FUNDAMENTAL STUDY OF THE CHARGE PROPERTY AND COAGULATION-DISPERSION BEHAVIOR OF ASPHALTENES

Abstract

 Asphaltenes interacted with resin components are dispersed in the oil component. When deterioration due to oxidation proceeds, these components form networks that disturb fluidity of asphalt binder. Asphaltenes have surface charges derived from their own functional groups, and the charge property of asphaltenes can affect the formation of asphaltene network. In this study, changes in charge property and coagulation-dispersion behavior of asphaltene due to deterioration were examined. The asphaltene of StAs coagulated at around pH4 and dispersed at high pH. Also, the zeta potential changed depending on pH. On the other hand, asphaltene of aged and recycled asphalt did not have significant coagulation state regardless of pH. The absolute values of the zeta potential of these asphaltenes were higher than that of StAs. It was suggested that this was caused by the increase of carbonyl functions due to degradation by oxidation.