摘要
应用分子动力学模拟方法研究十二烷基羧基甜菜碱(BS-12)在气/液界面的聚集行为,采用界面密度、径向分布函数、基团占有面积等参数分析BS-12气/液界面的聚集行为。结果表明:BS-12分子在气/液界面紧密排列形成紧密单分子层界面膜,界面膜厚度随着BS-12分子数增加而增大;BS-12分子亲水基团—N+—CH2—COO-中季氮阳离子与水分子相互作用高于亲水基团羧基与水分子间相互作用,加入Na+和Ca2+后羧基与水分子间的径向分布函数值没有变化,也未对扩散双电层产生较强的压缩作用,BS-12分子具有一定的抗盐能力,羧基阴离子与Ca2+间的相互作用高于与Na+间的相互作用,说明Ca2+影响BS-12分子的抗盐性能。
The aggregation behavior at the air/water interface was simulated by molecular dynamics simulation for Dodecyl dimethyl Betaine(BS-12).The data were analyzed by the method of radial distribution function and group occupation area.The simulation results show that the BS-12 surfactant can form a closely packed monolayer at the air/water interface,and the thickness of the interfacial film increases with the increase of the number of BS-12 molecules.The interaction between water molecules and cationic quaternary nitrogen in hydrophilic group of BS-12 molecules is stronger than that of carboxyl in—N+—CH2—COO-of hydrophilic group.There was no change in the radial distribution function between the carboxyl and water molecules after the addition of Na+and Ca2+,and also no strong squeezing effect on the diffusion double layer,that means the BS-12 molecule has a certain ability to resist salt.The interaction between carboxyl anions and Ca2+ions is higher than that of Na+ions,which indicates that Ca2+can affect the salt resistance of BS-12 molecules.
出处
《东北石油大学学报》
CAS
北大核心
2016年第4期114-120,共7页
Journal of Northeast Petroleum University
基金
黑龙江省教育厅资助项目(12521046)
东北石油大学培育基金资助项目(NEPUPY-1-11)
关键词
分子动力学模拟
十二烷基甜菜碱
气/液界面
表面张力
径向分布函数
molecular dynamics simulation
dodecyl dimethyl betaine
air/water interface
surface tension
radial distribution function
