The Relation of Initial Spreading Pressure of Polar Compounds on Water to Interfacial Tension, Work of Adhesion, and Solubility

摘要

An investigation was made of the effect of chain length and solubility upon the spreading on water of the homologous series of pure normal alcohols from 1-butanol to 1-decanol. Spreading pressures were measured at 20C using the piston-monolayer method. Each measured value corresponded to the semi-initial spreading pressure, which was equal, within experimental error, to the initial spreading pressure. Surface tensions of these alcohols were measured, as were the interfacial tensions with water. It is concluded that the spreading pressure of each alcohol, together with its surface tension, can be used to calculate reliably the interfacial tension and the reversible work of adhesion to water. Data for the spreading pressures on water of a variety of organic liquids are also given. With these data and literature values of the liquid surface tensions, calculations were made of the interfacial tensions and work of adhesion by means of the equations published by Pomerantz, Clinton, and Zisman. The calculated interfacial tension was plotted as a function of the best available literature value of the solubility of water in each organic liquid. Our results agreed well with Donahue and Bartell's logarithmic relationship between the interfacial tension and the degree of miscibility. A relationship is given from which solubility can be estimated from interfacial tension. Finally, the relation between the molar work of adhesion to water and the constitution of the adsorbed organic molecules is discussed. (Author)