Flocculation behavior layers

One of the possible ways to achieve this flocculation behavior is using inorganic salts in solution. By changing their concentration, the potential, as well as the double-layer thickness, will in gen al be modifled. As a consequence, the potential energy of interaction between the panicles can change from that of an essentially stable system to that of a rapidly coagulating suspension. Under certain conditions, illustrated in Fig. 7, a secondary minimum in the potential energy vs. distance curve may show up this ideal condition would correspond, as mentioned above, to the open flocculi that can be easily redi.sper.sed and hence are suitable for oral administration. 

Application of the electric double layer theory to soil minerals at a quantitative level is difficult because soil mineral surfaces at the microscopic scale are not well defined, that is, they are neither perfectly spherical nor flat, as the double layer requires. However, application of the double layer theory at a qualitative level is appropriate because it explains much of the behavior of soil minerals in solution, for example, dispersion, flocculation, soil permeability, and cation and/or anion adsorption. When equilibrium between the counterions at the surface (near the charged surface) and the equilibrium solution is met, the average concentration of the counterions at any... 

The object of this study was to clarify some aspects of the mechanism of shear-induced flocculation in colloidal dispersions. Vinyl chloride homopolymer and copolymer latices were prepared by emulsion polymerization using sodium dodecyl sulphate as emulsifier. Agglomeration behavior in these latices was studied by measuring the mechanical stability using a high speed stirring test. The latex particle size was measured by an analytical centrifuge. Molecular areas of emulsifier in the saturated adsorption layer at the surface of homopolymer and copolymer latex particles were estimated from adsorption titration data. 

Shear-Sensitive Systems. In addition to hydrodynamic effects and simple viscous behavior, the act of pigmentation creates a certain amount of complex behavior (13). If the particles are fine. Brownian movement (14-17) and rotational diffusion (14. 18. 19) are among the phenomena that cause dispersed systems to display complex rheology. The role of van der Waals forces in inducing flocculation (20) and the countervailing role of two electroviscous effects (17. 21. 22) in imparting stability, particularly in aqueous systems, have been noted. Steric repulsions appear to be the responsible factor in nonaqueous systems (23. 24). The adsorbed layer can be quite large (25-28). as detected by diffusion and density measurements of filled systems or by viscometry and normal stress differences (29). 

Comparing the time-scales of the various processes involved does not allow a clear description of the behavior of the Stern layer as the particles come closer to one another. It is likely that, if relaxation occurs, it does so—at least partially— during the collision. It is very important to take this behavior into account, since it is likely to influence the reversibility of flocculation. 

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