Molecular and Electrostatic Interaction Forces Acting on Drops

Molecular and Electrostatic Interaction Forces Acting on Drops 

Forces of molecular and electrostatic interactions between particles were discussed in great detail in Section 10.1, so we only need to cover some additional aspects that will be usefiil later on. 

At the absence of external forces (gravitational, centrifugal, electric), particles with zero charge and drops suspended in a quiescent liquid should be distributed uniformly. There is always interaction between particles electrostatic repulsion (for charged particles and particles surrounded by electric double layers), molecular attraction (the Van der Waals-London forces), hydrodynamic forces (forces arising due to the mutual influence of velocity fields of the liquid and the particles). 

Electrostatic forces between particles with equal charges help to ensure a uniform distribution of particles. The ability of the system to maintain a uniform distribution of particles in the liquid over a long time characterizes the system s 

In practice, in the majority two-phase disperse systems, the number of particles decreases with time, while their size simultaneously increases. For emulsions, the collision of two drops results in their coalescence with the formation of one drop of larger size. Colliding particles can form aggregates. Aggregation of particles occurs due to the forces of molecular attraction. 

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