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Suspensions of Colloidal Particles and Aggregates by Frank Babick download in ePub, pdf, iPad

The smaller the

This separation is achieved by addition of a flocculating or coagulating agent, which induce the aggregation of the suspended solids. In general, different phases have different charge affinities, so that an electrical double layer forms at any interface. This separation is achieved by inducing the aggregation processes between casein micelles by acidifying the milk or adding rennet. However, they are generally ineffective against viruses, which do not possess cell membranes. This is the reason that milk, fog, and clouds themselves appear to be white.

The temporary dipole and the induced dipoles are then attracted to each other. Therefore, aggregating particles sediment and this mechanism provides a way for separating them from suspension. Aerogels based on silica, carbon, alumina and other substances are available. It is in fact hydrophilic, since it forms strong hydrogen bonds with water. The coagulated clay accumulates as sediments which eventually form a geographical feature called a river delta.

These colloids are said to be lyophobic. Steric stabilization consists in covering the particles in polymers which prevents the particle to get close in the range of attractive forces. Examples of a stable and of an unstable colloidal dispersion. The aggregates are normally separated by sedimentation, leading to sewage sludge.

The properties of the water in

The properties of the water in the solution are not altered, other than the simple osmotic changes that would be caused by the presence of any solute. The smaller the particle, the smaller the number of surrounding molecules able to collide with it, and the more likely will random fluctuations occur in the number of collisions from different sides. For solid particles, this is usually accomplished by some kind of grinding process such as in a ball- or roller-mill.