Microstructure particles

The major difficulty in predicting the viscosity of these systems is due to the interplay between hydrodynamics, the colloid pair interaction energy and the particle microstructure. Whilst predictions for atomic fluids exist for the contribution of the microstructural properties of the system to the rheology, they obviously will not take account of the role of the solvent medium in colloidal systems. Many of these models depend upon the notion that the applied shear field distorts the local microstructure. The mathematical consequence of this is that they rely on the rate of change of the pair distribution function with distance over longer length scales than is the case for the shear modulus. Thus... 

Morphological analysis is concerned with particle characterization in the case of particle size, particle shape and particle texture. Particle texture may deal with the particle surface characteristics and also with the particle microstructure. Particle size and shape influence physical and chemical properties of particulate materials. Morphological analysis is being developed in order to facilitate a more accurate description of the properties and behavior of particulate systems from a fundamental knowledge of the characteristics of the particles of the system [1,2]. 

Catalyst Characterization. Particle size distributions of oven dried products were determined with a Microtrac Particle Size Analyzer. PH, PM, and PS are the diameters corresponding to the 90th, 50th, and 10th percentiles, respectively, on the distribution curve. Particle microstructures were obtained with an ISI-SX-40 scanning electron microscope. 

Solvent-particle interactions (viz. the HI) act instantaneously if the particle microstructure differs from the equilibrium one, but do not themselves determine the equilibrium structure [3,46]. If one assumes that glassy arrest is connected with the ability of the system to explore its configuration space and to approach its equilibrium structure, then it appears natural to assume that the solvent particle interactions are characterized by a finite time scale Thi and that they do not shift the glass transition nor affect the frozen glassy structure. HI would thus only lead to an increase of the high frequency viscosity above the solvent value this value shall be denoted as t]oo ... 

Particle Microstructure (NMR Spectroscopy and Elemental Analysis). The 29Si CP NMR spectra were much easier to obtain than the direct excitation spectra, because of the long spin-lattice relaxation time of the silicon nuclei. Nevertheless, direct excitation was used to obtain the quantitative results of the siloxane structure, because not all Q4 nuclei were detected with CP (Figure 3 and Table III) (47). 

Hoffman (68) attributed the shear thickening behavior to some order-disorder transition of particle microstructure, which was also observed by Ackerson and Pusey (153) and Wagner and Russel (71). This model was continued by Boersma et al. (148). They assumed that the shear thickening occurs when the shear forces overcome the interparticle forces. Hence, a dimensionless group, Nd, the ratio of the viscous to the repulsive forces, may be used to describe the transition ... 

Herrmann, J. and R. Bodmeier (1995). The effect of particle microstructure on the somatostatin release from poly(lactide) microspheres prepared by a W/OAV solvent evaporation method. Journal of Controlled Release 36(1-2) 63-71. 

In Fig. 5.15 high-resolution transition electron microscope (HRTEM) pictures compare the primary particle microstructure of an acetylene black (A) showing the typical planar graphite layers with the microstructure of Super P (B) showing the large distorted graphene layers. 

Figure 2.32 Effect of precipitation conditions and precursor characteristics on (A) particle morphology and (B) composite particle microstructure in spray pyrolysis. (From Ref. 89.)...

Zhao, J.-J., Duan, Y.-Y., Wang, X.-D., and Wang, B.-X. (2012) Effects of solid-gas coupling and pore and particle microstructures on the effective gaseous thermal conductivity in aerogels. /. Nanopart. Res., 14 1024, 1-15. 

During the stabilization process, particles (e.g., fat crystals) must collect at the emulsion droplet interface and provide a physical barrier to coalescence. The key factors that determine the influence of fat crystals on emulsion stabilization are (1) the wettability of the crystals at the interface, (2) interfacial film rheology, (3) particle microstructure (polymorphism and morphology), and (4) location of fat crystals (in the O/W dispersed emulsion or in the continuous W/O emulsion phase) (Johansson et al., 1995 Johansson and Bergenstahl, 1995 Rousseau, 2000). 

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