Molecular Dynamics Simulation of Self-Aggregation of Asphaltenes at an Oil/Water Interface: Formation and Destruction of the Asphaltene Protective Film Juan Liu Yapu Zhao Sili Ren 10.1021/ef5019737.s001 https://acs.figshare.com/articles/journal_contribution/Molecular_Dynamics_Simulation_of_Self_Aggregation_of_Asphaltenes_at_an_Oil_Water_Interface_Formation_and_Destruction_of_the_Asphaltene_Protective_Film/2048283 It is well known that asphaltene molecules play a significant role in stabilizing emulsions of water in crude oil or diluted bitumen solutions. Molecular dynamics simulations were employed to investigate the aggregation and orientation behaviors of asphaltene molecules in a vacuum and at various water surfaces. Two different continental model asphaltene molecules were employed in this work. It was found that the initially disordered asphaltenes quickly self-assembled into ordered nano­aggregates consisting of several molecules, in which the aromatic rings in asphaltenes were reoriented to form a face-to-face stacked structure. More importantly, statistical analysis indicates that most of the stacked polycyclic aromatic planes of asphaltene nano­aggregates tend to be perpendicular to the water surface. If the asphaltene molecules are considered as “stakes”, then the asphaltene nano­aggregate can be regarded as a “fence”. All the fence-like nano­aggregates were twined and knitted together, which pinned them perpendicularly on the water surface to form a steady protective film wrapping the water droplets. The mechanism of stabilization of the water/oil emulsions is thereby well understood. Demulsification processes using a chemical demulsifier were also studied. It was observed that the asphaltene protective film was destroyed by a demulsifier of ethyl cellulose molecules, leading to exposure of the water droplet. The results obtained in this work will be of significance in guiding the development of demulsification technology. 2015-12-17 07:21:54 water surface model asphaltene molecules Molecular Dynamics Simulation asphaltene molecules Molecular dynamics simulations ethyl cellulose molecules nano