Abstract
The adsorption and thermal desorption behaviours of seven model compounds containing asphalt-like functionalities were studied on silica. Adsorption isotherms of the model compounds were examined at 25°C and analyzed via the Langmuir isotherm. A series of temperature-programmed desorption (TPD) experiments was also conducted on the silica samples, the activation energy for desorption (Ed) being determined by conventional TPD analysis. The adsorption and thermal desorption behaviours were correlated in terms of the activation energy (Ed tot) for complete desorption. Dimethyl sulphoxide showed the strongest adsorption and the largest value for Ed tot, implying that the high energy consumption necessary to desorb such functionalities plays a key role in the durability of asphalt–aggregate bonding.