Flocculation mutual

Figure 5.18 shows a schematic representation of montmorillonite particles in dispersions. This diagram helps us to distinguish between different types of flocculation. Figure 5.18a depicts internal mutual flocculation which is described in Figure 5.15. As a result of electrostatic and van der Waals forces between the edges and...

Another way of improving the clarification of wines treated with bentonite consists of fining after a few days with a combination of siliceous earth (30 ml/hl) and gelatin (5 g/hl) (Section 10.10.1). The mutual flocculation of the negative (siliceous earth) and positive (gelatin) particles eliminates the finest bentonite particles from the wine. Siliceous earth does not affect the aromatic qualities of the wine. Sometimes, this fining even attenuates the... 

If, however, one sol is positively charged and the other negatively, they flocculate each other, at least if the mixing proportions are not too extreme This mutual flocculation is easily understood, as the particles attract each other strongly and form conglomerates which have only a very small charge or no charge at all ... 

When the sensitisation occurs in a system where hydrophobic and hydrophilic colloids arc oppositely charged, sensitization is easily explained as a form of mutual flocculation. An example is the flocculation of an (acid) gold sol which is negatively charged with an acidified (positively charged) gelatin solution In their dependence on the electrolyte concentration the flocculations show strong resemblance to complex coacervations (see volume II, chapter X). 

But sensitization is not restricted to cases of mutual flocculation it also exists when the two sols bear charges of the same sign ... 

It applies specifically to soft spheres and discusses the flocculation in terms of interpenetration of free polymer coils with the polymer sheaths surrounding the particles. Beyond a certain polymer concentration, the interpenetration of two polymer sheaths is easier than the mutual interpenetration of free polymer and attached polymer, resulting in attraction between the soft particles. 

Flocculation is the mutual aggregation of colliding droplets. In stationary emulsions, droplet collisions arise from Brownian motion (small droplets) and/or from the creaming/sedimentation process (larger droplets). In the latter, the mechanism is often referred to as sedimentation/creaming flocculation. Finally, droplet aggregation can also occur in sheared emulsions. It is important to point out that the droplet size distribution is not altered by the flocculation and creaming/sedimentation destabilization mechanisms. 

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