油水界面上沥青质/表面活性剂聚集吸附特性的MD 模拟研究

The aggregation/adsorption behaviors of asphaltenes and surfactants at the oil-water interfaces significantly affect the interfacial stability during heavy oil chemical flooding. Here we study the aggregation/adsorption characteristics of asphaltenes at interfaces and probe how their interactions with surfactants affect interfacial tension by combining molecular dynamics simulations with statistical physics method. The interfacial tension decreases with the increase of asphaltene at interfaces. Surfactants promote the dispersion of asphaltene aggregates at interfaces and reduce their adsorption via competitive adsorption. The reduction of interfacial tension is related to the interactions between asphaltenes and surfactants, particularly, SDBS with benzene ring structure have the most significant impact. By analyzing hydrogen bonding, aggregate structures, and intermolecular interaction energies, we reveal the microscopic mechanisms of asphaltenes/surfactants affecting interfacial tension. These findings provide important guidance for regulating interfacial stability and designing heavy oil chemical flooding systems.