Gas chromatography on porous polymer chromosorb-102 and its adsorption properties

Abstract

The nature of interactions with the surface of the porous polymer Chromosorb-102 has been investigated for substances of different classes. Relationships between the logarithm of the corrected retention times of the substances and the number of carbon atoms in their molecules have been plotted, and the free energies of adsorption on the surface of porous polymer have been measured for nine classes of organic substances relative to the normal alkanes containing the same number of carbon atoms in the molecule. Adsorption isotherms of water, diethyl ether and n-butanol have been calculated from the chromatograms obtained at different temperatures. The adsorption isotherm of water is convex towards the vapour pressure axis. The isosteric heats of adsorption have been calculated from these isotherms and their dependence on the quantity adsorbed has been approximately evaluated. The heat of adsorption of n-butanol is larger than that of diethyl ether owing to the additional specific interaction of the hydroxyl group of the alcohol with the phenyl group of the polymer, while the heat of adsorption of water is at low coverages very small owing to the weak adsorbate-adsorbent interaction but then increases owing to the strong adsorbate-adsorbate interaction.