On the synergistic effect of asphaltene and surfactant to reduce n-dodecane-water interfacial tension: insights from molecular dynamics simulations

The adsorption behaviours of three typical surfactants at n-dodecane-water and n-dodecane + asphaltene-water interfaces were systematically studied by atomic molecular dynamics (MD) simulation. The theoretical simulation results show that surfactants and asphaltene molecules have different synergistic effects in reducing interfacial tension. For surfactants SDBS and OP-10, the increase of interfacial concentration leads to the dissociation of asphaltene molecular aggregation structure and the further reduction of interfacial tension. However, DTAB showed the opposite effect. The increase of surfactant interfacial concentration leads to the increase of asphaltene aggregation. With the increase of surfactant interfacial concentration, the interaction between surfactant and asphaltene is not conducive to further reduce the interfacial tension.