| Abstract
| - Aggregated asphaltene structural models have been generated through a molecular simulationgeometry optimization process, using periodic boundary conditions. This methodology has beenvalidated by first applying it to a pure aromatic system. Initially, a random distribution of 35molecules was chosen and a geometry optimization process was performed, allowing the celldimensions to vary without restrictions. The structure factor (S(k)) of an optimized final cell wasobtained and compared with experimental results, and the agreement between theoretical andexperimental S(k) profiles was satisfactory. This methodology was next used in the analysis ofthe morphology of 32 asphaltene model molecules and their aromatic cores; asphaltene modelmolecules were taken from literature. It is remarkable that face-to-face stacking of asphalteneaggregates was observed, as well as π-offset and T-shaped stacking geometries. Finally, the effectof aliphatic chains on the aggregates was also analyzed.
|
