C12E6 and SDS Surfactants Simulated at the Vacuum-Water Interface
C12E6 and SDS Surfactants Simulated at the Vacuum-Water Interface
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DOI：
10.1021/la904615u
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发表时间：
2010-04-20
期刊：
影响因子：
3.9
通讯作者：
Striolo, Alberto
中科院分区：
文献类型：
--
作者：
Shi, Liu;Tummala, Naga Rajesh;Striolo, Alberto
使用分子动力学模拟研究了表面覆盖率对非离子六乙二醇单十二烷基醚 (C12E6) 和阴离子十二烷基硫酸钠 (SDS) 表面活性剂在真空水交错中聚集结构的影响。我们报告了两种表面活性剂的聚集形态和各种结构细节作为表面覆盖度的函数。我们的结果表明，与 SDS 相比，C12E6 尾部基团与真空水界面的垂直度较小。随着表面密度的增加，界面 C12E6 显示出从气相到液相的转变。然而，即使在考虑的最大覆盖范围下，与 SOS 相比，界面 C12E6 聚集体也显示出更多无序结构。随着每个分子的可用表面积的变化，罗斯表面活性剂在平面迁移率方面表现出非单调变化。结果根据两种表面活性剂的分子特征进行解释，特别强调表面活性剂头的性质，C12E6 的表面活性剂头是非离子的、长的和柔性的，而 SDS 的表面活性剂头是离子的、紧凑的和刚性的。
The effect of surface coverage on the aggregate structure for the nonionic hexaethylene glycol monododecyl ether (C12E6) and anionic sodium dodecyl sulfate (SDS) surfactants at vacuum water interlace has been studied using molecular dynamics simulations. We report the aggregate morphologies and various structural details of both surfactants as a function of surface coverage. Our results indicate that C12E6 tail groups orient less perpendicularly to the vacuum water interface compared to SDS ones. Interfacial C12E6 shows a transition from gaslike to liquidlike phases as the surface density increases. However, even at the largest coverage considered, interfacial C12E6 aggregates show more disordered structures compared to SOS ones. Roth surfactants exhibit a non-monotonic change in planar mobility as the available surface area per molecule varies. The results are interpreted on the basis of the molecular features of both surfactants, with particular emphasis on the properties of the surfactant heads, which are nonionic, long, and flexible for C12E6, as opposed to ionic, compact, and rigid for SDS.