle size, morphology and biological activity of the molecule [19, 20]. The principal disadvantage of this process is the lack of control over particle formation. This has been observed to be true in batch operating conditions because the level of saturation is not maintained. 

This section is principally devoted to the preparation of thermally sensitive hydrogel particles using the batch polymerization process. The effect of each reactant and parameter (initiator, temperature, cross-linker agent) on the polymerization process (polymerization kinetic, conversion, final particle size, morphology, water-soluble polymer, etc.) is presented and discussed. For the... 

Rational formulation relies on a thorough understanding of the physicochemical properties of the material. Ideally the mechanical properties should be determined at an early stage in the development process. It must, however, be borne in mind that the properties are sample dependent, and changes in particle size, morphology and so on during development will affect the compaction properties. 

By changing variables numerous products can be manufactured. Control of molecular weight, composition, additives, grafting, particle sizing, morphology, and cross-linking produces products with a wide variety of physical properties. 

A few varieties of nonsilicate oxide ceramic powders synthesized through alkoxide processing are presented here. These oxide powders were developed for the use of electronic, optical, and high-temperature structural applications. For each material, we start with a brief description of the synthesis, which is followed by powder characteristics (e.g., particle sizes, morphologies, and size distributions) and densification behavior and some properties of dense material. 

Oxide Supported Metallic Catalysts.- The local geometry about a metal atom provided by EXAFS may, in principle, provide a guide to the mean particle size, morphology, atomic distribution, cluster-support, and metal-adsorbate interactions. How much of this information is available in a particular case may also be a function of some of these same variables eg- particle size and structural order. But by a series of related experiments, the effects of sample history on catalyst structure may be identified. 

Clark, J. S. T. C. Hussey, 1996. Estimating the mass flux of charcoal particles from sedimentary records effects of particle size, morphology and orientation. The Holocene 6 129-144. Dartnell, P. J. V. Gardner, 1993. Digital imaging of sediment cores for archives and research. J. Sed. Petrol. 63 750-751. 

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