Liu Zi-Yu, Wang Ce, Zhou He, Wang Yanlei, Zhang Lei, Zhang Lu, Zhao Sui
Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.
Department of Engineering Mechanics, and Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, People's Republic of China.
J Mol Model. 2017 Apr;23(4):112. doi: 10.1007/s00894-017-3285-0. Epub 2017 Mar 13.
The effect of sodium branched-alkylbenzene sulfonates on the NaCl solution/oil interface was studied via classical molecular dynamics simulation. The interfacial properties were found to depend on the surfactant concentration and to change dramatically when the concentration exceeded a critical value, the simulated limit area (A ). When A is not close to the theoretical saturated adsorption area (A ), the surfactant cannot produce ultralow interfacial tension (IFT). When A is equal or almost equal to A , the effect of the structure of the surfactant must be considered to determine if ultralow IFT is possible: if the sizes of the hydrophobic and hydrophilic groups in the surfactant are similar, the surfactant can produce ultralow interfacial tension (and vice versa). Based on the results of these studies, the effect of surfactant structure on the interfacial properties of the system was investigated, and a method of gauging the IFTs produced by different surfactants was proposed that should prove very useful when designing the optimal surfactant structure to achieve ultralow IFT. Graphical Abstract The interfacial properties of water/surfactant/oil system, such as interfacial thickness and IFT, depending on the surfactant concentration and changing dramatically when the concentration exceed a critical value.
通过经典分子动力学模拟研究了支链烷基苯磺酸钠对氯化钠溶液/油界面的影响。发现界面性质取决于表面活性剂浓度，当浓度超过临界值即模拟极限面积（A）时会发生显著变化。当A不接近理论饱和吸附面积（A）时，表面活性剂无法产生超低界面张力（IFT）。当A等于或几乎等于A时，必须考虑表面活性剂的结构效应来确定是否可能产生超低IFT：如果表面活性剂中疏水基团和亲水基团的大小相似，则表面活性剂可以产生超低界面张力（反之亦然）。基于这些研究结果，研究了表面活性剂结构对体系界面性质的影响，并提出了一种衡量不同表面活性剂产生IFT的方法，该方法在设计实现超低IFT的最佳表面活性剂结构时应非常有用。图形摘要水/表面活性剂/油体系的界面性质，如界面厚度和IFT，取决于表面活性剂浓度，当浓度超过临界值时会发生显著变化。
