Use of Gamma Energy Distribution to Model the Gas Chromatographic TemperatureDependence of Solute Retention on Aryl-Siloxane Chemically Modified Porous Carbon

摘要

A new equation is derived for the corrected specific retention volume of aninfinitely dilute solute on an energetically heterogeneous surface. The equation, which is based on a gamma type distribution for the adsorption energy, is used to model the temperature dependence of the specific retention volume for benzene chromatographed on four different chemically modified porous carbon adsorbents. Biphasic behavior in plots are interpreted in terms of differing energetic heterogeneities of the modified carbons. Since it is well-known that surface heterogeneity, especially under dilute conditions, substantially influences the adsorption process, gas solid chromatography (GSC), which permits measurements to be made at low concentrations, is an attractive technique for studying surface and structural differences of adsorbents and catalysts.