The Association Behavior and Structure of Vacuum Residue-Related Materials in Solution

摘要

Solution structures of asphaltenes (n-heptane insoluble fractions) and maltenes (n-heptane soluble fractions) obtained by extraction of vacuum residues were studied by measuring tide surface tensions of their solutions in toluene, 1-methylnaphthalene, or quinoline. In toluene and 1-methylnaphthalene (1-MN), the surface tensions of maltenes decreased with increasing concentration, and a discontinuity point much like a critical micelle concentration (CMC) was observed. For the asphaitenes there were only small changes in surface tension with increasing concentration. In quinoline, however, asphaitenes and maltenes displayed surface activity and exhibited a discontinuity point in the range 0.006 - 0.03 g/L. Self-association for these components correlated fairly well with their intrinsic cohesive energy.