Solid-solution interface equilibria for aromatic molecules adsorbed from non-aromatic media. Aromatic hydrocarbons

Abstract

Adsorption and heats of wetting data have been obtained for the systems benzene, naphthalene and anthracene on Graphon and Spheron 6 using some or all of the solvents cyclohexane, carbon tetrachloride and cyclohexanone, i.e., solvents with increasing dielectric constants and with differing competitive ability for the adsorbent surface.

Adsorption equilibrium is interpreted in terms of a monolayer model with a flat orientation of aromatic molecules on the surface. Thermodynamic quantities for adsorption of the aromatic molecules, ΔH₁, ΔG₁ and ΔS₁ are calculated, and an attempt is made to correlate the trends observed with plausible models of the adsorption process. The enthalpies of adsorption are also discussed in terms of specific and non-specific interactions at the interface.