ABSTRACT
Thin liquid films arise spontaneously in all colloid and disperse systems with a liquid disperse media. They are formed always when two particles of the disperse phase (solid particles, liquid drops, or gas bubbles) come close to each other. The liquid film is a symmetric film when both approaching particles originate from the same disperse phase with the same composition of substances, i.e., the symmetric liquid film divides two equal micro-phases. Such thin liquid films are the emulsion films, the foam films, and the films between the particles of a sol. In more complicated cases, when two particles with different composition of substances approach each other, an asymmetric liquid film is formed. These are all cases of heterocoagulation. The most important asymmetric films are the wetting films – thin liquid films which divide a solid and a gas phase.
