Evaluation of surface composition of surface active water-alcohol type mixtures: a comparison of semiempirical models.
We study adsorption at planar liquid-vapor interface of surface active binary mixtures and test three well-known models for the composition of surface phase. The models were originally presented by Guggenheim. These are compared to results for model fluids from density functional theory (DFT). The model of Laaksonen and Kulmala is in best agreement with DFT calculations. Surface mole fraction of the solute component from the Guggenheim model exceeds one for a mixture with high surface activity. The failure of the Guggenheim model is also evident in our calculations for water-methanol, water-ethanol, and water-n-propanol mixtures.
Salonen
Martta
M
Department of Physical Sciences, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki, Finland.
Malila
Jussi
J
Napari
Ismo
I
Laaksonen
Ari
A
D000433:1-Propanol / Q000737:chemistry; D000327:Adsorption; D000438:Alcohols / Q000737:chemistry; D000465:Algorithms; D002627:Chemistry, Physical / Q000379:methods*; D003198:Computer Simulation; D000432:Methanol / Q000737:chemistry; D015233:Models, Statistical; D008962:Models, Theoretical; D013499:Surface Properties; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
D000438:Alcohols; D014867:Water; D000433:1-Propanol; D000432:Methanol