Modelling of dilational visco-elasticity of adsorbed layers with multiple kinetic processes

In this work, a generalisation of a method to calculate the dilational visco-elasticity of surfactant adsorbed layers is presented. This theoretical approach allows surface relaxation processes to be taken into account, and the effect of their kinetic aspect on the viscous behaviour of the adsorbed layer is studied. The proposed method is rather general because it requires only the condition of small deviation from the equilibrium of the system, being based on the linear system formalism. Examples of application of this method are presented concerning surfactant changing their molar area and insoluble monolayer with chemical reaction. The expressions of the dilational visco-elasticity versus frequency, found with the present method, are in agreement with the results obtained in previous theoretical works and by other authors. (c) 2005 Elsevier B.V. All rights reserved.