Statistical molecular calculation of thermodynamic parameters of adsorption of aromatic hydrocarbons on graphite. Part 2.—Polymethyl and monoalkyl benzenes

Abstract

A statistical molecular calculation is carried out of Henry's constant, K₁, and of the differential change in internal energy, ΔU₁, for the adsorption of all the methyl and some monoalkyl derivatives of benzene on the basal plane of graphite at zero surface coverage. Thermodynamic parameters of adsorption of all the benzene derivatives investigated, calculated using the atom–atom approximation, are close to those obtained experimentally by adsorption chromatography on graphitized thermal carbon black. The basic reason for the difference between the thermodynamic parameters of adsorption of the structural isomers of polymethyl- and monoalkyl-derivatives of benzene on graphitized thermal carbon blacks lies in the differing geometric structure of their molecules.