Surfactant adsorption model, evaluation

A core-flood for adsorption determination consists of injecting a measured volume of surfactant solution containing a nonadsorbing tracer into a brine-saturated core and collecting effluent fractions at the core outlet. Chemical analysis of the effluent samples allows the calculation of an adsorption level based on material balance considerations and also results in a set of effluent profiles for the surfactant and the tracer. In addition to the material balance, adsorption is evaluated by matching experimental effluent concentrations from the core-floods with a convection—dispersion—adsorption numerical model. The model parameters then allow calculation of a complete adsorption isotherm. 

Theoretical models for equilibrium adsorption of nonionic and ionic surfactants at the gas-liquid interface have been developed, critically reviewed, and evaluated using experimental data for surface tension. The thermodynamic... 

To evaluate the adsorption of chelates and organic ligands, such as surfactants, a simple adsorption isotherm model may be used. The perhaps most straightforward model has been developed by Langmuir. Assuming that the surface is basic and the adsorbate is acidic in the Bronsted or the Lewis sense, we obtain for the displacement of the solvent liquid (L) molecules by the adsorbate (A) ... 

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