%A WANG Lijuan, SHI Jing, ZHAO Fangjian %T Molecular dynamics simulation of zwitterionic surfactant sulfobetaine at the vapor/liquid interface %0 Journal Article %D 2014 %J Journal of Shandong University(Engineering Science) %R 10.6040/j.issn.1672-3961.0.2014.058 %P 83-89 %V 44 %N 6 %U {http://gxbwk.njournal.sdu.edu.cn/CN/abstract/article_972.shtml} %8 %X The aggregation morphology of zwitterionic surfactant dodecyl hydroxy-propyl sulfobetaine at the vapor-liquid interface was investigated using molecular dynamics method, and the effect of film stability was discussed. Depending on the interface formation energy, the increasing number of surfactant molecules at the interface helped the stability of liquid membrane. Through the radial distribution functions between the head groups of surfactant and water molecules, the water molecules around surfactant molecules were divided into three types, bound water, trapped water and free water. There were important relationships between the stability of foam and the ability of surfactant binding with water molecules through hydrogen bonding and electrostatic interaction. The results showed that this zwitterionic surfactant had strong binding effect to water molecules in the stability of foam.