Enthalpy of adsorption for hydrocarbons on concrete by inverse gas chromatography

Enthalpies of adsorption, ΔHa, are reported for several light hydrocarbons on normal construction concrete. ΔHa, which are a measure of the adhesion strength of a molecule on a surface, were determined by gas–solid chromatography with a packed column containing 60–80 mesh concrete particles. With this approach, the specific retention volume for a compound is measured as a function of temperature, and these data are used to calculate ΔHa. For the hydrocarbons studied, we found that ΔHa was relatively large for unsaturated hydrocarbons. These are the first determinations of ΔHa of hydrocarbons on construction concrete, but useful comparisons with other ionic solids such as clays can be made.