Multiple potential barriers for orientation of sorbed water vapour on chondroitin-4-sulphate

Abstract

Dielectric absorption of water sorbed on chondroitin-4-sulphate was studied at microwave frequencies. Using a solution-like model for the composite sorbent and sorbate system, two absorption maxima were found and the corresponding potential barriers for orientation of the water molecule were calculated. The two barriers were ascribed to two different sorption sites in correspondence with previous infra-red and heat-of-sorption studies. The potential barriers of 2340 cal/mole was ascribed to adsorption on the —NH groups and that of 2590 cal/mole to adsorption on the —OH groups.