十二烷基苯磺酸钠和无机阳离子之间相互作用的密度泛函理论研究（英文）

发布时间：2019-06-04 22:49

【摘要】：研究阴离子表面活性剂和阳离子之间的相互作用对于理解阴离子表面活性剂的沉淀和溶解现象具有十分重要的理论和实际意义,但关于两者相互作用的相关理论模型鲜有报道。本文采用密度泛函理论(DFT)方法研究了十二烷基苯磺酸根阴离子(DBS~-)与阳离子(Na~+,Mg~(2+)和Ca~(2+))在溶液内及气/液界面处的相互作用。在溶液内,在两种不同溶液环境中(水相和正十二烷)构建DBS~-/阳离子相互作用模型,并对其进行优化。结果表明,DBS~-能够与阳离子以双齿结构稳定结合。DBS~-与阳离子的结合能不仅取决于参与的无机盐离子种类,还与溶剂的性质有关。在气/液界面处,DBS~-与六个水分子相互作用形成的水合物DBS~-·6H_2O最为稳定。但是,无机盐离子的引入会严重破坏DBS~-·6H_2O水合物的水化层结构。本文定义无量纲参量def用来对水化层结构的变化程度进行评价。无机盐离子对DBS~-·6H_2O水化层结构破坏程度的顺序为:Ca~(2+)Mg~(2+)Na~+。电荷分析结果表明水化层在十二烷基苯磺酸钠(SDBS)头基与阳离子的相互作用中起了重要作用。
[Abstract]:It is of great theoretical and practical significance to study the interaction between anionic surfactants and cations in order to understand the precipitation and dissolution of anionic surfactants, but the related theoretical models of the interaction between anionic surfactants and cations are rarely reported. In this paper, the interaction between laurylbenzene sulfonic acid anion (DBS~-) and cations (Na~, Mg~ (2) and Ca~ (2) in solution and at the gas / liquid interface has been studied by density functional theory (DFT). In the solution, the DBS~-/ cationic interaction model was constructed and optimized in two different solution environments (aqueous phase and n-Dodecane). The results show that DBS~- can bind stably to cations in double dentate structure. The binding energy of DBS ~-to cations depends not only on the type of inorganic salt ions involved, but also on the properties of solvents. The hydrate DBS~- 6H2O formed by the interaction of DBS~- with six water molecules is the most stable at the gas / liquid interface. However, the introduction of inorganic salt ions will seriously destroy the hydration layer structure of DBS~- 6H _ 2O hydrate. In this paper, the dimensionless parameter def is defined to evaluate the degree of change of hydration layer structure. The order of damage of inorganic salt ions to the structure of DBS~- 6H _ 2O hydration layer is as follows: Ca~ (2) Mg~ (2) Na~. The results of charge analysis show that the hydration layer plays an important role in the interaction between (SDBS) head group and cations.
【作者单位】：中国石化胜利油田有限公司地质科学研究院;中国石油大学(华东)理学院;山东省高校新能源物理与材料科学重点实验室;
【基金】：supported by the Petro China Innovation Foundation,China(2015D-5006-0213) Fundamental Research Funds for the Central Universities,China(14CX02221A,14CX06157A)~~
【分类号】：O641.3

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