Interfacial assignment of branched-alkyl benzene sulfonates: A molecular simulation
Interfacial assignment of branched-alkyl benzene sulfonates: A molecular simulation
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支链烷基苯磺酸盐的界面分配：分子模拟
DOI：
10.1063/1.4935339
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发表时间：
2015-11-01
期刊：
影响因子：
1.6
通讯作者：
Zhang, Lu
中科院分区：
文献类型：
--
作者：
Liu, Zi-Yu;Wei, Ning;Zhang, Lu
采用分子动力学模拟方法研究了支链烷基苯磺酸钠分子在壬烷/水界面上的取向，为优化表面活性剂结构以获得超低界面张力（IFT）提供了理论依据.通过二维密度分布，发现当表面活性剂浓度继续增加时，单分子膜会发生坍塌。从而确定了单分子膜的精确范围，并可进行取向分析。根据模拟结果，对支链烷基苯磺酸盐在油水界面上的界面分配进行了判断，并讨论了疏水尾部结构对表面活性剂分配的影响。疏水尺寸越大，由于空间位阻作用，表面活性剂占据面积的变化速率越慢，表面活性剂Meta疏水尾部在低于塌缩浓度时越倾向于向油相延伸。此外，界面模型的崩溃，增加空间位阻和界面表面活性剂分子之间的电荷排斥力，负责的表面活性剂的浓度和结构的影响已被假定。(C)2015年作者。除非另有说明，否则所有文章内容均根据Creative Commons Attribution 3.0 Unported License许可。
A molecular dynamics simulation was conducted to analyze orientations of sodium branched-alkyl benzene sulfonates molecules at nonane/water interface, which is helpful to design optimal surfactant structures to achieve ultralow interfacial tension (IFT). Through the two dimensional density profiles, monolayer collapses are found when surfactant concentration continues to increase. Thus the precise scope of monolayer is certain and orientation can be analyzed. Based on the simulated results, we verdict the interfacial assignment of branched-alkyl benzene sulfonates at the oil-water interface, and discuss the effect of hydrophobic tail structure on surfactant assignment. Bigger hydrophobic size can slow the change rate of surfactant occupied area as steric hindrance, and surfactant meta hydrophobic tails have a stronger tendency to stretch to the oil phase below the collapsed concentration. Furthermore, an interfacial model with reference to collapse, increasing steric hindrance and charge repulsive force between interfacial surfactant molecules, responsible for effecting of surfactant concentration and structure has been supposed. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.