SURFACE-TENSION OF REAL SOLUTIONS

A theory of surface tension and adsorption for two-component real solutions is presented. The theory takes into account intermolecular interactions and molecular volumes of individual components of the solution. A derived adsorption isotherm is reducible to the Frumkin isotherm. Definitions of parameters characteristic of the Frumkin isotherm are given. The theory is successfully used to describe the surface properties (the surface tension, surface concentrations and activities) for the n-butanol-formamide solution. The influence of the intermolecular interaction present in the bulk of solution and at the surface layer on the surface properties of solutions is discussed. An explanation is given of some unexpected adsorption behaviors observed earlier (Randles and Behr, J. Electroanal. Chem. 35, 389 (1972); Janaszewski et al., Fluid Phase Equil. 9, 1138 (1982)). © 1993 Academic Press, Inc.