Thermodynamics of two-dimensional cluster formation at the water/air interface. A quantum chemical approach

In the framework of the parametric method 3 quantum chemical approximation reasonable values are obtained for the thermo-dynamic characteristics of the cluster formation for the fatty alcohol series C_nH_2n+1OH (n = 8–16) with various structures at the air/water interface. The calculated values of the enthalpy, the entropy and the Gibbs energy for the formation of a definite cluster structure can be satisfactorily represented by a linear dependence on the number of CH₂ groups in the alcohol molecule. The data obtained from the surface pressure—area isotherms are in qualitative, and for the Gibbs energy also in quantitative, agreement with the results of the quantum chemical calculations.