Molecular dynamics simulation study on p-p stacking of Gemini surfactants in oil/water systems

作者：Ma, Jule; Xiao, Peiwen; Wang, Pingmei; Han, Xue; Luo, Jianhui; Shi, Ruifang; Wang, Xuan; Song, Xianyu; Zhao, Shuangliang^*

来源：CHINESE JOURNAL OF CHEMICAL ENGINEERING, 2022, 50: 335-346.

DOI：10.1016/j.cjche.2022.06.010

• Surfactants
• Interface
• Interfacial tension
• pi-pi stacking
• Microemulsion
• Molecular simulation

Whereas the pi-pi stacking interactions at oil/water interfaces can affect interfacial structures hence the interfacial properties, the underlying microscopic mechanism remains largely unknown. We reported an all-atom molecular dynamics (MD) simulation study to demonstrate how the Gemini surfactants with pyrenyl groups affect the interfacial properties, structural conformations, and the motion of molecules in the water/n-octane/surfactant ternary systems. It is found that the pyrenyl groups tend to be vertical to the interface owing to the pi-pi stacking interaction. Besides, a synergistic effect between the p-p interaction and steric hindrance is found, which jointly affects the coalescence of liquid droplets. Therefore, the existence of aromatic groups and a moderate number of surfactants helps to form microemulsion. This work provides a molecular understanding of Gemini surfactants with aromatic groups in microemulsion preparation and applications.

• 单位
  华东理工大学; 广西大学