  The structure of ionic adsorption layers is studied via a proper
thermodynamic treatment of the electrostatic and non-electrostatic interactions
between the surfactant ions as well as of the effect of thermodynamic
non-locality. The analysis is also applied to phase transitions into the ionic
adsorption layer, which interfere further with the oscillatory-diffusive
structure of the electric double layer and hydrodynamic stability of squeezing
waves in thin liquid films.
