The effect of the binding of counterions with the adsorption complexes of ionic surfactants on the adsorption isotherms was considered, and the modified Hill-de Beer and Fowler adsorption isotherms were obtained. The dynamic surface tension of aqueous solutions of cationic surfactants (hydrochlorides of amines with a hydrocarbon chain length of C-12-C-18) was determined by the Wilhelmy plate method, and the diffusion coefficients were calculated taking into account deviation of the adsorption system from the ideal behavior. Contributions from the lateral long-range interactions of the surfactants, the diffusion barrier, and the electrostatic interaction of surfactant ions to the energetics of a process were estimated.