Theoretical Study on π-π Interactions in Asphaltene Molecular Aggregates

Quantum mechanical and molecular dynamics methods were used to study the π-π interactions in asphaltene molecular aggregates. The results show that the π-π interactions between asphaltene molecules increase with the increase of molecular aromatic rings' number. The heteroatoms significantly increase the π-π interaction energies between the asphaltene molecules. The type and length of the asphaltene molecule branches show considerable influence on π-π interaction energies. When asphaltene aggregates contain multiple π-π interactions, the intermolecular interaction force increases significantly. In the process of forming π-π interactions between asphaltene molecules, a small amount of electron transfer between molecules occurs. The dispersion force is the main factor in the π-π interaction force. © 2019, Editorial Office of Acta Petrolei Sinica(Petroleum Processing Section). All right reserved.