Properties of a liquid/solid interfacial phase at high pressures

Abstract

A negative apparent adsorption onto activated charcoal has been observed for methyl alcohol, ethyl alcohol, n-propyl alcohol, n-heptane, methylcyclopentane and methylcyclohexane under pressures of 0.1–196.2 MPa and at temperatures of 298.2–348.2 K. The adsorption isotherm exhibits a straight line with a negative slope over a wide range of the liquid-phase density, indicating that the volume and the density of the adsorbed phase do not vary with pressure. The characteristic behaviour of the adsorption isotherms is interpreted as an indication that the adsorbed phase includes void spaces resulting from the differences in size among the helium molecule, an admolecule and an adsorbent pore. The linear parts of the adsorption isotherms have successfully been generalized, indicating the validity of the interpretation of the experimental results. Data on the pressure dependence of the interfacial tension are also presented.