Sur les Erreurs Causées par L'Évaporation dans les Mesures de Tension Superficielle

Abstract

AbstractEvaporation of solute in aqueous solutions of long chain alcohols and acids may cause important errors in measures of the surface tensions of these solutions.The work described in the present paper has shown that, even in a closed vessel, the vapour pressure of the solute is not uniform and particularly with the pendant drop method, the heavy vapours do not remain near the drop, where the surface tension is measured.The du Nouy ring method and the pendant drop method have been improved to avoid evaporation.Various anomalies, found in the literature, have been shown to be due to evaporation, especially the «bag» effect found by Addison with decyl alcohol solutions, and the minimum in the time curves of surface tension observed by Ward and Ottman with capric acid solutions.