Experimental Study of the Distribution of Fatty Compounds Between Bi- and Tridimensional Phases at the Surface of Different Supports and of the Sorption Properties of the Films

Abstract

Studies of the variation of the logarithm of the retention volume of an auxiliary solute with the reciprocal of the absolute temperature for fatty alcohols and normal paraffins bring out the physical transformations of the different kinds of monolayers these stationary phases form on siliceous supports. Monolayers are never found on a silanized Chromosorb. The presence or absence of a monolayer, as well as the transition temperatures of the surface phases, characterize the surface of a support. The retention properties of the films show that chromatographic separation is connected with solution or adsorption phenomena depending on whether or not the stationary phase possesses functional groups. Separation is also strongly influenced by the pore size, the solute and the temperature. In consequence new corrections are required for the calculation of specific retention volumes in these stationary phases.