Adsorption at the liquid–vapor interface of a binary liquid mixture

Abstract

It is shown that the coefficient of ellipticity measures the adsorption at the liquid–vapor interface of a binary liquid mixture. The cyclohexane–aniline system has been studied. Measurements as a continuous function of temperature are reported for concentrations about the critical point. A discontinuity in the adsorption is observed at the phase boundary, which becomes a logarithmic singularity at the critical point. Adsorption isotherms are presented.