Hassan Pezeshki Modarres - Department of Chemical and petroleum Engineering, Sharif University of Technology, Tehran, Iran
Reza Roosta Azad - Department of Chemical and petroleum Engineering, Sharif University of Technology, Tehran, Iran

Biosurfactants play important role in Microbial Enhanced Oil Recovery (MEOR). In this study molecular dynamics simulation is performed to study the behavior of surfactin, a well known biosurfactant, at the Water/Decane interface. In fact, decane is chosen as a representative of oil for simplification.Results show that a single surfactin molecule migrates from water phase into water/decane interface and settles at the interface. On the other hand, by increasing the number of surfactins we observe that after migration into the interface, some of surfactin molecules enter completely into the organic phase. Investigation of hydrogen binds between surfactinwater and surfactin-surfactin molecules reveals that surfactin enters completely into the organic phase because of hydrogen binding between surfactin molecules. In the case of a single surfactin molecule, hydrogen binding between surfactin and water molecules constrains surfactin at the interface and don’t allow it to enter completely into the organic phase. On the other hand, by increasing the number of surfactin molecules, surfactins make hydrogen binds between each other and occupy hydrogen binding sites instead of water. Hence, surfactin can completely enter the organic phase.

Surfactin, Molecular Dynamics simulation, Hydrogen bind, Decane