Aggregates size distribution

Fig. 4. Aggregate size distributions by electron microscope image analysis (D and centrifugal (Z9 sedimentations for N220 and N351 carbon blacks (8).

Particle size and particle aggregate size distribution is now being used for monitoring product stability and functional properties in a range of food emulsion systems24. 

Fig. 2.23. Schematic picture of the aggregate size distribution well above the CMC for (a) a strongly cooperative association into micelles, (b) a weakly cooperative process, and (c) a noncooperative association...

Consider a micellar solution at equilibrium that is subject to a sudden temperature change (T-jump). At the new temperature the equilibrium aggregate size distribution will be somewhat different and a redistribution of micellar sizes will occur. Aniansson and Wall now made the important observation that when scheme (5.1) represents the kinetic elementary step, and when there is a strong minimum in the micelle size distribution as in Fig. 2.23(a) the redistribution of micelle sizes is a two-step process. In the first and faster step relaxation occurs to a quasi-equilibrium state which is formed under the constraint that the total number of micelles remains constant. Thus the fast process involves reactions in scheme (5.1) for aggregates of sizes close to the maximum in the distribution. This process is characterized by an exponential relaxation with a time constant Tj equal to... 

So far LII has only been applied for aerosol processes without the consideration of particles dispersed in liquids. First, investigations were carried out with re-dispersed carbon blacks. Besides furnace blacks (Printex A, G, 25, 35, and 55), various gas carbon black particles (FW 18, Colour Black SI60 and S170, Printex U and U140) were also considered. The particles were suspended in different liquids and dispersed by ultrasonic excitation. The stability of the suspension was recorded by measuring the aggregate size distribution (diffusion diameter) with DLS. Moreover, this was done before and after the LII measurements in order to control the stability of the particle suspension. To achieve LII... 

A well-defined transition point in the aggregation process emerges as that separating two different types of behavior of the aggregate size distribution function. A critical concentration corresponding to this transition point is defined which is a close lower bound on the cmc values usually reported. 

Figure 2. Aggregate size distributions for A = 50, < = 4,5, n , = 50, and n =40. The curves are labeled for various values of the reduced single amphiphlle concentration...

The transition in shape of the aggregate size distribution occurs when the size distribution displays a horizontal. inflexion point, i.e., when... 

Fig. 21 Aggregate size distribution obtained from TEM-analysis (in-rubber state) of E-SBR-samples filled with 50 phr N330 at various mixing times, as indicated [115]...

Keren, R. 1980, Effect of titration rate on pH and drying process on cation exchange capacity reduction and aggregate size distribution of montmorilIonite hydroxy-Al complexes. Soil Sci. Soc. Am. J. 44 1209-1212. 

The results of this study show that ultrasonic absorption techniques, when used in conjunction with other aggregate properties, provide important kinetic information about the partitioning process of alcohols tetween ionic micelles and the bulk phase. The effect of hydrocarbon chain length of the alcohol on the exit rates of monomer surfactant and alcohol components from the mixed micelles, aggregate size distribution, and the electrostatic stabilization of the head group region of the micelles will be considered. As well, previously unreported data for water- 1-butoxyethanol-DTAB will be used to extend conclusions based on previous work [2,3]. 

Logsdon, S.l).. I). Gimdne/, and R.R. Allmaras. 1996. Friiclal eluiiiulcii/ulion ol aggregate size distribution The question ol scale invariance. Soil Sci. .Sot Am I Mill / I I to. 

Micelle size and structure are stabilized by surfactant interactions and bonding. Therefore additives that destabilize micellar structure also disrupt the interactions and bonding of the surfactants adsorbed at the oil-aqueous interface. The disruption of the surfactant interactions and bonding at the interface leads to a weakening of the interfacial film and thereby promotes coalescence. The micellar aggregate size distributions for surfactant systems under consideration for chemical flooding,... 

The micellar aggregate size distribution is also important because large micellar aggregates plug reservoir pores with small throat diameters (28). This plugging may cause poor oil recovery. 

The objectives of this study was to determine the changes in micellar aggregate size distributions caused by oil/water ratio, co-surfactant and three phase development in petroleum sulfonate systems and by a co-surfactant in a caustic system. 

It has been shown in our recent publications (6 9 7, 27) that the addition of a co-surfactant greatly enhances the coalescence rates of oil droplets. The co-surfactant must have disrupted the surfactant interactions at the oil-aqueous interface. We have also previously reported the significant changes in micellar aggregate size distribution caused by the equilibration of the aqueous surfactant solution against the crude oil. 

The very low interfacial tensions reported for many crude oil-caustic systems should permit substantial reduction of residual oil saturation by the mobilization of trapped oil. We have discussed earlier that crude oil-caustic tension is low initially where reactants meet at a fresh interface but the interfacial tension increases as reaction products diffuse into the bulk phases. The technique of determining micellar aggregate size distributions could be used to study the diffusion of the reaction products into the aqueous phase. 

The reason for understanding the effect of n-hexanol on the micellar aggregate size distribution in the caustic systems are similar to those for the sulfonate systems presented earlier. 

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