Shear homogeneous

In direct space successive layers are sheared homogeneously along cylindrical surfaces, one relative to the adjacent one, as a consequence of the circumference increase for successive layers. In diffraction space the locus of the corresponding reciprocal lattice node is generated by a point on a straight line which is rolling without sliding on a circle in a plane perpendicular to the tube axis. Such a locus... 

The term ME is often incorrectly used in the literature to describe oil and water dispersions of small droplet size produced by prolonged ultrasound mixing, high-shear homogenization, and microfluidisation, that is, submicrometer emulsions. The major differences between a microemulsion and a coarse emulsion are shown in Table 1. 

Internal batch mixers are batch systems that have both a lower-shear homogenizing region and a localized high-shearing section. Refer to the schematic disgram in Figure 6.20. 

High-shear homogenization and ultrasound were initially used for the production of solid hpid nanodispersions [7,8], Both methods are widespread and easy to handle. However, in many cases, bimodal size distributions are obtained with one population in the micrometer range. In addition, metal contamination has to be considered if ultrasound is used. 

The influence of lipid composition on particle size was also confirmed for SLN produced via high-shear homogenization [21], The average particle size of Witepsol W35 SLN was found to be significantly smaller (117.0 1.8 nm) than the average particle size of Dynasan 118 SLN (175.1 3.5 nm). Witepsol W35 contains shorter fatty acid chains and considerable amounts of mono- and diglycerides, which possess surface-active properties. 

A widely practiced method is the reuse of leftover solubilizer for the dispersion of the feed material. In this case, the feed consists of partially solubilized resin that is reacted with a solubilizer-rich bath through the use of an ultrasonic or a high-shear homogenizer. 

Citral BP 228°C Acacia gum Emulsifier 30%-40%-50% Shear homogenizer Leaflash Bhandari et al. (1992)... 

Efficient combination of static and dynamic elements in the process chambers that leads to a high degree of shear homogenization... 

In early reports on the formation of double emulsions only one set of emulsifiers and an inversion process were used. Such preparations were done in one step, but the stability was in most cases questionable. It was difficult to control the distribution of the emulsifiers within the two interfaces. There was fast migration of the emulsifiers between the phases that destabilized the emulsions. In most recent emulsion formulations the emulsions are prepared in two steps. At first, a high-shear homogenization is applied to the water that is added to the solution of the oil and the hydrophobic emulsifiers, to obtain a stable W/0 emulsion. In the second step the W/0 emulsion is gently added with stirring (not homogenization) to the water and hydrophilic emulsifiers solution (Fig. 2). The droplet size distribution of a typical classical double emulsion ranges from 10 to 50 pm. 

Fig. 18.19 Computed spinodals at constant shear rates, y = 0.01 — 1.0 s for a shear homogenizing blend (Soontaranun et al. 1996)...

It is easy to confirm this difference in behavior. Two stable Iranian Heavy/2.5% w/w sodium chloride solution emulsions (90% oil/ 10% salt solution v/v) were prepared by high-shear homogenizing. 

Guo, X Zhao, W Pang, X Liao, X Hu, X Wu, J. Emulsion stabilizing properties of pectins extracted by high hydrostatic pressure, high-speed shearing homogenization and traditional thermal methods A comparative study. Food Hydrocolloids, v. 35, p. 217-225,2014. 

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