十二烷基苯磺酸钠在癸烷-水界面吸附的MD模拟  

Molecular Dynamics Simulation of the Adsorption of Sodium Dodecyl Benzene Sulfonate at the Decane-Water Interface

作　　者：温伯尧[1] 孙成珍[1] 车煜全 白博峰[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,西安710049 [2]新疆油田分公司采气一厂,克拉玛依834000

出　　处：《工程热物理学报》2016年第5期1011-1015,共5页Journal of Engineering Thermophysics

基　　金：国家自然科学基金杰出青年科学基金项目(No.51425603);国家自然科学基金青年科学基金项目(No.51506166)

摘　　要：本文采用分子动力学方法研究了具有十二烷基苯磺酸钠(SDBS)吸附的癸烷-水界面的微观特性,从浓度分布和分子构象出发,分析界面分子排布对癸烷-水界面微观结构和性质的影响。模拟结果表明癸烷水界面厚度约为0.378nm,界面处水分子偶极矩方向和癸烷分子倾向于与界面平行;SDBS在界面的吸附使得界面厚度增大,油水相互作用减弱,扰乱了水和癸烷分子在界面的定向排列;同时,发现癸烷水界面存在空隙,结合亲水基强烈的静电作用,使得界面处水分子扩散加剧,界面变形能力增强。Molecular dynamics method was employed to explore the micro-characteristic of decane-water interface with the adsorption of sodium dodecyl benzene sulfonate（SDBS）.We analyzed the effect of interfacial molecular arrangement on the micro-structure and properties of oil-water interface from concentration distribution and molecular conformation insights.The results show that the thickness of decane-water interface is 0.378 nm.Both decane molecules and the dipole moment of water molecules tend to be parallel to the interface.The aggregation of surfactants at the interface increases the thickness of oil-water interface,therefore weakening the oil-water interaction and disrupting the directional alignment of water and decane molecules.Meanwhile,we found that there are some cavities at the decane-water interface,combining with the strong electrostatic interaction between hydrophilic groups and water molecules,can aggravate the diffusion of water molecules at the interface,thus enhancing the deformation ability of the interface.

关 键 词：油水界面 界面结构 分子构象 分子动力学 

分 类 号：TE357[石油与天然气工程—油气田开发工程]