Dodecyl sulfate with tetramethylammonium counterions has been employed to systematically investigate the influence of different static electric fields on molecular structural properties, surface tension, by adopting molecular dynamics (MD) simulations with IR and sum frequency generation (SFG) spectrum calculations. The results indicated that dodecyl sulfate (DS^–) and large organic TMA⁺ counterions can form a mixed adsorption layer in which one head group of DS^– is surrounded by two tetramethylammonium (TMA⁺) and one water molecule. Additionally, it was observed that the surface tension significantly decreases with the increasing static electric field strength since the surfactant stands straighter at the interface as the electric field increases. The result can be instructively adopted in the manufacturing field to control surface tension. Moreover, it was found that the SFG stretch intensities of methylene decrease and the stretch intensities of the methyl group increase with increasing static electric fields. The result indicated that the static electric fields can make DS^– more orderly and upright at the interface.

中文翻译：

---

十二烷基硫酸盐与大有机抗衡离子的电场诱导界面行为：分子动力学研究。

十二烷基硫酸盐与四甲基铵抗衡离子已被用于通过采用IR的分子动力学（MD）模拟和总频率生成（SFG）频谱计算来系统研究不同静电场对分子结构特性，表面张力的影响。结果表明，十二烷基硫酸盐（DS ^–）和较大的有机TMA ⁺抗衡离子可形成一个混合吸附层，其中DS ^–的一个头基被两个四甲基铵（TMA ⁺）和一个水分子。另外，观察到表面张力随着静电场强度的增加而显着降低，因为当电场增加时，表面活性剂在界面处更直。该结果可以在制造领域中指导性地采用以控制表面张力。此外，发现随着静电场的增加，亚甲基的SFG拉伸强度降低并且甲基的拉伸强度升高。结果表明，静电场可以使DS ^–在界面处更加有序和直立。