SURFACE AND INTERFACIAL BEHAVIOR OF ISOMERIC BUTANEDIOLS

The adsorption of isomeric butanediols at the free surface of the aque ous solution has been studied by measuring the surface pressure and th e adsorption potential shift. Surface excesses, determined from the Gi bbs equation, have been worked out by testing three adsorption isother ms. The adsorption patterns indicate that isomers whose molecules can provide intramolecular hydrogen bonds behave differently from those on ly providing intermolecular interactions. In particular, the former is omer group exhibits somewhat more hydrophobic features. Adsorption at the free surface of the solution has been compared with that at the Hg \solution interface for butane-1,4-diol only. A higher surface activit y at the Hg electrode has been interpreted in terms of the prevalence of metal-adsorbate interactions via the functional groups. The surface potential of the pure solvents has also been measured with respect to water and compared with calculations based on the ''macroscopic model '' recently proposed by the present authors.