Particle aggregation
The aggregation is a ( loose ) assembly of atoms, molecules and / or ions to a larger association, the aggregate. The common storage is caused by van der Waals forces, intermolecular forces and other types of chemical bonds. If the units are made up of molecules of the same, we speak of association and associates.
In a wider sense can also be crystalline or amorphous primary particles into larger aggregates, which means the bonded particles coalesce or agglomerate. Then consists in dispersing the particular need to " grind " these aggregates by mechanical force again.